fix: only send when there are updates

coder · DanielleMaywood · Jul 14, 2025 · Jul 3, 2025 · Jul 7, 2025 · Jul 7, 2025
commit 1768f7b275cc39cb487748efb7b0383e55f2092c
diff --git a/agent/agentcontainers/api.go b/agent/agentcontainers/api.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"maps"
 	"net/http"
 	"os"
 	"path"
@@ -646,13 +647,29 @@ func (api *API) updateContainers(ctx context.Context) error {
 	api.mu.Lock()
 	defer api.mu.Unlock()
 
+	var knownDevcontainers map[string]codersdk.WorkspaceAgentDevcontainer
+	if len(api.updateChans) > 0 {
+		knownDevcontainers = maps.Clone(api.knownDevcontainers)
+	}
+
 	api.processUpdatedContainersLocked(ctx, updated)
 
-	// Broadcast our updates
-	for _, ch := range api.updateChans {
-		select {
-		case ch <- struct{}{}:
-		default:
+	if len(api.updateChans) > 0 {
+		statesAreEqual := maps.EqualFunc(
+			knownDevcontainers,
+			api.knownDevcontainers,
+			func(dc1, dc2 codersdk.WorkspaceAgentDevcontainer) bool {
+				return dc1.Equals(dc2)
+			})
+
+		if !statesAreEqual {
+			// Broadcast our updates
+			for _, ch := range api.updateChans {
+				select {
+				case ch <- struct{}{}:
+				default:
+				}
+			}
 		}
 	}
 

diff --git a/agent/agentcontainers/api_test.go b/agent/agentcontainers/api_test.go
@@ -445,14 +445,95 @@ func TestAPI(t *testing.T) {
 	t.Run("Watch", func(t *testing.T) {
 		t.Parallel()
 
-		fakeContainer1 := fakeContainer(t)
-		fakeContainer2 := fakeContainer(t)
-		fakeContainer3 := fakeContainer(t)
-
 		makeResponse := func(cts ...codersdk.WorkspaceAgentContainer) codersdk.WorkspaceAgentListContainersResponse {
 			return codersdk.WorkspaceAgentListContainersResponse{Containers: cts}
 		}
 
