introduce service hooks

loader/loader_test.go

@@ -3509,3 +3509,49 @@ services:
 		},
 	})
 }
+
+func TestLoadServiceHooks(t *testing.T) {
+	p, err := loadYAML(`
+name: load-service-hooks
+services:
+  test:
+    post_start:
+      - command: echo start
+        user: root
+        privileged: true
+        working_dir: /
+        environment:
+          - FOO=BAR
+    pre_stop:
+      - command: echo stop
+        user: root
+        working_dir: /
+        environment:
+          FOO: BAR
+
+`)
+	assert.NilError(t, err)
+	start := p.Services["test"].PostStart
+	assert.DeepEqual(t, start, []types.ServiceHook{
+		{
+			Command:    types.ShellCommand{"echo", "start"},
+			User:       "root",
+			Privileged: true,
+			WorkingDir: "/",
+			Environment: types.MappingWithEquals{
+				"FOO": strPtr("BAR"),
+			},
+		},
+	})
+	stop := p.Services["test"].PreStop
+	assert.DeepEqual(t, stop, []types.ServiceHook{
+		{
+			Command:    types.ShellCommand{"echo", "stop"},
+			User:       "root",
+			WorkingDir: "/",
+			Environment: types.MappingWithEquals{
+				"FOO": strPtr("BAR"),
+			},
+		},
+	})
+}

schema/compose-spec.json

@@ -370,6 +370,8 @@
           },
           "uniqueItems": true
         },
+        "post_start": {"type": "array", "items": {"$ref": "#/definitions/service_hook"}},
+        "pre_stop": {"type": "array", "items": {"$ref": "#/definitions/service_hook"}},
         "privileged": {"type": ["boolean", "string"]},
         "profiles": {"$ref": "#/definitions/list_of_strings"},
         "pull_policy": {"type": "string", "enum": [
@@ -816,6 +818,20 @@
       ]
     },
 
+    "service_hook": {
+      "id": "#/definitions/service_hook",
+      "type": "object",
+      "properties": {
+        "command": {"$ref": "#/definitions/command"},
+        "user": {"type": "string"},
+        "privileged": {"type": ["boolean", "string"]},
+        "working_dir": {"type": "string"},
+        "environment": {"$ref": "#/definitions/list_or_dict"}
+      },
+      "additionalProperties": false,
+      "patternProperties": {"^x-": {}}
+    },
+
     "env_file": {
       "oneOf": [
         {"type": "string"},