feat: support templating in diagnose command (#9393)

cmd/skaffold/app/cmd/diagnose.go

@@ -30,6 +30,7 @@ import (
 	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/runner/runcontext"
 	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/schema/latest"
 	schemaUtil "github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/schema/util"
+	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/tags"
 	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/util"
 	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/version"
 	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/yaml"
@@ -38,6 +39,8 @@ import (
 var (
 	yamlOnly   bool
 	outputFile string
+
+	enableTemplating bool
 	// for testing
 	getRunContext = runcontext.GetRunContext
 	getCfgs       = parser.GetAllConfigs
@@ -52,6 +55,7 @@ func NewCmdDiagnose() *cobra.Command {
 		WithCommonFlags().
 		WithFlags([]*Flag{
 			{Value: &yamlOnly, Name: "yaml-only", DefValue: false, Usage: "Only prints the effective skaffold.yaml configuration"},
+			{Value: &enableTemplating, Name: "enable-templating", DefValue: false, Usage: "Render supported templated fields with golang template engine"},
 			{Value: &outputFile, Name: "output", Shorthand: "o", DefValue: "", Usage: "File to write diagnose result"},
 		}).
 		NoArgs(doDiagnose)
@@ -82,10 +86,16 @@ func doDiagnose(ctx context.Context, out io.Writer) error {
 	for i := range configs {
 		configs[i].(*latest.SkaffoldConfig).Dependencies = nil
 	}
+	if enableTemplating {
+		if err := tags.ApplyTemplates(configs); err != nil {
+			return err
+		}
+	}
 	buf, err := yaml.MarshalWithSeparator(configs)
 	if err != nil {
 		return fmt.Errorf("marshalling configuration: %w", err)
 	}
+
 	out.Write(buf)
 
 	return nil

docs-v2/content/en/docs/references/cli/_index.md

@@ -903,6 +903,7 @@ Examples:
 Options:
       --assume-yes=false: If true, skaffold will skip yes/no confirmation from the user and default to yes
   -c, --config='': File for global configurations (defaults to $HOME/.skaffold/config)
+      --enable-templating=false: Render supported templated fields with golang template engine
   -f, --filename='skaffold.yaml': Path or URL to the Skaffold config file
   -m, --module=[]: Filter Skaffold configs to only the provided named modules
   -o, --output='': File to write diagnose result
@@ -924,6 +925,7 @@ Env vars:
 
 * `SKAFFOLD_ASSUME_YES` (same as `--assume-yes`)
 * `SKAFFOLD_CONFIG` (same as `--config`)
+* `SKAFFOLD_ENABLE_TEMPLATING` (same as `--enable-templating`)
 * `SKAFFOLD_FILENAME` (same as `--filename`)
 * `SKAFFOLD_MODULE` (same as `--module`)
 * `SKAFFOLD_OUTPUT` (same as `--output`)

integration/diagnose_test.go

@@ -28,7 +28,7 @@ import (
 	"github.com/GoogleContainerTools/skaffold/v2/testutil"
 )
 
-func TestDiagnose(t *testing.T) {
+func TestDiagnoseExamples(t *testing.T) {
 	examples, err := folders("examples")
 	failNowIfError(t, err)
 	if len(examples) == 0 {
@@ -49,28 +49,44 @@ func TestDiagnose(t *testing.T) {
 	}
 }
 
-func TestDiagnoseOutputFile(t *testing.T) {
+func TestDiagnose(t *testing.T) {
 	tests := []struct {
 		description string
 		dir         string
 		outputFile  string
+		args        []string
+		envs        map[string]string
 	}{
 		{
 			description: "single skaffold.yaml outside of source dir",
 			dir:         "testdata/diagnose/temp-config",
 			outputFile:  "abc.txt",
 		},
+		{
+			description: "apply replacements to templates in skaffold.yaml",
+			dir:         "testdata/diagnose/direct-templates",
+			outputFile:  "abc.txt",
+			args:        []string{"--enable-templating"},
+			envs:        map[string]string{"AAA": "aaa"},
+		},
 	}
 
 	for _, test := range tests {
 		MarkIntegrationTest(t, CanRunWithoutGcp)
 		testutil.Run(t, test.description, func(t *testutil.T) {
+			if test.envs != nil {
+				for k, v := range test.envs {
+					t.Setenv(k, v)
+				}
+			}
 			tmpDir := testutil.NewTempDir(t.T)
 			configContents, err := os.ReadFile(filepath.Join(test.dir, "skaffold.yaml"))
 			t.CheckNoError(err)
 			templ, err := os.ReadFile(filepath.Join(test.dir, "diagnose.tmpl"))
 			tmpDir.Write("skaffold.yaml", string(configContents))
-			skaffold.Diagnose("--yaml-only", "--output", tmpDir.Path(test.outputFile), "-f", tmpDir.Path("skaffold.yaml")).
+			args := []string{"--yaml-only", "--output", tmpDir.Path(test.outputFile), "-f", tmpDir.Path("skaffold.yaml")}
+			args = append(args, test.args...)
+			skaffold.Diagnose(args...).
 				InDir(test.dir).RunOrFail(t.T)
 			t.CheckNoError(err)
 			outTemplate := template.Must(template.New("tmpl").Parse(string(templ)))