+		fakeContainer1 := fakeContainer(t, func(c *codersdk.WorkspaceAgentContainer) {
+			c.ID = "container1"
+			c.FriendlyName = "devcontainer1"
+			c.Image = "busybox:latest"
+			c.Labels = map[string]string{
+				agentcontainers.DevcontainerLocalFolderLabel: "/home/coder/project1",
+				agentcontainers.DevcontainerConfigFileLabel:  "/home/coder/project1/.devcontainer/devcontainer.json",
+			}
+		})
+
+		fakeContainer2 := fakeContainer(t, func(c *codersdk.WorkspaceAgentContainer) {
+			c.ID = "container2"
+			c.FriendlyName = "devcontainer2"
+			c.Image = "ubuntu:latest"
+			c.Labels = map[string]string{
+				agentcontainers.DevcontainerLocalFolderLabel: "/home/coder/project2",
+				agentcontainers.DevcontainerConfigFileLabel:  "/home/coder/project2/.devcontainer/devcontainer.json",
+			}
+		})
+
+		stages := []struct {
+			containers []codersdk.WorkspaceAgentContainer
+			expected   codersdk.WorkspaceAgentListContainersResponse
+		}{
+			{
+				containers: []codersdk.WorkspaceAgentContainer{fakeContainer1},
+				expected: codersdk.WorkspaceAgentListContainersResponse{
+					Containers: []codersdk.WorkspaceAgentContainer{fakeContainer1},
+					Devcontainers: []codersdk.WorkspaceAgentDevcontainer{
+						{
+							Name:            "project1",
+							WorkspaceFolder: fakeContainer1.Labels[agentcontainers.DevcontainerLocalFolderLabel],
+							ConfigPath:      fakeContainer1.Labels[agentcontainers.DevcontainerConfigFileLabel],
+							Status:          "running",
+							Container:       &fakeContainer1,
+						},
+					},
+				},
+			},
+			{
+				containers: []codersdk.WorkspaceAgentContainer{fakeContainer1, fakeContainer2},
+				expected: codersdk.WorkspaceAgentListContainersResponse{
+					Containers: []codersdk.WorkspaceAgentContainer{fakeContainer1, fakeContainer2},
+					Devcontainers: []codersdk.WorkspaceAgentDevcontainer{
+						{
+							Name:            "project1",
+							WorkspaceFolder: fakeContainer1.Labels[agentcontainers.DevcontainerLocalFolderLabel],
+							ConfigPath:      fakeContainer1.Labels[agentcontainers.DevcontainerConfigFileLabel],
+							Status:          "running",
+							Container:       &fakeContainer1,
+						},
+						{
+							Name:            "project2",
+							WorkspaceFolder: fakeContainer2.Labels[agentcontainers.DevcontainerLocalFolderLabel],
+							ConfigPath:      fakeContainer2.Labels[agentcontainers.DevcontainerConfigFileLabel],
+							Status:          "running",
+							Container:       &fakeContainer2,
+						},
+					},
+				},
+			},
+			{
+				containers: []codersdk.WorkspaceAgentContainer{fakeContainer2},
+				expected: codersdk.WorkspaceAgentListContainersResponse{
+					Containers: []codersdk.WorkspaceAgentContainer{fakeContainer2},
+					Devcontainers: []codersdk.WorkspaceAgentDevcontainer{
+						{
+							Name:            "",
+							WorkspaceFolder: fakeContainer1.Labels[agentcontainers.DevcontainerLocalFolderLabel],
+							ConfigPath:      fakeContainer1.Labels[agentcontainers.DevcontainerConfigFileLabel],
+							Status:          "stopped",
+							Container:       nil,
+						},
+						{
+							Name:            "project2",
+							WorkspaceFolder: fakeContainer2.Labels[agentcontainers.DevcontainerLocalFolderLabel],
+							ConfigPath:      fakeContainer2.Labels[agentcontainers.DevcontainerConfigFileLabel],
+							Status:          "running",
+							Container:       &fakeContainer2,
+						},
+					},
+				},
+			},
+		}
+
 		var (
 			ctx               = testutil.Context(t, testutil.WaitShort)
 			mClock            = quartz.NewMock(t)
@@ -467,7 +548,7 @@ func TestAPI(t *testing.T) {
 		api := agentcontainers.NewAPI(logger,
 			agentcontainers.WithClock(mClock),
 			agentcontainers.WithContainerCLI(mLister),
-			agentcontainers.WithContainerLabelIncludeFilter("this.label.does.not.exist.ignore.devcontainers", "true"),
+			agentcontainers.WithWatcher(watcher.NewNoop()),
 		)
 		api.Start()
 		defer api.Close()
@@ -484,16 +565,10 @@ func TestAPI(t *testing.T) {
 			defer res.Body.Close()
 		}
 
-		for _, mockResponse := range []codersdk.WorkspaceAgentListContainersResponse{
-			makeResponse(),
-			makeResponse(fakeContainer1),
-			makeResponse(fakeContainer1, fakeContainer2),
-			makeResponse(fakeContainer1, fakeContainer2, fakeContainer3),
-			makeResponse(fakeContainer1, fakeContainer2),
-			makeResponse(fakeContainer1),
-			makeResponse(),
-		} {
-			mLister.EXPECT().List(gomock.Any()).Return(mockResponse, nil)
+		mLister.EXPECT().DetectArchitecture(gomock.Any(), gomock.Any()).Return("<none>", nil).AnyTimes()
+
+		for _, stage := range stages {
+			mLister.EXPECT().List(gomock.Any()).Return(codersdk.WorkspaceAgentListContainersResponse{Containers: stage.containers}, nil)
 
 			// Given: We allow the update loop to progress
 			_, aw := mClock.AdvanceNext()
@@ -504,11 +579,21 @@ func TestAPI(t *testing.T) {
 			require.NoError(t, err)
 			require.Equal(t, websocket.MessageText, mt)
 
-			// Then: We expect the receieved message matches the mocked response.
+			// Then: We expect the receieved message matches the expected response.
 			var got codersdk.WorkspaceAgentListContainersResponse
 			err = json.Unmarshal(msg, &got)
 			require.NoError(t, err)
-			require.Equal(t, mockResponse, got)
+
+			require.Equal(t, stage.expected.Containers, got.Containers)
+			require.Len(t, got.Devcontainers, len(stage.expected.Devcontainers))
+			for j, expectedDev := range stage.expected.Devcontainers {
+				gotDev := got.Devcontainers[j]
+				require.Equal(t, expectedDev.Name, gotDev.Name)
+				require.Equal(t, expectedDev.WorkspaceFolder, gotDev.WorkspaceFolder)
+				require.Equal(t, expectedDev.ConfigPath, gotDev.ConfigPath)
+				require.Equal(t, expectedDev.Status, gotDev.Status)
+				require.Equal(t, expectedDev.Container, gotDev.Container)
+			}
 		}
 	})
 

diff --git a/coderd/workspaceagents_test.go b/coderd/workspaceagents_test.go
@@ -1406,14 +1406,27 @@ func TestWatchWorkspaceAgentDevcontainers(t *testing.T) {
 			return agents
 		}).Do()
 
