coder · DanielleMaywood · Jun 23, 2025 · Jun 20, 2025 · Jun 20, 2025 · Jun 20, 2025
diff --git a/agent/agentcontainers/api.go b/agent/agentcontainers/api.go
@@ -8,6 +8,7 @@ import (
 	"os"
 	"path"
 	"path/filepath"
+	"regexp"
 	"runtime"
 	"slices"
 	"strings"
@@ -39,6 +40,8 @@ const (
 	// by tmpfs or other mounts. This assumes the container root filesystem is
 	// read-write, which seems sensible for devcontainers.
 	coderPathInsideContainer = "/.coder-agent/coder"
+
+	maxAgentNameLength = 64
 )
 
 // API is responsible for container-related operations in the agent.
@@ -583,10 +586,11 @@ func (api *API) processUpdatedContainersLocked(ctx context.Context, updated code
 		if dc.Container != nil {
 			if !api.devcontainerNames[dc.Name] {
 				// If the devcontainer name wasn't set via terraform, we
-				// use the containers friendly name as a fallback which
-				// will keep changing as the devcontainer is recreated.
-				// TODO(mafredri): Parse the container label (i.e. devcontainer.json) for customization.
-				dc.Name = safeFriendlyName(dc.Container.FriendlyName)
+				// will attempt to create an agent name based on the workspace
+				// folder's name. If it is not possible to generate a valid
+				// agent name based off of the folder name (i.e. no valid characters),
+				// we will instead fall back to using the container's friendly name.
+				dc.Name = safeAgentName(path.Base(filepath.ToSlash(dc.WorkspaceFolder)), dc.Container.FriendlyName)
 			}
 		}
 
@@ -631,6 +635,38 @@ func (api *API) processUpdatedContainersLocked(ctx context.Context, updated code
 	api.containersErr = nil
 }
 
+var consecutiveHyphenRegex = regexp.MustCompile("-+")
+
+// `safeAgentName` returns a safe agent name derived from a folder name,
+// falling back to the container’s friendly name if needed.
+func safeAgentName(name string, friendlyName string) string {
+	// Keep only ASCII letters and digits, replacing everything
+	// else with a hyphen.
+	var sb strings.Builder
+	for _, r := range strings.ToLower(name) {
+		if (r >= 'a' && r <= 'z') || (r >= '0' && r <= '9') {
+			_, _ = sb.WriteRune(r)
+		} else {
+			_, _ = sb.WriteRune('-')
+		}
+	}
+
+	// Remove any consecutive hyphens, and then trim any leading
+	// and trailing hyphens.
+	name = consecutiveHyphenRegex.ReplaceAllString(sb.String(), "-")
+	name = strings.Trim(name, "-")
+
+	// Ensure the name of the agent doesn't exceed the maximum agent
+	// name length.
+	name = name[:min(len(name), maxAgentNameLength)]
+
+	if provisioner.AgentNameRegex.Match([]byte(name)) {
+		return name
+	}
+
+	return safeFriendlyName(friendlyName)
+}
+
 // safeFriendlyName returns a API safe version of the container's
 // friendly name.
 //

