GitHub Enterprise support (#658)

* Add option to specify custom GitHub instance

* Use correct GHE API endpoint URLs

Co-authored-by: Markus Wolf <knister.peter@shadowrun-clan.de>

* Extract slug from GitHub Enterprise URLs

Co-authored-by: Markus Wolf <knister.peter@shadowrun-clan.de>

* Use GITHUB_TOKEN for clone authenticate if provided

This change will allow use authentication for cloning actions
from private repositories or github enterprise instances.

Co-Authored-By: Markus Wolf <knister.peter@shadowrun-clan.de>

* Add section about using act on GitHub Enterprise to README

Co-authored-by: Markus Wolf <knister.peter@shadowrun-clan.de>

* Set GitHubInstance in runnerConfig in runner_test

Co-authored-by: Markus Wolf <knister.peter@shadowrun-clan.de>

Co-authored-by: hackercat <me@hackerc.at>
Co-authored-by: Markus Wolf <knister.peter@shadowrun-clan.de>

README.md

@@ -129,6 +129,7 @@ It will save that information to `~/.actrc`, please refer to [Configuration](#co
       --env stringArray                 env to make available to actions with optional value (e.g. --e myenv=foo or -s myenv)
       --env-file string                 environment file to read and use as env in the containers (default ".env")
   -e, --eventpath string                path to event JSON file
+      --github-instance string          GitHub instance to use. Don't use this if you are not using GitHub Enterprise Server. (default "github.com")
   -g, --graph                           draw workflows
   -h, --help                            help for act
       --insecure-secrets                NOT RECOMMENDED! Doesn't hide secrets while printing logs.
@@ -306,6 +307,15 @@ act -e pull-request.json
 
 Act will properly provide `github.head_ref` and `github.base_ref` to the action as expected.
 
+# GitHub Enterprise
+
+Act supports using and authenticating against private GitHub Enterprise servers.
+To use your custom GHE server, set the CLI flag `--github-instance` to your hostname (e.g. `github.company.com`).
+
+Please note that if your GHE server requires authentication, we will use the secret provided via `GITHUB_TOKEN`.
+
+Please also see the [official documentation for GitHub actions on GHE](https://docs.github.com/en/enterprise-server@3.0/admin/github-actions/about-using-actions-in-your-enterprise) for more information on how to use actions.
+
 # Support
 
 Need help? Ask on [Gitter](https://gitter.im/nektos/act)!

cmd/input.go

@@ -29,6 +29,7 @@ type Input struct {
 	containerArchitecture string
 	noWorkflowRecurse     bool
 	useGitIgnore          bool
+	githubInstance        string
 }
 
 func (i *Input) resolve(path string) string {

cmd/root.go

@@ -61,6 +61,7 @@ func Execute(ctx context.Context, version string) {
 	rootCmd.PersistentFlags().BoolVarP(&input.insecureSecrets, "insecure-secrets", "", false, "NOT RECOMMENDED! Doesn't hide secrets while printing logs.")
 	rootCmd.PersistentFlags().StringVarP(&input.envfile, "env-file", "", ".env", "environment file to read and use as env in the containers")
 	rootCmd.PersistentFlags().StringVarP(&input.containerArchitecture, "container-architecture", "", "", "Architecture which should be used to run containers, e.g.: linux/amd64. If not specified, will use host default architecture. Requires Docker server API Version 1.41+. Ignored on earlier Docker server platforms.")
+	rootCmd.PersistentFlags().StringVarP(&input.githubInstance, "github-instance", "", "github.com", "GitHub instance to use. Don't use this if you are not using GitHub Enterprise Server.")
 	rootCmd.SetArgs(args())
 
 	if err := rootCmd.Execute(); err != nil {
@@ -254,6 +255,7 @@ func newRunCommand(ctx context.Context, input *Input) func(*cobra.Command, []str
 			UsernsMode:            input.usernsMode,
 			ContainerArchitecture: input.containerArchitecture,
 			UseGitIgnore:          input.useGitIgnore,
+			GitHubInstance:        input.githubInstance,
 		}
 		r, err := runner.New(config)
 		if err != nil {

pkg/common/git.go

@@ -15,6 +15,7 @@ import (
 
 	git "github.com/go-git/go-git/v5"
 	"github.com/go-git/go-git/v5/plumbing"
+	"github.com/go-git/go-git/v5/plumbing/transport/http"
 	"github.com/go-ini/ini"
 	log "github.com/sirupsen/logrus"
 )
@@ -142,12 +143,12 @@ func findGitPrettyRef(head, root, sub string) (string, error) {
 }
 
