postgresql Postgres + Go + Docker-compose无法ping数据库：拨号TCP 127.0.0.1：5432：连接：连接被拒绝

vmdwslir  于 2022-11-23  发布在  PostgreSQL
关注(0)|答案(1)|浏览(149)

这不是我的golang脚本，但我应该在这个任务中使用它们： Package 主体

import (
    "database/sql"
    "fmt"
    _ "github.com/lib/pq"
    "log"
    "net/http"

    "github.com/caarlos0/env"
    "github.com/prometheus/client_golang/prometheus"
    "github.com/prometheus/client_golang/prometheus/promhttp"
)

type config struct {
    PostgresUri   string `env:"POSTGRES_URI" envDefault:"postgres://root:pass@127.0.0.1/postgres"`
    ListenAddress string `env:"LISTEN_ADDRESS" envDefault:":5432"`
}

var (
    db          *sql.DB
    errorsCount = prometheus.NewCounterVec(
        prometheus.CounterOpts{
            Name: "gocalc_errors_count",
            Help: "Gocalc Errors Count Per Type",
        },
        []string{"type"},
    )

    requestsCount = prometheus.NewCounter(
        prometheus.CounterOpts{
            Name: "gocalc_requests_count",
            Help: "Gocalc Requests Count",
        })
)

func main() {
    var err error

    // Initing prometheus
    prometheus.MustRegister(errorsCount)
    prometheus.MustRegister(requestsCount)

    // Getting env
    cfg := config{}
    if err = env.Parse(&cfg); err != nil {
        fmt.Printf("%+v\n", err)
    }

    // Connecting to database
    db, err = sql.Open("postgres", cfg.PostgresUri)
    if err != nil {
        log.Fatalf("Can't connect to postgresql: %v", err)
    }
    defer db.Close()

    err = db.Ping()
    if err != nil {
        log.Fatalf("Can't ping database: %v", err)
    }

    http.HandleFunc("/", handler)
    http.Handle("/metrics", promhttp.Handler())
    log.Fatal(http.ListenAndServe(cfg.ListenAddress, nil))
}

func handler(w http.ResponseWriter, r *http.Request) {
    requestsCount.Inc()

    keys, ok := r.URL.Query()["q"]
    if !ok || len(keys[0]) < 1 {
        errorsCount.WithLabelValues("missing").Inc()
        log.Println("Url Param 'q' is missing")
        http.Error(w, "Bad Request", 400)
        return
    }
    q := keys[0]
    log.Println("Got query: ", q)

    var result string
    sqlStatement := fmt.Sprintf("SELECT (%s)::numeric", q)
    row := db.QueryRow(sqlStatement)
    err := row.Scan(&result)

    if err != nil {
        log.Println("Error from db: %s", err)
        errorsCount.WithLabelValues("db").Inc()
        http.Error(w, "Internal Server Error", 500)
        return
    }

    fmt.Fprintf(w, "query %s; result %s", q, result)
}

这是我的docker-compose：

version: "3"
services:
  db:
    image: postgres:10
    environment:
      - POSTGRES_PASSWORD=pass
      - POSTGRES_USER=root
    expose:
      - 5432
    
  backend:
    image: dkr-14-gocalc:latest
    environment:
      - POSTGRES_URI=postgres://root:pass@db/postgres
      - LISTEN_ADDRESS=7000
    depends_on:
      - postgres
  proxy:
    image: nginx
    volumes:
      - type: bind
        source: ./nginx.conf
        target: /etc/nginx/conf.d/default.conf
    ports:
      - 8000:80
    depends_on: 
      - backend

而且是dkr 14-gocalc的图像：

FROM golang:1.19.1-alpine AS builder
ENV GO111MODULE=auto
WORKDIR /go/src/

RUN apk add --no-cache git 
COPY main.go ./
 
#init is initializing and writting new go.mod in current dir.
RUN go mod init main.go

RUN go get -d -v github.com/caarlos0/env \
    && go get -d -v github.com/prometheus/client_golang/prometheus \
    && go get -d -v github.com/prometheus/client_golang/prometheus/promhttp \
    && go get -d -v github.com/lib/pq \   
    && go get -d -v database/sql \
    && go get -d -v fmt \
    && go get -d -v log \
    && go get -d -v net/http
    
RUN go build -o app .

FROM alpine:3.10.3
RUN apk --no-cache add ca-certificates
WORKDIR /root/
COPY --from=builder /go/src/app ./
CMD ["./app"]

我应该让docker组成环境与3个服务GO+POSTGRES+NGINX。任务的主要思想是了解环境。数据库应该有密码和golalc应该连接到这个数据库。但我做错了什么？
这是我的日志：

