Implementation of the Prometheus endpoint (#1669)

Implementation of the http://{metricsAddress}/metrics Prometheus endpoint.

authority/authority.go

@@ -104,6 +104,9 @@ type Authority struct {
 
 	// If true, do not output initialization logs
 	quietInit bool
+
+	// Called whenever applicable, in order to instrument the authority.
+	meter Meter
 }
 
 // Info contains information about the authority.
@@ -126,6 +129,7 @@ func New(cfg *config.Config, opts ...Option) (*Authority, error) {
 		config:       cfg,
 		certificates: new(sync.Map),
 		validateSCEP: true,
+		meter:        noopMeter{},
 	}
 
 	// Apply options.
@@ -134,6 +138,9 @@ func New(cfg *config.Config, opts ...Option) (*Authority, error) {
 			return nil, err
 		}
 	}
+	if a.keyManager != nil {
+		a.keyManager = &instrumentedKeyManager{a.keyManager, a.meter}
+	}
 
 	if !a.skipInit {
 		// Initialize authority from options or configuration.
@@ -151,6 +158,7 @@ func NewEmbedded(opts ...Option) (*Authority, error) {
 	a := &Authority{
 		config:       &config.Config{},
 		certificates: new(sync.Map),
+		meter:        noopMeter{},
 	}
 
 	// Apply options.
@@ -159,6 +167,9 @@ func NewEmbedded(opts ...Option) (*Authority, error) {
 			return nil, err
 		}
 	}
+	if a.keyManager != nil {
+		a.keyManager = &instrumentedKeyManager{a.keyManager, a.meter}
+	}
 
 	// Validate required options
 	switch {
@@ -337,6 +348,8 @@ func (a *Authority) init() error {
 		if err != nil {
 			return err
 		}
+
+		a.keyManager = &instrumentedKeyManager{a.keyManager, a.meter}
 	}
 
 	// Initialize linkedca client if necessary. On a linked RA, the issuer

authority/authorize.go

@@ -286,16 +286,16 @@ func (a *Authority) authorizeRevoke(ctx context.Context, token string) error {
 // extra extension cannot be found, authorize the renewal by default.
 //
 // TODO(mariano): should we authorize by default?
-func (a *Authority) authorizeRenew(ctx context.Context, cert *x509.Certificate) error {
+func (a *Authority) authorizeRenew(ctx context.Context, cert *x509.Certificate) (provisioner.Interface, error) {
 	serial := cert.SerialNumber.String()
 	var opts = []interface{}{errs.WithKeyVal("serialNumber", serial)}
 
 	isRevoked, err := a.IsRevoked(serial)
 	if err != nil {
-		return errs.Wrap(http.StatusInternalServerError, err, "authority.authorizeRenew", opts...)
+		return nil, errs.Wrap(http.StatusInternalServerError, err, "authority.authorizeRenew", opts...)
 	}
 	if isRevoked {
-		return errs.Unauthorized("authority.authorizeRenew: certificate has been revoked", opts...)
+		return nil, errs.Unauthorized("authority.authorizeRenew: certificate has been revoked", opts...)
 	}
 	p, err := a.LoadProvisionerByCertificate(cert)
 	if err != nil {
@@ -305,13 +305,13 @@ func (a *Authority) authorizeRenew(ctx context.Context, cert *x509.Certificate)
 		// returns the noop provisioner if this happens, and it allows
 		// certificate renewals.
 		if p, ok = a.provisioners.LoadByCertificate(cert); !ok {
-			return errs.Unauthorized("authority.authorizeRenew: provisioner not found", opts...)
+			return nil, errs.Unauthorized("authority.authorizeRenew: provisioner not found", opts...)
 		}
 	}
 	if err := p.AuthorizeRenew(ctx, cert); err != nil {
-		return errs.Wrap(http.StatusInternalServerError, err, "authority.authorizeRenew", opts...)
+		return nil, errs.Wrap(http.StatusInternalServerError, err, "authority.authorizeRenew", opts...)
 	}
-	return nil
+	return p, nil
 }
 
 // authorizeSSHCertificate returns an error if the given certificate is revoked.

authority/authorize_test.go

@@ -876,7 +876,7 @@ func TestAuthority_authorizeRenew(t *testing.T) {
 		t.Run(name, func(t *testing.T) {
 			tc := genTestCase(t)
 
-			err := tc.auth.authorizeRenew(context.Background(), tc.cert)
+			_, err := tc.auth.authorizeRenew(context.Background(), tc.cert)
 			if err != nil {
 				if assert.NotNil(t, tc.err) {
 					var sc render.StatusCodedError

authority/config/config.go

@@ -83,6 +83,7 @@ type Config struct {
 	Templates        *templates.Templates `json:"templates,omitempty"`
 	CommonName       string               `json:"commonName,omitempty"`
 	CRL              *CRLConfig           `json:"crl,omitempty"`
+	MetricsAddress   string               `json:"metricsAddress,omitempty"`
 	SkipValidation   bool                 `json:"-"`
 
 	// Keeps record of the filename the Config is read from
@@ -327,6 +328,12 @@ func (c *Config) Validate() error {
 		return errors.Errorf("invalid address %s", c.Address)
 	}
 
+	if addr := c.MetricsAddress; addr != "" {
+		if _, _, err := net.SplitHostPort(addr); err != nil {
+			return errors.Errorf("invalid metrics address %q", c.Address)
+		}
+	}
+
 	if c.TLS == nil {
 		c.TLS = &DefaultTLSOptions
 	} else {

authority/meter.go

@@ -0,0 +1,87 @@
+package authority
+
+import (
+	"crypto"
+	"io"
+
+	"go.step.sm/crypto/kms"
+	kmsapi "go.step.sm/crypto/kms/apiv1"
+
+	"github.com/smallstep/certificates/authority/provisioner"
+)
+
+// Meter wraps the set of defined callbacks for metrics gatherers.
+type Meter interface {
+	// X509Signed is called whenever an X509 certificate is signed.
+	X509Signed(provisioner.Interface, error)
+
+	// X509Renewed is called whenever an X509 certificate is renewed.
+	X509Renewed(provisioner.Interface, error)
+
+	// X509Rekeyed is called whenever an X509 certificate is rekeyed.
+	X509Rekeyed(provisioner.Interface, error)
+
+	// X509WebhookAuthorized is called whenever an X509 authoring webhook is called.
+	X509WebhookAuthorized(provisioner.Interface, error)
+
+	// X509WebhookEnriched is called whenever an X509 enriching webhook is called.
+	X509WebhookEnriched(provisioner.Interface, error)
+
+	// SSHSigned is called whenever an SSH certificate is signed.
+	SSHSigned(provisioner.Interface, error)
+
+	// SSHRenewed is called whenever an SSH certificate is renewed.
+	SSHRenewed(provisioner.Interface, error)
+
+	// SSHRekeyed is called whenever an SSH certificate is rekeyed.
+	SSHRekeyed(provisioner.Interface, error)
+
+	// SSHWebhookAuthorized is called whenever an SSH authoring webhook is called.
+	SSHWebhookAuthorized(provisioner.Interface, error)
+
+	// SSHWebhookEnriched is called whenever an SSH enriching webhook is called.
+	SSHWebhookEnriched(provisioner.Interface, error)
+
+	// KMSSigned is called per KMS signer signature.
+	KMSSigned(error)
+}
+
+// noopMeter implements a noop [Meter].
+type noopMeter struct{}
+
+func (noopMeter) SSHRekeyed(provisioner.Interface, error)            {}
+func (noopMeter) SSHRenewed(provisioner.Interface, error)            {}
+func (noopMeter) SSHSigned(provisioner.Interface, error)             {}
+func (noopMeter) SSHWebhookAuthorized(provisioner.Interface, error)  {}
+func (noopMeter) SSHWebhookEnriched(provisioner.Interface, error)    {}
+func (noopMeter) X509Rekeyed(provisioner.Interface, error)           {}
+func (noopMeter) X509Renewed(provisioner.Interface, error)           {}
+func (noopMeter) X509Signed(provisioner.Interface, error)            {}
+func (noopMeter) X509WebhookAuthorized(provisioner.Interface, error) {}
+func (noopMeter) X509WebhookEnriched(provisioner.Interface, error)   {}
+func (noopMeter) KMSSigned(error)                                    {}
+
+type instrumentedKeyManager struct {
+	kms.KeyManager
+	meter Meter
+}
+
+func (i *instrumentedKeyManager) CreateSigner(req *kmsapi.CreateSignerRequest) (s crypto.Signer, err error) {
+	if s, err = i.KeyManager.CreateSigner(req); err == nil {
+		s = &instrumentedKMSSigner{s, i.meter}
+	}
+
+	return
+}
+
+type instrumentedKMSSigner struct {
+	crypto.Signer
+	meter Meter
+}
+
+func (i *instrumentedKMSSigner) Sign(rand io.Reader, digest []byte, opts crypto.SignerOpts) (signature []byte, err error) {
+	signature, err = i.Signer.Sign(rand, digest, opts)
+	i.meter.KMSSigned(err)
+
+	return
+}

