Merge pull request #15452 from ComradeProgrammer/docker-env

feat: direct image build on containerd via docker-env

cmd/minikube/cmd/docker-env.go

@@ -25,6 +25,7 @@ import (
 	"net/url"
 	"os"
 	"os/exec"
+	"runtime"
 	"strconv"
 	"strings"
 	"time"
@@ -47,6 +48,7 @@ import (
 	"k8s.io/minikube/pkg/minikube/out"
 	"k8s.io/minikube/pkg/minikube/reason"
 	"k8s.io/minikube/pkg/minikube/shell"
+	"k8s.io/minikube/pkg/minikube/sshagent"
 	"k8s.io/minikube/pkg/minikube/sysinit"
 	pkgnetwork "k8s.io/minikube/pkg/network"
 	kconst "k8s.io/minikube/third_party/kubeadm/app/constants"
@@ -295,6 +297,7 @@ docker-cli install instructions: https://minikube.sigs.k8s.io/docs/tutorials/doc
 		}
 
 		cname := ClusterFlagValue()
+
 		co := mustload.Running(cname)
 
 		driverName := co.CP.Host.DriverName
@@ -306,14 +309,42 @@ docker-cli install instructions: https://minikube.sigs.k8s.io/docs/tutorials/doc
 		if len(co.Config.Nodes) > 1 {
 			exit.Message(reason.EnvMultiConflict, `The docker-env command is incompatible with multi-node clusters. Use the 'registry' add-on: https://minikube.sigs.k8s.io/docs/handbook/registry/`)
 		}
+		cr := co.Config.KubernetesConfig.ContainerRuntime
+		// nerdctld supports amd64 and arm64
+		if err := dockerEnvSupported(cr, driverName); err != nil {
+			exit.Message(reason.Usage, err.Error())
+		}
 
-		if co.Config.KubernetesConfig.ContainerRuntime != constants.Docker {
-			exit.Message(reason.Usage, `The docker-env command is only compatible with the "docker" runtime, but this cluster was configured to use the "{{.runtime}}" runtime.`,
-				out.V{"runtime": co.Config.KubernetesConfig.ContainerRuntime})
+		// for the sake of docker-env command, start nerdctl and nerdctld
+		if cr == constants.Containerd {
+			out.WarningT("Using the docker-env command with the containerd runtime is a highly experimental feature, please provide feedback or contribute to make it better")
+
+			startNerdctld()
+
+			// docker-env on containerd depends on nerdctld (https://github.com/afbjorklund/nerdctld) as "docker" daeomn
+			// and nerdctld daemon must be used with ssh connection (it is set in kicbase image's Dockerfile)
+			// so directly set --ssh-host --ssh-add to true, even user didn't specify them
+			sshAdd = true
+			sshHost = true
+
+			// start the ssh-agent
+			if err := sshagent.Start(cname); err != nil {
+				exit.Message(reason.SSHAgentStart, err.Error())
+			}
+			// cluster config must be reloaded
+			// otherwise we won't be able to get SSH_AUTH_SOCK and SSH_AGENT_PID from cluster config.
+			co = mustload.Running(cname)
+
+			// set the ssh-agent envs for current process
+			os.Setenv("SSH_AUTH_SOCK", co.Config.SSHAuthSock)
+			os.Setenv("SSH_AGENT_PID", strconv.Itoa(co.Config.SSHAgentPID))
 		}
 
 		r := co.CP.Runner
-		ensureDockerd(cname, r)
+
+		if cr == constants.Docker {
+			ensureDockerd(cname, r)
+		}
 
 		d := co.CP.Host.Driver
 		port := constants.DockerDaemonPort
@@ -381,14 +412,18 @@ docker-cli install instructions: https://minikube.sigs.k8s.io/docs/tutorials/doc
 			if err != nil {
 				exit.Error(reason.IfSSHClient, "Error with ssh-add", err)
 			}
-
 			cmd := exec.Command(path, d.GetSSHKeyPath())
 			cmd.Stderr = os.Stderr
+			cmd.Env = append(cmd.Env, fmt.Sprintf("SSH_AUTH_SOCK=%s", co.Config.SSHAuthSock))
+			cmd.Env = append(cmd.Env, fmt.Sprintf("SSH_AGENT_PID=%d", co.Config.SSHAgentPID))
 			err = cmd.Run()
 			if err != nil {
 				exit.Error(reason.IfSSHClient, "Error with ssh-add", err)
 			}
 		}
+
+		// eventually, run something similar to ssh --append-known
+		appendKnownHelper(nodeName, true)
 	},
 }
 
@@ -539,6 +574,8 @@ func dockerEnvVars(ec DockerEnvConfig) map[string]string {
 	envSSH := map[string]string{
 		constants.DockerHostEnv:            sshURL(ec.username, ec.hostname, ec.sshport),
 		constants.MinikubeActiveDockerdEnv: ec.profile,
+		constants.SSHAuthSock:              ec.sshAuthSock,
+		constants.SSHAgentPID:              agentPID,
 	}
 
 	var rt map[string]string
@@ -630,6 +667,20 @@ func tryDockerConnectivity(bin string, ec DockerEnvConfig) ([]byte, error) {
 	return c.CombinedOutput()
 }
 
