Add artifact support for HCP Packer registry (#190)

* Add artifact support for HCP Packer registry

Working off of the official documentation
(https://www.packer.io/docs/plugins/hcp-support).  This should now allow
utilization of the hcp_packer_registry block
(https://www.packer.io/docs/templates/hcl_templates/blocks/build/hcp_packer_registry)
and support adding Vultr snapshots to the HCP Packer registry.

* Make artifact tests pass

builder/vultr/artifact.go

@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"log"
 
+	registryimage "github.com/hashicorp/packer-plugin-sdk/packer/registry/image"
+
 	"github.com/vultr/govultr/v2"
 )
 
@@ -15,8 +17,14 @@ type Artifact struct {
 	// The Description of the snapshot
 	Description string
 
-	// The client for making
+	// The client for making changes
 	client *govultr.Client
+
+	// config definition from the builder
+	config *Config
+
+	// State data used by HCP container registry
+	StateData map[string]interface{}
 }
 
 func (a *Artifact) BuilderId() string {
@@ -36,7 +44,20 @@ func (a *Artifact) String() string {
 }
 
 func (a *Artifact) State(name string) interface{} {
-	return nil
+	if name == registryimage.ArtifactStateURI {
+		img, err := registryimage.FromArtifact(a,
+			registryimage.WithID(a.SnapshotID),
+			registryimage.WithProvider("Vultr"),
+			registryimage.WithRegion(a.config.RegionID),
+		)
+
+		if err != nil {
+			log.Printf("[DEBUG] error encountered when creating a registry image %v", err)
+			return nil
+		}
+		return img
+	}
+	return a.StateData[name]
 }
 
 func (a *Artifact) Destroy() error {

builder/vultr/artifact_test.go

@@ -15,7 +15,7 @@ func TestArtifact_Impl(t *testing.T) {
 }
 
 func TestArtifactId(t *testing.T) {
-	a := &Artifact{"d455d0246e8e6", "packer-test", nil}
+	a := &Artifact{"d455d0246e8e6", "packer-test", nil, nil, nil}
 	expected := "d455d0246e8e6"
 
 	if a.Id() != expected {
@@ -24,7 +24,7 @@ func TestArtifactId(t *testing.T) {
 }
 
 func TestArtifactString(t *testing.T) {
-	a := &Artifact{"d455d0246e8e6", "packer-test", nil}
+	a := &Artifact{"d455d0246e8e6", "packer-test", nil, nil, nil}
 	expected := "Vultr Snapshot: packer-test (d455d0246e8e6)"
 
 	if a.String() != expected {

builder/vultr/builder.go

@@ -85,6 +85,7 @@ func (b *Builder) Run(ctx context.Context, ui packer.Ui, hook packer.Hook) (ret
 	artifact := &Artifact{
 		SnapshotID:  snapshot.ID,
 		Description: snapshot.Description,
+		config:      &b.config,
 		client:      client,
 	}
 

vendor/modules.txt

@@ -216,6 +216,7 @@ github.com/hashicorp/packer-plugin-sdk/multistep
 github.com/hashicorp/packer-plugin-sdk/multistep/commonsteps
 github.com/hashicorp/packer-plugin-sdk/net
 github.com/hashicorp/packer-plugin-sdk/packer
+github.com/hashicorp/packer-plugin-sdk/packer/registry/image
 github.com/hashicorp/packer-plugin-sdk/packerbuilderdata
 github.com/hashicorp/packer-plugin-sdk/pathing
 github.com/hashicorp/packer-plugin-sdk/plugin