Jenkins 问题汇总

1. 未安装 Maven

ERROR: A Maven installation needs to be available for this project to be built.Either your server has no Maven installations defined, or the requested Maven version does not exist.
Finished: FAILURE

原因：Jenkins 默认是没有安装 Maven 的。

解决办法：使用全局工具配置，自动安装 Maven。

在pipeline{}中添加自动下载工具命令

tools {
    maven 'Apache-maven-3.8.6'
}

2. 用 SSH 凭证方式连接 Git 失败

Failed to connect to repository : Command "git ls-remote -h -- git@github.com:xxx/xxx.git HEAD" returned status code 128:
stdout:
stderr: No ECDSA host key is known for github.com and you have requested strict checking.
Host key verification failed.
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

原因：首次连接可能会出现此错误。

解决办法：Dashboard > Manage Jenkins > Config Global Security  修改验证策略为 Accpt first connection。

3. 部署 jar 包到 nexus 失败

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-deploy-plugin:2.8.2:deploy (default-deploy) on project home-api: Deployment failed: repository element was not specified in the POM inside distributionManagement element or in -DaltDeploymentRepository=id::layout::url parameter -> [Help 1]

原因：未在pom文件中配置分发管理。

解决办法：在pom.xml文件中添加distributionManagement节点，使用分发管理将项目打成jar包，直接上传到指定服务器。

snapshotRepository是快照版本，repository是正式版本。

需要注意的是，这里的id应该与setting.xml文件中server节点下的id相同。

<distributionManagement>
    <snapshotRepository>
        <id>nexus-public</id>
        <name>Nexus Snapshot Repository</name>
        <url>http://ori-nexus.com/repository/maven-snapshots/</url>
    </snapshotRepository>
    <repository>
        <id>nexus-public</id>
        <name>Nexus Release Repository</name>
        <url>http://ori-nexus.com/repository/maven-releases/</url>
    </repository>
</distributionManagement>

4. 上传 jar 包再次失败

status: 413 Request Entity Too Large -> [Help 1]

原因：使用了nginx作为nexus服务的反向代理，nginx不允许上传过大的文件。

解决办法：可以把client_max_body_size根据需要调大。

server {
  listen 80;
  server_name ori-nexus.com;
  client_max_body_size 30M;

  proxy_set_header Host $host;
  proxy_set_header X-Real-IP $remote_addr;
  proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

  location / {
    proxy_pass http://nexus:8081;
  }
}

 重新加载配置文件使之生效：docker exec -it nginx-proxy /usr/sbin/nginx -s reload