Golang中遇到Panic: dial tcp 192.168.160.2:3305: connect: connection refused错误求助
Golang中遇到Panic: dial tcp 192.168.160.2:3305: connect: connection refused错误求助
每次运行 docker-compose up 时，我都会遇到这个错误。
//错误
> $ docker-compose up --build
Creating network "bucket-api_fullstack" with driver "bridge"
Building bucket
Step 1/17 : FROM golang:1.15-alpine as builder
---> 3dae2ccc15b8
Step 2/17 : RUN mkdir /app
---> Using cache
---> 70dd1c583533
Step 3/17 : ADD . /app
---> Using cache
---> 4586c50cca46
Step 4/17 : WORKDIR /app
---> Using cache
---> c3a943c24b9e
Step 5/17 : RUN go clean --modcache
---> Using cache
---> 200b57f5142e
Step 6/17 : RUN go mod download
---> Using cache
---> 25e6672cddbe
Step 7/17 : RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o main ./src/
---> Using cache
---> 625a83d39c9d
Step 8/17 : FROM alpine:latest
---> e50c909a8df2
Step 9/17 : RUN apk --no-cache add ca-certificates
---> Using cache
---> 9fb84fe65803
Step 10/17 : RUN apk add --no-cache git make musl-dev go
---> Using cache
---> 81520138b2d7
Step 11/17 : COPY --from=builder /app/main .
---> Using cache
---> c285894862aa
Step 12/17 : ENV GOROOT /usr/lib/go
---> Using cache
---> c5a2790f18cb
Step 13/17 : ENV GOPATH /go
---> Using cache
---> 8fdf6d244cd1
Step 14/17 : ENV PATH /go/bin:$PATH
---> Using cache
---> a40c53d193c1
Step 15/17 : RUN mkdir -p ${GOPATH}/src ${GOPATH}/bin
---> Using cache
---> b199ed72e3f5
Step 16/17 : EXPOSE 8084
---> Using cache
---> 4ab9ad5a24af
Step 17/17 : CMD ["./main"]
---> Using cache
---> 4f1478c4b83f
Successfully built 4f1478c4b83f
Successfully tagged bucketapi:latest
Creating bucket-database ... done
Creating bucket-api ... done
Attaching to bucket-database, bucket-api
bucket-api | rbucket pagal!123 bucket-database 3305 rb_db
bucket-api | panic: dial tcp 192.168.160.2:3305: connect: connection refused
bucket-api |
bucket-api | goroutine 1 [running]:
bucket-api |
bucket-api | /app/src/datasources/mysql/bucket_db/bucket_db.go:51 +0x554
bucket-database | 2021-02-12 11:50:17+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 8.0.23-1debian10 started.
bucket-database | 2021-02-12 11:50:17+00:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'
bucket-database | 2021-02-12 11:50:17+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 8.0.23-1debian10 started.
bucket-database | 2021-02-12T11:50:18.393432Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.23) starting as process 1
bucket-database | 2021-02-12T11:50:18.941771Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
bucket-database | 2021-02-12T11:50:23.269865Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
bucket-database | 2021-02-12T11:50:23.974635Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Bind-address: '::' port: 33060, socket: /var/run/mysqld/mysqlx.sock
bucket-database | 2021-02-12T11:50:24.336745Z 0 [System] [MY-010229] [Server] Starting XA crash recovery...
bucket-database | 2021-02-12T11:50:24.357326Z 0 [System] [MY-010232] [Server] XA crash recovery finished.
bucket-database | 2021-02-12T11:50:25.059647Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
bucket-database | 2021-02-12T11:50:25.060266Z 0 [System] [MY-013602] [Server] Channel mysql_main configured to support TLS. Encrypted connections are now supported for this channel.
bucket-database | 2021-02-12T11:50:25.191338Z 0 [Warning] [MY-011810] [Server] Insecure configuration for --pid-file: Location '/var/run/mysqld' in the path is accessible to all OS users. Consider choosing a different directory.
bucket-database | 2021-02-12T11:50:25.327133Z 0 [System] [MY-010931] [Server] /usr/sbin/mysqld: ready for connections. Version: '8.0.23' socket: '/var/run/mysqld/mysqld.sock'
port: 3306 MySQL Community Server - GPL.
bucket-api exited with code 2
这是我的 DOCKER-COMPOSE 文件
> version: '3.8'
>
> services:
> # MYSQL DATABASE DOCKER
> bucket-mysql:
> image: mysql:latest
> container_name: bucket-database
> command: --default-authentication-plugin=mysql_native_password
> ports:
> - "127.0.0.1:3305:3306"
> environment:
> MYSQL_ROOT_PASSWORD: "pagal!123"
> MYSQL_USER: "rbucket"
> 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
> environment:
> MYSQL_ROOT_PASSWORD: "pagal!123"
> MYSQL_USER: "rbucket"
> MYSQL_PASSWORD: "pagal!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
这是我的 DOCKER 文件
> #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 .