+func dockerEnvSupported(containerRuntime, driverName string) error {
+	if runtime.GOARCH != "amd64" && runtime.GOARCH != "arm64" {
+		return fmt.Errorf("the docker-env command only supports amd64 & arm64 architectures")
+	}
+	if containerRuntime != constants.Docker && containerRuntime != constants.Containerd {
+		return fmt.Errorf("the docker-env command only supports the docker and containerd runtimes")
+	}
+	// we only support containerd-env on the Docker driver
+	if containerRuntime == constants.Containerd && driverName != driver.Docker {
+		return fmt.Errorf("the docker-env command only supports the containerd runtime with the docker driver")
+	}
+	return nil
+}
+
 func init() {
 	defaultNoProxyGetter = &EnvNoProxyGetter{}
 	dockerEnvCmd.Flags().BoolVar(&noProxy, "no-proxy", false, "Add machine IP to NO_PROXY environment variable")

cmd/minikube/cmd/ssh-host.go

@@ -45,69 +45,76 @@ var sshHostCmd = &cobra.Command{
 	Short: "Retrieve the ssh host key of the specified node",
 	Long:  "Retrieve the ssh host key of the specified node.",
 	Run: func(cmd *cobra.Command, args []string) {
-		cname := ClusterFlagValue()
-		co := mustload.Running(cname)
-		if co.CP.Host.DriverName == driver.None {
-			exit.Message(reason.Usage, "'none' driver does not support 'minikube ssh-host' command")
-		}
+		appendKnownHelper(nodeName, appendKnown)
+	},
+}
 
-		var err error
-		var n *config.Node
-		if nodeName == "" {
-			n = co.CP.Node
-		} else {
-			n, _, err = node.Retrieve(*co.Config, nodeName)
-			if err != nil {
-				exit.Message(reason.GuestNodeRetrieve, "Node {{.nodeName}} does not exist.", out.V{"nodeName": nodeName})
-			}
-		}
+func appendKnownHelper(nodeName string, appendKnown bool) {
+	cname := ClusterFlagValue()
+	co := mustload.Running(cname)
+	if co.CP.Host.DriverName == driver.None {
+		exit.Message(reason.Usage, "'none' driver does not support 'minikube ssh-host' command")
+	}
 
-		scanArgs := []string{"-t", "rsa"}
-
-		keys, err := machine.RunSSHHostCommand(co.API, *co.Config, *n, "ssh-keyscan", scanArgs)
+	var err error
+	var n *config.Node
+	if nodeName == "" {
+		n = co.CP.Node
+	} else {
+		n, _, err = node.Retrieve(*co.Config, nodeName)
 		if err != nil {
-			// This is typically due to a non-zero exit code, so no need for flourish.
-			out.ErrLn("ssh-keyscan: %v", err)
-			// It'd be nice if we could pass up the correct error code here :(
+			exit.Message(reason.GuestNodeRetrieve, "Node {{.nodeName}} does not exist.", out.V{"nodeName": nodeName})
+		}
+	}
+
+	scanArgs := []string{"-t", "rsa"}
+
+	keys, err := machine.RunSSHHostCommand(co.API, *co.Config, *n, "ssh-keyscan", scanArgs)
+	if err != nil {
+		// This is typically due to a non-zero exit code, so no need for flourish.
+		out.ErrLn("ssh-keyscan: %v", err)
+		// It'd be nice if we could pass up the correct error code here :(
+		os.Exit(1)
+	}
+
+	if appendKnown {
+		addr, port, err := machine.GetSSHHostAddrPort(co.API, *co.Config, *n)
+		if err != nil {
+			out.ErrLn("GetSSHHostAddrPort: %v", err)
 			os.Exit(1)
 		}
 
-		if appendKnown {
-			addr, port, err := machine.GetSSHHostAddrPort(co.API, *co.Config, *n)
-			if err != nil {
-				out.ErrLn("GetSSHHostAddrPort: %v", err)
-				os.Exit(1)
-			}
-
-			host := addr
-			if port != 22 {
-				host = fmt.Sprintf("[%s]:%d", addr, port)
-			}
-			knownHosts := filepath.Join(homedir.HomeDir(), ".ssh", "known_hosts")
-
-			fmt.Fprintf(os.Stderr, "Host added: %s (%s)\n", knownHosts, host)
-			if sshutil.KnownHost(host, knownHosts) {
-				return
-			}
-
-			f, err := os.OpenFile(knownHosts, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0600)
-			if err != nil {
-				out.ErrLn("OpenFile: %v", err)
-				os.Exit(1)
-			}
-			defer f.Close()
-
-			_, err = f.WriteString(keys)
-			if err != nil {
-				out.ErrLn("WriteString: %v", err)
-				os.Exit(1)
-			}
+		host := addr
+		if port != 22 {
+			host = fmt.Sprintf("[%s]:%d", addr, port)
+		}
+		knownHosts := filepath.Join(homedir.HomeDir(), ".ssh", "known_hosts")
 
