feat: Add pause container support (runfinch#185)

Signed-off-by: Arjun Raja Yogidas <arjunry@amazon.com>

Author: coderbirju

Makefile

@@ -3,7 +3,7 @@
 
 GINKGO = go run github.com/onsi/ginkgo/v2/ginkgo
 # Common ginkgo options: -v for verbose mode, --focus="test name" for running single tests
-GFLAGS ?= --race --randomize-all --randomize-suites --vv
+GFLAGS ?= --race --randomize-all --randomize-suites 
 BIN = $(PWD)/bin
 FINCH_DAEMON_PROJECT_ROOT ?= $(shell pwd)
 

api/handlers/container/container.go

@@ -36,6 +36,7 @@ type Service interface {
 	Stats(ctx context.Context, cid string) (<-chan *types.StatsJSON, error)
 	ExecCreate(ctx context.Context, cid string, config types.ExecConfig) (string, error)
 	Kill(ctx context.Context, cid string, options ncTypes.ContainerKillOptions) error
+	Pause(ctx context.Context, cid string, options ncTypes.ContainerPauseOptions) error
 }
 
 // RegisterHandlers register all the supported endpoints related to the container APIs.
@@ -60,6 +61,7 @@ func RegisterHandlers(r types.VersionedRouter, service Service, conf *config.Con
 	r.HandleFunc("/{id:.*}/stats", h.stats, http.MethodGet)
 	r.HandleFunc("/{id:.*}/exec", h.exec, http.MethodPost)
 	r.HandleFunc("/{id:.*}/kill", h.kill, http.MethodPost)
+	r.HandleFunc("/{id:.*}/pause", h.pause, http.MethodPost)
 }
 
 // newHandler creates the handler that serves all the container related APIs.

api/handlers/container/pause.go

@@ -0,0 +1,57 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package container
+
+import (
+	"net/http"
+	"os"
+
+	"github.com/containerd/containerd/v2/pkg/namespaces"
+	ncTypes "github.com/containerd/nerdctl/v2/pkg/api/types"
+	"github.com/gorilla/mux"
+
+	"github.com/runfinch/finch-daemon/api/response"
+	"github.com/runfinch/finch-daemon/pkg/errdefs"
+)
+
+// pause pauses a running container.
+func (h *handler) pause(w http.ResponseWriter, r *http.Request) {
+	cid, ok := mux.Vars(r)["id"]
+	if !ok || cid == "" {
+		response.JSON(w, http.StatusBadRequest, response.NewErrorFromMsg("must specify a container ID"))
+		return
+	}
+
+	ctx := namespaces.WithNamespace(r.Context(), h.Config.Namespace)
+
+	devNull, err := os.OpenFile("/dev/null", os.O_WRONLY, 0600)
+	if err != nil {
+		response.JSON(w, http.StatusBadRequest, response.NewErrorFromMsg("failed to open /dev/null"))
+		return
+	}
+	defer devNull.Close()
+
+	globalOpt := ncTypes.GlobalCommandOptions(*h.Config)
+	options := ncTypes.ContainerPauseOptions{
+		GOptions: globalOpt,
+		Stdout:   devNull,
+	}
+
+	err = h.service.Pause(ctx, cid, options)
+	if err != nil {
+		var code int
+		switch {
+		case errdefs.IsNotFound(err):
+			code = http.StatusNotFound
+		case errdefs.IsConflict(err):
+			code = http.StatusConflict
+		default:
+			code = http.StatusInternalServerError
+		}
+		response.JSON(w, code, response.NewError(err))
+		return
+	}
+
+	response.Status(w, http.StatusNoContent)
+}

