feat: add named errors to cloud config

Changes errors created by cloud config to be standardized so that any
other packages relying on the cloud config can check if the error is of
the same "type".

Signed-off-by: Daniel J. Holmes (jaitaiwan) <dan@jaitaiwan.dev>

pkg/config/config.go

@@ -18,6 +18,7 @@ limitations under the License.
 package config
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -71,31 +72,41 @@ type ClustersConfig struct {
 	Clusters []*proxmoxpool.ProxmoxCluster `yaml:"clusters,omitempty"`
 }
 
+// Errors for Reading Cloud Config
+var (
+	ErrMissingPVERegion       = errors.New("missing PVE region in cloud config")
+	ErrMissingPVEAPIURL       = errors.New("missing PVE API URL in cloud config")
+	ErrAuthCredentialsMissing = errors.New("user or token credentials are required")
+	ErrInvalidAuthCredentials = errors.New("must specify one of user or token credentials, not both")
+	ErrInvalidCloudConfig     = errors.New("invalid cloud config")
+	ErrInvalidNetworkMode     = fmt.Errorf("invalid network mode, valid modes are %v", ValidNetworkModes)
+)
+
 // ReadCloudConfig reads cloud config from a reader.
 func ReadCloudConfig(config io.Reader) (ClustersConfig, error) {
 	cfg := ClustersConfig{}
 
 	if config != nil {
 		if err := yaml.NewDecoder(config).Decode(&cfg); err != nil {
-			return ClustersConfig{}, err
+			return ClustersConfig{}, errors.Join(ErrInvalidCloudConfig, err)
 		}
 	}
 
 	for idx, c := range cfg.Clusters {
 		if c.Username != "" && c.Password != "" {
 			if c.TokenID != "" || c.TokenSecret != "" {
-				return ClustersConfig{}, fmt.Errorf("cluster #%d: token_id and token_secret are not allowed when username and password are set", idx+1)
+				return ClustersConfig{}, fmt.Errorf("cluster #%d: %w", idx+1, ErrInvalidAuthCredentials)
 			}
 		} else if c.TokenID == "" || c.TokenSecret == "" {
-			return ClustersConfig{}, fmt.Errorf("cluster #%d: either username and password or token_id and token_secret are required", idx+1)
+			return ClustersConfig{}, fmt.Errorf("cluster #%d: %w", idx+1, ErrAuthCredentialsMissing)
 		}
 
 		if c.Region == "" {
-			return ClustersConfig{}, fmt.Errorf("cluster #%d: region is required", idx+1)
+			return ClustersConfig{}, fmt.Errorf("cluster #%d: %w", idx+1, ErrMissingPVERegion)
 		}
 
 		if c.URL == "" || !strings.HasPrefix(c.URL, "http") {
-			return ClustersConfig{}, fmt.Errorf("cluster #%d: url is required", idx+1)
+			return ClustersConfig{}, fmt.Errorf("cluster #%d: %w", idx+1, ErrMissingPVEAPIURL)
 		}
 	}
 
@@ -109,7 +120,7 @@ func ReadCloudConfig(config io.Reader) (ClustersConfig, error) {
 
 	// Validate network mode is valid
 	if !slices.Contains(ValidNetworkModes, cfg.Features.Network.Mode) {
-		return ClustersConfig{}, fmt.Errorf("invalid network mode: %s, valid modes are %v", cfg.Features.Network.Mode, ValidNetworkModes)
+		return ClustersConfig{}, ErrInvalidNetworkMode
 	}
 
 	return cfg, nil

pkg/config/config_test.go

@@ -44,6 +44,7 @@ clusters:
 `))
 
 	assert.NotNil(t, err)
+	assert.ErrorIs(t, err, providerconfig.ErrInvalidCloudConfig)
 	assert.NotNil(t, cfg)
 
 	// Non full config
@@ -54,6 +55,7 @@ clusters:
 `))
 
 	assert.NotNil(t, err)
+	assert.ErrorIs(t, err, providerconfig.ErrAuthCredentialsMissing)
 	assert.NotNil(t, cfg)
 
 	// Valid config with one cluster
@@ -142,6 +144,7 @@ clusters:
     password: "secret"
 `))
 	assert.NotNil(t, err)
+	assert.ErrorIs(t, err, providerconfig.ErrMissingPVERegion)
 
 	// Errors when empty url
 	_, err = providerconfig.ReadCloudConfig(strings.NewReader(`
@@ -155,6 +158,7 @@ clusters:
     password: "secret"
 `))
 	assert.NotNil(t, err)
+	assert.ErrorIs(t, err, providerconfig.ErrMissingPVEAPIURL)
 
 	// Errors when invalid url protocol
 	_, err = providerconfig.ReadCloudConfig(strings.NewReader(`
@@ -168,6 +172,7 @@ clusters:
     password: "secret"
 `))
 	assert.NotNil(t, err)
+	assert.ErrorIs(t, err, providerconfig.ErrMissingPVEAPIURL)
 }
 
 func TestNetworkConfig(t *testing.T) {