authority/options.go

@@ -381,3 +381,16 @@ func readCertificateBundle(pemCerts []byte) ([]*x509.Certificate, error) {
 	}
 	return certs, nil
 }
+
+// WithMeter is an option that sets the authority's [Meter] to the provided one.
+func WithMeter(m Meter) Option {
+	if m == nil {
+		m = noopMeter{}
+	}
+
+	return func(a *Authority) (_ error) {
+		a.meter = m
+
+		return
+	}
+}

authority/ssh.go

@@ -146,7 +146,13 @@ func (a *Authority) GetSSHBastion(ctx context.Context, user, hostname string) (*
 }
 
 // SignSSH creates a signed SSH certificate with the given public key and options.
-func (a *Authority) SignSSH(_ context.Context, key ssh.PublicKey, opts provisioner.SignSSHOptions, signOpts ...provisioner.SignOption) (*ssh.Certificate, error) {
+func (a *Authority) SignSSH(ctx context.Context, key ssh.PublicKey, opts provisioner.SignSSHOptions, signOpts ...provisioner.SignOption) (*ssh.Certificate, error) {
+	cert, prov, err := a.signSSH(ctx, key, opts, signOpts...)
+	a.meter.SSHSigned(prov, err)
+	return cert, err
+}
+
+func (a *Authority) signSSH(_ context.Context, key ssh.PublicKey, opts provisioner.SignSSHOptions, signOpts ...provisioner.SignOption) (*ssh.Certificate, provisioner.Interface, error) {
 	var (
 		certOptions []sshutil.Option
 		mods        []provisioner.SSHCertModifier
@@ -155,7 +161,7 @@ func (a *Authority) SignSSH(_ context.Context, key ssh.PublicKey, opts provision
 
 	// Validate given options.
 	if err := opts.Validate(); err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 
 	// Set backdate with the configured value
@@ -184,7 +190,7 @@ func (a *Authority) SignSSH(_ context.Context, key ssh.PublicKey, opts provision
 		// validate the given SSHOptions
 		case provisioner.SSHCertOptionsValidator:
 			if err := o.Valid(opts); err != nil {
-				return nil, errs.BadRequestErr(err, "error validating ssh certificate options")
+				return nil, prov, errs.BadRequestErr(err, "error validating ssh certificate options")
 			}
 
 		// call webhooks
@@ -192,7 +198,7 @@ func (a *Authority) SignSSH(_ context.Context, key ssh.PublicKey, opts provision
 			webhookCtl = o
 
 		default:
-			return nil, errs.InternalServer("authority.SignSSH: invalid extra option type %T", o)
+			return nil, prov, errs.InternalServer("authority.SignSSH: invalid extra option type %T", o)
 		}
 	}
 
@@ -205,8 +211,8 @@ func (a *Authority) SignSSH(_ context.Context, key ssh.PublicKey, opts provision
 	}
 
 	// Call enriching webhooks
-	if err := callEnrichingWebhooksSSH(webhookCtl, cr); err != nil {
-		return nil, errs.ApplyOptions(
+	if err := a.callEnrichingWebhooksSSH(prov, webhookCtl, cr); err != nil {
+		return nil, prov, errs.ApplyOptions(
 			errs.ForbiddenErr(err, err.Error()),
 			errs.WithKeyVal("signOptions", signOpts),
 		)
@@ -216,20 +222,21 @@ func (a *Authority) SignSSH(_ context.Context, key ssh.PublicKey, opts provision
 	certificate, err := sshutil.NewCertificate(cr, certOptions...)
 	if err != nil {
 		var te *sshutil.TemplateError
-		if errors.As(err, &te) {
-			return nil, errs.ApplyOptions(
+		switch {
+		case errors.As(err, &te):
+			return nil, prov, errs.ApplyOptions(
 				errs.BadRequestErr(err, err.Error()),
 				errs.WithKeyVal("signOptions", signOpts),
 			)
-		}
-		// explicitly check for unmarshaling errors, which are most probably caused by JSON template syntax errors
-		if strings.HasPrefix(err.Error(), "error unmarshaling certificate") {
-			return nil, errs.InternalServerErr(templatingError(err),
+		case strings.HasPrefix(err.Error(), "error unmarshaling certificate"):
+			// explicitly check for unmarshaling errors, which are most probably caused by JSON template syntax errors
+			return nil, prov, errs.InternalServerErr(templatingError(err),
 				errs.WithKeyVal("signOptions", signOpts),
 				errs.WithMessage("error applying certificate template"),
 			)
+		default:
+			return nil, prov, errs.Wrap(http.StatusInternalServerError, err, "authority.SignSSH")
 		}
-		return nil, errs.Wrap(http.StatusInternalServerError, err, "authority.SignSSH")
 	}
 
 	// Get actual *ssh.Certificate and continue with provisioner modifiers.
@@ -238,13 +245,13 @@ func (a *Authority) SignSSH(_ context.Context, key ssh.PublicKey, opts provision
 	// Use SignSSHOptions to modify the certificate validity. It will be later
 	// checked or set if not defined.
 	if err := opts.ModifyValidity(certTpl); err != nil {
-		return nil, errs.BadRequestErr(err, err.Error())
+		return nil, prov, errs.BadRequestErr(err, err.Error())
 	}
 
 	// Use provisioner modifiers.
 	for _, m := range mods {
 		if err := m.Modify(certTpl, opts); err != nil {
-			return nil, errs.ForbiddenErr(err, "error creating ssh certificate")
+			return nil, prov, errs.ForbiddenErr(err, "error creating ssh certificate")
 		}
 	}
 
@@ -253,32 +260,32 @@ func (a *Authority) SignSSH(_ context.Context, key ssh.PublicKey, opts provision
 	switch certTpl.CertType {
 	case ssh.UserCert:
 		if a.sshCAUserCertSignKey == nil {
-			return nil, errs.NotImplemented("authority.SignSSH: user certificate signing is not enabled")
+			return nil, prov, errs.NotImplemented("authority.SignSSH: user certificate signing is not enabled")
 		}
 		signer = a.sshCAUserCertSignKey
 	case ssh.HostCert:
 		if a.sshCAHostCertSignKey == nil {
-			return nil, errs.NotImplemented("authority.SignSSH: host certificate signing is not enabled")
+			return nil, prov, errs.NotImplemented("authority.SignSSH: host certificate signing is not enabled")
 		}
 		signer = a.sshCAHostCertSignKey
 	default:
-		return nil, errs.InternalServer("authority.SignSSH: unexpected ssh certificate type: %d", certTpl.CertType)
+		return nil, prov, errs.InternalServer("authority.SignSSH: unexpected ssh certificate type: %d", certTpl.CertType)
 	}
 