api/handlers/container/pause_test.go

@@ -0,0 +1,110 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package container
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+
+	ncTypes "github.com/containerd/nerdctl/v2/pkg/api/types"
+	"github.com/containerd/nerdctl/v2/pkg/config"
+	"github.com/golang/mock/gomock"
+	"github.com/gorilla/mux"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+	"github.com/runfinch/finch-daemon/pkg/errdefs"
+
+	"github.com/runfinch/finch-daemon/mocks/mocks_container"
+	"github.com/runfinch/finch-daemon/mocks/mocks_logger"
+)
+
+var _ = Describe("Container Pause API", func() {
+	var (
+		mockCtrl *gomock.Controller
+		logger   *mocks_logger.Logger
+		service  *mocks_container.MockService
+		h        *handler
+		rr       *httptest.ResponseRecorder
+		_        ncTypes.GlobalCommandOptions
+		_        error
+	)
+
+	BeforeEach(func() {
+		mockCtrl = gomock.NewController(GinkgoT())
+		defer mockCtrl.Finish()
+		logger = mocks_logger.NewLogger(mockCtrl)
+		service = mocks_container.NewMockService(mockCtrl)
+		c := config.Config{}
+		h = newHandler(service, &c, logger)
+		rr = httptest.NewRecorder()
+	})
+
+	Context("pause handler", func() {
+		It("should return 204 No Content on successful pause", func() {
+			req, err := http.NewRequest(http.MethodPost, "/containers/id1/pause", nil)
+			Expect(err).Should(BeNil())
+			req = mux.SetURLVars(req, map[string]string{"id": "id1"})
+
+			service.EXPECT().Pause(gomock.Any(), "id1", gomock.Any()).DoAndReturn(
+				func(ctx context.Context, cid string, opts ncTypes.ContainerPauseOptions) error {
+					return nil
+				})
+
+			h.pause(rr, req)
+			Expect(rr.Body.String()).Should(BeEmpty())
+			Expect(rr).Should(HaveHTTPStatus(http.StatusNoContent))
+		})
+
+		It("should return 400 when container ID is missing", func() {
+			req, err := http.NewRequest(http.MethodPost, "/containers//pause", nil)
+			Expect(err).Should(BeNil())
+			req = mux.SetURLVars(req, map[string]string{"id": ""})
+
+			h.pause(rr, req)
+			Expect(rr.Body).Should(MatchJSON(`{"message": "must specify a container ID"}`))
+			Expect(rr).Should(HaveHTTPStatus(http.StatusBadRequest))
+		})
+
+		It("should return 404 when service returns a not found error", func() {
+			req, err := http.NewRequest(http.MethodPost, "/containers/id1/pause", nil)
+			Expect(err).Should(BeNil())
+			req = mux.SetURLVars(req, map[string]string{"id": "id1"})
+
+			service.EXPECT().Pause(gomock.Any(), "id1", gomock.Any()).Return(
+				errdefs.NewNotFound(fmt.Errorf("container not found")))
+
+			h.pause(rr, req)
+			Expect(rr.Body).Should(MatchJSON(`{"message": "container not found"}`))
+			Expect(rr).Should(HaveHTTPStatus(http.StatusNotFound))
+		})
+
+		It("should return 409 when service returns a conflict error", func() {
+			req, err := http.NewRequest(http.MethodPost, "/containers/id1/pause", nil)
+			Expect(err).Should(BeNil())
+			req = mux.SetURLVars(req, map[string]string{"id": "id1"})
+
+			service.EXPECT().Pause(gomock.Any(), "id1", gomock.Any()).Return(
+				errdefs.NewConflict(fmt.Errorf("container already paused")))
+
+			h.pause(rr, req)
+			Expect(rr.Body).Should(MatchJSON(`{"message": "container already paused"}`))
+			Expect(rr).Should(HaveHTTPStatus(http.StatusConflict))
+		})
+
+		It("should return 500 when service returns an internal error", func() {
+			req, err := http.NewRequest(http.MethodPost, "/containers/id1/pause", nil)
+			Expect(err).Should(BeNil())
+			req = mux.SetURLVars(req, map[string]string{"id": "id1"})
+
+			service.EXPECT().Pause(gomock.Any(), "id1", gomock.Any()).Return(
+				fmt.Errorf("unexpected internal error"))
+
+			h.pause(rr, req)
+			Expect(rr.Body).Should(MatchJSON(`{"message": "unexpected internal error"}`))
+			Expect(rr).Should(HaveHTTPStatus(http.StatusInternalServerError))
+		})
+	})
+})

e2e/e2e_test.go

@@ -52,6 +52,7 @@ func TestRun(t *testing.T) {
 		tests.ContainerKill(opt)
 		tests.ContainerInspect(opt)
 		tests.ContainerWait(opt)
+		tests.ContainerPause(opt)
 
 		// functional test for volume APIs
 		tests.VolumeList(opt)

