在现代软件开发中，Docker已经成为了一个不可或缺的工具，它能够帮助开发人员快速构建、部署和管理应用程序。而Golang作为一种高效、简洁的编程语言，也备受开发者的青睐。那么，如何在Docker中使用Golang开发应用程序呢？本文将为大家介绍如何编写一个Golang应用程序的Dockerfile，并利用chromedp库实现Web自动化测试。如果你对Golang、Docker以及Web自动化测试感兴趣的话，不妨继续往下看。

问题内容

我有一个 golang 代码，它使用 chromedp 连接到用户的本地 chrome 这是我的代码：

package main

import (
    "context"
    "fmt"
    "log"
    "os"
    "time"

    "github.com/chromedp/chromedp"
    "github.com/gin-gonic/gin"
)

func main() {
    api := gin.default()

    api.get("api/jwt", func(c *gin.context) {
        opts := append(chromedp.defaultexecallocatoroptions[:],
            chromedp.flag("headless", false),
            chromedp.flag("disable-gpu", true),
            chromedp.flag("no-sandbox", true),
            chromedp.flag("disable-dev-shm-usage", true),
            chromedp.flag("disable-browser-side-navigation", true),
            chromedp.flag("disable-infobars", true),
            chromedp.flag("disable-extensions", true),
            chromedp.flag("disable-notifications", true),
            chromedp.flag("disable-default-apps", true),
            chromedp.flag("disable-background-timer-throttling", true),
            chromedp.flag("disable-backgrounding-occluded-windows", true),
            chromedp.flag("disable-renderer-backgrounding", true),
        )

        allocctx, cancel := chromedp.newexecallocator(context.background(), opts...)
        defer cancel()

        ctx, cancel := chromedp.newcontext(allocctx)
        defer cancel()

        var localstoragedata string // declaração da variável localstoragedata

        err := chromedp.run(ctx,
            chromedp.navigate("https://csonlinetenant.b2clogin.com/csonlinetenant.onmicrosoft.com/oauth2/v2.0/authorize"),
            chromedp.sleep(5*time.second),
            chromedp.waitvisible(`#fgh`),
            chromedp.sendkeys(`#fghfg`, "fghfgh"),
            chromedp.sendkeys(`#xcvxcv`, "xcxcvcxv"),
            chromedp.click(`#thgh`, chromedp.byid),
            chromedp.sleep(5*time.second),
            chromedp.click(`dfgd`, chromedp.byid),
            chromedp.sleep(15*time.second),
            chromedp.evaluateasdevtools(`localstorage.getitem('c')`, &localstoragedata),
        )
        if err != nil {
            log.printf("error: %v", err)
            return
        }

        fmt.println("bearer", localstoragedata)

        // restante do código...

        c.json(200, gin.h{
            "success": localstoragedata,
        })
    })

    listenaddr := os.getenv("listen")

    if val, ok := os.lookupenv("functions_customhandler_port"); ok {
        listenaddr = ":" + val
    }
    if listenaddr == "" {
        listenaddr = ":8080"
    }

    api.run(listenaddr)
}

所以我制作了一个 dockerfile，其中包含我的客户使用此应用程序所需的内容（我安装了 chrome 并在图像中构建了我的 golang）

docker 文件：

from golang:1.20 as build-stage

workdir /app

# instale as dependências do chrome
run wget -q -o - https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add - 
    && echo "deb http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list
run apt-get update && apt-get -y install google-chrome-stable
run chrome &


copy go.mod go.sum ./
run go mod download

copy *.go ./

run cgo_enabled=0 goos=linux go build -o /dockergo

# run the tests in the container
from build-stage as run-test-stage
run go test -v ./...

# deploy the application binary into a lean image
from gcr.io/distroless/base-debian11 as build-release-stage

workdir /

copy --from=build-stage /dockergo /dockergo

expose 8080

user nonroot:nonroot

entrypoint ["/dockergo"]

图像构建成功并且没有令人头痛的情况 但是当在本地测试 docker 映像时，我收到此错误：

Error: exec: "google-chrome": executable file not found in $PATH

这个错误是什么意思？我的 chrome 没有运行？我怎样才能运行它？

解决方法

chrome浏览器仅安装在build-stage中。它在 build-release-stage 创建的最终映像中不可用。

我尝试使用此 dockerfile 安装 chrome：

# deploy the application binary into a lean image
from gcr.io/distroless/base-debian11 as build-release-stage

run wget -q -o - https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add - 
    && echo "deb http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list
run apt-get update && apt-get -y install google-chrome-stable
run chrome &

但失败并显示以下消息：

...
step 2/4 : run wget -q -o - https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add -     && echo "deb http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list
 ---> running in 7596202a5684
failed to create shim task: oci runtime create failed: runc create failed: unable to start container process: exec: "/bin/sh": stat /bin/sh: no such file or directory: unknown

我认为你必须选择另一个可以轻松安装 chrome 的基础映像。更好的选择是使用 chromedp/headless-shell 作为基础镜像。该图像包含 chrome 的无头 shell，该 shell 非常小。下面的演示 dockerfile 还显示了首先编译测试二进制文件，然后在 chromedp/headless-shell 映像中运行测试：

FROM golang:1.20.5-buster AS build-stage

WORKDIR /app

COPY go.mod go.sum ./
RUN go mod download

COPY . .

RUN CGO_ENABLED=0 go build -o dockergo
# Build the test binary
RUN CGO_ENABLED=0 go test -c -o dockergo.test

# Run the tests in the container
FROM chromedp/headless-shell:114.0.5735.199 AS run-test-stage

WORKDIR /app
# Copy other files that is needed to run the test (testdata?).
COPY . .
COPY --from=build-stage /app/dockergo.test ./dockergo.test
RUN /app/dockergo.test -test.v

# Deploy the application binary into a lean image
FROM chromedp/headless-shell:114.0.5735.199 AS build-release-stage

COPY --from=build-stage /app/dockergo /dockergo

EXPOSE 8080

ENTRYPOINT ["/dockergo"]