+		fmt.Fprintf(os.Stderr, "Host added: %s (%s)\n", knownHosts, host)
+		if sshutil.KnownHost(host, knownHosts) {
 			return
 		}
 
-		fmt.Printf("%s", keys)
-	},
+		f, err := os.OpenFile(knownHosts, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0600)
+		if err != nil {
+			out.ErrLn("OpenFile: %v", err)
+			os.Exit(1)
+		}
+
+		_, err = f.WriteString(keys)
+		if err != nil {
+			out.ErrLn("WriteString: %v", err)
+			f.Close()
+			os.Exit(1)
+		}
+
+		if err := f.Close(); err != nil {
+			out.ErrLn("Close: %v", err)
+			os.Exit(1)
+		}
+
+		return
+	}
 }
 
 func init() {

cmd/minikube/cmd/start.go

@@ -2007,3 +2007,33 @@ func isTwoDigitSemver(ver string) bool {
 	majorMinorOnly := regexp.MustCompile(`^(?P<major>0|[1-9]\d*)\.(?P<minor>0|[1-9]\d*)$`)
 	return majorMinorOnly.MatchString(ver)
 }
+
+func startNerdctld() {
+	// for containerd runtime using ssh, we have installed nerdctld and nerdctl into kicbase
+	// These things will be included in the ISO/Base image in the future versions
+
+	// copy these binaries to the path of the containerd node
+	co := mustload.Running(ClusterFlagValue())
+	runner := co.CP.Runner
+
+	// and set 777 to these files
+	if out, err := runner.RunCmd(exec.Command("sudo", "chmod", "777", "/usr/local/bin/nerdctl", "/usr/local/bin/nerdctld")); err != nil {
+		exit.Error(reason.StartNerdctld, fmt.Sprintf("Failed setting permission for nerdctl: %s", out.Output()), err)
+	}
+
+	// sudo systemctl start nerdctld.socket
+	if out, err := runner.RunCmd(exec.Command("sudo", "systemctl", "start", "nerdctld.socket")); err != nil {
+		exit.Error(reason.StartNerdctld, fmt.Sprintf("Failed to enable nerdctld.socket: %s", out.Output()), err)
+	}
+	// sudo systemctl start nerdctld.service
+	if out, err := runner.RunCmd(exec.Command("sudo", "systemctl", "start", "nerdctld.service")); err != nil {
+		exit.Error(reason.StartNerdctld, fmt.Sprintf("Failed to enable nerdctld.service: %s", out.Output()), err)
+	}
+
+	// set up environment variable on remote machine. docker client uses 'non-login & non-interactive shell' therefore the only way is to modify .bashrc file of user 'docker'
+	// insert this at 4th line
+	envSetupCommand := exec.Command("/bin/bash", "-c", "sed -i '4i export DOCKER_HOST=unix:///run/nerdctld.sock' .bashrc")
+	if out, err := runner.RunCmd(envSetupCommand); err != nil {
+		exit.Error(reason.StartNerdctld, fmt.Sprintf("Failed to set up DOCKER_HOST: %s", out.Output()), err)
+	}
+}

deploy/kicbase/Dockerfile

@@ -49,6 +49,8 @@ ARG CRI_DOCKERD_VERSION="v0.3.3"
 ARG CRI_DOCKERD_COMMIT="b58acf8f78f9d7bce1241d1cddb0932e7101f278"
 ARG CNI_PLUGINS_VERSION="v1.3.0"
 ARG TARGETARCH
+ARG NERDCTL_VERSION="1.0.0"
+ARG NERDCTLD_VERSION="0.2.0"
 
 # copy in static files (configs, scripts)
 COPY deploy/kicbase/10-network-security.conf /etc/sysctl.d/10-network-security.conf
@@ -59,6 +61,8 @@ COPY deploy/kicbase/containerd_docker_io_hosts.toml /etc/containerd/certs.d/dock
 COPY deploy/kicbase/clean-install /usr/local/bin/clean-install
 COPY deploy/kicbase/entrypoint /usr/local/bin/entrypoint
 COPY deploy/kicbase/CHANGELOG ./CHANGELOG
+COPY deploy/kicbase/nerdctld/nerdctld.socket  /etc/systemd/system/nerdctld.socket
+COPY deploy/kicbase/nerdctld/nerdctld.service  /etc/systemd/system/nerdctld.service
 COPY --from=auto-pause /src/cmd/auto-pause/auto-pause-${TARGETARCH} /bin/auto-pause
 
 # Install dependencies, first from apt, then from release tarballs.
@@ -136,6 +140,18 @@ RUN clean-install \
     # libglib2.0-0 is required for conmon, which is required for podman
     libglib2.0-0
 
