在主要服務中依賴其他服務的docker-compose execute命令

Question

在項目中，我有一個Dockerfile用nodejs圖像。 在docker-compose.yml文件中，我有兩個服務：從Dockerfile構建的server和使用postgres映像的db 。

Dockerfile獲取映像，為項目創建目錄，運行npm install並設置CMD ["npm", "start"] 。

我docker-compose.yml的內容：

version: "2"
services:
  server:
    build: .
    ports:
     - "5000:5000"
    volumes:
      - ./:/usr/src/app
    links:
      - db
  db:
    image: postgres:9.6.2
    ports:
      - "5432:5432"
    volumes:
      - db_data:/var/lib/postgres
    restart: always
    environment:
      POSTGRES_PASSWORD: devel
      POSTGRES_USER: devel
      POSTGRES_DB: devel

volumes:
  db_data:

在我的項目中，我將db-migrate與db-migrate-pg驅動程序配合使用，當我嘗試執行遷移時，出現下一個錯誤：7

[ERROR] Error: connect ECONNREFUSED 127.0.0.1:5432
at Object.exports._errnoException (util.js:1026:11)
at exports._exceptionWithHostPort (util.js:1049:20)
at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1136:14)
npm info lifecycle project-js@1.0.0~migrate-up: Failed to exec migrate-up script
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! project-js@1.0.0 migrate-up: `db-migrate up`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the project-js@1.0.0 migrate-up script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /root/.npm/_logs/2017-07-12T17_31_10_049Z-debug.log

數據庫的配置正確，因為我可以在PgAdmin上使用它。 我不知道如何訪問顯示錯誤的文件，因為容器在執行結束后停止了運行。

編輯：

這是錯誤中命名文件的完整輸出：

0 info it worked if it ends with ok
1 verbose cli [ '/usr/local/bin/node',
1 verbose cli   '/usr/local/bin/npm',
1 verbose cli   'run',
1 verbose cli   'migrate-up' ]
2 info using npm@5.0.0
3 info using node@v8.0.0
4 verbose run-script [ 'premigrate-up', 'migrate-up', 'postmigrate-up' ]
5 info lifecycle project-js@1.0.0~premigrate-up: project-js@1.0.0
6 silly lifecycle project-js@1.0.0~premigrate-up: no script for premigrate-up, continuing
7 info lifecycle project-js@1.0.0~migrate-up: project-js@1.0.0
8 verbose lifecycle project-js@1.0.0~migrate-up: unsafe-perm in lifecycle true
9 verbose lifecycle project-js@1.0.0~migrate-up: PATH: /usr/local/lib/node_modules/npm/bin/node-gyp-bin:/usr/src/app/node_modules/.bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
10 verbose lifecycle project-js@1.0.0~migrate-up: CWD: /usr/src/app
11 silly lifecycle project-js@1.0.0~migrate-up: Args: [ '-c', 'db-migrate up' ]
12 silly lifecycle project-js@1.0.0~migrate-up: Returned: code: 1  signal: null
13 info lifecycle project-js@1.0.0~migrate-up: Failed to exec migrate-up script
14 verbose stack Error: project-js@1.0.0 migrate-up: `db-migrate up`
14 verbose stack Exit status 1
14 verbose stack     at EventEmitter.<anonymous> (/usr/local/lib/node_modules/npm/lib/utils/lifecycle.js:283:16)
14 verbose stack     at emitTwo (events.js:125:13)
14 verbose stack     at EventEmitter.emit (events.js:213:7)
14 verbose stack     at ChildProcess.<anonymous> (/usr/local/lib/node_modules/npm/lib/utils/spawn.js:40:14)
14 verbose stack     at emitTwo (events.js:125:13)
14 verbose stack     at ChildProcess.emit (events.js:213:7)
14 verbose stack     at maybeClose (internal/child_process.js:887:16)
14 verbose stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:208:5)
15 verbose pkgid project-js@1.0.0
16 verbose cwd /usr/src/app
17 verbose Linux 4.8.0-58-generic
18 verbose argv "/usr/local/bin/node" "/usr/local/bin/npm" "run" "migrate-up"
19 verbose node v8.0.0
20 verbose npm  v5.0.0
21 error code ELIFECYCLE
22 error errno 1
23 error project-js@1.0.0 migrate-up: `db-migrate up`
23 error Exit status 1
24 error Failed at the project-js@1.0.0 migrate-up script.
24 error This is probably not a problem with npm. There is likely additional logging output above.
25 verbose exit [ 1, true ]

Answer 1

從server容器的角度來看，postgres在這里：

db:5432

每個容器都有自己的網絡接口，因此每個容器都有自己的本地主機。
docker-compose為您的容器創建一個網絡並將其放入其中。 作為獎勵，您可以獲得DNS解析，然后他們可以使用他們的服務名稱互相交談。

---

問：我不知道如何訪問顯示錯誤的文件，因為容器在執行結束后停止了。

做這個 ：

last_stopped_container=$(docker ps -q -l)
docker cp $last_stopped_container:/root/.npm/_logs/2017-07-12T17_31_10_049Z-debug.log debug.log
cat debug.log

---

另外，請使用depends_on而不是links以獲得一些依賴啟動：

depends_on:
  - db

正如我所看到的，您在服務器啟動的一開始就在運行db-migrations。 這可能導致在短時間內無法使用PostgreSQL。 如果是這樣，請執行以下操作：

docker-compose up -d db
# wait just a few seconds
docker-compose up server

這不是很優雅。 因此，您將需要使用更強大的解決方案： https : //github.com/vishnubob/wait-for-it 。 下載該腳本，將其放在服務器映像中並按以下方式使用：

  server:
    build: .
      command: /wait-for-it.sh db:5432 -- npm run #or whatever node command you have
    ports:
     - "5000:5000"
    volumes:
      - ./:/usr/src/app
    links:
      - db