fix(docker): preserve Docker client context and improve preflight diagnostics

cmd/internal/agentworkspace/up.go

@@ -421,7 +421,7 @@ func (w *workspaceInitializer) ensureDockerInstalled(ctx context.Context) (strin
 	dockerCmd := w.getDockerCommand()
 
 	if command.Exists(dockerCmd) {
-		log.Debug("docker command exists, skipping installation")
+		log.Debug("docker CLI found")
 		return "", nil
 	}
 

e2e/e2e_suite_test.go

@@ -14,6 +14,7 @@ import (
 	_ "github.com/devsy-org/devsy/e2e/tests/configread"
 	_ "github.com/devsy-org/devsy/e2e/tests/context"
 	_ "github.com/devsy-org/devsy/e2e/tests/delivery"
+	_ "github.com/devsy-org/devsy/e2e/tests/dockercontext"
 	_ "github.com/devsy-org/devsy/e2e/tests/dockerinstall"
 	_ "github.com/devsy-org/devsy/e2e/tests/down"
 	_ "github.com/devsy-org/devsy/e2e/tests/exec"

e2e/tests/dockercontext/dockercontext.go

@@ -0,0 +1,144 @@
+package dockercontext
+
+import (
+	"context"
+	"os"
+	"os/exec"
+	"path/filepath"
+
+	"github.com/devsy-org/devsy/e2e/framework"
+	docker "github.com/devsy-org/devsy/pkg/docker"
+	"github.com/onsi/ginkgo/v2"
+	"github.com/onsi/gomega"
+)
+
+var _ = ginkgo.Describe(
+	"docker context test suite",
+	ginkgo.Label("docker-context"),
+	func() {
+		var (
+			initialDir   string
+			dockerHelper *docker.DockerHelper
+			f            *framework.Framework
+		)
+
+		ginkgo.BeforeEach(func(ctx context.Context) {
+			var err error
+			initialDir, err = os.Getwd()
+			framework.ExpectNoError(err)
+
+			dockerHelper = &docker.DockerHelper{DockerCommand: "docker"}
+			if pingErr := dockerHelper.Ping(ctx); pingErr != nil {
+				ginkgo.Skip("docker daemon is unreachable: " + pingErr.Error())
+			}
+
+			f, err = framework.SetupDockerProvider(filepath.Join(initialDir, "bin"), "docker")
+			framework.ExpectNoError(err)
+		})
+
+		ginkgo.It(
+			"persisted non-default Docker context survives credential injection",
+			ginkgo.SpecTimeout(framework.TimeoutShort()),
+			func(ctx context.Context) {
+				const testContextName = "devsy-test"
+
+				_ = exec.CommandContext(ctx, "docker", "context", "rm", testContextName).Run()
+
+				err := exec.CommandContext(
+					ctx,
+					"docker",
+					"context",
+					"create",
+					testContextName,
+					"--docker",
+					"host=unix:///var/run/docker.sock",
+				).Run()
+				framework.ExpectNoError(err)
+				ginkgo.DeferCleanup(func(cleanupCtx context.Context) {
+					_ = exec.CommandContext(cleanupCtx, "docker", "context", "use", "default").Run()
+					_ = exec.CommandContext(cleanupCtx, "docker", "context", "rm", testContextName).
+						Run()
+				})
+
+				err = exec.CommandContext(ctx, "docker", "context", "use", testContextName).Run()
+				framework.ExpectNoError(err)
+
+				origContext, hasContext := os.LookupEnv("DOCKER_CONTEXT")
+				origHost, hasHost := os.LookupEnv("DOCKER_HOST")
+				_ = os.Unsetenv("DOCKER_CONTEXT")
+				_ = os.Unsetenv("DOCKER_HOST")
+				ginkgo.DeferCleanup(func() {
+					if hasContext {
+						_ = os.Setenv("DOCKER_CONTEXT", origContext)
+					}
+					if hasHost {
+						_ = os.Setenv("DOCKER_HOST", origHost)
+					}
+				})
+
+				tempDir, err := framework.CopyToTempDir("tests/up/testdata/docker")
+				framework.ExpectNoError(err)
+				ginkgo.DeferCleanup(framework.CleanupTempDir, initialDir, tempDir)
+				ginkgo.DeferCleanup(f.DevsyWorkspaceDelete, tempDir)
+
+				stdout, stderr, err := f.DevsyUpStreams(ctx, tempDir)
+				framework.ExpectNoError(err)
+
+				combined := stdout + "\n" + stderr
+				gomega.Expect(combined).To(gomega.ContainSubstring("context=" + testContextName))
+			},
+		)
+
+		ginkgo.It(
+			"explicit DOCKER_CONTEXT overrides the persisted default",
+			ginkgo.SpecTimeout(framework.TimeoutShort()),
+			func(ctx context.Context) {
+				const explicitContextName = "devsy-test-explicit"
+
+				_ = exec.CommandContext(ctx, "docker", "context", "rm", explicitContextName).Run()
+
+				err := exec.CommandContext(
+					ctx,
+					"docker",
+					"context",
+					"create",
+					explicitContextName,
+					"--docker",
+					"host=unix:///var/run/docker.sock",
+				).Run()
+				framework.ExpectNoError(err)
+				ginkgo.DeferCleanup(func(cleanupCtx context.Context) {
+					_ = exec.CommandContext(cleanupCtx, "docker", "context", "rm", explicitContextName).
+						Run()
+				})
+
+				err = exec.CommandContext(ctx, "docker", "context", "use", "default").Run()
+				framework.ExpectNoError(err)
+
+				origContext, hasContext := os.LookupEnv("DOCKER_CONTEXT")
+				_ = os.Setenv("DOCKER_CONTEXT", explicitContextName)
+				ginkgo.DeferCleanup(func() {
+					if hasContext {
+						_ = os.Setenv("DOCKER_CONTEXT", origContext)
+					} else {
+						_ = os.Unsetenv("DOCKER_CONTEXT")
+					}
+				})
+
+				tempDir, err := framework.CopyToTempDir("tests/up/testdata/docker")
+				framework.ExpectNoError(err)
+				ginkgo.DeferCleanup(framework.CleanupTempDir, initialDir, tempDir)
+				ginkgo.DeferCleanup(f.DevsyWorkspaceDelete, tempDir)
+
+				stdout, stderr, err := f.DevsyUpStreams(ctx, tempDir)
+				framework.ExpectNoError(err)
+
+				combined := stdout + "\n" + stderr
+				gomega.Expect(combined).
+					To(gomega.ContainSubstring("context=" + explicitContextName))
+				gomega.Expect(combined).
+					To(gomega.ContainSubstring("docker_context=" + explicitContextName))
+			},
+		)
+	},
+)

