I want to learn Jenkins so I installed it on my Kubernetes setup (Minikube locally) using the jenkins/jenkins:lts image. But when I log in to Jenkins is has the problem of not being able to connect to the plugins server. I have used many hours going through Stackowerflow etc to find a solution, like changing the url from https://updates.jenkins.io/update-center.json to just using http.
I’m not behind a corporate firewall, it’s just on a local machine connected to an ordinary router. Do I really need to set up a proxy server or is there another fix?
Hello @MichaelSoegaard and welcome to this community 
What kind of logs do you have regarding the network?
Is that a timeout?
Would you be able to try a simple docker-compose sample on your machine?
also do you have the actual error message? “doesn’t work” doesn’t tell us much
@poddingue I did try just to run the image with docker run and it worked fine. I will try docker-compose as well.
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So basically I followed the official docs on installing in Kubernetes. When I go the basic yaml route I encounter the problem described here. The first time Jenkins is starting and I log in, I get this screen:
In the log it throws this error:
WARNING hudson.model.UpdateCenter#updateDefaultSite: Upgrading Jenkins. Failed to update the default Update Site 'default'. Plugin upgrades may fail.
This is the full log:
2023-01-23 19:41:31.681+0000 [id=28] WARNING hudson.model.UpdateCenter#updateDefaultSite: Upgrading Jenkins. Failed to update the default Update Site 'default'. Plugin upgrades may fail.
java.net.UnknownHostException: updates.jenkins.io
at java.base/java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:229)
at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.base/java.net.Socket.connect(Socket.java:609)
at java.base/sun.security.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:305)
at java.base/sun.net.NetworkClient.doConnect(NetworkClient.java:177)
at java.base/sun.net.www.http.HttpClient.openServer(HttpClient.java:507)
at java.base/sun.net.www.http.HttpClient.openServer(HttpClient.java:602)
at java.base/sun.net.www.protocol.https.HttpsClient.<init>(HttpsClient.java:266)
at java.base/sun.net.www.protocol.https.HttpsClient.New(HttpsClient.java:373)
at java.base/sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(AbstractDelegateHttpsURLConnection.java:207)
at java.base/sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1187)
at java.base/sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:1081)
at java.base/sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:193)
at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1592)
at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1520)
at java.base/sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:250)
at hudson.model.DownloadService.loadJSON(DownloadService.java:122)
at hudson.model.UpdateSite.updateDirectlyNow(UpdateSite.java:219)
at hudson.model.UpdateSite.updateDirectlyNow(UpdateSite.java:214)
at hudson.model.UpdateCenter.updateDefaultSite(UpdateCenter.java:2672)
at jenkins.install.SetupWizard.init(SetupWizard.java:209)
at jenkins.install.InstallState$InitialSecuritySetup.initializeState(InstallState.java:182)
at jenkins.model.Jenkins.setInstallState(Jenkins.java:1134)
at jenkins.install.InstallUtil.proceedToNextStateFrom(InstallUtil.java:99)
at jenkins.install.InstallState$Unknown.initializeState(InstallState.java:88)
at jenkins.model.Jenkins$15.run(Jenkins.java:3500)
at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:177)
at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:305)
at jenkins.model.Jenkins$5.runTask(Jenkins.java:1161)
at org.jvnet.hudson.reactor.Reactor$2.run(Reactor.java:221)
at org.jvnet.hudson.reactor.Reactor$Node.run(Reactor.java:120)
at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:70)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:829)
2023-01-23 19:41:31.681+0000 [id=42] INFO hudson.util.Retrier#start: The attempt #1 to do the action check updates server failed with an allowed exception:
java.net.UnknownHostException: updates.jenkins.io
at java.base/java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:229)
at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.base/java.net.Socket.connect(Socket.java:609)
at java.base/sun.security.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:305)
at java.base/sun.net.NetworkClient.doConnect(NetworkClient.java:177)
at java.base/sun.net.www.http.HttpClient.openServer(HttpClient.java:507)
at java.base/sun.net.www.http.HttpClient.openServer(HttpClient.java:602)
at java.base/sun.net.www.protocol.https.HttpsClient.<init>(HttpsClient.java:266)
at java.base/sun.net.www.protocol.https.HttpsClient.New(HttpsClient.java:373)
at java.base/sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(AbstractDelegateHttpsURLConnection.java:207)
at java.base/sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1187)
at java.base/sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:1081)
at java.base/sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:193)
at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1592)
at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1520)
at java.base/sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:250)
at hudson.model.DownloadService.loadJSON(DownloadService.java:122)
at hudson.model.UpdateSite.updateDirectlyNow(UpdateSite.java:219)
at hudson.model.UpdateSite.updateDirectlyNow(UpdateSite.java:214)
at hudson.PluginManager.checkUpdatesServer(PluginManager.java:2039)
at hudson.util.Retrier.start(Retrier.java:62)
at hudson.PluginManager.doCheckUpdatesServer(PluginManager.java:2010)
at jenkins.DailyCheck.execute(DailyCheck.java:93)
at hudson.model.AsyncPeriodicWork.lambda$doRun$0(AsyncPeriodicWork.java:102)
at java.base/java.lang.Thread.run(Thread.java:829)
2023-01-23 19:41:31.682+0000 [id=28] INFO jenkins.InitReactorRunner$1#onAttained: Completed initialization
2023-01-23 19:41:31.683+0000 [id=42] INFO hudson.util.Retrier#start: Calling the listener of the allowed exception 'updates.jenkins.io' at the attempt #1 to do the action check updates server
2023-01-23 19:41:31.688+0000 [id=42] INFO hudson.util.Retrier#start: Attempted the action check updates server for 1 time(s) with no success
2023-01-23 19:41:31.691+0000 [id=42] SEVERE hudson.PluginManager#doCheckUpdatesServer: Error checking update sites for 1 attempt(s). Last exception was: UnknownHostException: updates.jenkins.io
2023-01-23 19:41:31.704+0000 [id=22] INFO hudson.lifecycle.Lifecycle#onReady: Jenkins is fully up and running
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this is def a dns issue
Googling i see some people have had minikube issues. I’ve not found anything really useful. Debugging DNS Resolution | Kubernetes is the best i could find.
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