无法从Golang容器连接到Postgres Docker容器 [英] Can't connect to Postgres docker container from Golang container

问题描述

我有一个使用golang构建的Web服务器。

I have a web server built using golang. It works successfully when I test it locally.

但是，当我为Web服务器构建docker映像时，它无法连接到正在运行的Postgres容器。

However, when I build a docker image for my web server, it can't connect to a running Postgres container.

这是我的 docker-compose.yml ：

version: '2'
services:
    go:
        image: golang:1.7
        volumes:
          - ./:/server/http
        ports:
            - "80:8080"
        links:
            - postgres
            - mongodb
            - redis
        environment:
            DEBUG: 'true'
            PORT: '8080'

    postgres:
        image: onjin/alpine-postgres:9.5
        restart: unless-stopped
        ports:
            - "5432:5432"
        environment:
            LC_ALL: C.UTF-8
            POSTGRES_USER: user
            POSTGRES_PASSWORD: pass
            POSTGRES_DB: mydb
    mongodb:
        image: mvertes/alpine-mongo:3.2.3
        restart: unless-stopped
        ports:
            - "27017:27017"

    redis:
        image: sickp/alpine-redis:3.2.2
        restart: unless-stopped
        ports:
            - "6379:6379"

我的 Dockerfile ：

FROM golang:1.7

RUN mkdir -p /home/app

WORKDIR /home/app

COPY . /home/app

RUN make deps && make

ENTRYPOINT ["./bin/api-test"]

EXPOSE 8080

我正在使用的Postgres连接字符串：

The Postgres connection string I am using:

postgresql://user:pass@host/mydb?sslmode=disable

对于主机，我尝试使用 localhost 并返回以下错误：

For host, I tried localhost and it returns the following error:

dial tcp [::1]:5432: getsockopt: connection refused

尝试 postgres 并返回以下内容：

Tried postgres and it returns the following:

dial tcp 202.71.99.194:5432: getsockopt: connection refused

尝试运行此命令的IP地址，该命令返回 172.19.0.3 ：

Tried the IP address I get running this command which returns 172.19.0.3:

docker inspect apitest_postgres_1 | grep IPAddress

其中 apitest_postgres_1 是Postgres容器名称。它还返回了此错误：

where apitest_postgres_1 is Postgres container name. It also returned this error:

dial tcp 172.19.0.3:5432: getsockopt: connection timed out

你能告诉我我在这里想念的吗？我对Docker缺乏经验，这花了很长时间研究解决方案。

Can you please tell me what I am missing here? I am inexperienced with docker and this took a long time investigating for a solution.

编辑：
我使用以下命令运行golang docker该命令：

I run my golang docker using this command:

docker run --env-file ./example.env --rm -it -p 8080:8080  api-test

example.env 是文件

编辑2：
我将连接字符串更改为以下内容：

Edit 2: I changed the connection string to the following:

postgresql://user:pass@postgres:5432?sslmode=disable

它将返回以下错误：

dial tcp: lookup postgres on 192.168.65.1:53: no such host

我的主意是我的Mac是这里的问题。我的默认DNS是 8.8.8.8 ，这应该没问题。

I'm getting the idea that my mac is the issue here. My default DNS is 8.8.8.8 which should not be a problem.

推荐答案

看起来像是拉图像而不是构建自己的图像。

Looks like you're pulling go image instead of building you're own image.

而不是 image：golang：1.7 替换为 build：。来构建并使用您的 Dockerfile 。

Instead of image: golang:1.7 replace it with build: . to build and use your Dockerfile.

另外，您可能需要传递postgres环境变量 DB_HOST ， DB_USER ， DB_PASS 等。您可以实现这一点，但是创建例如 docker.env 文件，然后添加 env_file 在您的go app docker-compose.yml 文件下：

Also you might need to pass postgres environment variables DB_HOST, DB_USER, DB_PASS etc. you can achieve that but creating for example docker.env file and then add env_file under your go app docker-compose.yml file:

docker.env示例：

Example docker.env :

DB_HOST=postgres
DB_USER=user
DB_PASS=pass
DB_NAME=mydb

正确的docker-compose.yml：

Corrected docker-compose.yml :

version: '2'
services:
    app:
        build: .
        volumes:
          - ./:/server/http
        ports:
            - "80:8080"
        links:
            - postgres
            - mongodb
            - redis
        environment:
            DEBUG: 'true'
            PORT: '8080'
        env_file: 
          - docker.env

    postgres:
        image: onjin/alpine-postgres:9.5
        restart: unless-stopped
        ports:
            - "5432:5432"
        environment:
            LC_ALL: C.UTF-8
            POSTGRES_USER: user
            POSTGRES_PASSWORD: pass
            POSTGRES_DB: mydb

    mongodb:
        image: mvertes/alpine-mongo:3.2.3
        restart: unless-stopped
        ports:
            - "27017:27017"

    redis:
        image: sickp/alpine-redis:3.2.2
        restart: unless-stopped
        ports:
            - "6379:6379"

这篇关于无法从Golang容器连接到Postgres Docker容器的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！