我无法使用 docker-compose 从服务器容器连接 mysql 容器

Question

I have been trying to connect golang container with the mysql container for nearly 5 days and every time I face the Issue about the "connection refused" problem, So I have added the Wait so that golang container wait for connection when the Mysql container is preparing itself...but adding that Wait command in docker file and docker compose file doesn't resolve anything.

This is the Error I have been facing

 docker-compose up
Creating network "bucket-api_fullstack" with driver "br
Creating bucket-database ... done
Creating bucket-api      ... done
Attaching to bucket-database, bucket-api
bucket-api      | -------------------------------------
bucket-api      |  docker-compose-wait 2.7.2
bucket-api      | ---------------------------
bucket-api      | Starting with configuration:
bucket-api      |  - Hosts to be waiting for: [bucket-m
bucket-api      |  - Timeout before failure: 300 second
bucket-api      |  - TCP connection timeout before retr
bucket-api      |  - Sleeping time before checking for 
bucket-api      |  - Sleeping time once all hosts are a
bucket-api      |  - Sleeping time between retries: 30 
bucket-api      | -------------------------------------
bucket-api      | Checking availability of bucket-mysql
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-database | 2021-02-13 06:01:44+00:00 [Note] [Ent MySQL Server 8.0.23-1debian10 started.
bucket-database | 2021-02-13 06:01:44+00:00 [Note] [Entd user 'mysql'
bucket-database | 2021-02-13 06:01:44+00:00 [Note] [Ent MySQL Server 8.0.23-1debian10 started.
bucket-database | 2021-02-13T06:01:45.306754Z 0 [Systemn/mysqld (mysqld 8.0.23) starting as process 1
bucket-database | 2021-02-13T06:01:45.415685Z 1 [Systemnitialization has started.
bucket-database | 2021-02-13T06:01:47.738724Z 1 [Systemnitialization has ended.
bucket-database | 2021-02-13T06:01:48.172811Z 0 [System ready for connections. Bind-address: '::' port: 33060,.sock
bucket-database | 2021-02-13T06:01:48.350857Z 0 [System XA crash recovery...
bucket-database | 2021-02-13T06:01:48.357430Z 0 [System recovery finished.
bucket-database | 2021-02-13T06:01:48.743684Z 0 [Warninificate ca.pem is self signed.
bucket-database | 2021-02-13T06:01:48.744238Z 0 [System
mysql_main configured to support TLS. Encrypted connect channel.
bucket-database | 2021-02-13T06:01:48.918000Z 0 [Warnine configuration for --pid-file: Location '/var/run/mysqo all OS users. Consider choosing a different directory
bucket-database | 2021-02-13T06:01:49.233036Z 0 [Systemn/mysqld: ready for connections. Version: '8.0.23'  socck'  port: 3306  MySQL Community Server - GPL.
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Timeout! After 300 seconds some hosts
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Timeout! After 300 seconds some hosts
bucket-api exited with code 1
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Host bucket-mysql:3305 not yet availa
bucket-api      | Timeout! After 300 seconds some hosts
bucket-api exited with code 1
bucket-api      | Host bucket-mysql:3305 not yet availa

This is my Dockerfile

  #Builder image build the go binary : Setting the alias as builder
FROM golang:1.15-alpine as builder
RUN mkdir /app

# add this file directory to the image
ADD . /app
# directory where the source file execution takes place
WORKDIR /app

# RUN some go commands
RUN go clean --modcache
RUN go mod download
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o main ./src/

# Our production image used to run our app
FROM alpine:latest
RUN apk --no-cache add ca-certificates
RUN apk add --no-cache git make musl-dev go
COPY --from=builder /app/main .

# Add docker-compose-wait tool -------------------
ENV WAIT_VERSION 2.7.2
ADD https://github.com/ufoscout/docker-compose-wait/releases/download/$WAIT_VERSION/wait /wait
RUN chmod +x /wait


# Configure GO
ENV GOROOT /usr/lib/go
ENV GOPATH /go
ENV PATH /go/bin:$PATH

RUN mkdir -p ${GOPATH}/src ${GOPATH}/bin
EXPOSE 8084
CMD ["./main"]