-		devContainer = codersdk.WorkspaceAgentContainer{
-			ID:           uuid.NewString(),
+		fakeContainer1 = codersdk.WorkspaceAgentContainer{
+			ID:           "container1",
 			CreatedAt:    dbtime.Now(),
-			FriendlyName: testutil.GetRandomName(t),
+			FriendlyName: "container1",
 			Image:        "busybox:latest",
 			Labels: map[string]string{
-				agentcontainers.DevcontainerLocalFolderLabel: "/home/coder/project",
-				agentcontainers.DevcontainerConfigFileLabel:  "/home/coder/project/.devcontainer/devcontainer.json",
+				agentcontainers.DevcontainerLocalFolderLabel: "/home/coder/project1",
+				agentcontainers.DevcontainerConfigFileLabel:  "/home/coder/project1/.devcontainer/devcontainer.json",
+			},
+			Running: true,
+			Status:  "running",
+		}
+
+		fakeContainer2 = codersdk.WorkspaceAgentContainer{
+			ID:           "container1",
+			CreatedAt:    dbtime.Now(),
+			FriendlyName: "container2",
+			Image:        "busybox:latest",
+			Labels: map[string]string{
+				agentcontainers.DevcontainerLocalFolderLabel: "/home/coder/project2",
+				agentcontainers.DevcontainerConfigFileLabel:  "/home/coder/project2/.devcontainer/devcontainer.json",
 			},
 			Running: true,
 			Status:  "running",
@@ -1424,6 +1437,71 @@ func TestWatchWorkspaceAgentDevcontainers(t *testing.T) {
 		}
 	)
 
+	stages := []struct {
+		containers []codersdk.WorkspaceAgentContainer
+		expected   codersdk.WorkspaceAgentListContainersResponse
+	}{
+		{
+			containers: []codersdk.WorkspaceAgentContainer{fakeContainer1},
+			expected: codersdk.WorkspaceAgentListContainersResponse{
+				Containers: []codersdk.WorkspaceAgentContainer{fakeContainer1},
+				Devcontainers: []codersdk.WorkspaceAgentDevcontainer{
+					{
+						Name:            "project1",
+						WorkspaceFolder: fakeContainer1.Labels[agentcontainers.DevcontainerLocalFolderLabel],
+						ConfigPath:      fakeContainer1.Labels[agentcontainers.DevcontainerConfigFileLabel],
+						Status:          "running",
+						Container:       &fakeContainer1,
+					},
+				},
+			},
+		},
+		{
+			containers: []codersdk.WorkspaceAgentContainer{fakeContainer1, fakeContainer2},
+			expected: codersdk.WorkspaceAgentListContainersResponse{
+				Containers: []codersdk.WorkspaceAgentContainer{fakeContainer1, fakeContainer2},
+				Devcontainers: []codersdk.WorkspaceAgentDevcontainer{
+					{
+						Name:            "project1",
+						WorkspaceFolder: fakeContainer1.Labels[agentcontainers.DevcontainerLocalFolderLabel],
+						ConfigPath:      fakeContainer1.Labels[agentcontainers.DevcontainerConfigFileLabel],
+						Status:          "running",
+						Container:       &fakeContainer1,
+					},
+					{
+						Name:            "project2",
+						WorkspaceFolder: fakeContainer2.Labels[agentcontainers.DevcontainerLocalFolderLabel],
+						ConfigPath:      fakeContainer2.Labels[agentcontainers.DevcontainerConfigFileLabel],
+						Status:          "running",
+						Container:       &fakeContainer2,
+					},
+				},
+			},
+		},
+		{
+			containers: []codersdk.WorkspaceAgentContainer{fakeContainer2},
+			expected: codersdk.WorkspaceAgentListContainersResponse{
+				Containers: []codersdk.WorkspaceAgentContainer{fakeContainer2},
+				Devcontainers: []codersdk.WorkspaceAgentDevcontainer{
+					{
+						Name:            "",
+						WorkspaceFolder: fakeContainer1.Labels[agentcontainers.DevcontainerLocalFolderLabel],
+						ConfigPath:      fakeContainer1.Labels[agentcontainers.DevcontainerConfigFileLabel],
+						Status:          "stopped",
+						Container:       nil,
+					},
+					{
+						Name:            "project2",
+						WorkspaceFolder: fakeContainer2.Labels[agentcontainers.DevcontainerLocalFolderLabel],
+						ConfigPath:      fakeContainer2.Labels[agentcontainers.DevcontainerConfigFileLabel],
+						Status:          "running",
+						Container:       &fakeContainer2,
+					},
+				},
+			},
+		},
+	}
+
 	mCCLI.EXPECT().List(gomock.Any()).Return(makeResponse(), nil)
 