 	// Check if authority is allowed to sign the certificate
 	if err := a.isAllowedToSignSSHCertificate(certTpl); err != nil {
 		var ee *errs.Error
 		if errors.As(err, &ee) {
-			return nil, ee
+			return nil, prov, ee
 		}
-		return nil, errs.InternalServerErr(err,
+		return nil, prov, errs.InternalServerErr(err,
 			errs.WithMessage("authority.SignSSH: error creating ssh certificate"),
 		)
 	}
 
 	// Send certificate to webhooks for authorization
-	if err := callAuthorizingWebhooksSSH(webhookCtl, certificate, certTpl); err != nil {
-		return nil, errs.ApplyOptions(
+	if err := a.callAuthorizingWebhooksSSH(prov, webhookCtl, certificate, certTpl); err != nil {
+		return nil, prov, errs.ApplyOptions(
 			errs.ForbiddenErr(err, "authority.SignSSH: error signing certificate"),
 		)
 	}
@@ -286,21 +293,21 @@ func (a *Authority) SignSSH(_ context.Context, key ssh.PublicKey, opts provision
 	// Sign certificate.
 	cert, err := sshutil.CreateCertificate(certTpl, signer)
 	if err != nil {
-		return nil, errs.Wrap(http.StatusInternalServerError, err, "authority.SignSSH: error signing certificate")
+		return nil, prov, errs.Wrap(http.StatusInternalServerError, err, "authority.SignSSH: error signing certificate")
 	}
 
 	// User provisioners validators.
 	for _, v := range validators {
 		if err := v.Valid(cert, opts); err != nil {
-			return nil, errs.ForbiddenErr(err, "error validating ssh certificate")
+			return nil, prov, errs.ForbiddenErr(err, "error validating ssh certificate")
 		}
 	}
 
-	if err = a.storeSSHCertificate(prov, cert); err != nil && !errors.Is(err, db.ErrNotImplemented) {
-		return nil, errs.Wrap(http.StatusInternalServerError, err, "authority.SignSSH: error storing certificate in db")
+	if err := a.storeSSHCertificate(prov, cert); err != nil && !errors.Is(err, db.ErrNotImplemented) {
+		return nil, prov, errs.Wrap(http.StatusInternalServerError, err, "authority.SignSSH: error storing certificate in db")
 	}
 
-	return cert, nil
+	return cert, prov, nil
 }
 
 // isAllowedToSignSSHCertificate checks if the Authority is allowed to sign the SSH certificate.
@@ -310,12 +317,18 @@ func (a *Authority) isAllowedToSignSSHCertificate(cert *ssh.Certificate) error {
 
 // RenewSSH creates a signed SSH certificate using the old SSH certificate as a template.
 func (a *Authority) RenewSSH(ctx context.Context, oldCert *ssh.Certificate) (*ssh.Certificate, error) {
+	cert, prov, err := a.renewSSH(ctx, oldCert)
+	a.meter.SSHRenewed(prov, err)
+	return cert, err
+}
+
+func (a *Authority) renewSSH(ctx context.Context, oldCert *ssh.Certificate) (*ssh.Certificate, provisioner.Interface, error) {
 	if oldCert.ValidAfter == 0 || oldCert.ValidBefore == 0 {
-		return nil, errs.BadRequest("cannot renew a certificate without validity period")
+		return nil, nil, errs.BadRequest("cannot renew a certificate without validity period")
 	}
 
 	if err := a.authorizeSSHCertificate(ctx, oldCert); err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 
 	// Attempt to extract the provisioner from the token.
@@ -348,36 +361,41 @@ func (a *Authority) RenewSSH(ctx context.Context, oldCert *ssh.Certificate) (*ss
 	switch certTpl.CertType {
 	case ssh.UserCert:
 		if a.sshCAUserCertSignKey == nil {
-			return nil, errs.NotImplemented("renewSSH: user certificate signing is not enabled")
+			return nil, prov, errs.NotImplemented("renewSSH: user certificate signing is not enabled")
 		}
 		signer = a.sshCAUserCertSignKey
 	case ssh.HostCert:
 		if a.sshCAHostCertSignKey == nil {
-			return nil, errs.NotImplemented("renewSSH: host certificate signing is not enabled")
+			return nil, prov, errs.NotImplemented("renewSSH: host certificate signing is not enabled")
 		}
 		signer = a.sshCAHostCertSignKey
 	default:
-		return nil, errs.InternalServer("renewSSH: unexpected ssh certificate type: %d", certTpl.CertType)
+		return nil, prov, errs.InternalServer("renewSSH: unexpected ssh certificate type: %d", certTpl.CertType)
 	}
 
 	// Sign certificate.
 	cert, err := sshutil.CreateCertificate(certTpl, signer)
 	if err != nil {
-		return nil, errs.Wrap(http.StatusInternalServerError, err, "signSSH: error signing certificate")
+		return nil, prov, errs.Wrap(http.StatusInternalServerError, err, "signSSH: error signing certificate")
 	}
 
-	if err = a.storeRenewedSSHCertificate(prov, oldCert, cert); err != nil && !errors.Is(err, db.ErrNotImplemented) {
-		return nil, errs.Wrap(http.StatusInternalServerError, err, "renewSSH: error storing certificate in db")
+	if err := a.storeRenewedSSHCertificate(prov, oldCert, cert); err != nil && !errors.Is(err, db.ErrNotImplemented) {
+		return nil, prov, errs.Wrap(http.StatusInternalServerError, err, "renewSSH: error storing certificate in db")
 	}
 
-	return cert, nil
+	return cert, prov, nil
 }
 
 // RekeySSH creates a signed SSH certificate using the old SSH certificate as a template.
 func (a *Authority) RekeySSH(ctx context.Context, oldCert *ssh.Certificate, pub ssh.PublicKey, signOpts ...provisioner.SignOption) (*ssh.Certificate, error) {
-	var validators []provisioner.SSHCertValidator
+	cert, prov, err := a.rekeySSH(ctx, oldCert, pub, signOpts...)
+	a.meter.SSHRekeyed(prov, err)
+	return cert, err
+}
 
+func (a *Authority) rekeySSH(ctx context.Context, oldCert *ssh.Certificate, pub ssh.PublicKey, signOpts ...provisioner.SignOption) (*ssh.Certificate, provisioner.Interface, error) {
 	var prov provisioner.Interface
+	var validators []provisioner.SSHCertValidator
 	for _, op := range signOpts {
 		switch o := op.(type) {
 		// Capture current provisioner
@@ -387,16 +405,16 @@ func (a *Authority) RekeySSH(ctx context.Context, oldCert *ssh.Certificate, pub
 		case provisioner.SSHCertValidator:
 			validators = append(validators, o)
 		default:
-			return nil, errs.InternalServer("rekeySSH; invalid extra option type %T", o)
+			return nil, prov, errs.InternalServer("rekeySSH; invalid extra option type %T", o)
 		}
 	}
 
 	if oldCert.ValidAfter == 0 || oldCert.ValidBefore == 0 {
-		return nil, errs.BadRequest("cannot rekey a certificate without validity period")
+		return nil, prov, errs.BadRequest("cannot rekey a certificate without validity period")
 	}
 
 	if err := a.authorizeSSHCertificate(ctx, oldCert); err != nil {
-		return nil, err
+		return nil, prov, err
 	}
 
