Docker应用程序容器无法与我的MySQL容器通信
我正在使用docker compose将两个容器组合在一起,以帮助自己更好地熟悉docker,但我似乎不明白为什么我的两个容器不能相互通信 我的应用程序的dockerfile是:Docker应用程序容器无法与我的MySQL容器通信,mysql,docker,go,docker-compose,Mysql,Docker,Go,Docker Compose,我正在使用docker compose将两个容器组合在一起,以帮助自己更好地熟悉docker,但我似乎不明白为什么我的两个容器不能相互通信 我的应用程序的dockerfile是: FROM golang ADD . /go/src WORKDIR /go/src RUN go get github.com/go-sql-driver/mysql RUN go get github.com/gorilla/mux RUN go build -o bin/main main.go app.go m
FROM golang
ADD . /go/src
WORKDIR /go/src
RUN go get github.com/go-sql-driver/mysql
RUN go get github.com/gorilla/mux
RUN go build -o bin/main main.go app.go model.go
ENTRYPOINT /go/src/bin/main
EXPOSE 8080
我的docker-compose.yml是
version: '3'
services:
db:
image: mysql:5.7
volumes:
- db_data:/var/lib/mysql
restart: always
ports:
- "3306:3306"
expose:
- "3306"
environment:
MYSQL_ROOT_PASSWORD: testrootpassword
MYSQL_DATABASE: testing
MYSQL_USER: testuser
MYSQL_PASSWORD: testpassword
api:
depends_on:
- db
build: .
ports:
- "8080:8080"
# restart: always
environment:
APP_DB_HOST: db:3306
APP_DB_NAME: testing
APP_DB_USERNAME: testuser
APP_DB_PASSWORD: testpassword
volumes:
db_data:
主应用程序仅在端口8080上启动服务器,并尝试建立与SQL的连接。全面实施如下:
app.go
package main
import (
"database/sql"
"encoding/json"
"fmt"
"log"
"net/http"
"strconv"
_ "github.com/go-sql-driver/mysql"
"github.com/gorilla/mux"
)
type App struct {
Router *mux.Router
DB *sql.DB
}
func (a *App) Initialize(user, password, dbname string) {
connectionString :=
fmt.Sprintf("%s:%s@/%s", user, password, dbname)
var err error
a.DB, err = sql.Open("mysql", connectionString)
if err != nil {
log.Fatal(err)
}
a.ensureTableExists()
a.Router = mux.NewRouter()
a.initializeRoutes()
}
func (a *App) ensureTableExists() {
if _, err := a.DB.Exec(tableCreationQuery); err != nil {
log.Fatal(err)
}
}
func (a *App) Run(addr string) {
log.Fatal(http.ListenAndServe(":8080", a.Router))
}
func (a *App) initializeRoutes() {
a.Router.HandleFunc("/", a.sayHello).Methods("GET")
a.Router.HandleFunc("/products", a.getProducts).Methods("GET")
a.Router.HandleFunc("/product", a.createProduct).Methods("POST")
a.Router.HandleFunc("/product/{id:[0-9]+}", a.getProduct).Methods("GET")
a.Router.HandleFunc("/product/{id:[0-9]+}", a.updateProduct).Methods("PUT")
a.Router.HandleFunc("/product/{id:[0-9]+}", a.deleteProduct).Methods("DELETE")
}
func (a *App) sayHello(w http.ResponseWriter, r *http.Request) {
fmt.Fprintf(w, "Hello Luca!")
