feat(config): add local-path extends support for devcontainer.json

.github/workflows/pr-ci.yml

@@ -192,6 +192,18 @@ jobs:
             install-kind: false
             requires-secret: false
 
+          - label: extends
+            runner: ubuntu-latest
+            free-disk-space: false
+            install-kind: false
+            requires-secret: false
+
+          - label: extends-up
+            runner: ubuntu-latest
+            free-disk-space: false
+            install-kind: false
+            requires-secret: false
+
           - label: down
             runner: ubuntu-latest
             free-disk-space: false

e2e/e2e_suite_test.go

@@ -13,6 +13,8 @@ import (
 	_ "github.com/devsy-org/devsy/e2e/tests/dockerinstall"
 	_ "github.com/devsy-org/devsy/e2e/tests/down"
 	_ "github.com/devsy-org/devsy/e2e/tests/exec"
+	_ "github.com/devsy-org/devsy/e2e/tests/extends"
+	_ "github.com/devsy-org/devsy/e2e/tests/extends-up"
 	_ "github.com/devsy-org/devsy/e2e/tests/ide"
 	_ "github.com/devsy-org/devsy/e2e/tests/integration"
 	_ "github.com/devsy-org/devsy/e2e/tests/logs"

e2e/tests/extends-up/extends_up.go

@@ -0,0 +1,45 @@
+package extendsup
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/devsy-org/devsy/e2e/framework"
+	"github.com/onsi/ginkgo/v2"
+	"github.com/onsi/gomega"
+)
+
+var _ = ginkgo.Describe("extends up", ginkgo.Label("extends-up"), func() {
+	var initialDir string
+
+	ginkgo.BeforeEach(func() {
+		var err error
+		initialDir, err = os.Getwd()
+		framework.ExpectNoError(err)
+	})
+
+	ginkgo.It("starts container with merged config from extends chain", func(ctx context.Context) {
+		f, err := framework.SetupDockerProvider(filepath.Join(initialDir, "bin"), "docker")
+		framework.ExpectNoError(err)
+
+		tempDir, err := framework.CopyToTempDir("tests/extends-up/testdata/up-extends")
+		framework.ExpectNoError(err)
+		ginkgo.DeferCleanup(framework.CleanupTempDir, initialDir, tempDir)
+		ginkgo.DeferCleanup(f.DevsyWorkspaceDelete, tempDir)
+
+		err = f.DevsyUp(ctx, tempDir)
+		framework.ExpectNoError(err)
+
+		// Verify env from parent (base.json)
+		out, err := f.DevsySSH(ctx, tempDir, "echo -n $FROM_BASE")
+		framework.ExpectNoError(err)
+		gomega.Expect(strings.TrimSpace(out)).To(gomega.Equal("base-value"))
+
+		// Verify env from child (devcontainer.json)
+		out, err = f.DevsySSH(ctx, tempDir, "echo -n $FROM_CHILD")
+		framework.ExpectNoError(err)
+		gomega.Expect(strings.TrimSpace(out)).To(gomega.Equal("child-value"))
+	}, ginkgo.SpecTimeout(framework.TimeoutLong()))
+})

e2e/tests/extends-up/testdata/up-extends/.devcontainer/base.json

@@ -0,0 +1,6 @@
+{
+  "image": "ghcr.io/devsy-org/test-images/go:1",
+  "containerEnv": {
+    "FROM_BASE": "base-value"
+  }
+}

e2e/tests/extends-up/testdata/up-extends/.devcontainer/devcontainer.json

@@ -0,0 +1,7 @@
+{
+  "extends": "base.json",
+  "name": "extends-up-test",
+  "containerEnv": {
+    "FROM_CHILD": "child-value"
+  }
+}

