feat(config): Env/file support for Worker description

CHANGELOG.md

@@ -6,6 +6,9 @@ Canonical reference for changes, improvements, and bugfixes for Boundary.
 
 ### New and Improved
 
+* config: The `description` field for workers now supports being set
+  from environment variables or a file on disk
+  ([PR](https://github.com/hashicorp/boundary/pull/1783))
 * config: The `max_open_connections` field for the database field in controllers now supports being set
   from environment variables or a file on disk
   ([PR](https://github.com/hashicorp/boundary/pull/1776))

internal/cmd/config/config.go

@@ -376,6 +376,14 @@ func Parse(d string) (*Config, error) {
 			return nil, errors.New("Worker name contains non-printable characters")
 		}
 
+		result.Worker.Description, err = parseutil.ParsePath(result.Worker.Description)
+		if err != nil && !errors.Is(err, parseutil.ErrNotAUrl) {
+			return nil, fmt.Errorf("Error parsing worker description: %w", err)
+		}
+		if !strutil.Printable(result.Worker.Description) {
+			return nil, errors.New("Worker description contains non-printable characters")
+		}
+
 		if result.Worker.TagsRaw != nil {
 			switch t := result.Worker.TagsRaw.(type) {
 			// We allow `tags` to be a simple string containing a URL with schema.

internal/cmd/config/config_test.go

@@ -1007,6 +1007,61 @@ func TestControllerDescription(t *testing.T) {
 	}
 }
 
+func TestWorkerDescription(t *testing.T) {
+	tests := []struct {
+		name           string
+		in             string
+		envDescription string
+		expDescription string
+		expErr         bool
+		expErrStr      string
+	}{
+		{
+			name: "Valid worker description from env var",
+			in: `
+			worker {
+				description = "env://WORKER_DESCRIPTION"
+			}`,
+			envDescription: "Test worker description",
+			expDescription: "Test worker description",
+			expErr:         false,
+		}, {
+			name: "Invalid worker description",
+			in: `
+			worker {
+				description = "\uTest worker description"
+			}`,
+			expErr:    true,
+			expErrStr: "At 3:22: illegal char escape",
+		}, {
+			name: "Not a URL, non-printable description",
+			in: `
+			worker {
+				description = "\x00"
+			}`,
+			expErr:    true,
+			expErrStr: "Worker description contains non-printable characters",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Setenv("WORKER_DESCRIPTION", tt.envDescription)
+			c, err := Parse(tt.in)
+			if tt.expErr {
+				require.EqualError(t, err, tt.expErrStr)
+				require.Nil(t, c)
+				return
+			}
+
+			require.NoError(t, err)
+			require.NotNil(t, c)
+			require.NotNil(t, c.Worker)
+			require.Equal(t, tt.expDescription, c.Worker.Description)
+		})
+	}
+}
+
 func TestPluginExecutionDir(t *testing.T) {
 	tests := []struct {
 		name                  string

website/content/docs/configuration/worker.mdx

@@ -23,6 +23,9 @@ worker {
   the name will be read.
 
 - `description` - Specifies a friendly description of this worker.
+  This value can be a direct description string, can refer to a file on disk
+  (file://) from which a description will be read; or an env var (env://) from
+  which the description will be read.
 
 - `public_addr` - Specifies the public host or IP address (and optionally port)
   at which the worker can be reached _by clients for proxying_. This defaults to