}
func (a *App) getProduct(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
id, err := strconv.Atoi(vars["id"])
if err != nil {
respondWithError(w, http.StatusBadRequest, "Invalid product ID")
return
}
p := product{ID: id}
if err := p.getProduct(a.DB); err != nil {
switch err {
case sql.ErrNoRows:
respondWithError(w, http.StatusNotFound, "Product not found")
default:
respondWithError(w, http.StatusInternalServerError, err.Error())
}
return
}
respondWithJSON(w, http.StatusOK, p)
}
func (a *App) getProducts(w http.ResponseWriter, r *http.Request) {
products, err := getProducts(a.DB)
if err != nil {
respondWithError(w, http.StatusInternalServerError, err.Error())
return
}
respondWithJSON(w, http.StatusOK, products)
}
func (a *App) createProduct(w http.ResponseWriter, r *http.Request) {
var p product
decoder := json.NewDecoder(r.Body)
if err := decoder.Decode(&p); err != nil {
respondWithError(w, http.StatusBadRequest, "Invalid request payload")
return
}
defer r.Body.Close()
if err := p.createProduct(a.DB); err != nil {
respondWithError(w, http.StatusInternalServerError, err.Error())
return
}
respondWithJSON(w, http.StatusCreated, p)
}
func (a *App) updateProduct(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
id, err := strconv.Atoi(vars["id"])
if err != nil {
respondWithError(w, http.StatusBadRequest, "Invalid product ID")
return
}
var p product
decoder := json.NewDecoder(r.Body)
if err := decoder.Decode(&p); err != nil {
respondWithError(w, http.StatusBadRequest, "Invalid resquest payload")
return
}
defer r.Body.Close()
p.ID = id
if err := p.updateProduct(a.DB); err != nil {
respondWithError(w, http.StatusInternalServerError, err.Error())
return
}
respondWithJSON(w, http.StatusOK, p)
}
func (a *App) deleteProduct(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
id, err := strconv.Atoi(vars["id"])
if err != nil {
respondWithError(w, http.StatusBadRequest, "Invalid Product ID")
return
}
p := product{ID: id}
if err := p.deleteProduct(a.DB); err != nil {
respondWithError(w, http.StatusInternalServerError, err.Error())
return
}
respondWithJSON(w, http.StatusOK, map[string]string{"result": "success"})
}
func respondWithError(w http.ResponseWriter, code int, message string) {
respondWithJSON(w, code, map[string]string{"error": message})
}
func respondWithJSON(w http.ResponseWriter, code int, payload interface{}) {
response, _ := json.Marshal(payload)
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(code)
w.Write(response)
}
const tableCreationQuery = `CREATE TABLE IF NOT EXISTS products
(
id SERIAL,
name TEXT NOT NULL,
price NUMERIC(10,2) NOT NULL DEFAULT 0.00,
CONSTRAINT products_pkey PRIMARY KEY (id)
)`
要运行应用程序,我使用docker命令docker compose up-d--build
,它可以很好地构建应用程序。当我运行docker ps
时,它只显示我的SQL server已启动,当我查看api容器的日志时,它显示一行代码,上面写着2017/10/01 06:54:14拨号tcp 127.0.0.1:3306:getsockopt:连接被拒绝
。我用硬编码的连接字符串在本地运行应用程序,它运行得很好。我真的不知道发生了什么,所以希望有人能帮助我
干杯 代码中有两个问题。一个是
a.Initialize(
os.Getenv("APP_DB_USERNAME"),
os.Getenv("APP_DB_PASSWORD"),
os.Getenv("APP_DB_NAME"))
您尚未使用APP\u DB\u HOST
初始化数据库,因此您将直接转到localhost
其次,在程序开始时连接到数据库,数据库实际启动需要一些时间。因此,您需要在代码中进行一些重试和超时,或者您应该等待数据库启动,然后运行main命令
查看一个bash脚本,它可以在容器中使用,等待mysql数据库启动,然后运行主程序
编辑-1:更新的dockerfile
下面是您的github repo的更新dockerfile
他还需要为容器提供名称
db
,否则容器将无法在Docker网络上使用名称db
container\u name:db
@mayberg,默认情况下,在compose网络中可以发现服务名称。因此,您不需要容器名称:db
,因为他的服务名称已经是db
,所以根本不需要这样做。在这种情况下,更好的选择是使用网络别名,而不是更改容器名称谢谢!这也将改善我的配置!我将主机添加到连接字符串中,并尝试使用wait-for-it库,但仍然失败。如果这不是太多的要求,你能看到我的实施,让我知道我要去哪里吗wrong@user2901304,您可以使用等待它。sh
不是在生成期间,而是在容器运行时使用。您应该删除RUN./wait…
和ENTRYPOINT…
并使用CMD./wait/wait-for-it.sh--host=db--port=3306--timeout=60--/go/src/bin/main
。我检查过了,它对我很好
a.Initialize(
os.Getenv("APP_DB_USERNAME"),
os.Getenv("APP_DB_PASSWORD"),
os.Getenv("APP_DB_NAME"))
FROM golang
ADD . /go/src
WORKDIR /go/src
RUN go get github.com/go-sql-driver/mysql
RUN go get github.com/gorilla/mux
RUN go build -o bin/main main.go app.go model.go
RUN git clone https://github.com/vishnubob/wait-for-it.git
CMD ./wait-for-it/wait-for-it.sh --host=db --port=3306 --timeout=60 -- /go/src/bin/main
EXPOSE 8080