Add support for reading dockerfileSnippet from file

Author: stuartleeks

internal/pkg/devcontainers/snippet.go

@@ -20,6 +20,12 @@ import (
 	dora_parser "github.com/bradford-hamilton/dora/pkg/parser"
 )
 
+type SubstitutionValues struct {
+	Name       string
+	UserName   string
+	HomeFolder string
+}
+
 type DevcontainerSnippetType string
 
 const (
@@ -45,10 +51,11 @@ const (
 )
 
 type FolderSnippetAction struct {
-	Type       FolderSnippetActionType `json:"type"`
-	SourcePath string                  `json:"source"`  // for mergeJSON this is snippet-relative path to JSON. for copyAndRun this is the script filename
-	TargetPath string                  `json:"target"`  // for mergeJSON this is project-relative path to JSON
-	Content    string                  `json:"content"` // for dockerfileSnippet this is the content to include
+	Type        FolderSnippetActionType `json:"type"`
+	SourcePath  string                  `json:"source"`      // for mergeJSON this is snippet-relative path to JSON. for copyAndRun this is the script filename
+	TargetPath  string                  `json:"target"`      // for mergeJSON this is project-relative path to JSON
+	Content     string                  `json:"content"`     // for dockerfileSnippet this is the content to include
+	ContentPath string                  `json:"contentPath"` // for dockerfileSnippet this is the path to content to include
 }
 
 // FolderSnippet maps to the content of the snippet.json file for folder-based snippets
@@ -220,11 +227,23 @@ func addFolderSnippetToDevContainer(projectFolder string, snippet *DevcontainerS
 				return err
 			}
 		case FolderSnippetActionDockerfileSnippet:
-			if action.Content == "" {
-				return fmt.Errorf("content must be set for %s actions", action.Type)
+			var content string
+			if action.Content != "" {
+				if action.ContentPath != "" {
+					return fmt.Errorf("can only set one of content and contentPath")
+				}
+				content = action.Content + "\n"
+			} else if action.ContentPath != "" {
+				buf, err = ioutil.ReadFile(filepath.Join(snippet.Path, action.ContentPath))
+				if err != nil {
+					return err
+				}
+				content = string(buf)
+			} else {
+				return fmt.Errorf("one of content and contentPath must be set for %s actions", action.Type)
 			}
 			dockerfileFilename := filepath.Join(projectFolder, ".devcontainer", "Dockerfile")
-			err = insertDockerfileSnippet(projectFolder, dockerfileFilename, action.Content+"\n")
+			err = insertDockerfileSnippet(projectFolder, dockerfileFilename, content)
 			if err != nil {
 				return err
 			}
@@ -368,12 +387,6 @@ func loadJSONDocument(path string) (*dora_ast.RootNode, error) {
 	return &baseDocument, nil
 }
 
-type SubstitutionValues struct {
-	Name       string
-	UserName   string
-	HomeFolder string
-}
-
 func getSubstitutionValuesFromFile(devContainerJsonPath string) (*SubstitutionValues, error) {
 	// This doesn't use standard `json` pkg as devcontainer.json permits comments (and the default templates include them!)
 

internal/pkg/devcontainers/snippet_test.go

@@ -472,7 +472,7 @@ RUN echo hi2
 `, string(buf))
 }
 
-func TestFolderAddSnippet_InsertsSnippetsInDockerfile(t *testing.T) {
+func TestFolderAddSnippet_InsertsTextSnippetsInDockerfile(t *testing.T) {
 
 	root, _ := ioutil.TempDir("", "devcontainer*")
 	defer os.RemoveAll(root)
@@ -539,6 +539,77 @@ RUN echo hi2
 `, string(buf))
 }
 
+func TestFolderAddSnippet_InsertsFileSnippetInDockerfile(t *testing.T) {
+
+	root, _ := ioutil.TempDir("", "devcontainer*")
+	defer os.RemoveAll(root)
+
+	// set up snippet
+	snippetFolder := filepath.Join(root, "snippets/test1")
+	_ = os.MkdirAll(snippetFolder, 0755)
+	snippetJSONFilename := filepath.Join(snippetFolder, "snippet.json")
+	_ = ioutil.WriteFile(snippetJSONFilename, []byte(`{
+		"actions": [
+			{
+				"type": "dockerfileSnippet",
+				"content": "ENV FOO=BAR"
+			},
+			{
+				"type": "dockerfileSnippet",
+				"contentPath": "Dockerfile"
+			}
+		]
+	}`), 0755)
+	snippetDockerfileFilename := filepath.Join(snippetFolder, "Dockerfile")
+	_ = ioutil.WriteFile(snippetDockerfileFilename, []byte(`# from snippet file
+ENV WIBBLE BIBBLE
+`), 0755)
+
+	// set up devcontainer
+	targetFolder := filepath.Join(root, "target")
+	devcontainerFolder := filepath.Join(targetFolder, ".devcontainer")
+	_ = os.MkdirAll(devcontainerFolder, 0755)
+
+	_ = ioutil.WriteFile(filepath.Join(devcontainerFolder, "Dockerfile"), []byte(`FROM foo
+RUN echo hi
+
+# __DEVCONTAINER_SNIPPET_INSERT__ 
+
+RUN echo hi2
+`), 0755)
+	_ = ioutil.WriteFile(filepath.Join(devcontainerFolder, "devcontainer.json"), []byte(`{
+	"name" : "testname"
+}`), 0755)
+
+	// Add snippet
+	snippet := DevcontainerSnippet{
+		Name: "test",
+		Path: snippetFolder,
+		Type: DevcontainerSnippetTypeFolder,
+	}
+	err := addSnippetToDevcontainer(targetFolder, &snippet)
+	if !assert.NoError(t, err) {
+		return
+	}
+
+	buf, err := ioutil.ReadFile(filepath.Join(devcontainerFolder, "Dockerfile"))
+	if !assert.NoError(t, err) {
+		return
+	}
+	assert.Equal(t, `FROM foo
+RUN echo hi
+
+ENV FOO=BAR
+
+# from snippet file
+ENV WIBBLE BIBBLE
+
+# __DEVCONTAINER_SNIPPET_INSERT__ 
+
+RUN echo hi2
+`, string(buf))
+}
+
 func TestFolderAddSnippet_PerformsSubstitutionWithoutUserName(t *testing.T) {
 
 	root, _ := ioutil.TempDir("", "devcontainer*")