integration/testdata/diagnose/direct-templates/diagnose.tmpl

@@ -0,0 +1,52 @@
+apiVersion: skaffold/v4beta11
+kind: Config
+build:
+  artifacts:
+    - image: skaffold-helm
+      context: {{.Root}}
+      docker:
+        dockerfile: Dockerfile
+        buildArgs:
+          key1: aaa
+    - image: skaffold-ko
+      context: {{.Root}}
+      ko:
+        fromImage: gcr.io/distroless/static-debian11:nonroot
+        dependencies:
+          paths:
+            - '**/*.go'
+            - go.*
+        env:
+          - first=aaa
+        labels:
+          xxx: aaa
+  tagPolicy:
+    gitCommit: {}
+  local:
+    concurrency: 1
+manifests:
+  kustomize:
+    paths:
+      - {{.Root}}/aaa
+      - {{.Root}}/aaa
+  helm:
+    releases:
+      - name: aaa
+        chartPath: {{.Root}}/aaa
+        valuesFiles:
+          - {{.Root}}/aaa
+        namespace: aaa
+        setValues:
+          aaa: aaa
+          bbb: aaa
+        setValueTemplates:
+          image.tag: aaa
+deploy:
+  kubectl:
+    defaultNamespace: aaa
+  logs:
+    prefix: container
+portForward:
+  - resourceName: aaa
+    namespace: aaa
+    address: 127.0.0.1

integration/testdata/diagnose/direct-templates/skaffold.yaml

@@ -0,0 +1,44 @@
+apiVersion: skaffold/v4beta11
+kind: Config
+build:
+  artifacts:
+    - image: skaffold-helm
+      docker:
+        buildArgs:
+          "key1": "{{.AAA}}"
+    - image: skaffold-ko
+      ko:
+        dependencies:
+          paths:
+            - "**/*.go"
+            - go.*
+        fromImage: gcr.io/distroless/static-debian11:nonroot
+        env:
+          - "first={{.AAA}}"
+        labels:
+          xxx: "{{.AAA}}"
+
+manifests:
+  kustomize:
+    paths:
+      - "{{.AAA}}"
+      - "{{.AAA}}"
+  helm:
+    releases:
+      - name: "{{.AAA}}"
+        chartPath: "{{.AAA}}"
+        valuesFiles:
+          - "{{.AAA}}"
+        namespace: "{{.AAA}}"
+        setValues:
+          aaa: "{{.AAA}}"
+          bbb: "{{.AAA}}"
+        setValueTemplates:
+          image:
+            tag: "{{.AAA}}"
+deploy:
+  kubectl:
+    defaultNamespace: "{{.AAA}}"
+portForward:
+  - namespace: "{{.AAA}}"
+    resourceName: "{{.AAA}}"

pkg/skaffold/schema/latest/config.go

@@ -191,10 +191,10 @@ type PortForwardResource struct {
 	Type ResourceType `yaml:"resourceType,omitempty"`
 
 	// Name is the name of the Kubernetes resource or local container to port forward.
-	Name string `yaml:"resourceName,omitempty"`
+	Name string `yaml:"resourceName,omitempty" skaffold:"template"`
 
 	// Namespace is the namespace of the resource to port forward. Does not apply to local containers.
-	Namespace string `yaml:"namespace,omitempty"`
+	Namespace string `yaml:"namespace,omitempty" skaffold:"template"`
 
 	// Port is the resource port that will be forwarded.
 	Port util.IntOrString `yaml:"port,omitempty"`
@@ -294,7 +294,7 @@ type EnvTemplateTagger struct {
 	// The template is executed against the current environment,
 	// with those variables injected.
 	// For example: `{{.RELEASE}}`.
-	Template string `yaml:"template,omitempty" yamltags:"required"`
+	Template string `yaml:"template,omitempty" yamltags:"required" skaffold:"template"`
 }
 
 // DateTimeTagger *beta* tags images with the build timestamp.
@@ -790,7 +790,7 @@ type RemoteManifest struct {
 type Kustomize struct {
 	// Paths is the path to Kustomization files.
 	// Defaults to `["."]`.
-	Paths []string `yaml:"paths,omitempty" skaffold:"filepath"`
+	Paths []string `yaml:"paths,omitempty" skaffold:"filepath,template"`
 
 	// BuildArgs are additional args passed to `kustomize build`.
 	BuildArgs []string `yaml:"buildArgs,omitempty"`
@@ -935,7 +935,7 @@ type KubectlDeploy struct {
 	RemoteManifests []string `yaml:"remoteManifests,omitempty"`
 
 	// DefaultNamespace is the default namespace passed to kubectl on deployment if no other override is given.
-	DefaultNamespace *string `yaml:"defaultNamespace,omitempty"`
+	DefaultNamespace *string `yaml:"defaultNamespace,omitempty" skaffold:"template"`
 
