chore: add set docker host by current context

pkg/skaffold/docker/client.go

@@ -22,6 +22,7 @@ import (
 	"fmt"
 	"net/http"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"sort"
 	"strings"
@@ -107,6 +108,21 @@ func newEnvAPIClient() ([]string, client.CommonAPIClient, error) {
 		} else {
 			opts = append(opts, client.FromEnv)
 		}
+	} else {
+		log.Entry(context.TODO()).Infof("DOCKER_HOST env is not set, using the host from docker context.")
+
+		command := exec.Command("docker", "context", "inspect", "--format", "{{.Endpoints.docker.Host}}")
+		out, err := util.RunCmdOut(context.TODO(), command)
+		if err != nil {
+			// docker cli not installed.
+			log.Entry(context.TODO()).Warnf("Could not get docker context: %s, falling back to the default docker host", err)
+		} else {
+			s := strings.TrimSpace(string(out))
+			// output can be empty if user uses docker as alias for podman
+			if len(s) > 0 {
+				opts = append(opts, client.WithHost(s))
+			}
+		}
 	}
 
 	cli, err := client.NewClientWithOpts(opts...)

pkg/skaffold/docker/client_test.go

@@ -32,6 +32,7 @@ func TestNewEnvClient(t *testing.T) {
 	tests := []struct {
 		description string
 		envs        map[string]string
+		command     *testutil.FakeCmd
 		shouldErr   bool
 	}{
 		{
@@ -55,10 +56,28 @@ func TestNewEnvClient(t *testing.T) {
 			},
 			shouldErr: false,
 		},
+		{
+			description: "DOCKER_HOST not set",
+			command:     testutil.CmdRunOut("docker context inspect --format {{.Endpoints.docker.Host}}", ""),
+			shouldErr:   false,
+		},
+		{
+			description: "DOCKER_HOST not set, output invalid host",
+			command:     testutil.CmdRunOut("docker context inspect --format {{.Endpoints.docker.Host}}", "invalid host"),
+			shouldErr:   true,
+		},
+		{
+			description: "DOCKER_HOST not set, ignore error",
+			command:     testutil.CmdRunOutErr("docker context inspect --format {{.Endpoints.docker.Host}}", "", fmt.Errorf("cannot get context")),
+			shouldErr:   false,
+		},
 	}
 	for _, test := range tests {
 		testutil.Run(t, test.description, func(t *testutil.T) {
 			t.SetEnvs(test.envs)
+			if test.command != nil {
+				t.Override(&util.DefaultExecCommand, test.command)
+			}
 
 			env, _, err := newEnvAPIClient()
 
@@ -145,15 +164,18 @@ DOCKER_HOST`),
 		},
 		{
 			description: "minikube exit code 64 (minikube < 1.13.0) - fallback to host docker",
-			command:     testutil.CmdRunOutErr("minikube docker-env --shell none -p minikube", "", fmt.Errorf("fail: %w", &oldBadUsageErr{})),
+			command: testutil.CmdRunOutErr("minikube docker-env --shell none -p minikube", "", fmt.Errorf("fail: %w", &oldBadUsageErr{})).
+				AndRunOut("docker context inspect --format {{.Endpoints.docker.Host}}", ""),
 		},
 		{
 			description: "minikube exit code 51 (minikube >= 1.13.0) - fallback to host docker",
-			command:     testutil.CmdRunOutErr("minikube docker-env --shell none -p minikube", "", fmt.Errorf("fail: %w", &driverConflictErr{})),
+			command: testutil.CmdRunOutErr("minikube docker-env --shell none -p minikube", "", fmt.Errorf("fail: %w", &driverConflictErr{})).
+				AndRunOut("docker context inspect --format {{.Endpoints.docker.Host}}", ""),
 		},
 		{
 			description: "minikube exit code 89 - fallback to host docker",
-			command:     testutil.CmdRunOutErr("minikube docker-env --shell none -p minikube", "", fmt.Errorf("fail: %w", &exGuestUnavailable{})),
+			command: testutil.CmdRunOutErr("minikube docker-env --shell none -p minikube", "", fmt.Errorf("fail: %w", &exGuestUnavailable{})).
+				AndRunOut("docker context inspect --format {{.Endpoints.docker.Host}}", ""),
 		},
 	}
 	for _, test := range tests {

pkg/skaffold/test/structure/structure_test.go

@@ -41,7 +41,7 @@ func TestNewRunner(t *testing.T) {
 			return "", semver.Version{}, errors.New("not found")
 		})
 
-		t.Override(&util.DefaultExecCommand, testutil.CmdRun("container-structure-test test -v warn --image image:tag --config "+tmpDir.Path("test.yaml")))
+		t.Override(&util.DefaultExecCommand, testutil.CmdRunOut("docker context inspect --format {{.Endpoints.docker.Host}}", "").AndRun("container-structure-test test -v warn --image image:tag --config "+tmpDir.Path("test.yaml")))
 
 		testCase := &latest.TestCase{
 			ImageName:      "image",