providers: support for vendor-data in proxmoxve

This PR adds support for reading Ignition data out of the
vendor-data file so we can leave the cloud-config in the
user-data file. It will always use the user-data file
if it has an any data in it over using the vendor-data
file.

docs/release-notes.md

@@ -14,6 +14,7 @@ Starting with this release, ignition-validate binaries are signed with the
 ### Features
 
 - Add Azure blob support for fetching ignition configs
+- Also check vendor-data for Ignition config on Proxmox VE
 
 ### Changes
 

docs/supported-platforms.md

@@ -24,7 +24,7 @@ Ignition is currently supported for the following platforms:
 * Bare Metal (`metal`) - Use the `ignition.config.url` kernel parameter to provide a URL to the configuration. The URL can use the `http://`, `https://`, `tftp://`, `s3://`, `arn:`, or `gs://` schemes to specify a remote config.
 * [Nutanix] (`nutanix`) - Ignition will read its configuration from the instance userdata via config drive. Cloud SSH keys are handled separately.
 * [OpenStack] (`openstack`) - Ignition will read its configuration from the instance userdata via either metadata service or config drive. Cloud SSH keys are handled separately.
-* [Proxmox VE] (`proxmoxve`) - Ignition will read its configuration from the instance userdata via config drive. Cloud SSH keys are handled separately.
+* [Proxmox VE] (`proxmoxve`) - Ignition will read its configuration from the instance userdata via config drive. If there isn't any valid Ignition configuration in userdata it will check the vendordata next. Cloud SSH keys are handled separately.
 * [Equinix Metal] (`packet`) - Ignition will read its configuration from the instance userdata. Cloud SSH keys are handled separately.
 * [IBM Power Systems Virtual Server] (`powervs`) - Ignition will read its configuration from the instance userdata. Cloud SSH keys are handled separately.
 * [QEMU] (`qemu`) - Ignition will read its configuration from the 'opt/com.coreos/config' key on the QEMU Firmware Configuration Device (available in QEMU 2.4.0 and higher).

internal/providers/proxmoxve/proxmoxve.go

@@ -40,7 +40,9 @@ import (
 )
 
 const (
-	cidataPath  = "/user-data"
+	ciuserdataPath = "/user-data"
+	// See https://bugzilla.proxmox.com/show_bug.cgi?id=2429 for more details about vendordata
+	civendordataPath = "/vendor-data"
 	deviceLabel = "cidata"
 )
 
@@ -123,20 +125,37 @@ func fetchConfigFromDevice(logger *log.Logger, ctx context.Context, path string)
 		)
 	}()
 
-	if !fileExists(filepath.Join(mnt, cidataPath)) {
-		return nil, nil
-	}
+	paths := []string{ciuserdataPath, civendordataPath}
+	header := []byte("#cloud-config\n")
 
-	contents, err := os.ReadFile(filepath.Join(mnt, cidataPath))
-	if err != nil {
-		return nil, err
-	}
+	for _, path := range paths {
+		fullPath := filepath.Join(mnt, path)
+		if !fileExists(fullPath) {
+			continue
+		}
 
-	header := []byte("#cloud-config\n")
-	if bytes.HasPrefix(contents, header) {
-		logger.Debug("config drive (%q) contains a cloud-config configuration, ignoring", path)
-		return nil, nil
+		contents, err := os.ReadFile(fullPath)
+		if err != nil {
+			// Log the error but continue to next file
+			logger.Debug("failed to read %q: %v", fullPath, err)
+			continue
+		}
+
+		// Skip if it's a cloud-config file
+		if bytes.HasPrefix(contents, header) {
+			logger.Debug("config drive (%q) contains a cloud-config configuration, ignoring", fullPath)
+			continue
+		}
+
+		// Check if there's actual content in the file
+		if len(contents) > 0 {
+			logger.Debug("config drive (%q) contains data", fullPath)
+			return contents, nil
+		}
+
+		logger.Debug("config drive (%q) is empty, ignoring", fullPath)
 	}
 
-	return contents, nil
+	// No valid configuration found in any of the files
+	return nil, nil
 }