 	backdate := a.config.AuthorityConfig.Backdate.Duration
@@ -423,37 +441,37 @@ func (a *Authority) RekeySSH(ctx context.Context, oldCert *ssh.Certificate, pub
 	switch cert.CertType {
 	case ssh.UserCert:
 		if a.sshCAUserCertSignKey == nil {
-			return nil, errs.NotImplemented("rekeySSH; user certificate signing is not enabled")
+			return nil, prov, errs.NotImplemented("rekeySSH; user certificate signing is not enabled")
 		}
 		signer = a.sshCAUserCertSignKey
 	case ssh.HostCert:
 		if a.sshCAHostCertSignKey == nil {
-			return nil, errs.NotImplemented("rekeySSH; host certificate signing is not enabled")
+			return nil, prov, errs.NotImplemented("rekeySSH; host certificate signing is not enabled")
 		}
 		signer = a.sshCAHostCertSignKey
 	default:
-		return nil, errs.BadRequest("unexpected certificate type '%d'", cert.CertType)
+		return nil, prov, errs.BadRequest("unexpected certificate type '%d'", cert.CertType)
 	}
 
 	var err error
 	// Sign certificate.
 	cert, err = sshutil.CreateCertificate(cert, signer)
 	if err != nil {
-		return nil, errs.Wrap(http.StatusInternalServerError, err, "signSSH: error signing certificate")
+		return nil, prov, errs.Wrap(http.StatusInternalServerError, err, "signSSH: error signing certificate")
 	}
 
 	// Apply validators from provisioner.
 	for _, v := range validators {
 		if err := v.Valid(cert, provisioner.SignSSHOptions{Backdate: backdate}); err != nil {
-			return nil, errs.ForbiddenErr(err, "error validating ssh certificate")
+			return nil, prov, errs.ForbiddenErr(err, "error validating ssh certificate")
 		}
 	}
 
-	if err = a.storeRenewedSSHCertificate(prov, oldCert, cert); err != nil && !errors.Is(err, db.ErrNotImplemented) {
-		return nil, errs.Wrap(http.StatusInternalServerError, err, "rekeySSH; error storing certificate in db")
+	if err := a.storeRenewedSSHCertificate(prov, oldCert, cert); err != nil && !errors.Is(err, db.ErrNotImplemented) {
+		return nil, prov, errs.Wrap(http.StatusInternalServerError, err, "rekeySSH; error storing certificate in db")
 	}
 
-	return cert, nil
+	return cert, prov, nil
 }
 
 func (a *Authority) storeSSHCertificate(prov provisioner.Interface, cert *ssh.Certificate) error {
@@ -653,28 +671,36 @@ func (a *Authority) getAddUserCommand(principal string) string {
 	return strings.ReplaceAll(cmd, "<principal>", principal)
 }
 
-func callEnrichingWebhooksSSH(webhookCtl webhookController, cr sshutil.CertificateRequest) error {
+func (a *Authority) callEnrichingWebhooksSSH(prov provisioner.Interface, webhookCtl webhookController, cr sshutil.CertificateRequest) (err error) {
 	if webhookCtl == nil {
-		return nil
+		return
 	}
-	whEnrichReq, err := webhook.NewRequestBody(
+
+	var whEnrichReq *webhook.RequestBody
+	if whEnrichReq, err = webhook.NewRequestBody(
 		webhook.WithSSHCertificateRequest(cr),
-	)
-	if err != nil {
-		return err
+	); err == nil {
+		err = webhookCtl.Enrich(whEnrichReq)
+
+		a.meter.SSHWebhookEnriched(prov, err)
 	}
-	return webhookCtl.Enrich(whEnrichReq)
+
+	return
 }
 
-func callAuthorizingWebhooksSSH(webhookCtl webhookController, cert *sshutil.Certificate, certTpl *ssh.Certificate) error {
+func (a *Authority) callAuthorizingWebhooksSSH(prov provisioner.Interface, webhookCtl webhookController, cert *sshutil.Certificate, certTpl *ssh.Certificate) (err error) {
 	if webhookCtl == nil {
-		return nil
+		return
 	}
-	whAuthBody, err := webhook.NewRequestBody(
+
+	var whAuthBody *webhook.RequestBody
+	if whAuthBody, err = webhook.NewRequestBody(
 		webhook.WithSSHCertificate(cert, certTpl),
-	)
-	if err != nil {
-		return err
+	); err == nil {
+		err = webhookCtl.Authorize(whAuthBody)
+
+		a.meter.SSHWebhookAuthorized(prov, err)
 	}
-	return webhookCtl.Authorize(whAuthBody)
+
+	return
 }

authority/tls.go

@@ -93,6 +93,12 @@ func withDefaultASN1DN(def *config.ASN1DN) provisioner.CertificateModifierFunc {
 
 // Sign creates a signed certificate from a certificate signing request.
 func (a *Authority) Sign(csr *x509.CertificateRequest, signOpts provisioner.SignOptions, extraOpts ...provisioner.SignOption) ([]*x509.Certificate, error) {
+	chain, prov, err := a.signX509(csr, signOpts, extraOpts...)
+	a.meter.X509Signed(prov, err)
+	return chain, err
+}
+
+func (a *Authority) signX509(csr *x509.CertificateRequest, signOpts provisioner.SignOptions, extraOpts ...provisioner.SignOption) ([]*x509.Certificate, provisioner.Interface, error) {
 	var (
 		certOptions    []x509util.Option
 		certValidators []provisioner.CertificateValidator
@@ -100,9 +106,9 @@ func (a *Authority) Sign(csr *x509.CertificateRequest, signOpts provisioner.Sign
 		certEnforcers  []provisioner.CertificateEnforcer
 	)
 
-	opts := []interface{}{errs.WithKeyVal("csr", csr), errs.WithKeyVal("signOptions", signOpts)}
+	opts := []any{errs.WithKeyVal("csr", csr), errs.WithKeyVal("signOptions", signOpts)}
 	if err := csr.CheckSignature(); err != nil {
-		return nil, errs.ApplyOptions(
+		return nil, nil, errs.ApplyOptions(
 			errs.BadRequestErr(err, "invalid certificate request"),
 			opts...,
 		)
@@ -111,10 +117,12 @@ func (a *Authority) Sign(csr *x509.CertificateRequest, signOpts provisioner.Sign
 	// Set backdate with the configured value
 	signOpts.Backdate = a.config.AuthorityConfig.Backdate.Duration
 
-	var prov provisioner.Interface
-	var pInfo *casapi.ProvisionerInfo
-	var attData *provisioner.AttestationData
-	var webhookCtl webhookController
+	var (
+		prov       provisioner.Interface
+		pInfo      *casapi.ProvisionerInfo
+		attData    *provisioner.AttestationData
+		webhookCtl webhookController
+	)
 	for _, op := range extraOpts {
 		switch k := op.(type) {
 		// Capture current provisioner
@@ -132,7 +140,7 @@ func (a *Authority) Sign(csr *x509.CertificateRequest, signOpts provisioner.Sign
 		// Validate the given certificate request.
 		case provisioner.CertificateRequestValidator:
 			if err := k.Valid(csr); err != nil {
-				return nil, errs.ApplyOptions(
+				return nil, prov, errs.ApplyOptions(
 					errs.ForbiddenErr(err, "error validating certificate request"),
 					opts...,
 				)
@@ -159,45 +167,46 @@ func (a *Authority) Sign(csr *x509.CertificateRequest, signOpts provisioner.Sign
 			webhookCtl = k
 
 		default:
-			return nil, errs.InternalServer("authority.Sign; invalid extra option type %T", append([]interface{}{k}, opts...)...)
+			return nil, prov, errs.InternalServer("authority.Sign; invalid extra option type %T", append([]any{k}, opts...)...)
 		}
 	}
 