+# Install nerdctl and nerdctld
+RUN export ARCH=$(dpkg --print-architecture) \
+    && if [ "$ARCH" = 'amd64' ] || [ "$ARCH" = 'arm64' ]; then \
+        echo "Installing nerdctl and nerdctld ..." && \
+        curl -L --retry 5 --output /tmp/nerdctl.tgz "https://github.com/containerd/nerdctl/releases/download/v${NERDCTL_VERSION}/nerdctl-${NERDCTL_VERSION}-linux-$ARCH.tar.gz" &&\
+        tar -C /usr/local/bin -xzvf /tmp/nerdctl.tgz &&\
+        curl -L --retry 5 --output /tmp/nerdctld.tgz "https://github.com/afbjorklund/nerdctld/releases/download/v${NERDCTLD_VERSION}/nerdctld-${NERDCTLD_VERSION}-linux-$ARCH.tar.gz" &&\
+        tar -C /usr/local/bin -xzvf /tmp/nerdctld.tgz &&\
+        chmod 777  /usr/local/bin/nerdctl &&\
+        chmod 777 /usr/local/bin/nerdctld; \
+    fi
+
 # install docker
 RUN sh -c "echo 'deb https://download.docker.com/linux/ubuntu jammy stable' > /etc/apt/sources.list.d/docker.list" && \
     curl -L https://download.docker.com/linux/ubuntu/gpg -o docker.key && \

deploy/kicbase/nerdctld/nerdctld.service

@@ -0,0 +1,11 @@
+[Unit]
+Description=nerdctld
+Requires=nerdctld.socket containerd.service
+After=nerdctld.socket containerd.service
+
+[Service]
+Type=notify
+Environment=CONTAINERD_NAMESPACE=k8s.io
+ExecStart=nerdctld --addr fd://
+[Install]
+WantedBy=multi-user.target

deploy/kicbase/nerdctld/nerdctld.socket

@@ -0,0 +1,9 @@
+[Unit]
+Description=nerdctld
+
+[Socket]
+ListenStream=/var/run/nerdctld.sock
+SocketMode=0666
+
+[Install]
+WantedBy=sockets.target

pkg/drivers/kic/types.go

@@ -24,10 +24,10 @@ import (
 
 const (
 	// Version is the current version of kic
-	Version = "v0.0.39-1688681246-16834"
+	Version = "v0.0.39-1689032083-15452"
 
 	// SHA of the kic base image
-	baseImageSHA = "849205234efc46da016f3a964268d7c76363fc521532c280d0e8a6bf1cc393b5"
+	baseImageSHA = "41e03f55414b4bc4a9169ee03de8460ddd2a95f539efd83fce689159a4e20667"
 	// The name of the GCR kicbase repository
 	gcrRepo = "gcr.io/k8s-minikube/kicbase-builds"
 	// The name of the Dockerhub kicbase repository

pkg/minikube/reason/reason.go

@@ -95,6 +95,8 @@ var (
 	InternalCacheLoad = Kind{ID: "MK_CACHE_LOAD", ExitCode: ExProgramError}
 	// minikube failed to load a Docker Machine CommandRunner
 	InternalCommandRunner = Kind{ID: "MK_COMMAND_RUNNER", ExitCode: ExProgramError}
+	// minikube failed to start nerdctld
+	StartNerdctld = Kind{ID: "MK_START_NERDCTLD", ExitCode: ExProgramError}
 	// minikube failed to generate shell command completion for a supported shell
 	InternalCompletion = Kind{ID: "MK_COMPLETION", ExitCode: ExProgramError}
 	// minikube failed to set an internal config value
@@ -426,6 +428,8 @@ var (
 	RuntimeEnable = Kind{ID: "RUNTIME_ENABLE", ExitCode: ExRuntimeError}
 	// minikube failed to cache images for the current container runtime
 	RuntimeCache = Kind{ID: "RUNTIME_CACHE", ExitCode: ExRuntimeError}
+	// minikube failed to start an ssh-agent when executing docker-env
+	SSHAgentStart = Kind{ID: "SSH_AGENT_START", ExitCode: ExRuntimeError}
 
