feat: Validate userdata (#593)

* feat: Validate userdata

Signed-off-by: Brad Beam <brad.beam@talos-systems.com>

pkg/userdata/errors.go

@@ -0,0 +1,38 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package userdata
+
+import "errors"
+
+var (
+	// General
+
+	// ErrRequiredSection denotes a section is required
+	ErrRequiredSection = errors.New("required userdata section")
+	// ErrInvalidVersion denotes that the config file version is invalid
+	ErrInvalidVersion = errors.New("invalid config version")
+
+	// Security
+
+	// ErrInvalidCert denotes that the certificate specified is invalid
+	ErrInvalidCert = errors.New("certificate is invalid")
+	// ErrInvalidCertType denotes that the certificate type is invalid
+	ErrInvalidCertType = errors.New("certificate type is invalid")
+
+	// Services
+
+	// ErrUnsupportedCNI denotes that the specified CNI is invalid
+	ErrUnsupportedCNI = errors.New("unsupported CNI driver")
+	// ErrInvalidTrustdToken denotes that a trustd token has not been specified
+	ErrInvalidTrustdToken = errors.New("trustd token is invalid")
+
+	// Networking
+
+	// ErrBadAddressing denotes that an incorrect combination of network
+	// address methods have been specified
+	ErrBadAddressing = errors.New("invalid network device addressing method")
+	// ErrInvalidAddress denotes that a bad address was provided
+	ErrInvalidAddress = errors.New("invalid network address")
+)