diff --git a/agent/agentcontainers/api_internal_test.go b/agent/agentcontainers/api_internal_test.go
@@ -0,0 +1,201 @@
+package agentcontainers
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/coder/coder/v2/provisioner"
+)
+
+func TestSafeAgentName(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name       string
+		folderName string
+		expected   string
+	}{
+		// Basic valid names
+		{
+			folderName: "simple",
+			expected:   "simple",
+		},
+		{
+			folderName: "with-hyphens",
+			expected:   "with-hyphens",
+		},
+		{
+			folderName: "123numbers",
+			expected:   "123numbers",
+		},
+		{
+			folderName: "mixed123",
+			expected:   "mixed123",
+		},
+
+		// Names that need transformation
+		{
+			folderName: "With_Underscores",
+			expected:   "with-underscores",
+		},
+		{
+			folderName: "With Spaces",
+			expected:   "with-spaces",
+		},
+		{
+			folderName: "UPPERCASE",
+			expected:   "uppercase",
+		},
+		{
+			folderName: "Mixed_Case-Name",
+			expected:   "mixed-case-name",
+		},
+
+		// Names with special characters that get replaced
+		{
+			folderName: "special@#$chars",
+			expected:   "special-chars",
+		},
+		{
+			folderName: "dots.and.more",
+			expected:   "dots-and-more",
+		},
+		{
+			folderName: "multiple___underscores",
+			expected:   "multiple-underscores",
+		},
+		{
+			folderName: "multiple---hyphens",
+			expected:   "multiple-hyphens",
+		},
+
+		// Edge cases with leading/trailing special chars
+		{
+			folderName: "-leading-hyphen",
+			expected:   "leading-hyphen",
+		},
+		{
+			folderName: "trailing-hyphen-",
+			expected:   "trailing-hyphen",
+		},
+		{
+			folderName: "_leading_underscore",
+			expected:   "leading-underscore",
+		},
+		{
+			folderName: "trailing_underscore_",
+			expected:   "trailing-underscore",
+		},
+		{
+			folderName: "---multiple-leading",
+			expected:   "multiple-leading",
+		},
+		{
+			folderName: "trailing-multiple---",
+			expected:   "trailing-multiple",
+		},
+
+		// Complex transformation cases
+		{
+			folderName: "___very---complex@@@name___",
+			expected:   "very-complex-name",
+		},
+		{
+			folderName: "my.project-folder_v2",
+			expected:   "my-project-folder-v2",
+		},
+
+		// Empty and fallback cases - now correctly uses friendlyName fallback
+		{
+			folderName: "",
+			expected:   "friendly-fallback",
+		},
+		{
+			folderName: "---",
+			expected:   "friendly-fallback",
+		},
+		{
+			folderName: "___",
+			expected:   "friendly-fallback",
+		},
+		{
+			folderName: "@#$",
+			expected:   "friendly-fallback",
+		},
+
+		// Additional edge cases
+		{
+			folderName: "a",
+			expected:   "a",
+		},
+		{
+			folderName: "1",
+			expected:   "1",
+		},
+		{
+			folderName: "a1b2c3",
+			expected:   "a1b2c3",
+		},
+		{
+			folderName: "CamelCase",
+			expected:   "camelcase",
+		},
+		{
+			folderName: "snake_case_name",
+			expected:   "snake-case-name",
+		},
+		{
+			folderName: "kebab-case-name",
+			expected:   "kebab-case-name",
+		},
+		{
+			folderName: "mix3d_C4s3-N4m3",
+			expected:   "mix3d-c4s3-n4m3",
+		},
+		{
+			folderName: "123-456-789",
+			expected:   "123-456-789",
+		},
+		{
+			folderName: "abc123def456",
+			expected:   "abc123def456",
+		},
+		{
+			folderName: "   spaces   everywhere   ",
+			expected:   "spaces-everywhere",
+		},
+		{
+			folderName: "unicode-café-naïve",
+			expected:   "unicode-caf-na-ve",
+		},
+		{
+			folderName: "path/with/slashes",
+			expected:   "path-with-slashes",
+		},
+		{
+			folderName: "file.tar.gz",
+			expected:   "file-tar-gz",
+		},
+		{
+			folderName: "version-1.2.3-alpha",
+			expected:   "version-1-2-3-alpha",
+		},
+
+		// Truncation test for names exceeding 64 characters
+		{
+			folderName: "this-is-a-very-long-folder-name-that-exceeds-sixty-four-characters-limit-and-should-be-truncated",
+			expected:   "this-is-a-very-long-folder-name-that-exceeds-sixty-four-characte",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.folderName, func(t *testing.T) {
+			t.Parallel()
+			name := safeAgentName(tt.folderName, "friendly-fallback")
+
+			assert.Equal(t, tt.expected, name)
+			assert.True(t, provisioner.AgentNameRegex.Match([]byte(name)))
+		})
+	}
+}
diff --git a/agent/agentcontainers/api_test.go b/agent/agentcontainers/api_test.go
@@ -897,26 +897,26 @@ func TestAPI(t *testing.T) {
 								FriendlyName: "project1-container",
 								Running:      true,
 								Labels: map[string]string{
-									agentcontainers.DevcontainerLocalFolderLabel: "/workspace/project",
-									agentcontainers.DevcontainerConfigFileLabel:  "/workspace/project/.devcontainer/devcontainer.json",
+									agentcontainers.DevcontainerLocalFolderLabel: "/workspace/project1",
+									agentcontainers.DevcontainerConfigFileLabel:  "/workspace/project1/.devcontainer/devcontainer.json",
 								},
 							},
 							{
 								ID:           "project2-container",
 								FriendlyName: "project2-container",
 								Running:      true,
 								Labels: map[string]string{
-									agentcontainers.DevcontainerLocalFolderLabel: "/home/user/project",
-									agentcontainers.DevcontainerConfigFileLabel:  "/home/user/project/.devcontainer/devcontainer.json",
+									agentcontainers.DevcontainerLocalFolderLabel: "/home/user/project2",
+									agentcontainers.DevcontainerConfigFileLabel:  "/home/user/project2/.devcontainer/devcontainer.json",
 								},
 							},
 							{
 								ID:           "project3-container",
 								FriendlyName: "project3-container",
 								Running:      true,
 								Labels: map[string]string{
-									agentcontainers.DevcontainerLocalFolderLabel: "/var/lib/project",
-									agentcontainers.DevcontainerConfigFileLabel:  "/var/lib/project/.devcontainer/devcontainer.json",
+									agentcontainers.DevcontainerLocalFolderLabel: "/var/lib/project3",
+									agentcontainers.DevcontainerConfigFileLabel:  "/var/lib/project3/.devcontainer/devcontainer.json",
 								},
 							},
 						},
@@ -1326,7 +1326,7 @@ func TestAPI(t *testing.T) {
 		// Allow initial agent creation and injection to succeed.
 		testutil.RequireSend(ctx, t, fakeSAC.createErrC, nil)
 		testutil.RequireSend(ctx, t, fakeDCCLI.readConfigErrC, func(envs []string) error {
-			assert.Contains(t, envs, "CODER_WORKSPACE_AGENT_NAME=test-container")
+			assert.Contains(t, envs, "CODER_WORKSPACE_AGENT_NAME=coder")
 			assert.Contains(t, envs, "CODER_WORKSPACE_NAME=test-workspace")
 			assert.Contains(t, envs, "CODER_WORKSPACE_OWNER_NAME=test-user")
 			assert.Contains(t, envs, "CODER_URL=test-subagent-url")
@@ -1349,7 +1349,7 @@ func TestAPI(t *testing.T) {
 