-	if err := callEnrichingWebhooksX509(webhookCtl, attData, csr); err != nil {
-		return nil, errs.ApplyOptions(
+	if err := a.callEnrichingWebhooksX509(prov, webhookCtl, attData, csr); err != nil {
+		return nil, prov, errs.ApplyOptions(
 			errs.ForbiddenErr(err, err.Error()),
 			errs.WithKeyVal("csr", csr),
 			errs.WithKeyVal("signOptions", signOpts),
 		)
 	}
 
-	cert, err := x509util.NewCertificate(csr, certOptions...)
+	crt, err := x509util.NewCertificate(csr, certOptions...)
 	if err != nil {
 		var te *x509util.TemplateError
-		if errors.As(err, &te) {
-			return nil, errs.ApplyOptions(
+		switch {
+		case errors.As(err, &te):
+			return nil, prov, errs.ApplyOptions(
 				errs.BadRequestErr(err, err.Error()),
 				errs.WithKeyVal("csr", csr),
 				errs.WithKeyVal("signOptions", signOpts),
 			)
-		}
-		// explicitly check for unmarshaling errors, which are most probably caused by JSON template (syntax) errors
-		if strings.HasPrefix(err.Error(), "error unmarshaling certificate") {
-			return nil, errs.InternalServerErr(templatingError(err),
+		case strings.HasPrefix(err.Error(), "error unmarshaling certificate"):
+			// explicitly check for unmarshaling errors, which are most probably caused by JSON template (syntax) errors
+			return nil, prov, errs.InternalServerErr(templatingError(err),
 				errs.WithKeyVal("csr", csr),
 				errs.WithKeyVal("signOptions", signOpts),
 				errs.WithMessage("error applying certificate template"),
 			)
+		default:
+			return nil, prov, errs.Wrap(http.StatusInternalServerError, err, "authority.Sign", opts...)
 		}
-		return nil, errs.Wrap(http.StatusInternalServerError, err, "authority.Sign", opts...)
 	}
 
 	// Certificate modifiers before validation
-	leaf := cert.GetCertificate()
+	leaf := crt.GetCertificate()
 
 	// Set default subject
 	if err := withDefaultASN1DN(a.config.AuthorityConfig.Template).Modify(leaf, signOpts); err != nil {
-		return nil, errs.ApplyOptions(
+		return nil, prov, errs.ApplyOptions(
 			errs.ForbiddenErr(err, "error creating certificate"),
 			opts...,
 		)
@@ -205,7 +214,7 @@ func (a *Authority) Sign(csr *x509.CertificateRequest, signOpts provisioner.Sign
 
 	for _, m := range certModifiers {
 		if err := m.Modify(leaf, signOpts); err != nil {
-			return nil, errs.ApplyOptions(
+			return nil, prov, errs.ApplyOptions(
 				errs.ForbiddenErr(err, "error creating certificate"),
 				opts...,
 			)
@@ -215,7 +224,7 @@ func (a *Authority) Sign(csr *x509.CertificateRequest, signOpts provisioner.Sign
 	// Certificate validation.
 	for _, v := range certValidators {
 		if err := v.Valid(leaf, signOpts); err != nil {
-			return nil, errs.ApplyOptions(
+			return nil, prov, errs.ApplyOptions(
 				errs.ForbiddenErr(err, "error validating certificate"),
 				opts...,
 			)
@@ -224,8 +233,8 @@ func (a *Authority) Sign(csr *x509.CertificateRequest, signOpts provisioner.Sign
 
 	// Certificate modifiers after validation
 	for _, m := range certEnforcers {
-		if err := m.Enforce(leaf); err != nil {
-			return nil, errs.ApplyOptions(
+		if err = m.Enforce(leaf); err != nil {
+			return nil, prov, errs.ApplyOptions(
 				errs.ForbiddenErr(err, "error creating certificate"),
 				opts...,
 			)
@@ -234,8 +243,8 @@ func (a *Authority) Sign(csr *x509.CertificateRequest, signOpts provisioner.Sign
 
 	// Process injected modifiers after validation
 	for _, m := range a.x509Enforcers {
-		if err := m.Enforce(leaf); err != nil {
-			return nil, errs.ApplyOptions(
+		if err = m.Enforce(leaf); err != nil {
+			return nil, prov, errs.ApplyOptions(
 				errs.ForbiddenErr(err, "error creating certificate"),
 				opts...,
 			)
@@ -243,12 +252,12 @@ func (a *Authority) Sign(csr *x509.CertificateRequest, signOpts provisioner.Sign
 	}
 
 	// Check if authority is allowed to sign the certificate
-	if err := a.isAllowedToSignX509Certificate(leaf); err != nil {
+	if err = a.isAllowedToSignX509Certificate(leaf); err != nil {
 		var ee *errs.Error
 		if errors.As(err, &ee) {
-			return nil, errs.ApplyOptions(ee, opts...)
+			return nil, prov, errs.ApplyOptions(ee, opts...)
 		}
-		return nil, errs.InternalServerErr(err,
+		return nil, prov, errs.InternalServerErr(err,
 			errs.WithKeyVal("csr", csr),
 			errs.WithKeyVal("signOptions", signOpts),
 			errs.WithMessage("error creating certificate"),
@@ -256,8 +265,8 @@ func (a *Authority) Sign(csr *x509.CertificateRequest, signOpts provisioner.Sign
 	}
 
 	// Send certificate to webhooks for authorization
-	if err := callAuthorizingWebhooksX509(webhookCtl, cert, leaf, attData); err != nil {
-		return nil, errs.ApplyOptions(
+	if err := a.callAuthorizingWebhooksX509(prov, webhookCtl, crt, leaf, attData); err != nil {
+		return nil, prov, errs.ApplyOptions(
 			errs.ForbiddenErr(err, "error creating certificate"),
 			opts...,
 		)
@@ -265,6 +274,7 @@ func (a *Authority) Sign(csr *x509.CertificateRequest, signOpts provisioner.Sign
 
 	// Sign certificate
 	lifetime := leaf.NotAfter.Sub(leaf.NotBefore.Add(signOpts.Backdate))
+
 	resp, err := a.x509CAService.CreateCertificate(&casapi.CreateCertificateRequest{
 		Template:    leaf,
 		CSR:         csr,
@@ -273,23 +283,22 @@ func (a *Authority) Sign(csr *x509.CertificateRequest, signOpts provisioner.Sign
 		Provisioner: pInfo,
 	})
 	if err != nil {
-		return nil, errs.Wrap(http.StatusInternalServerError, err, "authority.Sign; error creating certificate", opts...)
+		return nil, prov, errs.Wrap(http.StatusInternalServerError, err, "authority.Sign; error creating certificate", opts...)
 	}
 
-	fullchain := append([]*x509.Certificate{resp.Certificate}, resp.CertificateChain...)
+	chain := append([]*x509.Certificate{resp.Certificate}, resp.CertificateChain...)
 
