为 NodeJS + PostgreSQL Web 应用程序创建 Docker 映像

Question

我一直在阅读 Docker 的文档，但无法创建一个可以工作的镜像。

我有一个使用 PostgreSQL 作为数据库的 NodeJS 应用程序：

var connectionString = process.env.DATABASE_URL || 'postgres://localhost:5432/db';
var pg = require('pg');
var pgp = require('pg-promise')();
var db = pgp(connectionString);
db.func('some_storedProcedure').then(//...)
//...

我先根据Node's documentation为它创建了一个Dockerfile：

FROM node:argon

# Create app directory
RUN mkdir -p /app
WORKDIR /app

# Install app dependencies
COPY package.json /app
RUN npm install

# Bundle app source
COPY . /app

EXPOSE 5000

CMD [ "npm", "start" ]

然后我关注this post 使用 docker-compose 将数据库连接到它。 docker-compose.yml 文件看起来像：

web:


 build: .
  ports:
    - "5000:5000"
  volumes:
    - .:/app
  links:
    - db
  environment:
    DATABASE_URL: postgres://myuser:mypass@db:5432/db
db:
  image: postgres
  environment:
    POSTGRES_USER: myuser
    POSTGRES_PASSWORD: mypass

这是创建图像后使用这些文件运行 docker-compose up 时返回的（部分）内容。

npm info ok 
 ---> 87dbbae35721
Removing intermediate container c73f826a0b3d
Step 6 : COPY . /app
 ---> ec56bfc11d3c
Removing intermediate container 745ddf82d742
Step 7 : EXPOSE 5000
 ---> Running in b2be5aecd9d6
 ---> a7d126a7ea5e
Removing intermediate container b2be5aecd9d6
Step 8 : CMD npm start
 ---> Running in 0379d512c688
 ---> 266517f47311
Removing intermediate container 0379d512c688
Successfully built 266517f47311
WARNING: Image for service web was built because it did not already exist. To rebuild this image you must use `docker-compose build` or `docker-compose up --build`.
Starting imagename_db_1
Creating imagename_web_1
Attaching to imagename_db_1, imagename_web_1
web_1  | npm info it worked if it ends with ok
web_1  | npm info using npm@2.15.1
web_1  | npm info using node@v4.4.3
web_1  | npm info prestart SharedServer@5.8.0
web_1  | npm info start SharedServer@5.8.0
web_1  | 
web_1  | > SharedServer@5.8.0 start /app
web_1  | > node index.js
web_1  | 
web_1  | Wed, 27 Apr 2016 00:41:19 GMT body-parser deprecated bodyParser: use individual json/urlencoded middlewares at index.js:13:9
web_1  | Wed, 27 Apr 2016 00:41:19 GMT body-parser deprecated undefined extended: provide extended option at node_modules/body-parser/index.js:105:29
web_1  | Node app is running on port 5000
db_1   | LOG:  database system was interrupted; last known up at 2016-04-25 00:17:59 UTC
db_1   | LOG:  database system was not properly shut down; automatic recovery in progress
db_1   | LOG:  invalid record length at 0/17076E8
db_1   | LOG:  redo is not required
db_1   | LOG:  MultiXact member wraparound protections are now enabled
db_1   | LOG:  database system is ready to accept connections
db_1   | LOG:  autovacuum launcher started

当我访问 http://localhost:5000 时，我看到 Web 应用程序正在运行，但每当我启动尝试访问数据库的东西时，我都会收到 HTTP 500 错误，正文如下

code: "28P01"
file: "auth.c"
length: 98
line: "285"
name: "error"
routine: "auth_failed"
severity: "FATAL"

我做错了什么？我不确定我是否了解我在使用 Docker 做什么，我唯一的文档是构建特定环境的简单配方（或者至少，这是我所理解的）

谢谢。

Answer 1

检查 $PGDATA 中的 pg_hba.conf 是否允许来自 node.js 的连接。

默认情况下 pg_hba.conf 是这样的：

# TYPE  DATABASE        USER            ADDRESS                 METHOD

# "local" is for Unix domain socket connections only
local   all             all                                     trust
# IPv4 local connections:
host    all             all             127.0.0.1/32            trust
# IPv6 local connections:
host    all             all             ::1/128                 trust

这对于通过操作系统所有者的标准 psql 连接来说很好，因为它允许本地连接受信任的本地连接 IP 地址 127.0.0.1。但是，如果您在服务器上设置了 IP 地址，我猜您这样做了，那么您需要允许一个条目，因为在您的 node.js 配置中，您指的是“DB”主机。因此 ping "DB" 并添加该 IP 地址：

# TYPE  DATABASE        USER            ADDRESS                 METHOD

# "local" is for Unix domain socket connections only
local   all             all                                     trust
# IPv4 local connections:
host    all             all             127.0.0.1/32            trust
# IPv6 local connections:
host    all             all             ::1/128                 trust
host    db              myuser          <ip-for-db-host>        md5

更改该文件后，您需要执行 pg_ctl 重新加载。