e2e/tests/container_pause.go

@@ -0,0 +1,90 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package tests
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+	"github.com/runfinch/common-tests/command"
+	"github.com/runfinch/common-tests/option"
+
+	"github.com/runfinch/finch-daemon/api/response"
+	"github.com/runfinch/finch-daemon/e2e/client"
+)
+
+func ContainerPause(opt *option.Option) {
+	Describe("pause a container", func() {
+		var (
+			uClient *http.Client
+			version string
+			apiUrl  string
+		)
+
+		BeforeEach(func() {
+			uClient = client.NewClient(GetDockerHostUrl())
+			version = GetDockerApiVersion()
+			relativeUrl := fmt.Sprintf("/containers/%s/pause", testContainerName)
+			apiUrl = client.ConvertToFinchUrl(version, relativeUrl)
+		})
+
+		AfterEach(func() {
+			command.RemoveAll(opt)
+		})
+
+		It("should pause a running container", func() {
+			// Start a container that keeps running
+			command.Run(opt, "run", "-d", "--name", testContainerName, defaultImage, "sleep", "infinity")
+
+			res, err := uClient.Post(apiUrl, "application/json", nil)
+			Expect(err).Should(BeNil())
+			Expect(res.StatusCode).Should(Equal(http.StatusNoContent))
+
+			// Verify container is paused
+			output := command.StdoutStr(opt, "inspect", "--format", "{{.State.Status}}", testContainerName)
+			Expect(output).Should(Equal("paused"))
+		})
+
+		It("should fail to pause a non-existent container", func() {
+			res, err := uClient.Post(apiUrl, "application/json", nil)
+			Expect(err).Should(BeNil())
+			Expect(res.StatusCode).Should(Equal(http.StatusNotFound))
+
+			var body response.Error
+			err = json.NewDecoder(res.Body).Decode(&body)
+			Expect(err).Should(BeNil())
+		})
+
+		It("should fail to pause a non-running container", func() {
+			command.Run(opt, "create", "--name", testContainerName, defaultImage, "sleep", "infinity")
+
+			res, err := uClient.Post(apiUrl, "application/json", nil)
+			Expect(err).Should(BeNil())
+			Expect(res.StatusCode).Should(Equal(http.StatusConflict))
+
+			var body response.Error
+			err = json.NewDecoder(res.Body).Decode(&body)
+			Expect(err).Should(BeNil())
+
+			containerShouldExist(opt, testContainerName)
+		})
+
+		It("should fail to pause an already paused container", func() {
+			// Start and pause the container
+			command.Run(opt, "run", "-d", "--name", testContainerName, defaultImage, "sleep", "infinity")
+			command.Run(opt, "pause", testContainerName)
+
+			res, err := uClient.Post(apiUrl, "application/json", nil)
+			Expect(err).Should(BeNil())
+			Expect(res.StatusCode).Should(Equal(http.StatusConflict))
+
+			var body response.Error
+			err = json.NewDecoder(res.Body).Decode(&body)
+			Expect(err).Should(BeNil())
+		})
+	})
+}

internal/backend/container.go

@@ -37,6 +37,7 @@ type NerdctlContainerSvc interface {
 	RenameContainer(ctx context.Context, container containerd.Container, newName string, options types.ContainerRenameOptions) error
 	KillContainer(ctx context.Context, cid string, options types.ContainerKillOptions) error
 	ContainerWait(ctx context.Context, cid string, options types.ContainerWaitOptions) error
+	PauseContainer(ctx context.Context, cid string, options types.ContainerPauseOptions) error
 
 	// Mocked functions for container attach
 	GetDataStore() (string, error)
@@ -130,6 +131,10 @@ func (w *NerdctlWrapper) ContainerWait(ctx context.Context, cid string, options
 	return container.Wait(ctx, w.clientWrapper.client, []string{cid}, options)
 }
 
+func (w *NerdctlWrapper) PauseContainer(ctx context.Context, cid string, options types.ContainerPauseOptions) error {
+	return container.Pause(ctx, w.clientWrapper.client, []string{cid}, options)
+}
+
 func (w *NerdctlWrapper) GetNerdctlExe() (string, error) {
 	if w.nerdctlExe != "" {
 		return w.nerdctlExe, nil

internal/service/container/pause.go

@@ -0,0 +1,34 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package container
+
+import (
+	"context"
+	"fmt"
+
+	containerd "github.com/containerd/containerd/v2/client"
+	cerrdefs "github.com/containerd/errdefs"
+	ncTypes "github.com/containerd/nerdctl/v2/pkg/api/types"
+
+	"github.com/runfinch/finch-daemon/pkg/errdefs"
+)
+
+func (s *service) Pause(ctx context.Context, cid string, options ncTypes.ContainerPauseOptions) error {
+	cont, err := s.getContainer(ctx, cid)
+	if err != nil {
+		if cerrdefs.IsNotFound(err) {
+			return errdefs.NewNotFound(err)
+		}
+		return err
+	}
+	status := s.client.GetContainerStatus(ctx, cont)
+	if status != containerd.Running {
+		if status == containerd.Paused {
+			return errdefs.NewConflict(fmt.Errorf("container %s is already paused", cid))
+		}
+		return errdefs.NewConflict(fmt.Errorf("container %s is not running", cid))
+	}
+
+	return s.nctlContainerSvc.PauseContainer(ctx, cid, options)
+}