How to enable Docker containers launched by Jenkins to access certain ports on 127.0.0.1?

[ohMyJava]

Jenkins and plugins versions report

Jenkins Version: 2.450
docker plugin version: 1.6.2

What Operating System are you using (both controller, and any agents involved in the problem)?

Jenkins deployed in Docker container on Linux host

Reproduction steps

Fill in the host option in the container configuration, and NPE will be prompted.
Is there any way to allow Docker to access port 127.0.0.1 without configuring the host?

Expected Results

Enable Docker to access port 127.0.0.1

Actual Results

Unable to access port 127.0.0.1

Anything else?

No response

Are you interested in contributing a fix?

No response

[MarkEWaite]

I can't duplicate the problem that you are describing. I opened the cloud configuration on Jenkins 2.479.1 and in the Docker Agent Templates section I expanded the Container settings and entered as Hostname the value of the host where I run the Docker listener. No null pointer exception was reported. I'm running Docker plugin 1.7.0.

Does the same failure occur with Docker plugin 1.7.0 on a recent Jenkins version like 2.484?

[ohMyJava]

Thank you for your response.
When I follow the following steps: Define a Docker template ->Container settings ->Network Input Area
When entering host in the input box of Network configuration, NPE will be prompted

Error in provisioning; template='DockerTemplate{configVersion=2, labelString='f3646f65-8c16-449b-9f97-75c86e9768d3', connector=DockerComputerSSHConnector{sshKeyStrategy=InjectSSHKey{user='root'}, port=22, javaPath='/home/tools/java/jdk-11/bin/java'}, remoteFs='/home', instanceCap=1, mode=EXCLUSIVE, retentionStrategy=com.nirima.jenkins.plugins.docker.strategy.DockerOnceRetentionStrategy@29, dockerTemplateBase=DockerTemplateBase{image='a17sw/test_curl:ver1', dnsHosts=[host], network'='host', bindAllPorts=false, cpuPeriod=0, cpuQuota=0, privileged=true, tty=false}, removeVolumes=false, stopTimeout=10, pullStrategy=PULL_NEVER, pullTimeout=0, disabled=BySystem,0 ms,4 min 59 sec,Template provisioning failed.}' for cloud='10.12.16.119'
java.lang.NullPointerException
at java.base/java.util.Arrays.stream(Arrays.java:5614)
at java.base/java.util.stream.Stream.of(Stream.java:1188)
at io.jenkins.docker.connector.DockerComputerSSHConnector.getBindingForPort(DockerComputerSSHConnector.java:387)
at io.jenkins.docker.connector.DockerComputerSSHConnector.createLauncher(DockerComputerSSHConnector.java:333)
at io.jenkins.docker.connector.DockerComputerConnector.createLauncher(DockerComputerConnector.java:187)
at com.nirima.jenkins.plugins.docker.DockerTemplate.doProvisionNode(DockerTemplate.java:758)
at com.nirima.jenkins.plugins.docker.DockerTemplate.provisionNode(DockerTemplate.java:686)
at com.nirima.jenkins.plugins.docker.DockerCloud$1.run(DockerCloud.java:414)
at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:68)
at jenkins.util.ErrorLoggingExecutorService.lambda$wrap$0(ErrorLoggingExecutorService.java:51)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:834)

Nov 11, 2024 3:01:26 PM WARNING jenkins.util.ErrorLoggingExecutorService lambda$wrap$0
null
java.lang.NullPointerException
at java.base/java.util.Arrays.stream(Arrays.java:5614)
at java.base/java.util.stream.Stream.of(Stream.java:1188)
at io.jenkins.docker.connector.DockerComputerSSHConnector.getBindingForPort(DockerComputerSSHConnector.java:387)
at io.jenkins.docker.connector.DockerComputerSSHConnector.createLauncher(DockerComputerSSHConnector.java:333)
at io.jenkins.docker.connector.DockerComputerConnector.createLauncher(DockerComputerConnector.java:187)
at com.nirima.jenkins.plugins.docker.DockerTemplate.doProvisionNode(DockerTemplate.java:758)
at com.nirima.jenkins.plugins.docker.DockerTemplate.provisionNode(DockerTemplate.java:686)
at com.nirima.jenkins.plugins.docker.DockerCloud$1.run(DockerCloud.java:414)
at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:68)
at jenkins.util.ErrorLoggingExecutorService.lambda$wrap$0(ErrorLoggingExecutorService.java:51)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:834)

[MarkEWaite]

I can't duplicate that failure in my environment. I open the configuration page for my cloud agents, click the "Docker Agent Templates" button and expand the "Container settings". Then I enter "host" in the Network field and save it. No null pointer exception.