feat(config) Add env and file support to Plugins execution dir

CHANGELOG.md

@@ -5,6 +5,8 @@ Canonical reference for changes, improvements, and bugfixes for Boundary.
 ## Next
 
 ### New and Improved
+* config: The `execution_dir` field for plugins now supports being set from environment variables
+  or a file on disk.([PR](https://github.com/hashicorp/boundary/pull/1772))
 * config: The `description` field for controllers now supports being set
   from environment variables or a file on disk
   ([PR](https://github.com/hashicorp/boundary/pull/1766))

internal/cmd/config/config.go

@@ -496,6 +496,13 @@ func Parse(d string) (*Config, error) {
 		return nil, fmt.Errorf(`too many "events" nodes (max 1, got %d)`, len(eventList.Items))
 	}
 
+	if result.Plugins.ExecutionDir != "" {
+		result.Plugins.ExecutionDir, err = parseutil.ParsePath(result.Plugins.ExecutionDir)
+		if err != nil && !errors.Is(err, parseutil.ErrNotAUrl) {
+			return nil, fmt.Errorf("Error parsing plugins execution dir: %w", err)
+		}
+	}
+
 	return result, nil
 }
 

internal/cmd/config/config_test.go

@@ -837,13 +837,13 @@ func TestControllerDescription(t *testing.T) {
 			}`,
 			expErr:    true,
 			expErrStr: "At 3:22: illegal char escape",
-		},{
+		}, {
 			name: "Not a URL, non-printable description",
 			in: `
 			controller {
 				description = "\x00" 
 			}`,
-			expErr: true,
+			expErr:    true,
 			expErrStr: "Controller description contains non-printable characters",
 		},
 	}
@@ -863,4 +863,50 @@ func TestControllerDescription(t *testing.T) {
 			require.Equal(t, tt.expDescription, c.Controller.Description)
 		})
 	}
-}
+}
+
+func TestPluginExecutionDir(t *testing.T) {
+	tests := []struct {
+		name                  string
+		in                    string
+		envPluginExecutionDir string
+		expPluginExecutionDir string
+		expErr                bool
+		expErrStr             string
+	}{
+		{
+			name: "Valid plugin execution dir from env var",
+			in: `
+			plugins {
+  				execution_dir = "env://PLUGIN_EXEC_DIR"
+			}`,
+			envPluginExecutionDir: `/var/run/boundary/plugin-exec`,
+			expPluginExecutionDir: `/var/run/boundary/plugin-exec`,
+			expErr:                false,
+		}, {
+			name: "Invalid plugin execution dir  from env var",
+			in: `
+			plugins {
+  				execution_dir ="\ubad plugin directory"
+			}`,
+			expErr:    true,
+			expErrStr: "At 3:28: illegal char escape",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Setenv("PLUGIN_EXEC_DIR", tt.envPluginExecutionDir)
+			p, err := Parse(tt.in)
+			if tt.expErr {
+				require.EqualError(t, err, tt.expErrStr)
+				require.Nil(t, p)
+				return
+			}
+
+			require.NoError(t, err)
+			require.NotNil(t, p)
+			require.NotNil(t, p.Plugins)
+			require.Equal(t, tt.expPluginExecutionDir, p.Plugins.ExecutionDir)
+		})
+	}
+}

website/content/docs/configuration/plugins.mdx

@@ -21,6 +21,8 @@ plugins {
 ```
 
 - `execution_dir` - Specifies a directory that Boundary can use to write and
-  execute its built-in plugins. This directory must be writeable by the Boundary
-  user. If not set, Boundary will attempt to create a suitable directory in the
-  system temporary folder.
+  execute its built-in plugins. This value can be a direct directory string,
+  can refer to a file on disk (file://) from which a directory location will be
+  read; or an env var (env://) from which the directory location will be read.
+  This directory must be writeable by the Boundary user. If not set, Boundary will
+  attempt to create a suitable directory in the system temporary folder.