 // FindGithubRepo get the repo
-func FindGithubRepo(file string) (string, error) {
+func FindGithubRepo(file string, githubInstance string) (string, error) {
 	url, err := findGitRemoteURL(file)
 	if err != nil {
 		return "", err
 	}
-	_, slug, err := findGitSlug(url)
+	_, slug, err := findGitSlug(url, githubInstance)
 	return slug, err
 }
 
@@ -174,7 +175,7 @@ func findGitRemoteURL(file string) (string, error) {
 	return url, nil
 }
 
-func findGitSlug(url string) (string, string, error) {
+func findGitSlug(url string, githubInstance string) (string, string, error) {
 	if matches := codeCommitHTTPRegex.FindStringSubmatch(url); matches != nil {
 		return "CodeCommit", matches[2], nil
 	} else if matches := codeCommitSSHRegex.FindStringSubmatch(url); matches != nil {
@@ -183,6 +184,14 @@ func findGitSlug(url string) (string, string, error) {
 		return "GitHub", fmt.Sprintf("%s/%s", matches[1], matches[2]), nil
 	} else if matches := githubSSHRegex.FindStringSubmatch(url); matches != nil {
 		return "GitHub", fmt.Sprintf("%s/%s", matches[1], matches[2]), nil
+	} else if githubInstance != "github.com" {
+		gheHTTPRegex := regexp.MustCompile(fmt.Sprintf(`^https?://%s/(.+)/(.+?)(?:.git)?$`, githubInstance))
+		gheSSHRegex := regexp.MustCompile(fmt.Sprintf(`%s[:/](.+)/(.+).git$`, githubInstance))
+		if matches := gheHTTPRegex.FindStringSubmatch(url); matches != nil {
+			return "GitHubEnterprise", fmt.Sprintf("%s/%s", matches[1], matches[2]), nil
+		} else if matches := gheSSHRegex.FindStringSubmatch(url); matches != nil {
+			return "GitHubEnterprise", fmt.Sprintf("%s/%s", matches[1], matches[2]), nil
+		}
 	}
 	return "", url, nil
 }
@@ -218,9 +227,10 @@ func findGitDirectory(fromFile string) (string, error) {
 
 // NewGitCloneExecutorInput the input for the NewGitCloneExecutor
 type NewGitCloneExecutorInput struct {
-	URL string
-	Ref string
-	Dir string
+	URL   string
+	Ref   string
+	Dir   string
+	Token string
 }
 
 // CloneIfRequired ...
@@ -237,10 +247,24 @@ func CloneIfRequired(ctx context.Context, refName plumbing.ReferenceName, input
 			progressWriter = os.Stdout
 		}
 
-		r, err = git.PlainCloneContext(ctx, input.Dir, false, &git.CloneOptions{
-			URL:      input.URL,
-			Progress: progressWriter,
-		})
+		var cloneOptions git.CloneOptions
+		if input.Token != "" {
+			cloneOptions = git.CloneOptions{
+				URL:      input.URL,
+				Progress: progressWriter,
+				Auth: &http.BasicAuth{
+					Username: "token",
+					Password: input.Token,
+				},
+			}
+		} else {
+			cloneOptions = git.CloneOptions{
+				URL:      input.URL,
+				Progress: progressWriter,
+			}
+		}
+
+		r, err = git.PlainCloneContext(ctx, input.Dir, false, &cloneOptions)
 		if err != nil {
 			logger.Errorf("Unable to clone %v %s: %v", input.URL, refName, err)
 			return nil, err

pkg/common/git_test.go

@@ -34,7 +34,7 @@ func TestFindGitSlug(t *testing.T) {
 	}
 
 	for _, tt := range slugTests {
-		provider, slug, err := findGitSlug(tt.url)
+		provider, slug, err := findGitSlug(tt.url, "github.com")
 
 		assert.NoError(err)
 		assert.Equal(tt.provider, provider)

pkg/runner/run_context.go

@@ -503,7 +503,7 @@ func (rc *RunContext) getGithubContext() *githubContext {
 	}
 
