dockerEnv vs podmanEnv detection

Author: elasticdotventures

cmd/minikube/cmd/docker-env.go

@@ -121,6 +121,8 @@ type DockerShellConfig struct {
 	SSHAgentPID string
 }
 
+// DockerBackendDetector is a function variable for backend detection, allowing injection/mocking in tests.
+var DockerBackendDetector = DetectDockerBackend
 var (
 	noProxy              bool
 	sshHost              bool
@@ -382,6 +384,18 @@ docker-cli install instructions: https://minikube.sigs.k8s.io/docs/tutorials/doc
 			sshAgentPID: co.Config.SSHAgentPID,
 		}
 
+		// Detect backend (docker vs podman) and set ec.driver accordingly.
+		// This allows robust detection and is injectable/mocked for tests.
+		backend, err := DockerBackendDetector(func(name string, args ...string) ([]byte, error) {
+			cmd := exec.Command(name, args...)
+			return cmd.CombinedOutput()
+		})
+		if err != nil {
+			klog.Warningf("Failed to detect Docker backend, defaulting to driver: %v", err)
+		} else {
+			ec.driver = backend
+		}
+
 		dockerPath, err := exec.LookPath("docker")
 		if err != nil {
 			klog.Warningf("Unable to find docker in path - skipping connectivity check: %v", err)
@@ -586,7 +600,8 @@ func dockerEnvVars(ec DockerEnvConfig) map[string]string {
 	} else {
 		rt = envTCP
 	}
-	if os.Getenv(constants.MinikubeActiveDockerdEnv) == "" {
+	// Only add "existing" envs if the driver is podman
+	if ec.driver == "podman" && os.Getenv(constants.MinikubeActiveDockerdEnv) == "" {
 		for _, env := range constants.DockerDaemonEnvs {
 			if v := oci.InitialEnv(env); v != "" {
 				key := constants.MinikubeExistingPrefix + env
@@ -688,4 +703,36 @@ func init() {
 	dockerEnvCmd.Flags().StringVar(&shell.ForceShell, "shell", "", "Force environment to be configured for a specified shell: [fish, cmd, powershell, tcsh, bash, zsh], default is auto-detect")
 	dockerEnvCmd.Flags().StringVarP(&outputFormat, "output", "o", "", "One of 'text', 'yaml' or 'json'.")
 	dockerEnvCmd.Flags().BoolVarP(&dockerUnset, "unset", "u", false, "Unset variables instead of setting them")
+}
+	/*
+DetectDockerBackend probes the Docker CLI backend by running `docker info` and parsing the output
+for Podman signatures. Returns "docker" or "podman" as backend type.
+
+The detection logic looks for "Podman Engine" or "podman" in the "Server" or "Operating System" fields.
+The commandRunner argument allows injection/mocking for tests.
+*/
+func DetectDockerBackend(commandRunner func(name string, args ...string) ([]byte, error)) (string, error) {
+	output, err := commandRunner("docker", "info", "--format", "{{json .}}")
+	if err != nil {
+		return "", fmt.Errorf("failed to run docker info: %w", err)
+	}
+	// Try to parse as JSON and look for podman signatures
+	var info map[string]interface{}
+	if err := json.Unmarshal(output, &info); err == nil {
+		// Check "ServerVersion" or "OperatingSystem" fields for podman
+		if osField, ok := info["OperatingSystem"].(string); ok && strings.Contains(strings.ToLower(osField), "podman") {
+			return "podman", nil
+		}
+		if sv, ok := info["ServerVersion"].(string); ok && strings.Contains(strings.ToLower(sv), "podman") {
+			return "podman", nil
+		}
+		if sv, ok := info["Server"].(string); ok && strings.Contains(strings.ToLower(sv), "podman") {
+			return "podman", nil
+		}
+	}
+	// Fallback: look for "Podman" in raw output
+	if strings.Contains(strings.ToLower(string(output)), "podman") {
+		return "podman", nil
+	}
+	return "docker", nil
 }