 		// Verify agent was created.
 		require.Len(t, fakeSAC.created, 1)
-		assert.Equal(t, "test-container", fakeSAC.created[0].Name)
+		assert.Equal(t, "coder", fakeSAC.created[0].Name)
 		assert.Equal(t, "/workspaces/coder", fakeSAC.created[0].Directory)
 		assert.Len(t, fakeSAC.deleted, 0)
 
@@ -1405,7 +1405,7 @@ func TestAPI(t *testing.T) {
 	WaitStartLoop:
 		for {
 			// Agent reinjection will succeed and we will not re-create the
-			// agent, nor re-probe pwd.
+			// agent.
 			mCCLI.EXPECT().List(gomock.Any()).Return(codersdk.WorkspaceAgentListContainersResponse{
 				Containers: []codersdk.WorkspaceAgentContainer{testContainer},
 			}, nil).Times(1) // 1 update.
@@ -1468,7 +1468,7 @@ func TestAPI(t *testing.T) {
 		// Expect the agent to be recreated.
 		testutil.RequireSend(ctx, t, fakeSAC.createErrC, nil)
 		testutil.RequireSend(ctx, t, fakeDCCLI.readConfigErrC, func(envs []string) error {
-			assert.Contains(t, envs, "CODER_WORKSPACE_AGENT_NAME=test-container")
+			assert.Contains(t, envs, "CODER_WORKSPACE_AGENT_NAME=coder")
 			assert.Contains(t, envs, "CODER_WORKSPACE_NAME=test-workspace")
 			assert.Contains(t, envs, "CODER_WORKSPACE_OWNER_NAME=test-user")
 			assert.Contains(t, envs, "CODER_URL=test-subagent-url")
@@ -1910,8 +1910,8 @@ func TestAPI(t *testing.T) {
 				Running:      true,
 				CreatedAt:    time.Now(),
 				Labels: map[string]string{
-					agentcontainers.DevcontainerLocalFolderLabel: "/workspaces",
-					agentcontainers.DevcontainerConfigFileLabel:  "/workspace/.devcontainer/devcontainer.json",
+					agentcontainers.DevcontainerLocalFolderLabel: "/workspaces/coder",
+					agentcontainers.DevcontainerConfigFileLabel:  "/workspaces/coder/.devcontainer/devcontainer.json",
 				},
 			}
 		)
@@ -1953,13 +1953,13 @@ func TestAPI(t *testing.T) {
 		testutil.RequireSend(ctx, t, fSAC.createErrC, nil)
 		testutil.RequireSend(ctx, t, fDCCLI.readConfigErrC, func(env []string) error {
 			// We expect the wrong workspace agent name passed in first.
-			assert.Contains(t, env, "CODER_WORKSPACE_AGENT_NAME=test-container")
+			assert.Contains(t, env, "CODER_WORKSPACE_AGENT_NAME=coder")
 			return nil
 		})
 		testutil.RequireSend(ctx, t, fDCCLI.readConfigErrC, func(env []string) error {
 			// We then expect the agent name passed here to have been read from the config.
 			assert.Contains(t, env, "CODER_WORKSPACE_AGENT_NAME=custom-name")
-			assert.NotContains(t, env, "CODER_WORKSPACE_AGENT_NAME=test-container")
+			assert.NotContains(t, env, "CODER_WORKSPACE_AGENT_NAME=coder")
 			return nil
 		})