Merge pull request #4 from drone-plugins/secret_env

Added support for passing GITHUB_TOKEN

README.md

@@ -30,7 +30,7 @@ docker build \
 
 ## Plugin step usage
 
-Provide uses, with & env of github action to use in plugin step settings.
+Provide uses, with & env of github action to use in plugin step settings. Provide GITHUB_TOKEN as environment variable if it is required for an action.
 
 ```console
 steps:

plugin.go

@@ -11,9 +11,13 @@ import (
 )
 
 const (
-	workflowFile = "/tmp/workflow.yml"
-	webhookFile  = "/tmp/webhook"
 	envFile      = "/tmp/action.env"
+	secretFile   = "/tmp/action.secrets"
+	workflowFile = "/tmp/workflow.yml"
+)
+
+var (
+	secrets = []string{"GITHUB_TOKEN"}
 )
 
 type (
@@ -42,11 +46,19 @@ func (p Plugin) Exec() error {
 		return err
 	}
 
+	if err := utils.CreateEnvAndSecretFile(envFile, secretFile, secrets); err != nil {
+		return err
+	}
+
 	cmdArgs := []string{
 		"-W",
 		workflowFile,
 		"-P",
 		fmt.Sprintf("ubuntu-latest=%s", p.Action.Image),
+		"--secret-file",
+		secretFile,
+		"--env-file",
+		envFile,
 		"-b",
 		"--detect-event",
 	}

utils/env.go

@@ -0,0 +1,55 @@
+package utils
+
+import (
+	"os"
+	"strings"
+
+	"github.com/joho/godotenv"
+	"github.com/pkg/errors"
+)
+
+func CreateEnvAndSecretFile(envFile, secretFile string, secrets []string) error {
+	envVars := getEnvVars()
+
+	actionEnvVars := make(map[string]string)
+	for key, val := range envVars {
+		if !strings.HasPrefix(key, "PLUGIN_") && !Exists(secrets, key) {
+			actionEnvVars[key] = val
+		}
+	}
+
+	secretEnvVars := make(map[string]string)
+	for _, secretName := range secrets {
+		if os.Getenv(secretName) != "" {
+			secretEnvVars[secretName] = os.Getenv(secretName)
+		}
+	}
+
+	if err := godotenv.Write(actionEnvVars, envFile); err != nil {
+		return errors.Wrap(err, "failed to write environment variables file")
+	}
+	if err := godotenv.Write(secretEnvVars, secretFile); err != nil {
+		return errors.Wrap(err, "failed to write secret variables file")
+	}
+	return nil
+}
+
+// Return environment variables set in a map format
+func getEnvVars() map[string]string {
+	m := make(map[string]string)
+	for _, e := range os.Environ() {
+		if i := strings.Index(e, "="); i >= 0 {
+			m[e[:i]] = e[i+1:]
+		}
+	}
+	return m
+}
+
+func Exists(slice []string, val string) bool {
+	for _, item := range slice {
+		if item == val {
+			return true
+		}
+	}
+	return false
+}