 	// service check timed out while starting minikube dashboard
 	SvcCheckTimeout = Kind{ID: "SVC_CHECK_TIMEOUT", ExitCode: ExSvcTimeout}

site/content/en/docs/commands/start.md

@@ -26,7 +26,7 @@ minikube start [flags]
       --apiserver-names strings           A set of apiserver names which are used in the generated certificate for kubernetes.  This can be used if you want to make the apiserver available from outside the machine
       --apiserver-port int                The apiserver listening port (default 8443)
       --auto-update-drivers               If set, automatically updates drivers to the latest version. Defaults to true. (default true)
-      --base-image string                 The base image to use for docker/podman drivers. Intended for local development. (default "gcr.io/k8s-minikube/kicbase-builds:v0.0.39-1688681246-16834@sha256:849205234efc46da016f3a964268d7c76363fc521532c280d0e8a6bf1cc393b5")
+      --base-image string                 The base image to use for docker/podman drivers. Intended for local development. (default "gcr.io/k8s-minikube/kicbase-builds:v0.0.39-1689032083-15452@sha256:41e03f55414b4bc4a9169ee03de8460ddd2a95f539efd83fce689159a4e20667")
       --binary-mirror string              Location to fetch kubectl, kubelet, & kubeadm binaries from.
       --cache-images                      If true, cache docker images for the current bootstrapper and load them into the machine. Always false with --driver=none. (default true)
       --cert-expiration duration          Duration until minikube certificate expiration, defaults to three years (26280h). (default 26280h0m0s)

site/content/en/docs/contrib/errorcodes.en.md

@@ -49,6 +49,9 @@ minkube failed to cache and load cached images
 "MK_COMMAND_RUNNER" (Exit code ExProgramError)  
 minikube failed to load a Docker Machine CommandRunner  
 
+"MK_START_NERDCTLD" (Exit code ExProgramError)  
+minikube failed to start nerdctld  
+
 "MK_COMPLETION" (Exit code ExProgramError)  
 minikube failed to generate shell command completion for a supported shell  
 
@@ -403,6 +406,9 @@ minikube failed to enable the current container runtime
 "RUNTIME_CACHE" (Exit code ExRuntimeError)  
 minikube failed to cache images for the current container runtime  
 
+"SSH_AGENT_START" (Exit code ExRuntimeError)  
+minikube failed to start an ssh-agent when executing docker-env  
+
 "SVC_CHECK_TIMEOUT" (Exit code ExSvcTimeout)  
 service check timed out while starting minikube dashboard  
 

site/content/en/docs/contrib/tests.en.md

@@ -79,6 +79,9 @@ makes sure the --force-systemd flag worked with the cri-o container runtime
 ## TestForceSystemdEnv
 makes sure the MINIKUBE_FORCE_SYSTEMD environment variable works just as well as the --force-systemd flag
 
+## TestDockerEnvContainerd
+makes sure that minikube docker-env command works when the runtime is containerd
+
 ## TestKVMDriverInstallOrUpdate
 makes sure our docker-machine-driver-kvm2 binary can be installed properly
 

test/integration/docker_test.go

@@ -20,10 +20,16 @@ package integration
 
 import (
 	"context"
+	"fmt"
 	"os"
 	"os/exec"
+	"regexp"
+	"runtime"
 	"strings"
 	"testing"
+	"time"
+
+	"k8s.io/minikube/pkg/minikube/constants"
 )
 