This is my dockcer-compose file

version: '3.8'

services: 
  # MYSQL DATABASE DOCKER
  bucket-mysql:
    image: mysql:latest
    container_name: bucket-database
    command: --default-authentication-plugin=mysql_native_password
    ports: 
      - "3305:3306"
    expose: 
      - "3305"
    environment: 
      MYSQL_ROOT_PASSWORD: "123"
      MYSQL_USER: "bu"
      MYSQL_PASSWORD: "root"
      MYSQL_DATABASE: "rb_db"
    networks: 
      - fullstack
    volumes: 
      - database_mysql:/var/lib/mysql
    restart: always
    cap_add: 
      - SYS_NICE
    healthcheck: 
      test: ["CMD-SHELL", "echo 'select 1' |mysql -u root -p'pagal!123' --silent"]
      interval: 30s
      timeout: 20s
      retries: 6
  
  #API DOCKER 
  bucket:
    image: bucketapi
    build: . 
    container_name: bucket-api
    command: sh -c "/wait"
    environment:
      WAIT_HOSTS: bucket-mysql:3305
      WAIT_HOSTS_TIMEOUT: 300
      WAIT_SLEEP_INTERVAL: 30
      WAIT_HOST_CONNECT_TIMEOUT: 30
      MYSQL_ROOT_PASSWORD: "pagal!123"
      MYSQL_USER: "bu"
      MYSQL_PASSWORD: "123"
      MYSQL_DATABASE: "rb_db"
      # MYSQL_HOST: "bucket-database"
      # MYSQL_PORT: "3305"
    ports: 
      - "8084:8084"
    restart: on-failure
    # volumes: 
    #   - ./src:/usr/src/app/
    depends_on: 
      - bucket-mysql
    networks: 
      - fullstack


volumes: 
    database_mysql:
  
networks: 
  fullstack:
    driver: bridge

This is my Go MySQL connection code

func init() {
    // loaDerr := godotenv.Load()
    // if loaDerr != nil {
    //  log.Fatal("Error loading .env file")
    // }

    username := os.Getenv("MYSQL_USER")
    password := os.Getenv("MYSQL_ROOT_PASSWORD")
    host := os.Getenv("WAIT_HOSTS")
    port := os.Getenv("MYSQL_PORT")
    schema := os.Getenv("MYSQL_DATABASE")

    fmt.Println(username, password, host, port, schema)

    dataSourceName := fmt.Sprintf(
        "%s:%s@tcp(%s)/%s?charset=utf8&parseTime=True&loc=Local",
        username,
        password,
        host,
       // port,
        schema,
    )

    var err error
    //connect to the database server
    client, err = sql.Open("mysql", dataSourceName)
    if err != nil {
        panic(err)
    }

    //checking the connection
    if connectionErr := client.Ping(); connectionErr != nil {
        panic(connectionErr.Error())
    }

    fmt.Println("Database connection is been established succesfully")
}

please help me in this i have tried all the combinations but its not working, If I connect the mysql workbench with the running mysql container it connect normally and don't give any error but doing connection with docker and golang it giving me an error thankuu

Answer 1

In your DSN, you didn't set the port, which was changed from default 3306 -> 3305 in your docker-compose

 fmt.Println(username, password, host, port, schema)

    dataSourceName := fmt.Sprintf(
        "%s:%s@tcp(%s)/%s?charset=utf8&parseTime=True&loc=Local",
        username,
        password,
        host,
        schema,
    )

Add port to DSN

 fmt.Println(username, password, host, port, schema)

    dataSourceName := fmt.Sprintf(
        "%s:%s@tcp(%s:%s)/%s?charset=utf8&parseTime=True&loc=Local",
        username,
        password,
        host,
        port
        schema,
    )

Answer 2

Whenever you make a connection between containers, Docker uses the "normal" port the service listens on. If you're connecting to a MySQL or MariaDB container, it always uses port 3306; ports: aren't required for this case, and if they are, they're ignored.

services:
  bucket-mysql:
    image: mysql:latest
    # neither expose: nor ports: are required
  bucket:
    build: .
    environment:
      WAIT_HOSTS: bucket-mysql:3306 # ignores ports: remapping
      MYSQL_HOST: bucket-mysql
      # MYSQL_PORT: "3306"          # this is the default port

( expose: does almost nothing in modern Docker and it's safe to delete that; if you did have it, the port number there is the port number inside the container, and the mysql image already has EXPOSE 3306 in its Dockerfile. You can also safely rely on Compose's default values for networks: , container_name: , and the built image: name, plus you shouldn't usually need to override command: from what your Dockerfile specifies for its CMD . This might help simplify your docker-compose.yml file.)

Answer 3

Have a look at your setting:

WAIT_HOSTS: bucket-mysql:3305

You are using the same in your GO app and it should be 3306!

3305 is the port it is running on your host machine