FEAT: Adds support for updating HCP Packer registry channels

Enables specifying channels in the build configuration to automatically update existing HCP Packer registry channels to point to the new build version upon completion. Improves workflow automation and reduces manual channel management for users.

hcl2template/types.build.hcp_packer_registry.go

@@ -20,6 +20,8 @@ type HCPPackerRegistryBlock struct {
 	BucketLabels map[string]string
 	// Build labels
 	BuildLabels map[string]string
+	// Channels
+	Channels []string
 
 	HCL2Ref
 }
@@ -37,6 +39,7 @@ func (p *Parser) decodeHCPRegistry(block *hcl.Block, cfg *PackerConfig) (*HCPPac
 		Labels       map[string]string `hcl:"labels,optional"`
 		BucketLabels map[string]string `hcl:"bucket_labels,optional"`
 		BuildLabels  map[string]string `hcl:"build_labels,optional"`
+		Channels     []string          `hcl:"channels,optional"`
 		Config       hcl.Body          `hcl:",remain"`
 	}
 	ectx := cfg.EvalContext(BuildContext, nil)
@@ -69,6 +72,7 @@ func (p *Parser) decodeHCPRegistry(block *hcl.Block, cfg *PackerConfig) (*HCPPac
 
 	par.Slug = b.Slug
 	par.Description = b.Description
+	par.Channels = b.Channels
 
 	if len(b.Labels) > 0 && len(b.BucketLabels) > 0 {
 		diags = append(diags, &hcl.Diagnostic{

internal/hcp/api/service_build.go

@@ -118,3 +118,23 @@ func (c *Client) UploadSbom(
 	_, err := c.Packer.PackerServiceUploadSbom(params, nil)
 	return err
 }
+
+func (c *Client) UpdateChannel(
+	ctx context.Context,
+	bucketName, channelName string,
+	body *hcpPackerModels.HashicorpCloudPacker20230101UpdateChannelBody,
+) (*hcpPackerAPI.PackerServiceUpdateChannelOK, error) {
+
+	params := hcpPackerAPI.NewPackerServiceUpdateChannelParamsWithContext(ctx)
+	params.LocationOrganizationID = c.OrganizationID
+	params.LocationProjectID = c.ProjectID
+	params.BucketName = bucketName
+	params.ChannelName = channelName
+	params.Body = body
+	resp, err := c.Packer.PackerServiceUpdateChannel(params, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	return resp, nil
+}

internal/hcp/registry/types.bucket.go

@@ -36,6 +36,7 @@ type Bucket struct {
 	Destination                              string
 	BucketLabels                             map[string]string
 	BuildLabels                              map[string]string
+	Channels                                 []string
 	SourceExternalIdentifierToParentVersions map[string]ParentVersion
 	RunningBuilds                            map[string]chan struct{}
 	Version                                  *Version
@@ -94,6 +95,7 @@ func (bucket *Bucket) ReadFromHCPPackerRegistryBlock(registryBlock *hcl2template
 	bucket.Description = registryBlock.Description
 	bucket.BucketLabels = registryBlock.BucketLabels
 	bucket.BuildLabels = registryBlock.BuildLabels
+	bucket.Channels = registryBlock.Channels
 	// If there's already a Name this was set from env variable.
 	// In Packer, env variable overrides config values so we keep it that way for consistency.
 	if bucket.Name == "" && registryBlock.Slug != "" {
@@ -244,6 +246,30 @@ func (bucket *Bucket) uploadSbom(ctx context.Context, buildName string, sbom pac
 	return bucket.client.UploadSbom(ctx, bucket.Name, bucket.Version.Fingerprint, buildToUpdate.ID, sbom)
 }
 
+func (bucket *Bucket) updateChannels(ctx context.Context) error {
+	if len(bucket.Channels) == 0 {
+		return nil
+	}
+
+	log.Printf("[INFO] Updating %d channel(s) to point to version %s", len(bucket.Channels), bucket.Version.ID)
+
+	body := &hcpPackerModels.HashicorpCloudPacker20230101UpdateChannelBody{
+		VersionFingerprint: bucket.Version.Fingerprint,
+		UpdateMask:         "versionFingerprint",
+	}
+
+	for _, channel := range bucket.Channels {
+		log.Printf("[INFO] Updating channel %s to version %s", channel, bucket.Version.ID)
+		_, err := bucket.client.UpdateChannel(ctx, bucket.Name, channel, body)
+		if err != nil {
+			log.Printf("[ERROR] Failed to update channel %s: %s", channel, err)
+			return fmt.Errorf("failed to update channel %s: %w", channel, err)
+		}
+	}
+
+	return nil
+}
+
 // markBuildComplete should be called to set a build on the HCP Packer registry to DONE.
 // Upon a successful call markBuildComplete will publish all artifacts created by the named build,
 // and set the build to done. A build with no artifacts can not be set to DONE.
@@ -726,6 +752,12 @@ func (bucket *Bucket) doCompleteBuild(
 			parErr)
 	}
 
+	// Update channels after build is marked complete
+	channelErr := bucket.updateChannels(ctx)
+	if channelErr != nil {
+		log.Printf("[ERROR] Failed to update channels after completing build %s: %s", buildName, channelErr)
+	}
+
 	return append(packerSDKArtifacts, &registryArtifact{
 		BuildName:  buildName,
 		BucketName: bucket.Name,

website/content/docs/templates/hcl_templates/blocks/build/hcp_packer_registry.mdx

@@ -10,7 +10,7 @@ This topic provides reference information about the `hcp_packer_registry` block.
 
 ## Description
 
-The `hcp_packer_registry` block configures details about an image Packer creates or updates in the HCP Packer registry. Use the `hcp_packer_registry` block to customize the metadata Packer sends to HCP Packer Registry. 
+The `hcp_packer_registry` block configures details about an image Packer creates or updates in the HCP Packer registry. Use the `hcp_packer_registry` block to customize the metadata Packer sends to HCP Packer Registry.
 
 To get started with HCP Packer, refer to the [HCP Packer documentation](/hcp/docs/packer) or try the [Get Started with HCP Packer tutorials](/packer/tutorials/hcp-get-started).
 
@@ -77,5 +77,8 @@ Some nice description about the image which artifact is being published to HCP P
   Packer registry. Should contain a maximum of 255 characters. Defaults to
   `build.description` if not set.
 
+- `channels` ([]string) - List of channel to update to point to the new build
+  once the build is complete. Channels must already exist in the HCP Packer registry.
+
 - `labels` (map[string]string) - Deprecated in Packer 1.7.9. See [`bucket_labels`](#bucket_labels) for details.