feat(cli): display devcontainers in show command (#16515)

Displays running devcontainers into the `coder show` CLI command.

coderd/util/maps/maps.go

@@ -8,9 +8,14 @@ import (
 
 // Subset returns true if all the keys of a are present
 // in b and have the same values.
+// If the corresponding value of a[k] is the zero value in
+// b, Subset will skip comparing that value.
+// This allows checking for the presence of map keys.
 func Subset[T, U comparable](a, b map[T]U) bool {
+	var uz U
 	for ka, va := range a {
-		if vb, ok := b[ka]; !ok || va != vb {
+		ignoreZeroValue := va == uz
+		if vb, ok := b[ka]; !ok || (!ignoreZeroValue && va != vb) {
 			return false
 		}
 	}

coderd/util/maps/maps_test.go

@@ -11,8 +11,9 @@ func TestSubset(t *testing.T) {
 	t.Parallel()
 
 	for idx, tc := range []struct {
-		a        map[string]string
-		b        map[string]string
+		a map[string]string
+		b map[string]string
+		// expected value from Subset
 		expected bool
 	}{
 		{
@@ -50,6 +51,24 @@ func TestSubset(t *testing.T) {
 			b:        map[string]string{"a": "1", "b": "3"},
 			expected: false,
 		},
+		// Zero value
+		{
+			a:        map[string]string{"a": "1", "b": ""},
+			b:        map[string]string{"a": "1", "b": "3"},
+			expected: true,
+		},
+		// Zero value, but the other way round
+		{
+			a:        map[string]string{"a": "1", "b": "3"},
+			b:        map[string]string{"a": "1", "b": ""},
+			expected: false,
+		},
+		// Both zero values
+		{
+			a:        map[string]string{"a": "1", "b": ""},
+			b:        map[string]string{"a": "1", "b": ""},
+			expected: true,
+		},
 	} {
 		tc := tc
 		t.Run("#"+strconv.Itoa(idx), func(t *testing.T) {

coderd/workspaceagents_test.go

@@ -1076,7 +1076,8 @@ func TestWorkspaceAgentContainers(t *testing.T) {
 		pool, err := dockertest.NewPool("")
 		require.NoError(t, err, "Could not connect to docker")
 		testLabels := map[string]string{
-			"com.coder.test": uuid.New().String(),
+			"com.coder.test":  uuid.New().String(),
+			"com.coder.empty": "",
 		}
 		ct, err := pool.RunWithOptions(&dockertest.RunOptions{
 			Repository: "busybox",
@@ -1097,7 +1098,10 @@ func TestWorkspaceAgentContainers(t *testing.T) {
 			Repository: "busybox",
 			Tag:        "latest",
 			Cmd:        []string{"sleep", "infinity"},
-			Labels:     map[string]string{"com.coder.test": "ignoreme"},
+			Labels: map[string]string{
+				"com.coder.test":  "ignoreme",
+				"com.coder.empty": "",
+			},
 		}, func(config *docker.HostConfig) {
 			config.AutoRemove = true
 			config.RestartPolicy = docker.RestartPolicy{Name: "no"}