 // TestDockerFlags makes sure the --docker-env and --docker-opt parameters are respected
@@ -158,3 +164,94 @@ func TestForceSystemdEnv(t *testing.T) {
 		validateContainerdSystemd(ctx, t, profile)
 	}
 }
+
+// TestDockerEnvContainerd makes sure that minikube docker-env command works when the runtime is containerd
+func TestDockerEnvContainerd(t *testing.T) {
+	t.Log("running with", ContainerRuntime(), DockerDriver(), runtime.GOOS, runtime.GOARCH)
+	if ContainerRuntime() != constants.Containerd || !DockerDriver() || runtime.GOOS != "linux" {
+		t.Skip("skipping: TestDockerEnvContainerd can only be run with the containerd runtime on Docker driver")
+	}
+	profile := UniqueProfileName("dockerenv")
+	ctx, cancel := context.WithTimeout(context.Background(), Minutes(30))
+	defer CleanupWithLogs(t, profile, cancel)
+
+	// start the minikube with containerd runtime
+	args := append([]string{"start", "-p", profile}, StartArgs()...)
+	cmd := exec.CommandContext(ctx, Target(), args...)
+	startResult, err := Run(t, cmd)
+	if err != nil {
+		t.Errorf("failed to start minikube with args: %q : %v", startResult.Command(), err)
+	}
+	time.Sleep(time.Second * 10)
+
+	// execute 'minikube docker-env --ssh-host --ssh-add' and extract the 'DOCKER_HOST' environment value
+	cmd = exec.CommandContext(ctx, "/bin/bash", "-c", fmt.Sprintf("%s docker-env --ssh-host --ssh-add -p %s", Target(), profile))
+	result, err := Run(t, cmd)
+	if err != nil {
+		t.Errorf("failed to execute minikube docker-env --ssh-host --ssh-add, error: %v, output: %s", err, result.Output())
+	}
+
+	output := result.Output()
+	groups := regexp.MustCompile(`DOCKER_HOST="(\S*)"`).FindStringSubmatch(output)
+	if len(groups) < 2 {
+		t.Errorf("DOCKER_HOST doesn't match expected format, output is %s", output)
+	}
+	dockerHost := groups[1]
+	segments := strings.Split(dockerHost, ":")
+	if len(segments) < 3 {
+		t.Errorf("DOCKER_HOST doesn't match expected format, output is %s", dockerHost)
+	}
+
+	// get SSH_AUTH_SOCK
+	groups = regexp.MustCompile(`SSH_AUTH_SOCK=(\S*)`).FindStringSubmatch(output)
+	if len(groups) < 2 {
+		t.Errorf("failed to acquire SSH_AUTH_SOCK, output is %s", output)
+	}
+	sshAuthSock := groups[1]
+	// get SSH_AGENT_PID
+	groups = regexp.MustCompile(`SSH_AGENT_PID=(\S*)`).FindStringSubmatch(output)
+	if len(groups) < 2 {
+		t.Errorf("failed to acquire SSH_AUTH_PID, output is %s", output)
+	}
+	sshAgentPid := groups[1]
+
+	cmd = exec.CommandContext(ctx, "/bin/bash", "-c", fmt.Sprintf("SSH_AUTH_SOCK=%s SSH_AGENT_PID=%s DOCKER_HOST=%s docker version", sshAuthSock, sshAgentPid, dockerHost))
+
+	result, err = Run(t, cmd)
+	if err != nil {
+		t.Fatalf("failed to execute 'docker version', error: %v, output: %s", err, result.Output())
+	}
+	// if we are really connecting to nerdctld inside node, docker version output should have word 'nerdctl'
+	// If everything works properly, in the output of `docker version` you should be able to see something like
+	/*
+		Server:
+			nerdctl:
+			Version:          1.0.0
+			buildctl:
+			Version:          0.10.3
+			GitCommit:        c8d25d9a103b70dc300a4fd55e7e576472284e31
+			containerd:
+			Version:          1.6.10
+			GitCommit:        770bd0108c32f3fb5c73ae1264f7e503fe7b2661
+	*/
+	if !strings.Contains(result.Output(), "nerdctl") {
+		t.Fatal("failed to detect keyword 'nerdctl' in output of docker version")
+	}
+
+	// now try to build an image
+	cmd = exec.CommandContext(ctx, "/bin/bash", "-c", fmt.Sprintf("SSH_AUTH_SOCK=%s SSH_AGENT_PID=%s DOCKER_HOST=%s DOCKER_BUILDKIT=0 docker build -t local/minikube-dockerenv-containerd-test:latest testdata/docker-env", sshAuthSock, sshAgentPid, dockerHost))
+	result, err = Run(t, cmd)
+	if err != nil {
+		t.Errorf("failed to build images, error: %v, output:%s", err, result.Output())
+	}
+
+	// and check whether that image is really available
+	cmd = exec.CommandContext(ctx, "/bin/bash", "-c", fmt.Sprintf("SSH_AUTH_SOCK=%s SSH_AGENT_PID=%s DOCKER_HOST=%s docker image ls", sshAuthSock, sshAgentPid, dockerHost))
+	result, err = Run(t, cmd)
+	if err != nil {
+		t.Fatalf("failed to execute 'docker image ls', error: %v, output: %s", err, result.Output())
+	}
+	if !strings.Contains(result.Output(), "local/minikube-dockerenv-containerd-test") {
+		t.Fatal("failed to detect image 'local/minikube-dockerenv-containerd-test' in output of docker image ls")
+	}
+}

test/integration/testdata/docker-env/Dockerfile

@@ -0,0 +1,3 @@
+FROM alpine:latest
+
+CMD [ "/bin/bash" ]

translations/de.json

@@ -879,6 +879,7 @@
 	"Using rootless driver was required, but the current driver does not seem rootless": "",
 	"Using rootless {{.driver_name}} driver": "",
 	"Using the '{{.runtime}}' runtime with the 'none' driver is an untested configuration!": "Das Verwenden der '{{.runtime}}' Laufzeitumgebung mit dem 'none' Treiber ist eine ungetestete Konfiguration!",
+	"Using the docker-env command with the containerd runtime is a highly experimental feature, please provide feedback or contribute to make it better": "",
 	"Using the {{.driver}} driver based on existing profile": "Verwende den Treiber {{.driver}} basierend auf dem existierenden Profil",
 	"Using the {{.driver}} driver based on user configuration": "Verwende den Treiber {{.driver}} basierend auf der Benutzer-Konfiguration",
 	"Using {{.driver_name}} driver with root privileges": "",