e2e/tests/extends/extends.go

@@ -0,0 +1,164 @@
+package extends
+
+import (
+	"context"
+	"encoding/json"
+	"os"
+
+	"github.com/devsy-org/devsy/e2e/framework"
+	"github.com/onsi/ginkgo/v2"
+	"github.com/onsi/gomega"
+)
+
+var _ = ginkgo.Describe("extends property", ginkgo.Label("extends"), func() {
+	var initialDir string
+
+	ginkgo.BeforeEach(func() {
+		var err error
+		initialDir, err = os.Getwd()
+		framework.ExpectNoError(err)
+	})
+
+	ginkgo.It("resolves single-level extends inheriting parent fields", func(ctx context.Context) {
+		f := framework.NewDefaultFramework(initialDir + "/bin")
+		tempDir, err := framework.CopyToTempDirWithoutChdir(
+			"tests/extends/testdata/single-level",
+		)
+		framework.ExpectNoError(err)
+		ginkgo.DeferCleanup(func() { _ = os.RemoveAll(tempDir) })
+
+		stdout, _, err := readConfiguration(ctx, f, tempDir)
+		framework.ExpectNoError(err)
+
+		config := parseConfigFromOutput(stdout)
+		gomega.Expect(config).To(gomega.HaveKeyWithValue("name", "Single Level Child"))
+		gomega.Expect(config).To(
+			gomega.HaveKeyWithValue("image", "mcr.microsoft.com/devcontainers/base:ubuntu"),
+		)
+		gomega.Expect(config).To(gomega.HaveKeyWithValue("remoteUser", "vscode"))
+	}, ginkgo.SpecTimeout(framework.TimeoutShort()))
+
+	ginkgo.It("deep merges map fields from parent and child", func(ctx context.Context) {
+		f := framework.NewDefaultFramework(initialDir + "/bin")
+		tempDir, err := framework.CopyToTempDirWithoutChdir(
+			"tests/extends/testdata/deep-merge",
+		)
+		framework.ExpectNoError(err)
+		ginkgo.DeferCleanup(func() { _ = os.RemoveAll(tempDir) })
+
+		stdout, _, err := readConfiguration(ctx, f, tempDir)
+		framework.ExpectNoError(err)
+
+		config := parseConfigFromOutput(stdout)
+		gomega.Expect(config).To(gomega.HaveKeyWithValue("name", "Deep Merge Child"))
+
+		containerEnv, ok := config["containerEnv"].(map[string]any)
+		gomega.Expect(ok).To(gomega.BeTrue(), "containerEnv should be an object")
+		gomega.Expect(containerEnv).To(gomega.HaveKeyWithValue("SHARED_KEY", "from-child"))
+		gomega.Expect(containerEnv).To(gomega.HaveKeyWithValue("BASE_ONLY", "base-value"))
+		gomega.Expect(containerEnv).To(gomega.HaveKeyWithValue("CHILD_ONLY", "child-value"))
+
+		features, ok := config["features"].(map[string]any)
+		gomega.Expect(ok).To(gomega.BeTrue(), "features should be an object")
+		gomega.Expect(features).To(gomega.HaveKey("ghcr.io/devcontainers/features/node:1"))
+		gomega.Expect(features).To(gomega.HaveKey("ghcr.io/devcontainers/features/go:1"))
+	}, ginkgo.SpecTimeout(framework.TimeoutShort()))
+
+	ginkgo.It("replaces array fields entirely from child", func(ctx context.Context) {
+		f := framework.NewDefaultFramework(initialDir + "/bin")
+		tempDir, err := framework.CopyToTempDirWithoutChdir(
+			"tests/extends/testdata/array-replace",
+		)
+		framework.ExpectNoError(err)
+		ginkgo.DeferCleanup(func() { _ = os.RemoveAll(tempDir) })
+
+		stdout, _, err := readConfiguration(ctx, f, tempDir)
+		framework.ExpectNoError(err)
+
+		config := parseConfigFromOutput(stdout)
+		gomega.Expect(config).To(gomega.HaveKeyWithValue("name", "Array Replace Child"))
+		gomega.Expect(config).To(
+			gomega.HaveKeyWithValue("image", "mcr.microsoft.com/devcontainers/base:ubuntu"),
+		)
+
