fix: try finding a socket, otherwise fail, respect user choice (#1745)

* fix: try finding a socket, otherwise fail, respect user choice

* Update cmd/root.go

Co-authored-by: Jason Song <i@wolfogre.com>

* Update cmd/root.go

Co-authored-by: Jason Song <i@wolfogre.com>

---------

Co-authored-by: Jason Song <i@wolfogre.com>

cmd/root.go

@@ -80,7 +80,7 @@ func Execute(ctx context.Context, version string) {
 	rootCmd.PersistentFlags().StringVarP(&input.envfile, "env-file", "", ".env", "environment file to read and use as env in the containers")
 	rootCmd.PersistentFlags().StringVarP(&input.inputfile, "input-file", "", ".input", "input file to read and use as action input")
 	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.containerDaemonSocket, "container-daemon-socket", "", "/var/run/docker.sock", "Path to Docker daemon socket which will be mounted to containers")
+	rootCmd.PersistentFlags().StringVarP(&input.containerDaemonSocket, "container-daemon-socket", "", "", "URI to Docker Engine socket (e.g.: unix://~/.docker/run/docker.sock)")
 	rootCmd.PersistentFlags().StringVarP(&input.containerOptions, "container-options", "", "", "Custom docker container options for the job container without an options property in the job definition")
 	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.PersistentFlags().StringVarP(&input.artifactServerPath, "artifact-server-path", "", "", "Defines the path where the artifact server stores uploads and retrieves downloads from. If not specified the artifact server will not start.")
@@ -118,6 +118,33 @@ func configLocations() []string {
 	}
 }
 
+var commonSocketPaths = []string{
+	"/var/run/docker.sock",
+	"/var/run/podman/podman.sock",
+	"$HOME/.colima/docker.sock",
+	"$XDG_RUNTIME_DIR/docker.sock",
+	`\\.\pipe\docker_engine`,
+	"$HOME/.docker/run/docker.sock",
+}
+
+// returns socket path or false if not found any
+func socketLocation() (string, bool) {
+	if dockerHost, exists := os.LookupEnv("DOCKER_HOST"); exists {
+		return dockerHost, true
+	}
+
+	for _, p := range commonSocketPaths {
+		if _, err := os.Lstat(os.ExpandEnv(p)); err == nil {
+			if strings.HasPrefix(p, `\\.\`) {
+				return "npipe://" + os.ExpandEnv(p), true
+			}
+			return "unix://" + os.ExpandEnv(p), true
+		}
+	}
+
+	return "", false
+}
+
 func args() []string {
 	actrc := configLocations()
 
@@ -131,15 +158,6 @@ func args() []string {
 }
 
 func bugReport(ctx context.Context, version string) error {
-	var commonSocketPaths = []string{
-		"/var/run/docker.sock",
-		"/var/run/podman/podman.sock",
-		"$HOME/.colima/docker.sock",
-		"$XDG_RUNTIME_DIR/docker.sock",
-		`\\.\pipe\docker_engine`,
-		"$HOME/.docker/run/docker.sock",
-	}
-
 	sprintf := func(key, val string) string {
 		return fmt.Sprintf("%-24s%s\n", key, val)
 	}
@@ -150,19 +168,20 @@ func bugReport(ctx context.Context, version string) error {
 	report += sprintf("NumCPU:", fmt.Sprint(runtime.NumCPU()))
 
 	var dockerHost string
-	if dockerHost = os.Getenv("DOCKER_HOST"); dockerHost == "" {
+	var exists bool
-		dockerHost = "DOCKER_HOST environment variable is unset/empty."
+	if dockerHost, exists = os.LookupEnv("DOCKER_HOST"); !exists {
+		dockerHost = "DOCKER_HOST environment variable is not set"
+	} else if dockerHost == "" {
+		dockerHost = "DOCKER_HOST environment variable is empty."
 	}
 
 	report += sprintf("Docker host:", dockerHost)
 	report += fmt.Sprintln("Sockets found:")
 	for _, p := range commonSocketPaths {
-		if strings.HasPrefix(p, `$`) {
+		if _, err := os.Lstat(os.ExpandEnv(p)); err != nil {
-			v := strings.Split(p, `/`)[0]
-			p = strings.Replace(p, v, os.Getenv(strings.TrimPrefix(v, `$`)), 1)
-		}
-		if _, err := os.Stat(p); err != nil {
 			continue
+		} else if _, err := os.Stat(os.ExpandEnv(p)); err != nil {
+			report += fmt.Sprintf("\t%s(broken)\n", p)
 		} else {
 			report += fmt.Sprintf("\t%s\n", p)
 		}
@@ -342,6 +361,19 @@ func newRunCommand(ctx context.Context, input *Input) func(*cobra.Command, []str
 			return bugReport(ctx, cmd.Version)
 		}
 
+		var socketPath string
+		if input.containerDaemonSocket != "" {
+			socketPath = input.containerDaemonSocket
+		} else {
+			socket, found := socketLocation()
+			if !found && input.containerDaemonSocket == "" {
+				log.Errorln("daemon Docker Engine socket not found and containerDaemonSocket option was not set")
+			} else {
+				socketPath = socket
+			}
+		}
+		os.Setenv("DOCKER_HOST", socketPath)
+
 		if runtime.GOOS == "darwin" && runtime.GOARCH == "arm64" && input.containerArchitecture == "" {
 			l := log.New()
 			l.SetFormatter(&log.TextFormatter{
@@ -533,7 +565,7 @@ func newRunCommand(ctx context.Context, input *Input) func(*cobra.Command, []str
 			Privileged:                         input.privileged,
 			UsernsMode:                         input.usernsMode,
 			ContainerArchitecture:              input.containerArchitecture,
-			ContainerDaemonSocket:              input.containerDaemonSocket,
+			ContainerDaemonSocket:              socketPath,
 			ContainerOptions:                   input.containerOptions,
 			UseGitIgnore:                       input.useGitIgnore,
 			GitHubInstance:                     input.githubInstance,

pkg/container/docker_run.go

@@ -189,9 +189,6 @@ type containerReference struct {
 }
 
 func GetDockerClient(ctx context.Context) (cli client.APIClient, err error) {
-	// TODO: this should maybe need to be a global option, not hidden in here?
-	//       though i'm not sure how that works out when there's another Executor :D
-	//		 I really would like something that works on OSX native for eg
 	dockerHost := os.Getenv("DOCKER_HOST")
 
 	if strings.HasPrefix(dockerHost, "ssh://") {