pkg/docker/helper.go

@@ -178,6 +178,50 @@ func runCmdCombined(ctx context.Context, cmd *exec.Cmd) error {
 	return nil
 }
 
+const envUnset = "<unset>"
+
+// RuntimeDiagnostics resolves information about the effective docker runtime configuration.
+func (r *DockerHelper) RuntimeDiagnostics(ctx context.Context) map[string]string {
+	cctx, cancel := context.WithTimeout(ctx, 5*time.Second)
+	defer cancel()
+
+	diagnostics := map[string]string{
+		"command":        r.DockerCommand,
+		"docker_config":  resolveEnvValue(r.Environment, "DOCKER_CONFIG"),
+		"docker_host":    resolveEnvValue(r.Environment, "DOCKER_HOST"),
+		"docker_context": resolveEnvValue(r.Environment, "DOCKER_CONTEXT"),
+	}
+
+	if r.IsPodman() {
+		runtimeDiagnosticsPodman(r, diagnostics)
+		return diagnostics
+	}
+
+	r.runtimeDiagnosticsDocker(cctx, diagnostics)
+	return diagnostics
+}
+
+func resolveEnvValue(env []string, key string) string {
+	if val, ok := envValue(env, key); ok {
+		return val
+	}
+	if val := os.Getenv(key); val != "" {
+		return val
+	}
+	return envUnset
+}
+
+func runtimeDiagnosticsPodman(r *DockerHelper, diag map[string]string) {
+	diag["context"] = "<not applicable>"
+	if host := resolveEnvValue(r.Environment, "CONTAINER_HOST"); host != envUnset {
+		diag["endpoint"] = host
+	} else if host := resolveEnvValue(r.Environment, "DOCKER_HOST"); host != envUnset {
+		diag["endpoint"] = host
+	} else {
+		diag["endpoint"] = "<not applicable>"
+	}
+}
+
 // Ping reports whether the runtime daemon is reachable, returning its own
 // message (e.g. "Cannot connect to Podman") on failure. It runs a bare `info`
 // and judges reachability by exit status: `--format` field names differ
@@ -762,6 +806,70 @@ func (r *DockerHelper) buildCmd(ctx context.Context, args ...string) *exec.Cmd {
 	return cmd
 }
 
+func (r *DockerHelper) resolveDockerContext(ctx context.Context, envContext string) string {
+	if envContext != envUnset {
+		return envContext
+	}
+	out, err := r.buildCmd(ctx, "context", "show").Output()
+	if err == nil {
+		if cur := strings.TrimSpace(string(out)); cur != "" {
+			return cur
+		}
+	}
+	return "default"
+}
+
+func (r *DockerHelper) getEndpointFromContext(ctx context.Context, contextName string) string {
+	out, err := r.buildCmd(
+		ctx,
+		"context",
+		"inspect",
+		contextName,
+		"--format",
+		"{{.Endpoints.docker.Host}}",
+	).Output()
+	if err == nil {
+		if endpoint := strings.TrimSpace(string(out)); endpoint != "" && endpoint != "<no value>" {
+			return endpoint
+		}
+	}
+	return ""
+}
+
+func (r *DockerHelper) endpointForContext(ctx context.Context, contextName string) string {
+	if ep := r.getEndpointFromContext(ctx, contextName); ep != "" {
+		return ep
+	}
+	if contextName == "default" {
+		return "unix:///var/run/docker.sock"
+	}
+	return "<unknown>"
+}
+
+func (r *DockerHelper) resolveDockerEndpoint(
+	ctx context.Context,
+	activeContext, envContext, dockerHost string,
+) string {
+	if envContext != envUnset {
+		return r.endpointForContext(ctx, envContext)
+	}
+	if dockerHost != envUnset {
+		return dockerHost
+	}
+	return r.endpointForContext(ctx, activeContext)
+}
+
+func (r *DockerHelper) runtimeDiagnosticsDocker(ctx context.Context, diag map[string]string) {
+	activeContext := r.resolveDockerContext(ctx, diag["docker_context"])
+	diag["context"] = activeContext
+	diag["endpoint"] = r.resolveDockerEndpoint(
+		ctx,
+		activeContext,
+		diag["docker_context"],
+		diag["docker_host"],
+	)
+}
+
 // PrepareForGroupCancellation sets the Cancel function of the given exec.Cmd
 // to kill the entire process group, allowing for cleanup of child processes.
 // This is necessary because exec.Cmd does not automatically kill child processes