Merge pull request #6467 from dokku/registry-repo-template

Add ability to customize the registry repo with a template

docs/advanced-usage/registry-management.md

@@ -102,6 +102,16 @@ Setting the property value to an empty string will reset the value to the system
 dokku registry:set node-js-app image-repo
 ```
 
+### Templating the image repository name
+
+Instead of setting the image repository name on a per-app basis, it can be set via a template globally with the `image-repo-template` property:
+
+```shell
+dokku registry:set --global image-repo-template "my-awesome-prefix/{{ .AppName }}"
+```
+
+Dokku uses a Golang template and has access to the `AppName` variable as shown above.
+
 ### Pushing images on build
 
 To push the image on release, set the `push-on-release` property to `true` via the `registry:set` command. The default value for this property is `false`. Setting the property to `true` will result in the image being tagged with an ID that is incremented with every release. This tag will be what is used for running app code.

plugins/registry/functions.go

@@ -1,16 +1,42 @@
 package registry
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 	"os"
 	"strconv"
 	"strings"
+	"text/template"
 
 	"github.com/codeskyblue/go-sh"
 	"github.com/dokku/dokku/plugins/common"
 )
 
+func getImageRepoFromTemplate(appName string) (string, error) {
+	imageRepoTemplate := common.PropertyGet("registry", "--global", "image-repo-template")
+	if imageRepoTemplate == "" {
+		return "", nil
+	}
+
+	tmpl, err := template.New("template").Parse(imageRepoTemplate)
+	if err != nil {
+		return "", fmt.Errorf("Unable to parse image-repo-template: %w", err)
+	}
+
+	type templateData struct {
+		AppName string
+	}
+	data := templateData{AppName: appName}
+
+	var doc bytes.Buffer
+	if err := tmpl.Execute(&doc, data); err != nil {
+		return "", fmt.Errorf("Unable to execute image-repo-template: %w", err)
+	}
+
+	return strings.TrimSpace(doc.String()), nil
+}
+
 func getRegistryServerForApp(appName string) string {
 	value := common.PropertyGet("registry", appName, "server")
 	if value == "" {

plugins/registry/registry.go

@@ -10,7 +10,8 @@ var (
 
 	// GlobalProperties is a map of all valid global registry properties
 	GlobalProperties = map[string]bool{
-		"push-on-release": true,
-		"server":          true,
+		"image-repo-template": true,
+		"push-on-release":     true,
+		"server":              true,
 	}
 )

plugins/registry/report.go

@@ -13,15 +13,16 @@ func ReportSingleApp(appName string, format string, infoFlag string) error {
 	}
 
 	flags := map[string]common.ReportFunc{
-		"--registry-computed-image-repo":      reportComputedImageRepo,
-		"--registry-image-repo":               reportImageRepo,
-		"--registry-computed-push-on-release": reportComputedPushOnRelease,
-		"--registry-global-push-on-release":   reportGlobalPushOnRelease,
-		"--registry-push-on-release":          reportPushOnRelease,
-		"--registry-computed-server":          reportComputedServer,
-		"--registry-global-server":            reportGlobalServer,
-		"--registry-server":                   reportServer,
-		"--registry-tag-version":              reportTagVersion,
+		"--registry-computed-image-repo":        reportComputedImageRepo,
+		"--registry-image-repo":                 reportImageRepo,
+		"--registry-computed-push-on-release":   reportComputedPushOnRelease,
+		"--registry-global-push-on-release":     reportGlobalPushOnRelease,
+		"--registry-push-on-release":            reportPushOnRelease,
+		"--registry-computed-server":            reportComputedServer,
+		"--registry-global-server":              reportGlobalServer,
+		"--registry-global-image-repo-template": reportGlobalImageRepoTemplate,
+		"--registry-server":                     reportServer,
+		"--registry-tag-version":                reportTagVersion,
 	}
 
 	flagKeys := []string{}
@@ -36,8 +37,11 @@ func ReportSingleApp(appName string, format string, infoFlag string) error {
 }
 
 func reportComputedImageRepo(appName string) string {
-	imageRepo := reportImageRepo(appName)
-	imageRepo = strings.TrimSpace(imageRepo)
+	imageRepo := strings.TrimSpace(reportImageRepo(appName))
+	if imageRepo == "" {
+		imageRepo, _ = getImageRepoFromTemplate(appName)
+	}
+
 	if imageRepo == "" {
 		imageRepo = common.GetAppImageRepo(appName)
 	}
@@ -76,6 +80,10 @@ func reportComputedServer(appName string) string {
 	return strings.TrimSpace(server)
 }
 
+func reportGlobalImageRepoTemplate(appName string) string {
+	return common.PropertyGet("registry", "--global", "image-repo-template")
+}
+
 func reportGlobalServer(appName string) string {
 	return common.PropertyGet("registry", "--global", "server")
 }

plugins/registry/triggers.go

@@ -10,8 +10,15 @@ import (
 
 // TriggerDeployedAppImageRepo outputs the associated image repo to stdout
 func TriggerDeployedAppImageRepo(appName string) error {
-	imageRepo := common.PropertyGet("registry", appName, "image-repo")
-	imageRepo = strings.TrimSpace(imageRepo)
+	imageRepo := strings.TrimSpace(reportImageRepo(appName))
+	if imageRepo == "" {
+		var err error
+		imageRepo, err = getImageRepoFromTemplate(appName)
+		if err != nil {
+			return fmt.Errorf("Unable to determine image repo from template: %w", err)
+		}
+	}
+
 	if imageRepo == "" {
 		imageRepo = common.GetAppImageRepo(appName)
 	}