translations/es.json

@@ -711,7 +711,6 @@
 	"The cri socket path to be used": "La ruta del socket de cri",
 	"The cri socket path to be used.": "",
 	"The docker-env command is incompatible with multi-node clusters. Use the 'registry' add-on: https://minikube.sigs.k8s.io/docs/handbook/registry/": "",
-	"The docker-env command is only compatible with the \"docker\" runtime, but this cluster was configured to use the \"{{.runtime}}\" runtime.": "",
 	"The driver '{{.driver}}' is not supported on {{.os}}/{{.arch}}": "El controlador \"{{.driver}}\" no se puede utilizar en {{.os}}/{{.arch}}",
 	"The existing \"{{.name}}\" cluster was created using the \"{{.old}}\" driver, which is incompatible with requested \"{{.new}}\" driver.": "",
 	"The existing node configuration appears to be corrupt. Run 'minikube delete'": "",
@@ -878,6 +877,7 @@
 	"Using rootless driver was required, but the current driver does not seem rootless": "",
 	"Using rootless {{.driver_name}} driver": "",
 	"Using the '{{.runtime}}' runtime with the 'none' driver is an untested configuration!": "",
+	"Using the docker-env command with the containerd runtime is a highly experimental feature, please provide feedback or contribute to make it better": "",
 	"Using the {{.driver}} driver based on existing profile": "",
 	"Using the {{.driver}} driver based on user configuration": "",
 	"Using {{.driver_name}} driver with root privileges": "",

translations/fr.json

@@ -859,6 +859,7 @@
 	"Using rootless driver was required, but the current driver does not seem rootless": "L'utilisation d'un pilote sans root était nécessaire, mais le pilote actuel ne semble pas sans root",
 	"Using rootless {{.driver_name}} driver": "Utilisation du pilote {{.driver_name}} sans root",
 	"Using the '{{.runtime}}' runtime with the 'none' driver is an untested configuration!": "L'utilisation du runtime '{{.runtime}}' avec le pilote 'none' est une configuration non testée !",
+	"Using the docker-env command with the containerd runtime is a highly experimental feature, please provide feedback or contribute to make it better": "",
 	"Using the {{.driver}} driver based on existing profile": "Utilisation du pilote {{.driver}} basé sur le profil existant",
 	"Using the {{.driver}} driver based on user configuration": "Utilisation du pilote {{.driver}} basé sur la configuration de l'utilisateur",
 	"Using {{.driver_name}} driver with root privileges": "Utilisation du pilote {{.driver_name}} avec le privilège root",

translations/ja.json

@@ -824,6 +824,7 @@
 	"Using rootless driver was required, but the current driver does not seem rootless": "rootless ドライバー使用が必要でしたが、現在のドライバーは rootless が必要ないようです",
 	"Using rootless {{.driver_name}} driver": "rootless {{.driver_name}} ドライバー使用",
 	"Using the '{{.runtime}}' runtime with the 'none' driver is an untested configuration!": "' none' ドライバーでの '{{.runtime}}' ランタイム使用は、未テストの設定です！",
+	"Using the docker-env command with the containerd runtime is a highly experimental feature, please provide feedback or contribute to make it better": "",
 	"Using the {{.driver}} driver based on existing profile": "既存のプロファイルを元に、{{.driver}} ドライバーを使用します",
 	"Using the {{.driver}} driver based on user configuration": "ユーザーの設定に基づいて {{.driver}} ドライバーを使用します",
 	"Using {{.driver_name}} driver with root privileges": "root 権限を持つ {{.driver_name}} ドライバーを使用",

translations/ko.json

@@ -716,7 +716,6 @@
 	"The control plane node must be running for this command": "컨트롤 플레인 노드는 실행 상태여야 합니다",
 	"The cri socket path to be used.": "",
 	"The docker-env command is incompatible with multi-node clusters. Use the 'registry' add-on: https://minikube.sigs.k8s.io/docs/handbook/registry/": "",
-	"The docker-env command is only compatible with the \"docker\" runtime, but this cluster was configured to use the \"{{.runtime}}\" runtime.": "",
 	"The driver '{{.driver}}' is not supported on {{.os}}/{{.arch}}": "",
 	"The existing \"{{.name}}\" cluster was created using the \"{{.old}}\" driver, which is incompatible with requested \"{{.new}}\" driver.": "",
 	"The existing node configuration appears to be corrupt. Run 'minikube delete'": "",
@@ -877,6 +876,7 @@
 	"Using rootless driver was required, but the current driver does not seem rootless": "",
 	"Using rootless {{.driver_name}} driver": "",
 	"Using the '{{.runtime}}' runtime with the 'none' driver is an untested configuration!": "",
+	"Using the docker-env command with the containerd runtime is a highly experimental feature, please provide feedback or contribute to make it better": "",
 	"Using the {{.driver}} driver based on existing profile": "기존 프로필에 기반하여 {{.driver}} 드라이버를 사용하는 중",
 	"Using the {{.driver}} driver based on user configuration": "유저 환경 설정 정보에 기반하여 {{.driver}} 드라이버를 사용하는 중",
 	"Using {{.driver_name}} driver with root privileges": "",

