update puppet instructions to follow the new git url

howto/puppet.md

@@ -26,7 +26,7 @@ Here is how to make the change:
  1. To any change on the Puppet server, you will first need to clone
     the git repository:
 
-        git clone pauli.torproject.org:/srv/puppet.torproject.org/git/tor-puppet
+        git clone git@puppet.torproject.org:/srv/puppet.torproject.org/git/tor-puppet
 
     This needs to be only done once.
 
@@ -79,7 +79,7 @@ also confirm this tutorial is what is actually needed.
  1. To any change on the Puppet server, you will first need to clone
     the git repository:
 
-        git clone pauli.torproject.org:/srv/puppet.torproject.org/git/tor-puppet
+        git clone git@puppet.torproject.org:/srv/puppet.torproject.org/git/tor-puppet
 
     This needs to be only done once.
 
@@ -1091,30 +1091,35 @@ more information:
 
 ### Problems pushing to the Puppet server
 
-Normally, when you push new commits to the Puppet server, a hook runs
-and updates the working copy. But sometimes this fails with an error
-like:
+If you get this error when pushing commits to the Puppet server:
 
-    remote: error: unable to unlink old 'modules/ipsec/misc/config.yaml': Permission denied.
+    error: remote unpack failed: unable to create temporary object directory
 
-The problem, in such cases, is that the files in the `/etc/puppet/`
-checkout are not writable by your user. It could also happen that the
-repository itself (in `/srv/puppet.torproject.org/git/tor-puppet`)
-could have permission issues.
+... or, longer version:
 
-This problem is described in [issue 29663][] and is due to someone
-not pushing properly before you. To fix the permissions, try:
+    anarcat@curie:tor-puppet$ LANG=C git push 
+    Enumerating objects: 7, done.
+    Counting objects: 100% (7/7), done.
+    Delta compression using up to 4 threads
+    Compressing objects: 100% (3/3), done.
+    Writing objects: 100% (4/4), 772 bytes | 772.00 KiB/s, done.
+    Total 4 (delta 2), reused 0 (delta 0), pack-reused 0
+    error: remote unpack failed: unable to create temporary object directory
+    To puppet.torproject.org:/srv/puppet.torproject.org/git/tor-puppet
+     ! [remote rejected]   master -> master (unpacker error)
+    error: failed to push some refs to 'puppet.torproject.org:/srv/puppet.torproject.org/git/tor-puppet'
+    anarcat@curie:tor-puppet[1]$
 
-    sudo chown -R root:adm /etc/puppet
-    sudo chown :puppet /etc/puppet/secret
-    sudo chmod -R g+rw /etc/puppet
-    sudo chmod g-w /etc/puppet/secret
+It's because you're not using the `git` role account. Update your
+remote URL configuration to use `git@puppet.torproject.org` instead,
+with:
 
-[issue 29663]: https://gitlab.torproject.org/tpo/tpa/team/-/issues/29663
+    git remote set-url origin git@puppet.torproject.org:/srv/puppet.torproject.org/git/tor-puppet.git
 
-A similar recipe could be applied to the git repository, as
-needed. Hopefully this will be resolved when we start deploying with a
-role account instead.
+This is because we have switched to a role user for pushing changes to
+the Git repository, see [issue 29663][] for details.
+
+[issue 29663]: https://gitlab.torproject.org/tpo/tpa/team/-/issues/29663
 
 ### Puppet server CA renewal