Fix(connectors): resolve Docker host from active context

pkg/connectors/container_client.go

@@ -36,6 +36,8 @@ import (
 	"github.com/moby/term"
 )
 
+var execCommand = exec.Command
+
 type ContainerClient interface {
 	CreateContainer(opts ContainerOpts) (string, error)
 	StartContainer(containerId string) error
@@ -75,6 +77,10 @@ func NewContainerClient(driver string) (ContainerClient, error) {
 }
 
 func NewDockerClient() (*containerClient, error) {
+	if err := ConfigureDockerHost(); err != nil {
+		return nil, err
+	}
+
 	cli, err := client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation())
 
 	if err != nil {
@@ -102,6 +108,29 @@ func PingDockerHost() error {
 	return err
 }
 
+func ConfigureDockerHost() error {
+	if os.Getenv("DOCKER_HOST") != "" {
+		return nil
+	}
+
+	cmd := execCommand("docker", "context", "inspect", "--format", "{{.Endpoints.docker.Host}}")
+	out, err := cmd.Output()
+	if err != nil {
+		exitError, ok := err.(*exec.ExitError)
+		if ok && exitError.ExitCode() == 1 {
+			return nil
+		}
+		return fmt.Errorf("resolving docker context host: %w", err)
+	}
+
+	dockerHost := strings.TrimSpace(string(out))
+	if dockerHost != "" {
+		return os.Setenv("DOCKER_HOST", dockerHost)
+	}
+
+	return nil
+}
+
 func ConfigurePodmanHost() error {
 	switch runtime.GOOS {
 	case "windows":

pkg/connectors/container_client_test.go

@@ -0,0 +1,112 @@
+package connectors
+
+import (
+	"context"
+	"os"
+	"os/exec"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestConfigureDockerHost(t *testing.T) {
+	oldDockerHost := os.Getenv("DOCKER_HOST")
+	defer func() {
+		if oldDockerHost == "" {
+			os.Unsetenv("DOCKER_HOST")
+		} else {
+			os.Setenv("DOCKER_HOST", oldDockerHost)
+		}
+	}()
+
+	oldExecCommand := execCommand
+	defer func() {
+		execCommand = oldExecCommand
+	}()
+
+	t.Run("sets DOCKER_HOST from docker context", func(t *testing.T) {
+		os.Unsetenv("DOCKER_HOST")
+
+		execCommand = func(name string, args ...string) *exec.Cmd {
+			cmd := exec.Command(
+				os.Args[0],
+				"-test.run=TestHelperProcess",
+				"--",
+				"npipe:////./pipe/dockerDesktopLinuxEngine",
+			)
+			cmd.Env = append(os.Environ(), "GO_WANT_HELPER_PROCESS=1")
+			return cmd
+		}
+
+		require.NoError(t, ConfigureDockerHost())
+		assert.Equal(t, "npipe:////./pipe/dockerDesktopLinuxEngine", os.Getenv("DOCKER_HOST"))
+	})
+
+	t.Run("does not overwrite existing DOCKER_HOST", func(t *testing.T) {
+		require.NoError(t, os.Setenv("DOCKER_HOST", "existing-endpoint"))
+
+		require.NoError(t, ConfigureDockerHost())
+		assert.Equal(t, "existing-endpoint", os.Getenv("DOCKER_HOST"))
+	})
+
+	t.Run("returns error when docker context command fails", func(t *testing.T) {
+		os.Unsetenv("DOCKER_HOST")
+
+		execCommand = func(name string, args ...string) *exec.Cmd {
+			cmd := exec.Command(
+				os.Args[0],
+				"-test.run=TestHelperProcessFailure",
+			)
+			cmd.Env = append(os.Environ(), "GO_WANT_HELPER_PROCESS=1")
+			return cmd
+		}
+
+		err := ConfigureDockerHost()
+		require.Error(t, err)
+		assert.Contains(t, err.Error(), "resolving docker context host")
+	})
+}
+func TestNewDockerClient(t *testing.T) {
+	oldDockerHost := os.Getenv("DOCKER_HOST")
+	defer func() {
+		if oldDockerHost == "" {
+			os.Unsetenv("DOCKER_HOST")
+		} else {
+			os.Setenv("DOCKER_HOST", oldDockerHost)
+		}
+	}()
+
+	os.Unsetenv("DOCKER_HOST")
+
+	dockerClient, err := NewDockerClient()
+	require.NoError(t, err)
+	require.NotNil(t, dockerClient)
+
+	defer dockerClient.cli.Close()
+
+	ctx := context.Background()
+	_, err = dockerClient.cli.Ping(ctx)
+	require.NoError(t, err)
+}
+func TestHelperProcess(t *testing.T) {
+	if os.Getenv("GO_WANT_HELPER_PROCESS") != "1" {
+		return
+	}
+
+	for i, arg := range os.Args {
+		if arg == "--" && i+1 < len(os.Args) {
+			os.Stdout.WriteString(os.Args[i+1])
+			os.Exit(0)
+		}
+	}
+
+	os.Exit(1)
+}
+func TestHelperProcessFailure(t *testing.T) {
+	if os.Getenv("GO_WANT_HELPER_PROCESS") != "1" {
+		return
+	}
+
+	os.Exit(2)
+}