translations/pl.json

@@ -724,7 +724,6 @@
 	"The cri socket path to be used.": "",
 	"The docker service is currently not active": "Serwis docker jest nieaktywny",
 	"The docker-env command is incompatible with multi-node clusters. Use the 'registry' add-on: https://minikube.sigs.k8s.io/docs/handbook/registry/": "",
-	"The docker-env command is only compatible with the \"docker\" runtime, but this cluster was configured to use the \"{{.runtime}}\" runtime.": "",
 	"The driver '{{.driver}}' is not supported on {{.os}}/{{.arch}}": "Sterownik '{{.driver}} jest niewspierany przez system {{.os}}/{{.arch}}",
 	"The existing \"{{.name}}\" cluster was created using the \"{{.old}}\" driver, which is incompatible with requested \"{{.new}}\" driver.": "",
 	"The existing node configuration appears to be corrupt. Run 'minikube delete'": "",
@@ -887,6 +886,7 @@
 	"Using rootless driver was required, but the current driver does not seem rootless": "",
 	"Using rootless {{.driver_name}} driver": "",
 	"Using the '{{.runtime}}' runtime with the 'none' driver is an untested configuration!": "",
+	"Using the docker-env command with the containerd runtime is a highly experimental feature, please provide feedback or contribute to make it better": "",
 	"Using the {{.driver}} driver based on existing profile": "",
 	"Using the {{.driver}} driver based on user configuration": "",
 	"Using {{.driver_name}} driver with root privileges": "",

translations/ru.json

@@ -658,7 +658,6 @@
 	"The control plane node must be running for this command": "",
 	"The cri socket path to be used.": "",
 	"The docker-env command is incompatible with multi-node clusters. Use the 'registry' add-on: https://minikube.sigs.k8s.io/docs/handbook/registry/": "",
-	"The docker-env command is only compatible with the \"docker\" runtime, but this cluster was configured to use the \"{{.runtime}}\" runtime.": "",
 	"The driver '{{.driver}}' is not supported on {{.os}}/{{.arch}}": "",
 	"The existing \"{{.name}}\" cluster was created using the \"{{.old}}\" driver, which is incompatible with requested \"{{.new}}\" driver.": "",
 	"The existing node configuration appears to be corrupt. Run 'minikube delete'": "",
@@ -813,6 +812,7 @@
 	"Using rootless driver was required, but the current driver does not seem rootless": "",
 	"Using rootless {{.driver_name}} driver": "",
 	"Using the '{{.runtime}}' runtime with the 'none' driver is an untested configuration!": "",
+	"Using the docker-env command with the containerd runtime is a highly experimental feature, please provide feedback or contribute to make it better": "",
 	"Using the {{.driver}} driver based on existing profile": "Используется драйвер {{.driver}} на основе существующего профиля",
 	"Using the {{.driver}} driver based on user configuration": "Используется драйвер {{.driver}} на основе конфига пользователя",
 	"Using {{.driver_name}} driver with root privileges": "",

translations/strings.txt

@@ -658,7 +658,6 @@
 	"The control plane node must be running for this command": "",
 	"The cri socket path to be used.": "",
 	"The docker-env command is incompatible with multi-node clusters. Use the 'registry' add-on: https://minikube.sigs.k8s.io/docs/handbook/registry/": "",
-	"The docker-env command is only compatible with the \"docker\" runtime, but this cluster was configured to use the \"{{.runtime}}\" runtime.": "",
 	"The driver '{{.driver}}' is not supported on {{.os}}/{{.arch}}": "",
 	"The existing \"{{.name}}\" cluster was created using the \"{{.old}}\" driver, which is incompatible with requested \"{{.new}}\" driver.": "",
 	"The existing node configuration appears to be corrupt. Run 'minikube delete'": "",
@@ -813,6 +812,7 @@
 	"Using rootless driver was required, but the current driver does not seem rootless": "",
 	"Using rootless {{.driver_name}} driver": "",
 	"Using the '{{.runtime}}' runtime with the 'none' driver is an untested configuration!": "",
+	"Using the docker-env command with the containerd runtime is a highly experimental feature, please provide feedback or contribute to make it better": "",
 	"Using the {{.driver}} driver based on existing profile": "",
 	"Using the {{.driver}} driver based on user configuration": "",
 	"Using {{.driver_name}} driver with root privileges": "",

translations/zh-CN.json

@@ -989,6 +989,7 @@
 	"Using rootless driver was required, but the current driver does not seem rootless": "",
 	"Using rootless {{.driver_name}} driver": "",
 	"Using the '{{.runtime}}' runtime with the 'none' driver is an untested configuration!": "同时使用 'none' 驱动以及 '{{.runtime}}' 运行时是未经测试过的配置！",
+	"Using the docker-env command with the containerd runtime is a highly experimental feature, please provide feedback or contribute to make it better": "",
 	"Using the running {{.driver_name}} \"{{.profile_name}}\" VM ...": "使用正在运行的 {{.driver_name}} \"{{.profile_name}}\" 虚拟机",
 	"Using the {{.driver}} driver based on existing profile": "根据现有的配置文件使用 {{.driver}} 驱动程序",
 	"Using the {{.driver}} driver based on user configuration": "根据用户配置使用 {{.driver}} 驱动程序",