+		forwardPorts, ok := config["forwardPorts"].([]any)
+		gomega.Expect(ok).To(gomega.BeTrue(), "forwardPorts should be an array")
+		gomega.Expect(forwardPorts).To(gomega.HaveLen(1))
+		gomega.Expect(forwardPorts[0]).To(gomega.Equal("8080"))
+
+		// capAdd from parent should remain since child didn't set it
+		capAdd, ok := config["capAdd"].([]any)
+		gomega.Expect(ok).To(gomega.BeTrue(), "capAdd should be inherited from parent")
+		gomega.Expect(capAdd).To(gomega.ContainElement("SYS_PTRACE"))
+	}, ginkgo.SpecTimeout(framework.TimeoutShort()))
+
+	ginkgo.It("resolves multi-level extends chain", func(ctx context.Context) {
+		f := framework.NewDefaultFramework(initialDir + "/bin")
+		tempDir, err := framework.CopyToTempDirWithoutChdir(
+			"tests/extends/testdata/multi-level",
+		)
+		framework.ExpectNoError(err)
+		ginkgo.DeferCleanup(func() { _ = os.RemoveAll(tempDir) })
+
+		stdout, _, err := readConfiguration(ctx, f, tempDir)
+		framework.ExpectNoError(err)
+
+		config := parseConfigFromOutput(stdout)
+		gomega.Expect(config).To(gomega.HaveKeyWithValue("name", "Multi Level Child"))
+		gomega.Expect(config).To(
+			gomega.HaveKeyWithValue("image", "mcr.microsoft.com/devcontainers/base:ubuntu"),
+		)
+		gomega.Expect(config).To(gomega.HaveKeyWithValue("remoteUser", "vscode"))
+
+		containerEnv, ok := config["containerEnv"].(map[string]any)
+		gomega.Expect(ok).To(gomega.BeTrue(), "containerEnv should be an object")
+		gomega.Expect(containerEnv).To(gomega.HaveKeyWithValue("LEVEL", "child"))
+		gomega.Expect(containerEnv).To(gomega.HaveKeyWithValue("PARENT_ONLY", "parent-value"))
+		gomega.Expect(containerEnv).To(gomega.HaveKeyWithValue("GP_ONLY", "gp-value"))
+	}, ginkgo.SpecTimeout(framework.TimeoutShort()))
+
+	ginkgo.It("returns error on circular extends", func(ctx context.Context) {
+		f := framework.NewDefaultFramework(initialDir + "/bin")
+		tempDir, err := framework.CopyToTempDirWithoutChdir(
+			"tests/extends/testdata/cycle",
+		)
+		framework.ExpectNoError(err)
+		ginkgo.DeferCleanup(func() { _ = os.RemoveAll(tempDir) })
+
+		_, _, err = readConfiguration(ctx, f, tempDir)
+		framework.ExpectError(err)
+	}, ginkgo.SpecTimeout(framework.TimeoutShort()))
+
+	ginkgo.It("returns error when extends references missing file", func(ctx context.Context) {
+		f := framework.NewDefaultFramework(initialDir + "/bin")
+		tempDir, err := framework.CopyToTempDirWithoutChdir(
+			"tests/extends/testdata/missing-file",
+		)
+		framework.ExpectNoError(err)
+		ginkgo.DeferCleanup(func() { _ = os.RemoveAll(tempDir) })
+
+		_, _, err = readConfiguration(ctx, f, tempDir)
+		framework.ExpectError(err)
+	}, ginkgo.SpecTimeout(framework.TimeoutShort()))
+})
+
+func readConfiguration(
+	ctx context.Context,
+	f *framework.Framework,
+	workspaceFolder string,
+) (string, string, error) {
+	return f.ExecCommandCapture(ctx, []string{
+		"read-configuration",
+		"--workspace-folder", workspaceFolder,
+	})
+}
+
+func parseConfigFromOutput(stdout string) map[string]any {
+	var result map[string]any
+	err := json.Unmarshal([]byte(stdout), &result)
+	framework.ExpectNoError(err, "output should be valid JSON")
+
+	config, ok := result["configuration"].(map[string]any)
+	gomega.Expect(ok).To(gomega.BeTrue(), "configuration should be an object")
+	return config
+}

