swap out tag for tags since it's a list

add fixer for docker tag to tags change

fix/fixer.go

@@ -48,6 +48,7 @@ func init() {
 		"galaxy-command":             new(FixerGalaxyCommand),
 		"comm-config":                new(FixerCommConfig),
 		"ssh-wait-timeout":           new(FixerSSHTimout),
+		"docker-tag-tags":            new(FixerDockerTagtoTags),
 	}
 
 	FixerOrder = []string{
@@ -68,6 +69,7 @@ func init() {
 		"amazon-private-ip",
 		"amazon-temp-sec-cidrs",
 		"docker-email",
+		"docker-tag-tags",
 		"powershell-escapes",
 		"vmware-compaction",
 		"hyperv-deprecations",

fix/fixer_pp_docker_tag_tags.go

@@ -0,0 +1,108 @@
+package fix
+
+import (
+	"strings"
+
+	"github.com/mitchellh/mapstructure"
+)
+
+// FixerDockerTagtoTags renames tag to tags
+type FixerDockerTagtoTags struct{}
+
+func (FixerDockerTagtoTags) Fix(input map[string]interface{}) (map[string]interface{}, error) {
+	if input["post-processors"] == nil {
+		return input, nil
+	}
+
+	// Our template type we'll use for this fixer only
+	type template struct {
+		PP `mapstructure:",squash"`
+	}
+
+	// Decode the input into our structure, if we can
+	var tpl template
+	if err := mapstructure.Decode(input, &tpl); err != nil {
+		return nil, err
+	}
+
+	// Go through each post-processor and get out all the complex configs
+	pps := tpl.ppList()
+
+	for _, pp := range pps {
+		ppTypeRaw, ok := pp["type"]
+		if !ok {
+			continue
+		}
+
+		if ppType, ok := ppTypeRaw.(string); !ok {
+			continue
+		} else if ppType != "docker-tag" {
+			continue
+		}
+
+		// Create a []string to hold tag and tags values
+		allTags := []string{}
+
+		tagRaw, ok := pp["tag"]
+		if ok {
+			// Gather all "tag" into the []string
+			switch t := tagRaw.(type) {
+			case []interface{}:
+				for _, tag := range t {
+					allTags = append(allTags, tag.(string))
+				}
+			case []string:
+				allTags = append(allTags, t...)
+			case string:
+				tList := strings.Split(t, ",")
+				for _, tag := range tList {
+					allTags = append(allTags, strings.TrimSpace(tag))
+				}
+			}
+		}
+
+		// Now check to see if they already have the "tags" field
+		tagsRaw, ok := pp["tags"]
+		if ok {
+			// Gather all "tag" into the []string
+			switch t := tagsRaw.(type) {
+			case []interface{}:
+				for _, tag := range t {
+					allTags = append(allTags, tag.(string))
+				}
+			case []string:
+				allTags = append(allTags, t...)
+			case string:
+				tList := strings.Split(t, ",")
+				for _, tag := range tList {
+					allTags = append(allTags, strings.TrimSpace(tag))
+				}
+			}
+		}
+
+		// Now deduplicate the tags in the list so we don't tag the same thing
+		// multiple times.
+		deduplicater := map[string]bool{}
+		for _, tag := range allTags {
+			if ok := deduplicater[tag]; !ok {
+				deduplicater[tag] = true
+			}
+		}
+
+		finalTags := []string{}
+		for k := range deduplicater {
+			finalTags = append(finalTags, k)
+		}
+
+		// Delete tag key, and set tags key to the final deduplicated list.
+		delete(pp, "tag")
+		pp["tags"] = finalTags
+	}
+
+	input["post-processors"] = tpl.PostProcessors
+	return input, nil
+}
+
+func (FixerDockerTagtoTags) Synopsis() string {
+	return `Updates "docker" post-processor so any "tag" field is renamed to "tags".`
+}

fix/fixer_pp_docker_tag_tags_test.go

@@ -0,0 +1,52 @@
+package fix
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFixerDockerTags(t *testing.T) {
+	var _ Fixer = new(FixerVagrantPPOverride)
+}
+
+func TestFixerDockerTags_Fix(t *testing.T) {
+	var f FixerDockerTagtoTags
+
+	input := map[string]interface{}{
+		"post-processors": []interface{}{
+			map[string]interface{}{
+				"type": "docker-tag",
+				"tag":  "foo",
+				"tags": []string{"foo", "bar"},
+			},
+			[]interface{}{
+				map[string]interface{}{
+					"type": "docker-tag",
+					"tag":  []string{"baz"},
+					"tags": []string{"foo", "bar"},
+				},
+			},
+		},
+	}
+
+	expected := map[string]interface{}{
+		"post-processors": []interface{}{
+			map[string]interface{}{
+				"type": "docker-tag",
+				"tags": []string{"foo", "bar"},
+			},
+			[]interface{}{
+				map[string]interface{}{
+					"type": "docker-tag",
+					"tags": []string{"baz", "foo", "bar"},
+				},
+			},
+		},
+	}
+
+	output, err := f.Fix(input)
+	assert.NoError(t, err)
+
+	assert.Equalf(t, expected, output, "should have removed tag from template")
+}

post-processor/docker-tag/post-processor.go

@@ -20,9 +20,11 @@ const BuilderId = "packer.post-processor.docker-tag"
 type Config struct {
 	common.PackerConfig `mapstructure:",squash"`
 