-	// Wrap provisioner with extra information.
-	prov = wrapProvisioner(prov, attData)
+	// Wrap provisioner with extra information, if not nil
+	if prov != nil {
+		prov = wrapProvisioner(prov, attData)
+	}
 
 	// Store certificate in the db.
-	if err = a.storeCertificate(prov, fullchain); err != nil {
-		if !errors.Is(err, db.ErrNotImplemented) {
-			return nil, errs.Wrap(http.StatusInternalServerError, err,
-				"authority.Sign; error storing certificate in db", opts...)
-		}
+	if err := a.storeCertificate(prov, chain); err != nil && !errors.Is(err, db.ErrNotImplemented) {
+		return nil, prov, errs.Wrap(http.StatusInternalServerError, err, "authority.Sign; error storing certificate in db", opts...)
 	}
 
-	return fullchain, nil
+	return chain, prov, nil
 }
 
 // isAllowedToSignX509Certificate checks if the Authority is allowed
@@ -337,14 +346,25 @@ func (a *Authority) Rekey(oldCert *x509.Certificate, pk crypto.PublicKey) ([]*x5
 // of rekey), and 'NotBefore/NotAfter' (the validity duration of the new
 // certificate should be equal to the old one, but starting 'now').
 func (a *Authority) RenewContext(ctx context.Context, oldCert *x509.Certificate, pk crypto.PublicKey) ([]*x509.Certificate, error) {
+	chain, prov, err := a.renewContext(ctx, oldCert, pk)
+	if pk == nil {
+		a.meter.X509Renewed(prov, err)
+	} else {
+		a.meter.X509Rekeyed(prov, err)
+	}
+	return chain, err
+}
+
+func (a *Authority) renewContext(ctx context.Context, oldCert *x509.Certificate, pk crypto.PublicKey) ([]*x509.Certificate, provisioner.Interface, error) {
 	isRekey := (pk != nil)
 	opts := []errs.Option{
 		errs.WithKeyVal("serialNumber", oldCert.SerialNumber.String()),
 	}
 
 	// Check step provisioner extensions
-	if err := a.authorizeRenew(ctx, oldCert); err != nil {
-		return nil, errs.StatusCodeError(http.StatusInternalServerError, err, opts...)
+	prov, err := a.authorizeRenew(ctx, oldCert)
+	if err != nil {
+		return nil, prov, errs.StatusCodeError(http.StatusInternalServerError, err, opts...)
 	}
 
 	// Durations
@@ -414,15 +434,17 @@ func (a *Authority) RenewContext(ctx context.Context, oldCert *x509.Certificate,
 	//
 	// TODO(hslatman,maraino): consider adding policies too and consider if
 	// RenewSSH should check policies.
-	if err := a.constraintsEngine.ValidateCertificate(newCert); err != nil {
+	if err = a.constraintsEngine.ValidateCertificate(newCert); err != nil {
 		var ee *errs.Error
-		if errors.As(err, &ee) {
-			return nil, errs.StatusCodeError(ee.StatusCode(), err, opts...)
+		switch {
+		case errors.As(err, &ee):
+			return nil, prov, errs.StatusCodeError(ee.StatusCode(), err, opts...)
+		default:
+			return nil, prov, errs.InternalServerErr(err,
+				errs.WithKeyVal("serialNumber", oldCert.SerialNumber.String()),
+				errs.WithMessage("error renewing certificate"),
+			)
 		}
-		return nil, errs.InternalServerErr(err,
-			errs.WithKeyVal("serialNumber", oldCert.SerialNumber.String()),
-			errs.WithMessage("error renewing certificate"),
-		)
 	}
 
 	// The token can optionally be in the context. If the CA is running in RA
@@ -436,17 +458,16 @@ func (a *Authority) RenewContext(ctx context.Context, oldCert *x509.Certificate,
 		Token:    token,
 	})
 	if err != nil {
-		return nil, errs.StatusCodeError(http.StatusInternalServerError, err, opts...)
+		return nil, prov, errs.StatusCodeError(http.StatusInternalServerError, err, opts...)
 	}
 
-	fullchain := append([]*x509.Certificate{resp.Certificate}, resp.CertificateChain...)
-	if err = a.storeRenewedCertificate(oldCert, fullchain); err != nil {
-		if !errors.Is(err, db.ErrNotImplemented) {
-			return nil, errs.StatusCodeError(http.StatusInternalServerError, err, opts...)
-		}
+	chain := append([]*x509.Certificate{resp.Certificate}, resp.CertificateChain...)
+
+	if err = a.storeRenewedCertificate(oldCert, chain); err != nil && !errors.Is(err, db.ErrNotImplemented) {
+		return nil, prov, errs.StatusCodeError(http.StatusInternalServerError, err, opts...)
 	}
 
-	return fullchain, nil
+	return chain, prov, nil
 }
 
 // storeCertificate allows to use an extension of the db.AuthDB interface that
@@ -952,42 +973,52 @@ func templatingError(err error) error {
 	return errors.Wrap(cause, "error applying certificate template")
 }
 
-func callEnrichingWebhooksX509(webhookCtl webhookController, attData *provisioner.AttestationData, csr *x509.CertificateRequest) error {
+func (a *Authority) callEnrichingWebhooksX509(prov provisioner.Interface, webhookCtl webhookController, attData *provisioner.AttestationData, csr *x509.CertificateRequest) (err error) {
 	if webhookCtl == nil {
-		return nil
+		return
 	}
+
 	var attested *webhook.AttestationData
 	if attData != nil {
 		attested = &webhook.AttestationData{
 			PermanentIdentifier: attData.PermanentIdentifier,
 		}
 	}
-	whEnrichReq, err := webhook.NewRequestBody(
+
+	var whEnrichReq *webhook.RequestBody
+	if whEnrichReq, err = webhook.NewRequestBody(
 		webhook.WithX509CertificateRequest(csr),
 		webhook.WithAttestationData(attested),
-	)
-	if err != nil {
-		return err
+	); err == nil {
+		err = webhookCtl.Enrich(whEnrichReq)
+
+		a.meter.X509WebhookEnriched(prov, err)
 	}
-	return webhookCtl.Enrich(whEnrichReq)
+
+	return
 }
 
-func callAuthorizingWebhooksX509(webhookCtl webhookController, cert *x509util.Certificate, leaf *x509.Certificate, attData *provisioner.AttestationData) error {
+func (a *Authority) callAuthorizingWebhooksX509(prov provisioner.Interface, webhookCtl webhookController, cert *x509util.Certificate, leaf *x509.Certificate, attData *provisioner.AttestationData) (err error) {
 	if webhookCtl == nil {
-		return nil
+		return
 	}
+
 	var attested *webhook.AttestationData
 	if attData != nil {
 		attested = &webhook.AttestationData{
 			PermanentIdentifier: attData.PermanentIdentifier,
 		}
 	}
-	whAuthBody, err := webhook.NewRequestBody(
+
+	var whAuthBody *webhook.RequestBody
+	if whAuthBody, err = webhook.NewRequestBody(
 		webhook.WithX509Certificate(cert, leaf),
 		webhook.WithAttestationData(attested),
-	)
-	if err != nil {
-		return err
+	); err == nil {
+		err = webhookCtl.Authorize(whAuthBody)
+
+		a.meter.X509WebhookAuthorized(prov, err)
 	}
-	return webhookCtl.Authorize(whAuthBody)
+
+	return
 }

ca/ca.go

@@ -27,6 +27,7 @@ import (
 	adminAPI "github.com/smallstep/certificates/authority/admin/api"
 	"github.com/smallstep/certificates/authority/config"
 	"github.com/smallstep/certificates/db"
+	"github.com/smallstep/certificates/internal/metrix"
 	"github.com/smallstep/certificates/logging"
 	"github.com/smallstep/certificates/monitoring"
 	"github.com/smallstep/certificates/scep"
@@ -125,6 +126,7 @@ type CA struct {
 	config      *config.Config
 	srv         *server.Server
 	insecureSrv *server.Server
+	metricsSrv  *server.Server
 	opts        *options
 	renewer     *TLSRenewer
 	compactStop chan struct{}
@@ -163,6 +165,13 @@ func (ca *CA) Init(cfg *config.Config) (*CA, error) {
 		opts = append(opts, authority.WithQuietInit())
 	}
 
+	var meter *metrix.Meter
+	if ca.config.MetricsAddress != "" {
+		meter = metrix.New()
+
+		opts = append(opts, authority.WithMeter(meter))
+	}
+
 	webhookTransport := http.DefaultTransport.(*http.Transport).Clone()
 	opts = append(opts, authority.WithWebhookClient(&http.Client{Transport: webhookTransport}))
 