backend_1   | 2022/11/07 23:27:33 Can't ping database: dial tcp 127.0.0.1:5432: connect: connection refused
postgres_1  | The files belonging to this database system will be owned by user "postgres".
postgres_1  | This user must also own the server process.
postgres_1  | 
proxy_1     | /docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration
proxy_1     | /docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/
postgres_1  | The database cluster will be initialized with locale "en_US.utf8".
postgres_1  | The default database encoding has accordingly been set to "UTF8".
postgres_1  | The default text search configuration will be set to "english".
postgres_1  | 
postgres_1  | Data page checksums are disabled.
proxy_1     | /docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh
proxy_1     | 10-listen-on-ipv6-by-default.sh: info: Getting the checksum of /etc/nginx/conf.d/default.conf
postgres_1  | 
task14_backend_1 exited with code 1
proxy_1     | 10-listen-on-ipv6-by-default.sh: info: /etc/nginx/conf.d/default.conf differs from the packaged version
postgres_1  | fixing permissions on existing directory /var/lib/postgresql/data ... ok
postgres_1  | creating subdirectories ... ok
proxy_1     | /docker-entrypoint.sh: Launching /docker-entrypoint.d/20-envsubst-on-templates.sh
postgres_1  | selecting default max_connections ... 100
proxy_1     | /docker-entrypoint.sh: Launching /docker-entrypoint.d/30-tune-worker-processes.sh
postgres_1  | selecting default shared_buffers ... 128MB
postgres_1  | selecting default timezone ... Etc/UTC
postgres_1  | selecting dynamic shared memory implementation ... posix
proxy_1     | /docker-entrypoint.sh: Configuration complete; ready for start up
postgres_1  | creating configuration files ... ok
postgres_1  | running bootstrap script ... ok
postgres_1  | performing post-bootstrap initialization ... ok
postgres_1  | syncing data to disk ... ok
postgres_1  | 
postgres_1  | Success. You can now start the database server using:
postgres_1  | 
postgres_1  |     pg_ctl -D /var/lib/postgresql/data -l logfile start
postgres_1  | 
postgres_1  | 
postgres_1  | WARNING: enabling "trust" authentication for local connections
postgres_1  | You can change this by editing pg_hba.conf or using the option -A, or
postgres_1  | --auth-local and --auth-host, the next time you run initdb.
proxy_1     | 2022/11/07 23:27:33 [emerg] 1#1: host not found in upstream "backend" in /etc/nginx/conf.d/default.conf:5
proxy_1     | nginx: [emerg] host not found in upstream "backend" in /etc/nginx/conf.d/default.conf:5
postgres_1  | waiting for server to start....2022-11-07 23:27:33.704 UTC [48] LOG:  listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
postgres_1  | 2022-11-07 23:27:33.722 UTC [49] LOG:  database system was shut down at 2022-11-07 23:27:33 UTC
postgres_1  | 2022-11-07 23:27:33.729 UTC [48] LOG:  database system is ready to accept connections
postgres_1  |  done
postgres_1  | server started
task14_proxy_1 exited with code 1
postgres_1  | CREATE DATABASE
postgres_1  | 
postgres_1  | 
postgres_1  | /usr/local/bin/docker-entrypoint.sh: ignoring /docker-entrypoint-initdb.d/*
postgres_1  | 
postgres_1  | 2022-11-07 23:27:34.130 UTC [48] LOG:  received fast shutdown request
postgres_1  | waiting for server to shut down....2022-11-07 23:27:34.133 UTC [48] LOG:  aborting any active transactions
postgres_1  | 2022-11-07 23:27:34.135 UTC [48] LOG:  worker process: logical replication launcher (PID 55) exited with exit code 1
postgres_1  | 2022-11-07 23:27:34.135 UTC [50] LOG:  shutting down
postgres_1  | 2022-11-07 23:27:34.157 UTC [48] LOG:  database system is shut down
postgres_1  |  done
postgres_1  | server stopped
postgres_1  | 
postgres_1  | PostgreSQL init process complete; ready for start up.
postgres_1  | 
postgres_1  | 2022-11-07 23:27:34.254 UTC [1] LOG:  listening on IPv4 address "0.0.0.0", port 5432
postgres_1  | 2022-11-07 23:27:34.254 UTC [1] LOG:  listening on IPv6 address "::", port 5432
postgres_1  | 2022-11-07 23:27:34.259 UTC [1] LOG:  listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
postgres_1  | 2022-11-07 23:27:34.283 UTC [76] LOG:  database system was shut down at 2022-11-07 23:27:34 UTC
postgres_1  | 2022-11-07 23:27:34.294 UTC [1] LOG:  database system is ready to accept connections
postgresql

1条答案

按热度按时间
z31licg0

z31licg01#

问题可能在于如何在docker-compose.yaml文件中公开数据库容器。“connection refused”是这种情况下的典型错误。通常，我以不同的方式导出端口（在此代码中，我只报告了相关部分）：

docker-compose.yaml中的代码
version: "3"
services:
  db:
    image: postgres
    environment:
      - POSTGRES_PASSWORD=postgres
      - POSTGRES_USER=postgres
    ports:
      - "5432:5432"
主.开始
package main

import (
    "database/sql"
    "log"

    _ "github.com/lib/pq"
)

func main() {
    // Connecting to database
    db, err := sql.Open("postgres", "host=127.0.0.1 user=postgres password=postgres dbname=postgres port=5432 sslmode=disable")
    if err != nil {
        log.Fatalf("Can't connect to postgresql: %v", err)
    }
    defer db.Close()

    err = db.Ping()
    if err != nil {
        log.Fatalf("Can't ping database: %v", err)
    }
}

有了这个解决方案，我能够成功地直接从代码ping Postgres数据库。如果这有帮助，请告诉我。

编辑

与db示例交互的方式有一点不同：
1.如果您试图直接从主机联系数据库（如main.go文件），则必须使用您的机器的IP地址来引用它（例如，127.0.0.1）。
1.如果您尝试从Web容器中联系数据库，则必须使用类似于postgres://db:5432的名称，并将db作为主机名。
如果这能解释清楚一点，请告诉我。

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