-	Repository string   `mapstructure:"repository"`
-	Tag        []string `mapstructure:"tag"`
-	Force      bool
+	Repository string `mapstructure:"repository"`
+	// Kept for backwards compatability
+	Tag   []string `mapstructure:"tag"`
+	Tags  []string `mapstructure:"tags"`
+	Force bool
 
 	ctx interpolate.Context
 }
@@ -47,11 +49,23 @@ func (p *PostProcessor) Configure(raws ...interface{}) error {
 		return err
 	}
 
+	// combine Tag and Tags fields
+	allTags := p.config.Tags
+	allTags = append(allTags, p.config.Tag...)
+
+	p.config.Tags = allTags
+
 	return nil
 
 }
 
 func (p *PostProcessor) PostProcess(ctx context.Context, ui packer.Ui, artifact packer.Artifact) (packer.Artifact, bool, bool, error) {
+	if len(p.config.Tag) > 0 {
+		ui.Say("Deprecation warning: \"tag\" option has been replaced with " +
+			"\"tags\". In future versions of Packer, this configuration may " +
+			"not work. Please call `packer fix` on your template to update.")
+	}
+
 	if artifact.BuilderId() != BuilderId &&
 		artifact.BuilderId() != dockerimport.BuilderId {
 		err := fmt.Errorf(
@@ -69,8 +83,9 @@ func (p *PostProcessor) PostProcess(ctx context.Context, ui packer.Ui, artifact
 	importRepo := p.config.Repository
 	var lastTaggedRepo = importRepo
 	RepoTags := []string{}
-	if len(p.config.Tag) > 0 {
-		for _, tag := range p.config.Tag {
+
+	if len(p.config.Tags) > 0 {
+		for _, tag := range p.config.Tags {
 			local := importRepo + ":" + tag
 			ui.Message("Tagging image: " + artifact.Id())
 			ui.Message("Repository: " + local)

post-processor/docker-tag/post-processor.hcl2spec.go

@@ -18,6 +18,7 @@ type FlatConfig struct {
 	PackerSensitiveVars []string          `mapstructure:"packer_sensitive_variables" cty:"packer_sensitive_variables"`
 	Repository          *string           `mapstructure:"repository" cty:"repository"`
 	Tag                 []string          `mapstructure:"tag" cty:"tag"`
+	Tags                []string          `mapstructure:"tags" cty:"tags"`
 	Force               *bool             `cty:"force"`
 }
 
@@ -42,6 +43,7 @@ func (*FlatConfig) HCL2Spec() map[string]hcldec.Spec {
 		"packer_sensitive_variables": &hcldec.AttrSpec{Name: "packer_sensitive_variables", Type: cty.List(cty.String), Required: false},
 		"repository":                 &hcldec.AttrSpec{Name: "repository", Type: cty.String, Required: false},
 		"tag":                        &hcldec.AttrSpec{Name: "tag", Type: cty.List(cty.String), Required: false},
+		"tags":                       &hcldec.AttrSpec{Name: "tags", Type: cty.List(cty.String), Required: false},
 		"force":                      &hcldec.AttrSpec{Name: "force", Type: cty.Bool, Required: false},
 	}
 	return s

post-processor/docker-tag/post-processor_test.go

@@ -8,6 +8,7 @@ import (
 	"github.com/hashicorp/packer/builder/docker"
 	"github.com/hashicorp/packer/packer"
 	dockerimport "github.com/hashicorp/packer/post-processor/docker-import"
+	"github.com/stretchr/testify/assert"
 )
 
 func testConfig() map[string]interface{} {
@@ -166,3 +167,30 @@ func TestPostProcessor_PostProcess_NoTag(t *testing.T) {
 		t.Fatal("bad force")
 	}
 }
+
+func TestPostProcessor_PostProcess_Tag_vs_Tags(t *testing.T) {
+	testCases := []map[string]interface{}{
+		{
+			"tag":  "bar,buzz",
+			"tags": []string{"bang"},
+		},
+		{
+			"tag":  []string{"bar", "buzz"},
+			"tags": []string{"bang"},
+		},
+		{
+			"tag":  []string{"bar"},
+			"tags": []string{"buzz", "bang"},
+		},
+	}
+
+	for _, tc := range testCases {
+		var p PostProcessor
+		if err := p.Configure(tc); err != nil {
+			t.Fatalf("err: %s", err)
+		}
+		assert.ElementsMatchf(t, p.config.Tags, []string{"bar", "buzz", "bang"},
+			"tag and tags fields should be combined into tags fields. Recieved: %#v",
+			p.config.Tags)
+	}
+}

website/pages/docs/post-processors/docker-tag.mdx

@@ -30,7 +30,9 @@ settings are optional.
 
 - `repository` (string) - The repository of the image.
 
-- `tag` (array of strings) - The tag for the image. By default this is not set.
+- `tags` (array of strings) - A list of tags for the image. By default this is
+  not set. Valid examples include: `"tags": "mytag"` or
+  `"tags": ["mytag-1", "mytag-2"]`
 
 - `force` (boolean) - If true, this post-processor forcibly tag the image
   even if tag name is collided. Default to `false`. But it will be ignored if