Adds support for environment variable substitution for source container image (#4254)

Fixes: #4124

cli/azd/pkg/project/container_helper_test.go

@@ -352,7 +352,7 @@ func Test_ContainerHelper_Deploy(t *testing.T) {
 			)
 			serviceConfig := createTestServiceConfig("./src/api", ContainerAppTarget, ServiceLanguageTypeScript)
 
-			serviceConfig.Image = tt.image
+			serviceConfig.Image = osutil.NewExpandableString(tt.image)
 			serviceConfig.RelativePath = tt.project
 			serviceConfig.Docker.Registry = tt.registry
 
@@ -521,7 +521,7 @@ func Test_ContainerHelper_ConfiguredImage(t *testing.T) {
 			if tt.serviceName != "" {
 				serviceConfig.Name = tt.serviceName
 			}
-			serviceConfig.Image = tt.sourceImage
+			serviceConfig.Image = osutil.NewExpandableString(tt.sourceImage)
 			serviceConfig.Docker.Registry = tt.registry
 			serviceConfig.Docker.Image = tt.image
 			serviceConfig.Docker.Tag = tt.tag

cli/azd/pkg/project/framework_service_docker.go

@@ -345,7 +345,12 @@ func (p *dockerProject) Package(
 
 	// If we don't have an image ID from a docker build then an external source image is being used
 	if imageId == "" {
-		sourceImage, err := docker.ParseContainerImage(serviceConfig.Image)
+		sourceImageValue, err := serviceConfig.Image.Envsubst(p.env.Getenv)
+		if err != nil {
+			return nil, fmt.Errorf("substituting environment variables in image: %w", err)
+		}
+
+		sourceImage, err := docker.ParseContainerImage(sourceImageValue)
 		if err != nil {
 			return nil, fmt.Errorf("parsing source container image: %w", err)
 		}

cli/azd/pkg/project/framework_service_docker_test.go

@@ -392,7 +392,7 @@ func Test_DockerProject_Build(t *testing.T) {
 			serviceConfig := createTestServiceConfig(tt.project, ContainerAppTarget, tt.language)
 			serviceConfig.Project.Path = temp
 			serviceConfig.Docker = tt.dockerOptions
-			serviceConfig.Image = tt.image
+			serviceConfig.Image = osutil.NewExpandableString(tt.image)
 
 			if tt.hasDockerFile {
 				err := os.MkdirAll(serviceConfig.Path(), osutil.PermissionDirectory)
@@ -536,7 +536,7 @@ func Test_DockerProject_Package(t *testing.T) {
 			// Set the custom test options
 			serviceConfig.Docker = tt.docker
 			serviceConfig.RelativePath = tt.project
-			serviceConfig.Image = tt.image
+			serviceConfig.Image = osutil.NewExpandableString(tt.image)
 
 			if serviceConfig.RelativePath != "" {
 				npmProject := NewNpmProject(npm.NewCli(mockContext.CommandRunner), env)
@@ -544,7 +544,10 @@ func Test_DockerProject_Package(t *testing.T) {
 			}
 
 			buildOutputPath := ""
-			if serviceConfig.Image == "" && serviceConfig.RelativePath != "" {
+			sourceImage, err := serviceConfig.Image.Envsubst(env.Getenv)
+			require.NoError(t, err)
+
+			if sourceImage == "" && serviceConfig.RelativePath != "" {
 				buildOutputPath = "IMAGE_ID"
 			}
 

cli/azd/pkg/project/project.go

@@ -106,7 +106,7 @@ func Parse(ctx context.Context, yamlContent string) (*ProjectConfig, error) {
 		// TODO: Move parsing/validation requirements for service targets into their respective components.
 		// When working within container based applications users may be using external/pre-built images instead of source
 		// In this case it is valid to have not specified a language but would be required to specify a source image
-		if svc.Host == ContainerAppTarget && svc.Language == ServiceLanguageNone && svc.Image == "" {
+		if svc.Host == ContainerAppTarget && svc.Language == ServiceLanguageNone && svc.Image.Empty() {
 			return nil, fmt.Errorf("parsing service %s: must specify language or image", svc.Name)
 		}
 	}

cli/azd/pkg/project/service_config.go

@@ -27,7 +27,7 @@ type ServiceConfig struct {
 	// The output path for build artifacts
 	OutputPath string `yaml:"dist,omitempty"`
 	// The source image to use for container based applications
-	Image string `yaml:"image,omitempty"`
+	Image osutil.ExpandableString `yaml:"image,omitempty"`
 	// The optional docker options for configuring the output image
 	Docker DockerProjectOptions `yaml:"docker,omitempty"`
 	// The optional K8S / AKS options

cli/azd/pkg/project/service_manager.go

@@ -530,7 +530,7 @@ func (sm *serviceManager) GetFrameworkService(ctx context.Context, serviceConfig
 	var frameworkService FrameworkService
 
 	// Publishing from an existing image currently follows the same lifecycle as a docker project
-	if serviceConfig.Language == ServiceLanguageNone && serviceConfig.Image != "" {
+	if serviceConfig.Language == ServiceLanguageNone && !serviceConfig.Image.Empty() {
 		serviceConfig.Language = ServiceLanguageDocker
 	}
 

cli/azd/pkg/project/service_manager_test.go

@@ -16,6 +16,7 @@ import (
 	"github.com/azure/azure-dev/cli/azd/pkg/environment"
 	"github.com/azure/azure-dev/cli/azd/pkg/exec"
 	"github.com/azure/azure-dev/cli/azd/pkg/ext"
+	"github.com/azure/azure-dev/cli/azd/pkg/osutil"
 	"github.com/azure/azure-dev/cli/azd/pkg/tools"
 	"github.com/azure/azure-dev/cli/azd/test/mocks"
 	"github.com/azure/azure-dev/cli/azd/test/mocks/mockarmresources"
@@ -240,7 +241,7 @@ func Test_ServiceManager_GetFrameworkService(t *testing.T) {
 		env := environment.New("test")
 		sm := createServiceManager(mockContext, env, ServiceOperationCache{})
 		serviceConfig := createTestServiceConfig("", ServiceTargetFake, ServiceLanguageNone)
-		serviceConfig.Image = "nginx"
+		serviceConfig.Image = osutil.NewExpandableString("nginx")
 
 		framework, err := sm.GetFrameworkService(*mockContext.Context, serviceConfig)
 		require.NoError(t, err)

schemas/alpha/azure.yaml.json

@@ -85,7 +85,7 @@
                     },
                     "image": {
                         "type": "string",
-                        "title": "Optional. The source image to be used for the container image instead of building from source.",
+                        "title": "Optional. The source image to be used for the container image instead of building from source. Supports environment variable substitution.",
                         "description": "If omitted, container image will be built from source specified in the 'project' property. Setting both 'project' and 'image' is invalid."
                     },
                     "host": {

schemas/v1.0/azure.yaml.json

@@ -78,9 +78,9 @@
                         "type": "string",
                         "title": "Path to the service source code directory"
                     },
-"image": {
+                    "image": {
                         "type": "string",
-                        "title": "Optional. The source image to be used for the container image instead of building from source.",
+                        "title": "Optional. The source image to be used for the container image instead of building from source. Supports environment variable substitution.",
                         "description": "If omitted, container image will be built from source specified in the 'project' property. Setting both 'project' and 'image' is invalid."
                     },
                     "host": {