 	repoPath := rc.Config.Workdir
-	repo, err := common.FindGithubRepo(repoPath)
+	repo, err := common.FindGithubRepo(repoPath, rc.Config.GitHubInstance)
 	if err != nil {
 		log.Warningf("unable to get git repo: %v", err)
 	} else {
@@ -644,6 +644,11 @@ func (rc *RunContext) withGithubEnv(env map[string]string) map[string]string {
 	env["GITHUB_SERVER_URL"] = "https://github.com"
 	env["GITHUB_API_URL"] = "https://api.github.com"
 	env["GITHUB_GRAPHQL_URL"] = "https://api.github.com/graphql"
+	if rc.Config.GitHubInstance != "github.com" {
+		env["GITHUB_SERVER_URL"] = fmt.Sprintf("https://%s", rc.Config.GitHubInstance)
+		env["GITHUB_API_URL"] = fmt.Sprintf("https://%s/api/v3", rc.Config.GitHubInstance)
+		env["GITHUB_GRAPHQL_URL"] = fmt.Sprintf("https://%s/api/graphql", rc.Config.GitHubInstance)
+	}
 
 	job := rc.Run.Job()
 	if job.RunsOn() != nil {

pkg/runner/runner.go

@@ -38,6 +38,7 @@ type Config struct {
 	UsernsMode            string            // user namespace to use
 	ContainerArchitecture string            // Desired OS/architecture platform for running containers
 	UseGitIgnore          bool              // controls if paths in .gitignore should not be copied into container, default true
+	GitHubInstance        string            // GitHub instance to use, default "github.com"
 }
 
 // Resolves the equivalent host path inside the container

pkg/runner/runner_test.go

@@ -56,6 +56,7 @@ func runTestJobFile(ctx context.Context, t *testing.T, tjfi TestJobFileInfo, sec
 			ReuseContainers:       false,
 			ContainerArchitecture: tjfi.containerArchitecture,
 			Secrets:               secrets,
+			GitHubInstance:        "github.com",
 		}
 
 		runner, err := New(runnerConfig)

pkg/runner/step_context.go

@@ -70,7 +70,11 @@ func (sc *StepContext) Executor() common.Executor {
 		if remoteAction == nil {
 			return common.NewErrorExecutor(formatError(step.Uses))
 		}
-		if remoteAction.IsCheckout() && rc.getGithubContext().isLocalCheckout(step) {
+
+		remoteAction.URL = rc.Config.GitHubInstance
+
+		github := rc.getGithubContext()
+		if remoteAction.IsCheckout() && github.isLocalCheckout(step) {
 			return func(ctx context.Context) error {
 				common.Logger(ctx).Debugf("Skipping actions/checkout")
 				return nil
@@ -80,9 +84,10 @@ func (sc *StepContext) Executor() common.Executor {
 		actionDir := fmt.Sprintf("%s/%s", rc.ActionCacheDir(), strings.ReplaceAll(step.Uses, "/", "-"))
 		return common.NewPipelineExecutor(
 			common.NewGitCloneExecutor(common.NewGitCloneExecutorInput{
-				URL: remoteAction.CloneURL(),
-				Ref: remoteAction.Ref,
-				Dir: actionDir,
+				URL:   remoteAction.CloneURL(),
+				Ref:   remoteAction.Ref,
+				Dir:   actionDir,
+				Token: github.Token,
 			}),
 			sc.setupAction(actionDir, remoteAction.Path),
 			sc.runAction(actionDir, remoteAction.Path),
@@ -568,6 +573,7 @@ func (sc *StepContext) runAction(actionDir string, actionPath string) common.Exe
 }
 
 type remoteAction struct {
+	URL  string
 	Org  string
 	Repo string
 	Path string
@@ -575,7 +581,7 @@ type remoteAction struct {
 }
 
 func (ra *remoteAction) CloneURL() string {
-	return fmt.Sprintf("https://github.com/%s/%s", ra.Org, ra.Repo)
+	return fmt.Sprintf("https://%s/%s/%s", ra.URL, ra.Org, ra.Repo)
 }
 
 func (ra *remoteAction) IsCheckout() bool {
@@ -601,6 +607,7 @@ func newRemoteAction(action string) *remoteAction {
 		Repo: matches[2],
 		Path: matches[4],
 		Ref:  matches[6],
+		URL:  "github.com",
 	}
 }