Gerrit - Replicating to github

Question

I configured gerrit replication via

[remote "github"]
  url = [email protected]:MYUSERNAME/${name}.git
  push = +refs/heads/*:refs/heads/*
  push = +refs/tags/*:refs/tags/*
  timeout = 5
  replicationDelay = 0
  authGroup = Administrators

I can log in to github with the gerrit2 user as far as it is allowed from github site. Github is in the known hosts. However I get the following error:

[2013-06-04 20:04:54,472] ERROR com.googlesource.gerrit.plugins.replication.ReplicationQueue : Cannot replicate to [email protected]:MYUSERNAME/All-Projects.git
org.eclipse.jgit.errors.TransportException: [email protected]:MYUSERNAME/All-Projects.git: reject HostKey: github.com
    at org.eclipse.jgit.transport.JschConfigSessionFactory.getSession(JschConfigSessionFactory.java:142)
    at org.eclipse.jgit.transport.SshTransport.getSession(SshTransport.java:121)
    at org.eclipse.jgit.transport.TransportGitSsh$SshFetchConnection.<init>(TransportGitSsh.java:248)
    at org.eclipse.jgit.transport.TransportGitSsh.openFetch(TransportGitSsh.java:147)
    at com.googlesource.gerrit.plugins.replication.PushOne.listRemote(PushOne.java:409)
    at com.googlesource.gerrit.plugins.replication.PushOne.doPushAll(PushOne.java:357)
    at com.googlesource.gerrit.plugins.replication.PushOne.generateUpdates(PushOne.java:350)
    at com.googlesource.gerrit.plugins.replication.PushOne.pushVia(PushOne.java:298)
    at com.googlesource.gerrit.plugins.replication.PushOne.runImpl(PushOne.java:252)
    at com.googlesource.gerrit.plugins.replication.PushOne.runPushOperation(PushOne.java:207)
    at com.googlesource.gerrit.plugins.replication.PushOne.access$000(PushOne.java:71)
    at com.googlesource.gerrit.plugins.replication.PushOne$1.call(PushOne.java:186)
    at com.googlesource.gerrit.plugins.replication.PushOne$1.call(PushOne.java:183)
    at com.google.gerrit.server.util.RequestScopePropagator$5.call(RequestScopePropagator.java:222)
    at com.google.gerrit.server.util.RequestScopePropagator$4.call(RequestScopePropagator.java:201)
    at com.google.gerrit.server.git.PerThreadRequestScope$Propagator$1.call(PerThreadRequestScope.java:75)
    at com.googlesource.gerrit.plugins.replication.PushOne.run(PushOne.java:183)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:98)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:206)
    at com.google.gerrit.server.git.WorkQueue$Task.run(WorkQueue.java:337)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)
Caused by: com.jcraft.jsch.JSchException: reject HostKey: github.com
    at com.jcraft.jsch.Session.checkHost(Session.java:712)
    at com.jcraft.jsch.Session.connect(Session.java:313)
    at org.eclipse.jgit.transport.JschConfigSessionFactory.getSession(JschConfigSessionFactory.java:116)
    ... 25 more

Similar problem for ssh access with

url = ssh://[email protected]:443/MYUSERNAME/${name}.git

[2013-06-04 21:22:06,072] ERROR com.googlesource.gerrit.plugins.replication.ReplicationQueue : Cannot replicate to ssh://[email protected]:443/MYUSERNAME/All-Projects.git
org.eclipse.jgit.errors.TransportException: ssh://[email protected]:443/MYUSERNAME/All-Projects.git: reject HostKey: ssh.github.com
    at org.eclipse.jgit.transport.JschConfigSessionFactory.getSession(JschConfigSessionFactory.java:142)
    at org.eclipse.jgit.transport.SshTransport.getSession(SshTransport.java:121)
    at org.eclipse.jgit.transport.TransportGitSsh$SshFetchConnection.<init>(TransportGitSsh.java:248)
    at org.eclipse.jgit.transport.TransportGitSsh.openFetch(TransportGitSsh.java:147)
    at com.googlesource.gerrit.plugins.replication.PushOne.listRemote(PushOne.java:409)
    at com.googlesource.gerrit.plugins.replication.PushOne.doPushAll(PushOne.java:357)
    at com.googlesource.gerrit.plugins.replication.PushOne.generateUpdates(PushOne.java:350)
    at com.googlesource.gerrit.plugins.replication.PushOne.pushVia(PushOne.java:298)
    at com.googlesource.gerrit.plugins.replication.PushOne.runImpl(PushOne.java:252)
    at com.googlesource.gerrit.plugins.replication.PushOne.runPushOperation(PushOne.java:207)
    at com.googlesource.gerrit.plugins.replication.PushOne.access$000(PushOne.java:71)
    at com.googlesource.gerrit.plugins.replication.PushOne$1.call(PushOne.java:186)
    at com.googlesource.gerrit.plugins.replication.PushOne$1.call(PushOne.java:183)
    at com.google.gerrit.server.util.RequestScopePropagator$5.call(RequestScopePropagator.java:222)
    at com.google.gerrit.server.util.RequestScopePropagator$4.call(RequestScopePropagator.java:201)
    at com.google.gerrit.server.git.PerThreadRequestScope$Propagator$1.call(PerThreadRequestScope.java:75)
    at com.googlesource.gerrit.plugins.replication.PushOne.run(PushOne.java:183)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:98)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:206)
    at com.google.gerrit.server.git.WorkQueue$Task.run(WorkQueue.java:337)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)
Caused by: com.jcraft.jsch.JSchException: reject HostKey: ssh.github.com
    at com.jcraft.jsch.Session.checkHost(Session.java:712)
    at com.jcraft.jsch.Session.connect(Session.java:313)
    at org.eclipse.jgit.transport.JschConfigSessionFactory.getSession(JschConfigSessionFactory.java:116)
    ... 25 more

Answer 1

Log in (via SSH) as the user under which Gerrit is running.

I recommend you to set up a ~/.ssh/config for the Gerrit user like this:

Host github.com
    User git
    IdentityFile /path/to/the/private/key
    StrictHostKeyChecking no
    UserKnownHostsFile /dev/null

This sets up your SSH key ignores warnings about the (initially) unknown host.

If you can then connect via ssh github.com, we're almost there. Then try to clone the Github repository using the SSH URL.

Afterwards let Gerrit try to replicate again.

Plus then I would recommend to remove the authGroup setting from the replication.config.