 	// LifecycleHooks describes a set of lifecycle hooks that are executed before and after every deploy.
 	LifecycleHooks DeployHooks `yaml:"hooks,omitempty"`
@@ -989,32 +989,32 @@ type HelmDeployFlags struct {
 type HelmRelease struct {
 	// Name is the name of the Helm release.
 	// It accepts environment variables via the go template syntax.
-	Name string `yaml:"name,omitempty" yamltags:"required"`
+	Name string `yaml:"name,omitempty" yamltags:"required" skaffold:"template"`
 
 	// ChartPath is the local path to a packaged Helm chart or an unpacked Helm chart directory.
-	ChartPath string `yaml:"chartPath,omitempty" yamltags:"oneOf=chartSource" skaffold:"filepath"`
+	ChartPath string `yaml:"chartPath,omitempty" yamltags:"oneOf=chartSource" skaffold:"filepath,template"`
 
 	// RemoteChart refers to a remote Helm chart reference or URL.
 	RemoteChart string `yaml:"remoteChart,omitempty" yamltags:"oneOf=chartSource"`
 
 	// ValuesFiles are the paths to the Helm `values` files.
-	ValuesFiles []string `yaml:"valuesFiles,omitempty" skaffold:"filepath"`
+	ValuesFiles []string `yaml:"valuesFiles,omitempty" skaffold:"filepath,template"`
 
 	// Namespace is the Kubernetes namespace.
-	Namespace string `yaml:"namespace,omitempty"`
+	Namespace string `yaml:"namespace,omitempty" skaffold:"template"`
 
 	// Version is the version of the chart.
-	Version string `yaml:"version,omitempty"`
+	Version string `yaml:"version,omitempty" skaffold:"template"`
 
 	// SetValues are key-value pairs.
 	// If present, Skaffold will send `--set` flag to Helm CLI and append all pairs after the flag.
-	SetValues util.FlatMap `yaml:"setValues,omitempty"`
+	SetValues util.FlatMap `yaml:"setValues,omitempty" skaffold:"template"`
 
 	// SetValueTemplates are key-value pairs.
 	// If present, Skaffold will try to parse the value part of each key-value pair using
 	// environment variables in the system, then send `--set` flag to Helm CLI and append
 	// all parsed pairs after the flag.
-	SetValueTemplates util.FlatMap `yaml:"setValueTemplates,omitempty"`
+	SetValueTemplates util.FlatMap `yaml:"setValueTemplates,omitempty" skaffold:"template"`
 
 	// SetFiles are key-value pairs.
 	// If present, Skaffold will send `--set-file` flag to Helm CLI and append all pairs after the flag.
@@ -1547,7 +1547,7 @@ type DockerArtifact struct {
 
 	// BuildArgs are arguments passed to the docker build.
 	// For example: `{"key1": "value1", "key2": "{{ .ENV_VAR }}"}`.
-	BuildArgs map[string]*string `yaml:"buildArgs,omitempty"`
+	BuildArgs map[string]*string `yaml:"buildArgs,omitempty" skaffold:"template"`
 
 	// NetworkMode is passed through to docker and overrides the
 	// network configuration of docker builder. If unset, use whatever
@@ -1634,19 +1634,19 @@ type KoArtifact struct {
 	// These environment variables are only used at build time.
 	// They are _not_ set in the resulting container image.
 	// For example: `["GOPRIVATE=git.example.com", "GOCACHE=/workspace/.gocache"]`.
-	Env []string `yaml:"env,omitempty"`
+	Env []string `yaml:"env,omitempty" skaffold:"template"`
 
 	// Flags are additional build flags passed to `go build`.
 	// For example: `["-trimpath", "-v"]`.
-	Flags []string `yaml:"flags,omitempty"`
+	Flags []string `yaml:"flags,omitempty" skaffold:"template"`
 
 	// Labels are key-value string pairs to add to the image config.
 	// For example: `{"foo":"bar"}`.
-	Labels map[string]string `yaml:"labels,omitempty"`
+	Labels map[string]string `yaml:"labels,omitempty" skaffold:"template"`
 
 	// Ldflags are linker flags passed to the builder.
 	// For example: `["-buildid=", "-s", "-w"]`.
-	Ldflags []string `yaml:"ldflags,omitempty"`
+	Ldflags []string `yaml:"ldflags,omitempty" skaffold:"template"`
 
 	// Main is the location of the main package. It is the pattern passed to `go build`.
 	// If main is specified as a relative path, it is relative to the `context` directory.

pkg/skaffold/tags/paths.go

@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"path/filepath"
 	"reflect"
+	"slices"
 	"strings"
 
 	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/output/log"
@@ -122,5 +123,7 @@ func filepathTagExists(f reflect.StructField) bool {
 	if !ok {
 		return false
 	}
-	return t == "filepath"
+	split := strings.Split(t, ",")
+
+	return slices.Contains(split, "filepath")
 }