>
> # 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"]
我从此文件中收到错误
> //client info
>
> var (
>
> client *sql.DB
>
> )
>
> 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("MYSQL_HOST")
>
> 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)/%s?charset=utf8",
>
> 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)
>
> }
>
> fmt.Println("Database connection is been established succesfully")
>
> }
>
> //GetClient : this method returns the connected client database
>
> func GetClient() *sql.DB {
>
> return client
>
> }
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11 回复
我之前尝试过，它总是给我同样的错误。
更多关于Golang中遇到Panic: dial tcp 192.168.160.2:3305: connect: connection refused错误求助的实战系列教程也可以访问 https://www.itying.com/category-94-b0.html
NobbZ:
192.168.160.2
我认为这是 MySQL 容器的 IP 地址，因为我已经提到了附加了端口的 MySQL 容器名称。您能就这个问题给我提供一个参考吗？这对我将是巨大的帮助，谢谢。
我认为你可以尝试使用端口 3306 来连接 MySQL 容器。
就像你 ports 配置中最新的 ("3305:3306") 那样，你可能可以通过 <your_host>:3305 和 <mysql_container_ip>:3306 来连接 MySQL 服务器。
niteeshDubey:
192.168.160.2
这个IP地址属于谁？它是否属于那个在你的程序已经退出后才首次有输出的数据库？
那么，让你的程序依赖于数据库容器，并且在启动你的应用之前添加一段充裕的休眠时间，因为 docker-compose 没有容器“就绪”的概念。
我不熟悉Docker，所以这可能不相关，但是：
niteeshDubey:
ports: - "127.0.0.1:3305:3306"
在我看来，这似乎意味着MySQL只会监听来自MySQL服务器本身的传入连接。在Docker中，有没有办法可以监听任何IP，或者监听Docker提供的IP（我认为Docker可以做到这一点）？或许直接用 ":3305:3306"？
这个错误是因为你的Go应用在MySQL容器完全启动之前就尝试连接数据库。从日志可以看到，bucket-api容器在MySQL容器还在初始化时就尝试连接，导致连接被拒绝。
问题出现在depends_on只确保容器启动顺序，但不等待服务完全就绪。你需要让Go应用等待MySQL完全准备好再连接。
修改你的Go代码，添加重试逻辑：
package main
import (
"database/sql"
"fmt"
"log"
"os"
"time"
_ "github.com/go-sql-driver/mysql"
)
var (
client *sql.DB
)
func init() {
username := os.Getenv("MYSQL_USER")
password := os.Getenv("MYSQL_ROOT_PASSWORD")
host := os.Getenv("MYSQL_HOST")
port := os.Getenv("MYSQL_PORT")
schema := os.Getenv("MYSQL_DATABASE")
dataSourceName := fmt.Sprintf(
"%s:%s@tcp(%s:%s)/%s?charset=utf8",
username,
password,
host,
port,
schema,
)
var err error
maxRetries := 30
retryInterval := 2 * time.Second
for i := 0; i < maxRetries; i++ {
client, err = sql.Open("mysql", dataSourceName)
if err != nil {
log.Printf("Failed to open database (attempt %d/%d): %v", i+1, maxRetries, err)
time.Sleep(retryInterval)
continue
}
err = client.Ping()
if err != nil {
log.Printf("Failed to ping database (attempt %d/%d): %v", i+1, maxRetries, err)
client.Close()
time.Sleep(retryInterval)
continue
}
fmt.Println("Database connection established successfully")
return
}
log.Fatalf("Failed to connect to database after %d attempts", maxRetries)
}
func GetClient() *sql.DB {
return client
}
另外，确保你的docker-compose.yml中bucket服务等待MySQL健康检查通过：
version: '3.8'
services:
bucket-mysql:
image: mysql:latest
container_name: bucket-database
command: --default-authentication-plugin=mysql_native_password
ports:
- "127.0.0.1:3305:3306"
environment:
MYSQL_ROOT_PASSWORD: "pagal!123"
MYSQL_USER: "rbucket"
MYSQL_PASSWORD: "root"
MYSQL_DATABASE: "rb_db"
networks:
- fullstack
volumes:
- database_mysql:/var/lib/mysql
restart: always
healthcheck:
test: ["CMD", "mysqladmin", "ping", "-h", "localhost"]
timeout: 20s
retries: 10
interval: 10s
start_period: 40s
bucket:
image: bucketapi
build: .
container_name: bucket-api
environment:
MYSQL_ROOT_PASSWORD: "pagal!123"
MYSQL_USER: "rbucket"
MYSQL_PASSWORD: "pagal!123"
MYSQL_DATABASE: "rb_db"
MYSQL_HOST: "bucket-database"
MYSQL_PORT: "3306" # 注意这里应该是3306，不是3305
ports:
- "8084:8084"
depends_on:
bucket-mysql:
condition: service_healthy
networks:
- fullstack
volumes:
database_mysql:
networks:
fullstack:
driver: bridge
注意：在docker-compose中，bucket服务连接MySQL应该使用容器内部的端口3306，而不是映射到主机的3305。容器间通信使用服务名和内部端口。