e2e/tests/extends/testdata/array-replace/.devcontainer/base.json

@@ -0,0 +1,5 @@
+{
+  "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
+  "forwardPorts": [3000, 4000],
+  "capAdd": ["SYS_PTRACE"]
+}

e2e/tests/extends/testdata/array-replace/.devcontainer/devcontainer.json

@@ -0,0 +1,5 @@
+{
+  "extends": "base.json",
+  "name": "Array Replace Child",
+  "forwardPorts": [8080]
+}

e2e/tests/extends/testdata/cycle/.devcontainer/devcontainer.json

@@ -0,0 +1,4 @@
+{
+  "extends": "other.json",
+  "name": "Cycle A"
+}

e2e/tests/extends/testdata/cycle/.devcontainer/other.json

@@ -0,0 +1,4 @@
+{
+  "extends": "devcontainer.json",
+  "name": "Cycle B"
+}

e2e/tests/extends/testdata/deep-merge/.devcontainer/base.json

@@ -0,0 +1,12 @@
+{
+  "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
+  "containerEnv": {
+    "SHARED_KEY": "from-base",
+    "BASE_ONLY": "base-value"
+  },
+  "features": {
+    "ghcr.io/devcontainers/features/node:1": {
+      "version": "18"
+    }
+  }
+}

e2e/tests/extends/testdata/deep-merge/.devcontainer/devcontainer.json

@@ -0,0 +1,13 @@
+{
+  "extends": "base.json",
+  "name": "Deep Merge Child",
+  "containerEnv": {
+    "SHARED_KEY": "from-child",
+    "CHILD_ONLY": "child-value"
+  },
+  "features": {
+    "ghcr.io/devcontainers/features/go:1": {
+      "version": "1.21"
+    }
+  }
+}

e2e/tests/extends/testdata/missing-file/.devcontainer/devcontainer.json

@@ -0,0 +1,4 @@
+{
+  "extends": "nonexistent.json",
+  "name": "Missing File"
+}

e2e/tests/extends/testdata/multi-level/.devcontainer/devcontainer.json

@@ -0,0 +1,7 @@
+{
+  "extends": "parent.json",
+  "name": "Multi Level Child",
+  "containerEnv": {
+    "LEVEL": "child"
+  }
+}

e2e/tests/extends/testdata/multi-level/.devcontainer/grandparent.json

@@ -0,0 +1,8 @@
+{
+  "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
+  "remoteUser": "vscode",
+  "containerEnv": {
+    "LEVEL": "grandparent",
+    "GP_ONLY": "gp-value"
+  }
+}

e2e/tests/extends/testdata/multi-level/.devcontainer/parent.json

@@ -0,0 +1,7 @@
+{
+  "extends": "grandparent.json",
+  "containerEnv": {
+    "LEVEL": "parent",
+    "PARENT_ONLY": "parent-value"
+  }
+}

e2e/tests/extends/testdata/single-level/.devcontainer/base.json

@@ -0,0 +1,7 @@
+{
+  "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
+  "remoteUser": "vscode",
+  "containerEnv": {
+    "BASE_VAR": "from-base"
+  }
+}

e2e/tests/extends/testdata/single-level/.devcontainer/devcontainer.json

@@ -0,0 +1,4 @@
+{
+  "extends": "base.json",
+  "name": "Single Level Child"
+}

pkg/devcontainer/config/config.go

@@ -45,6 +45,9 @@ func CloneDevContainerConfig(config *DevContainerConfig) *DevContainerConfig {
 }
 
 type DevContainerConfigBase struct {
+	// Path to another devcontainer.json to inherit from.
+	Extends string `json:"extends,omitempty"`
+
 	// A name for the dev container which can be displayed to the user.
 	Name string `json:"name,omitempty"`