seems like my docker agent is unable to download maven and i don't know why.
My environment is behind a proxy and I sure configured proxy on the master and also on the docker. fun fact I can exec commands on the container and download manually, please see attach "proxy_works.png"

Any help please.
 
Started by user
manuh
Running as SYSTEM
Building remotely on
docker-agent-0003w435q1mm7 on docker
(docker-agent) in workspace /home/jenkins/workspace/java-test
The recommended git tool is: NONE
using credential manuh-gitlab
Cloning the remote Git repository
Cloning repository
http://192.168.100.4/manuh/maven-example.git
> git init /home/jenkins/workspace/java-test # timeout=10
Fetching upstream changes from
http://192.168.100.4/manuh/maven-example.git
> git --version # timeout=10
> git --version # 'git version 2.20.1'
using GIT_ASKPASS to set credentials manuh-gitlab
Setting http proxy: 192.168.100.214:3128
> git fetch --tags --force --progress –
http://192.168.100.4/manuh/maven-example.git
+refs/heads/:refs/remotes/origin/ # timeout=10
> git config remote.origin.url
http://192.168.100.4/manuh/maven-example.git

1. timeout=10
   > git config --add remote.origin.fetch +refs/heads/:refs/remotes/origin/ # timeout=10
   Avoid second fetch
   > git rev-parse refs/remotes/origin/master^{commit} # timeout=10
   Checking out Revision d429203aa304cba0a1beb7fda8219d916c1e2fce (refs/remotes/origin/master)
   > git config core.sparsecheckout # timeout=10
   > git checkout -f d429203aa304cba0a1beb7fda8219d916c1e2fce # timeout=10
   Commit message: "Merge pull request #264 from MarkEWaite/use-latest-compiler-plugin"
   > git rev-list --no-walk d429203aa304cba0a1beb7fda8219d916c1e2fce # timeout=10
   Unpacking
   https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.6.3/apache-maven-3.6.3-bin.zip
   to /home/jenkins/tools/hudson.tasks.Maven_MavenInstallation/maven3 on docker-agent-0003w435q1mm7 on docker
   ERROR: Failed to download
   https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.6.3/apache-maven-3.6.3-bin.zip
   from agent; will retry from controller
   Also: hudson.remoting.Channel$CallSiteStackTrace: Remote call to docker-agent-0003w435q1mm7
   at hudson.remoting.Channel.attachCallSiteStackTrace(Channel.java:1784)
   at hudson.remoting.UserRequest$ExceptionResponse.retrieve(UserRequest.java:356)
   at hudson.remoting.Channel.call(Channel.java:1000)
   at hudson.FilePath.act(FilePath.java:1193)
   at hudson.FilePath.act(FilePath.java:1182)
   at hudson.FilePath.installIfNecessaryFrom(FilePath.java:1045)
   at hudson.FilePath.installIfNecessaryFrom(FilePath.java:981)
   at hudson.tools.DownloadFromUrlInstaller.performInstallation(DownloadFromUrlInstaller.java:77)
   at hudson.tools.InstallerTranslator.getToolHome(InstallerTranslator.java:70)
   at hudson.tools.ToolLocationNodeProperty.getToolHome(ToolLocationNodeProperty.java:108)
   at hudson.tools.ToolInstallation.translateFor(ToolInstallation.java:221)
   at hudson.tasks.Maven$MavenInstallation.forNode(Maven.java:682)
   at hudson.tasks.Maven.perform(Maven.java:319)
   at hudson.tasks.BuildStepMonitor$1.perform(BuildStepMonitor.java:20)
   at hudson.model.AbstractBuild$AbstractBuildExecution.perform(AbstractBuild.java:816)
   at hudson.model.Build$BuildExecution.build(Build.java:199)
   at hudson.model.Build$BuildExecution.doRun(Build.java:164)
   at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:524)
   at hudson.model.Run.execute(Run.java:1897)
   at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:44)
   at hudson.model.ResourceController.execute(ResourceController.java:101)
   at hudson.model.Executor.run(Executor.java:442)
   java.net.UnknownHostException: repo.maven.apache.org
   at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:184)
   at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
   at java.net.Socket.connect(Socket.java:607)
   at sun.security.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:666)
   at sun.security.ssl.BaseSSLSocketImpl.connect(BaseSSLSocketImpl.java:173)
   at sun.net.NetworkClient.doConnect(NetworkClient.java:180)
   at sun.net.www.http.HttpClient.openServer(HttpClient.java:463)
   at sun.net.www.http.HttpClient.openServer(HttpClient.java:558)
   at sun.net.www.protocol.https.HttpsClient.<init>(HttpsClient.java:264)
   at sun.net.www.protocol.https.HttpsClient.New(HttpsClient.java:367)
   at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(AbstractDelegateHttpsURLConnection.java:191)
   at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1162)
   at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:1056)
   at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:177)
   at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1570)
   at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1498)
   at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:268)
   at java.net.URL.openStream(URL.java:1068)
   at hudson.FilePath$Unpack.invoke(FilePath.java:1081)
   at hudson.FilePath$Unpack.invoke(FilePath.java:1073)
   at hudson.FilePath$FileCallableWrapper.call(FilePath.java:3486)
   at hudson.remoting.UserRequest.perform(UserRequest.java:211)
   at hudson.remoting.UserRequest.perform(UserRequest.java:54)
   at hudson.remoting.Request$2.run(Request.java:376)
   at hudson.remoting.InterceptingExecutorService.lambda$wrap$0(InterceptingExecutorService.java:78)
   at java.util.concurrent.FutureTask.run(FutureTask.java:266)
   at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
   at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
   at java.lang.Thread.run(Thread.java:748)