@@ -318,6 +327,13 @@ func (ca *CA) Init(cfg *config.Config) (*CA, error) {
 		}
 	}
 
+	if meter != nil {
+		ca.metricsSrv = server.New(ca.config.MetricsAddress, meter, nil)
+		ca.metricsSrv.BaseContext = func(net.Listener) context.Context {
+			return baseContext
+		}
+	}
+
 	return ca, nil
 }
 
@@ -404,6 +420,14 @@ func (ca *CA) Run() error {
 		}()
 	}
 
+	if ca.metricsSrv != nil {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			errs <- ca.metricsSrv.ListenAndServe()
+		}()
+	}
+
 	wg.Add(1)
 	go func() {
 		defer wg.Done()
@@ -480,6 +504,13 @@ func (ca *CA) Reload() error {
 		}
 	}
 
+	if ca.metricsSrv != nil {
+		if err = ca.metricsSrv.Reload(newCA.metricsSrv); err != nil {
+			logContinue("Reload failed because metrics server could not be replaced.")
+			return errors.Wrap(err, "error reloading metrics server")
+		}
+	}
+
 	if err = ca.srv.Reload(newCA.srv); err != nil {
 		logContinue("Reload failed because server could not be replaced.")
 		return errors.Wrap(err, "error reloading server")

commands/app.go

@@ -251,7 +251,8 @@ To get a linked authority token:
 		ca.WithSSHUserPassword(sshUserPassword),
 		ca.WithIssuerPassword(issuerPassword),
 		ca.WithLinkedCAToken(token),
-		ca.WithQuiet(quiet))
+		ca.WithQuiet(quiet),
+	)
 	if err != nil {
 		fatal(err)
 	}

go.mod

@@ -21,6 +21,7 @@ require (
 	github.com/hashicorp/vault/api/auth/kubernetes v0.5.0
 	github.com/newrelic/go-agent/v3 v3.29.0
 	github.com/pkg/errors v0.9.1
+	github.com/prometheus/client_golang v1.15.1
 	github.com/rs/xid v1.5.0
 	github.com/sirupsen/logrus v1.9.3
 	github.com/slackhq/nebula v1.6.1
@@ -73,6 +74,7 @@ require (
 	github.com/aws/aws-sdk-go-v2/service/ssooidc v1.21.7 // indirect
 	github.com/aws/aws-sdk-go-v2/service/sts v1.26.7 // indirect
 	github.com/aws/smithy-go v1.19.0 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cenkalti/backoff/v3 v3.0.0 // indirect
 	github.com/cespare/xxhash v1.1.0 // indirect
 	github.com/cespare/xxhash/v2 v2.2.0 // indirect
@@ -125,6 +127,7 @@ require (
 	github.com/manifoldco/promptui v0.9.0 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.16 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
 	github.com/mgutz/ansi v0.0.0-20200706080929-d51e80ef957d // indirect
 	github.com/miekg/pkcs11 v1.1.1 // indirect
 	github.com/mitchellh/copystructure v1.2.0 // indirect
@@ -134,6 +137,9 @@ require (
 	github.com/peterbourgon/diskv/v3 v3.0.1 // indirect
 	github.com/pkg/browser v0.0.0-20210911075715-681adbf594b8 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/prometheus/client_model v0.4.0 // indirect
+	github.com/prometheus/common v0.42.0 // indirect
+	github.com/prometheus/procfs v0.9.0 // indirect
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect
 	github.com/ryanuber/go-glob v1.0.0 // indirect
 	github.com/schollz/jsonstore v1.1.0 // indirect

go.sum

@@ -72,6 +72,8 @@ github.com/aws/aws-sdk-go-v2/service/sts v1.26.7 h1:NzO4Vrau795RkUdSHKEwiR01FaGz
 github.com/aws/aws-sdk-go-v2/service/sts v1.26.7/go.mod h1:6h2YuIoxaMSCFf5fi1EgZAwdfkGMgDY+DVfa61uLe4U=
 github.com/aws/smithy-go v1.19.0 h1:KWFKQV80DpP3vJrrA9sVAHQ5gc2z8i4EzrLhLlWXcBM=
 github.com/aws/smithy-go v1.19.0/go.mod h1:NukqUGpCZIILqqiV0NIjeFh24kd/FAa4beRb6nbIUPE=
+github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
+github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/bgentry/speakeasy v0.1.0/go.mod h1:+zsyZBPWlz7T6j88CTgSN5bM796AkVf0kBD4zp0CCIs=
 github.com/cenkalti/backoff/v3 v3.0.0 h1:ske+9nBpD9qZsTBoF41nW5L+AIuFBKMeze18XQ3eG1c=
 github.com/cenkalti/backoff/v3 v3.0.0/go.mod h1:cIeZDE3IrqwwJl6VUwCN6trj1oXrTS4rc0ij+ULvLYs=
@@ -350,6 +352,8 @@ github.com/mattn/go-isatty v0.0.10/go.mod h1:qgIWMr58cqv1PHHyhnkY9lrL7etaEgOFcME
 github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
 github.com/mattn/go-isatty v0.0.16 h1:bq3VjFmv/sOjHtdEhmkEV4x1AJtvUvOJ2PFAZ5+peKQ=
 github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
+github.com/matttproud/golang_protobuf_extensions v1.0.4 h1:mmDVorXM7PCGKw94cs5zkfA9PSy5pEvNWRP0ET0TIVo=
+github.com/matttproud/golang_protobuf_extensions v1.0.4/go.mod h1:BSXmuO+STAnVfrANrmjBb36TMTDstsz7MSK+HVaYKv4=
 github.com/mgutz/ansi v0.0.0-20200706080929-d51e80ef957d h1:5PJl274Y63IEHC+7izoQE9x6ikvDFZS2mDVS3drnohI=
 github.com/mgutz/ansi v0.0.0-20200706080929-d51e80ef957d/go.mod h1:01TrycV0kFyexm33Z7vhZRXopbI8J3TDReVlkTgMUxE=
 github.com/miekg/pkcs11 v1.0.3-0.20190429190417-a667d056470f/go.mod h1:XsNlhZGX73bx86s2hdc/FuaLm2CPZJemRLMA+WTFxgs=
@@ -383,7 +387,15 @@ github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINE
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/posener/complete v1.1.1/go.mod h1:em0nMJCgc9GFtwrmVmEMR/ZL6WyhyjMBndrE9hABlRI=
+github.com/prometheus/client_golang v1.15.1 h1:8tXpTmJbyH5lydzFPoxSIJ0J46jdh3tylbvM1xCv0LI=
+github.com/prometheus/client_golang v1.15.1/go.mod h1:e9yaBhRPU2pPNsZwE+JdQl0KEt1N9XgF6zxWmaC0xOk=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
+github.com/prometheus/client_model v0.4.0 h1:5lQXD3cAg1OXBf4Wq03gTrXHeaV0TQvGfUooCfx1yqY=
+github.com/prometheus/client_model v0.4.0/go.mod h1:oMQmHW1/JoDwqLtg57MGgP/Fb1CJEYF2imWWhWtMkYU=
+github.com/prometheus/common v0.42.0 h1:EKsfXEYo4JpWMHH5cg+KOUWeuJSov1Id8zGR8eeI1YM=
+github.com/prometheus/common v0.42.0/go.mod h1:xBwqVerjNdUDjgODMpudtOMwlOwf2SaTr1yjz4b7Zbc=
+github.com/prometheus/procfs v0.9.0 h1:wzCHvIvM5SxWqYvwgVL7yJY8Lz3PKn49KQtpgMYJfhI=
+github.com/prometheus/procfs v0.9.0/go.mod h1:+pB4zwohETzFnmlpe6yd2lSc+0/46IYZRB/chUwxUZY=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
 github.com/rs/xid v1.2.1/go.mod h1:+uKXf+4Djp6Md1KODXJxgGQPKngRmWyn10oCKFzNHOQ=
@@ -540,6 +552,7 @@ golang.org/x/oauth2 v0.16.0 h1:aDkGMBSYxElaoP81NpoUoz2oo2R2wHdZpGToUxfyQrQ=
 golang.org/x/oauth2 v0.16.0/go.mod h1:hqZ+0LWXsiVoZpeld6jVt06P3adbS2Uu911W1SsJv2o=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -653,8 +666,8 @@ google.golang.org/protobuf v1.32.0 h1:pPC6BG5ex8PDFnkbrGU3EixyhKcQ2aDuBS36lqK/C7
 google.golang.org/protobuf v1.32.0/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
 gopkg.in/inconshreveable/log15.v2 v2.0.0-20180818164646-67afb5ed74ec/go.mod h1:aPpfJ7XW+gOuirDoZ8gHhLh3kZ1B08FtV2bbmy7Jv3s=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