 	_ = agenttest.New(t, client.URL, r.AgentToken, func(o *agent.Options) {
@@ -1433,7 +1511,6 @@ func TestWatchWorkspaceAgentDevcontainers(t *testing.T) {
 			agentcontainers.WithClock(mClock),
 			agentcontainers.WithContainerCLI(mCCLI),
 			agentcontainers.WithWatcher(watcher.NewNoop()),
-			agentcontainers.WithContainerLabelIncludeFilter("this.label.does.not.exist.ignore.devcontainers", "true"),
 		}
 	})
 
@@ -1451,23 +1528,30 @@ func TestWatchWorkspaceAgentDevcontainers(t *testing.T) {
 		closer.Close()
 	}()
 
-	for _, mockResponse := range []codersdk.WorkspaceAgentListContainersResponse{
-		makeResponse(),
-		makeResponse(devContainer),
-		makeResponse(),
-	} {
-		mCCLI.EXPECT().List(gomock.Any()).Return(mockResponse, nil)
+	mCCLI.EXPECT().DetectArchitecture(gomock.Any(), gomock.Any()).Return("<none>", nil).AnyTimes()
+	for _, stage := range stages {
+		mCCLI.EXPECT().List(gomock.Any()).Return(codersdk.WorkspaceAgentListContainersResponse{Containers: stage.containers}, nil)
 
 		_, aw := mClock.AdvanceNext()
 		aw.MustWait(ctx)
 
-		var resp codersdk.WorkspaceAgentListContainersResponse
+		var got codersdk.WorkspaceAgentListContainersResponse
 		select {
 		case <-ctx.Done():
-		case resp = <-containers:
+		case got = <-containers:
 		}
 		require.NoError(t, ctx.Err())
-		require.Equal(t, mockResponse, resp)
+
+		require.Equal(t, stage.expected.Containers, got.Containers)
+		require.Len(t, got.Devcontainers, len(stage.expected.Devcontainers))
+		for j, expectedDev := range stage.expected.Devcontainers {
+			gotDev := got.Devcontainers[j]
+			require.Equal(t, expectedDev.Name, gotDev.Name)
+			require.Equal(t, expectedDev.WorkspaceFolder, gotDev.WorkspaceFolder)
+			require.Equal(t, expectedDev.ConfigPath, gotDev.ConfigPath)
+			require.Equal(t, expectedDev.Status, gotDev.Status)
+			require.Equal(t, expectedDev.Container, gotDev.Container)
+		}
 	}
 }
 

diff --git a/codersdk/workspaceagents.go b/codersdk/workspaceagents.go
@@ -421,6 +421,15 @@ type WorkspaceAgentDevcontainer struct {
 	Error string `json:"error,omitempty"`
 }
 
+func (d WorkspaceAgentDevcontainer) Equals(other WorkspaceAgentDevcontainer) bool {
+	return d.ID == other.ID &&
+		d.Name == other.Name &&
+		d.WorkspaceFolder == other.WorkspaceFolder &&
+		d.Status == other.Status &&
+		d.Dirty == other.Dirty &&
+		d.Error == other.Error
-		d.Error == other.Error
+		d.Error == other.Error &&
+		(d.Container == nil && other.Container == nil || (d.Container != nil && other.Continer != nil && d.Container.ID == other.Container.ID)) &&
+		(d.Agent == nil && ... d.Agent.ID == ...
-		d.Error == other.Error
+		d.Error == other.Error &&
+		(d.Container == nil && other.Container == nil || (d.Container != nil && other.Continer != nil && d.Container.ID == other.Container.ID)) &&
+		(d.Agent == nil && ... d.Agent.ID == ...
+}
+
 // WorkspaceAgentDevcontainerAgent represents the sub agent for a
 // devcontainer.
 type WorkspaceAgentDevcontainerAgent struct {