cmd/minikube/cmd/docker-env_test.go

@@ -429,6 +429,17 @@ SSH_AGENT_PID: "29228"
 	}
 	for _, tc := range tests {
 		t.Run(tc.config.profile, func(t *testing.T) {
+			origDetector := DockerBackendDetector
+			defer func() { DockerBackendDetector = origDetector }()
+
+			// If this is the podman scenario, mock the backend detector
+			if tc.config.profile == "podmandriver" {
+				DockerBackendDetector = func(_ func(string, ...string) ([]byte, error)) (string, error) {
+					return "podman", nil
+				}
+				tc.config.driver = "docker" // initial value, will be overridden by detector
+			}
+
 			tc.config.EnvConfig.Shell = tc.shell
 			// set global variable
 			outputFormat = tc.output
@@ -454,6 +465,36 @@ SSH_AGENT_PID: "29228"
 
 		})
 	}
+
+	// Add a Podman scenario test case
+	t.Run("podmandriver", func(t *testing.T) {
+		origDetector := DockerBackendDetector
+		defer func() { DockerBackendDetector = origDetector }()
+		DockerBackendDetector = func(_ func(string, ...string) ([]byte, error)) (string, error) {
+			return "podman", nil
+		}
+		config := DockerEnvConfig{profile: "podmandriver", driver: "docker", hostIP: "127.0.0.1", port: 32842, certsDir: "/certs"}
+		config.EnvConfig.Shell = "bash"
+		var b []byte
+		buf := bytes.NewBuffer(b)
+		if err := dockerSetScript(config, buf); err != nil {
+			t.Errorf("setScript(%+v) error: %v", config, err)
+		}
+		got := buf.String()
+		// Podman should still output the same envs, but may add "existing" envs if present in the environment.
+		// For this test, just check the main envs are present.
+		wantSet := `export DOCKER_TLS_VERIFY="1"
+export DOCKER_HOST="tcp://127.0.0.1:32842"
+export DOCKER_CERT_PATH="/certs"
+export MINIKUBE_ACTIVE_DOCKERD="podmandriver"
+
+# To point your shell to minikube's docker-daemon, run:
+# eval $(minikube -p podmandriver docker-env)
+`
+		if diff := cmp.Diff(wantSet, got); diff != "" {
+			t.Errorf("setScript(podmandriver) mismatch (-want +got):\n%s\n\nraw output:\n%s\nquoted: %q", diff, got, got)
+		}
+	})
 }
 
 func TestValidDockerProxy(t *testing.T) {

site/content/en/docs/commands/podman-env.md

@@ -4,6 +4,14 @@ description: >
   Configure environment to use minikube's Podman service
 ---
 
+## Requirements
+
+- **Podman version 4.9.2 or newer is required.**
+- Support for Podman v3 and varlink-based communication has been removed. The `podman-env` command now configures your environment to use the Podman REST API socket, as required by Podman v4+.
+
+{{% pageinfo color="warning" %}}
+**Note:** If you are using an older version of Podman, please upgrade to at least v4.9.2 to use `minikube podman-env`. Legacy varlink-based workflows are no longer supported.
+{{% /pageinfo %}}
 
 ## minikube podman-env
 
@@ -30,7 +38,7 @@ minikube podman-env [flags]
       --add_dir_header                   If true, adds the file directory to the header of the log messages
       --alsologtostderr                  log to standard error as well as files (no effect when -logtostderr=true)
   -b, --bootstrapper string              The name of the cluster bootstrapper that will set up the Kubernetes cluster. (default "kubeadm")
-  -h, --help                             
+  -h, --help
       --log_backtrace_at traceLocation   when logging hits line file:N, emit a stack trace (default :0)
       --log_dir string                   If non-empty, write log files in this directory (no effect when -logtostderr=true)
       --log_file string                  If non-empty, use this log file (no effect when -logtostderr=true)