internal/metrix/meter.go

@@ -0,0 +1,196 @@
+// Package metrix implements stats-related functionality.
+package metrix
+
+import (
+	"net/http"
+	"strconv"
+	"time"
+
+	"github.com/smallstep/certificates/authority/provisioner"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+// New initializes and returns a new [Meter].
+func New() (m *Meter) {
+	initializedAt := time.Now()
+
+	m = &Meter{
+		uptime: prometheus.NewGaugeFunc(
+			prometheus.GaugeOpts(opts(
+				"",
+				"uptime_seconds",
+				"Number of seconds since service start",
+			)),
+			func() float64 {
+				return float64(time.Since(initializedAt) / time.Second)
+			},
+		),
+		ssh:  newProvisionerInstruments("ssh"),
+		x509: newProvisionerInstruments("x509"),
+		kms: &kms{
+			signed: prometheus.NewCounter(prometheus.CounterOpts(opts("kms", "signed", "Number of KMS-backed signatures"))),
+			errors: prometheus.NewCounter(prometheus.CounterOpts(opts("kms", "errors", "Number of KMS-related errors"))),
+		},
+	}
+
+	reg := prometheus.NewRegistry()
+
+	reg.MustRegister(
+		m.uptime,
+		m.ssh.rekeyed,
+		m.ssh.renewed,
+		m.ssh.signed,
+		m.x509.rekeyed,
+		m.x509.renewed,
+		m.x509.signed,
+		m.kms.signed,
+		m.kms.errors,
+	)
+
+	h := promhttp.HandlerFor(reg, promhttp.HandlerOpts{
+		Registry:            reg,
+		Timeout:             5 * time.Second,
+		MaxRequestsInFlight: 10,
+	})
+
+	mux := http.NewServeMux()
+	mux.Handle("/metrics", h)
+	m.Handler = mux
+
+	return
+}
+
+// Meter wraps the functionality of a Prometheus-compatible HTTP handler.
+type Meter struct {
+	http.Handler
+
+	uptime prometheus.GaugeFunc
+	ssh    *provisionerInstruments
+	x509   *provisionerInstruments
+	kms    *kms
+}
+
+// SSHRekeyed implements [authority.Meter] for [Meter].
+func (m *Meter) SSHRekeyed(p provisioner.Interface, err error) {
+	incrProvisionerCounter(m.ssh.rekeyed, p, err)
+}
+
+// SSHRenewed implements [authority.Meter] for [Meter].
+func (m *Meter) SSHRenewed(p provisioner.Interface, err error) {
+	incrProvisionerCounter(m.ssh.renewed, p, err)
+}
+
+// SSHSigned implements [authority.Meter] for [Meter].
+func (m *Meter) SSHSigned(p provisioner.Interface, err error) {
+	incrProvisionerCounter(m.ssh.signed, p, err)
+}
+
+// SSHAuthorized implements [authority.Meter] for [Meter].
+func (m *Meter) SSHWebhookAuthorized(p provisioner.Interface, err error) {
+	incrProvisionerCounter(m.ssh.webhookAuthorized, p, err)
+}
+
+// SSHEnriched implements [authority.Meter] for [Meter].
+func (m *Meter) SSHWebhookEnriched(p provisioner.Interface, err error) {
+	incrProvisionerCounter(m.ssh.webhookEnriched, p, err)
+}
+
+// X509Rekeyed implements [authority.Meter] for [Meter].
+func (m *Meter) X509Rekeyed(p provisioner.Interface, err error) {
+	incrProvisionerCounter(m.x509.rekeyed, p, err)
+}
+
+// X509Renewed implements [authority.Meter] for [Meter].
+func (m *Meter) X509Renewed(p provisioner.Interface, err error) {
+	incrProvisionerCounter(m.x509.renewed, p, err)
+}
+
+// X509Signed implements [authority.Meter] for [Meter].
+func (m *Meter) X509Signed(p provisioner.Interface, err error) {
+	incrProvisionerCounter(m.x509.signed, p, err)
+}
+
+// X509Authorized implements [authority.Meter] for [Meter].
+func (m *Meter) X509WebhookAuthorized(p provisioner.Interface, err error) {
+	incrProvisionerCounter(m.x509.webhookAuthorized, p, err)
+}
+
+// X509Enriched implements [authority.Meter] for [Meter].
+func (m *Meter) X509WebhookEnriched(p provisioner.Interface, err error) {
+	incrProvisionerCounter(m.x509.webhookEnriched, p, err)
+}
+
+func incrProvisionerCounter(cv *prometheus.CounterVec, p provisioner.Interface, err error) {
+	var name string
+	if p != nil {
+		name = p.GetName()
+	}
+
+	cv.WithLabelValues(name, strconv.FormatBool(err == nil)).Inc()
+}
+
+// KMSSigned implements [authority.Meter] for [Meter].
+func (m *Meter) KMSSigned(err error) {
+	if err == nil {
+		m.kms.signed.Inc()
+	} else {
+		m.kms.errors.Inc()
+	}
+}
+
+// provisionerInstruments wraps the counters exported by provisioners.
+type provisionerInstruments struct {
+	rekeyed *prometheus.CounterVec
+	renewed *prometheus.CounterVec
+	signed  *prometheus.CounterVec
+
+	webhookAuthorized *prometheus.CounterVec
+	webhookEnriched   *prometheus.CounterVec
+}
+
+func newProvisionerInstruments(subsystem string) *provisionerInstruments {
+	return &provisionerInstruments{
+		rekeyed: newCounterVec(subsystem, "rekeyed_total", "Number of certificates rekeyed",
+			"provisioner",
+			"success",
+		),
+		renewed: newCounterVec(subsystem, "renewed_total", "Number of certificates renewed",
+			"provisioner",
+			"success",
+		),
+		signed: newCounterVec(subsystem, "signed_total", "Number of certificates signed",
+			"provisioner",
+			"success",
+		),
+		webhookAuthorized: newCounterVec(subsystem, "webhook_authorized_total", "Number of authorizing webhooks called",
+			"provisioner",
+			"success",
+		),
+		webhookEnriched: newCounterVec(subsystem, "webhook_enriched_total", "Number of enriching webhooks called",
+			"provisioner",
+			"success",
+		),
+	}
+}
+
+type kms struct {
+	signed prometheus.Counter
+	errors prometheus.Counter
+}
+
+func newCounterVec(subsystem, name, help string, labels ...string) *prometheus.CounterVec {
+	opts := opts(subsystem, name, help)
+
+	return prometheus.NewCounterVec(prometheus.CounterOpts(opts), labels)
+}
+
+func opts(subsystem, name, help string) prometheus.Opts {
+	return prometheus.Opts{
+		Namespace: "step_ca",
+		Subsystem: subsystem,
+		Name:      name,
+		Help:      help,
+	}
+}