Add troubleshooting guidance for ssh connection failures.

For more thorough information about this commit, see:
https://tracker.ceph.com/issues/44905

Signed-off-by: Zac Dover <zac.dover@gmail.com>
Update doc/cephadm/troubleshooting.rst

Co-Authored-By: Michael Fritch <mfritch@suse.com>
ibid

Signed-off-by: Zac Dover <zac.dover@gmail.com>
Update doc/cephadm/troubleshooting.rst

Co-Authored-By: Sebastian Wagner <sebastian@spawnhost.de>
Update doc/cephadm/troubleshooting.rst

Co-Authored-By: Sebastian Wagner <sebastian@spawnhost.de>
Added mgfritch's suggestion regarding checking to see if the public key
is listed in the authorized_keys file.

Signed-off-by: Zac Dover <zac.dover@gmail.com>

diff --git a/doc/cephadm/troubleshooting.rst b/doc/cephadm/troubleshooting.rst
index 93f42025f7fbebf87d860a804036c914954bfa46..da4f55317b62f24f17706dbca6bcfd1cd569368a 100644 (file)
--- a/doc/cephadm/troubleshooting.rst
+++ b/doc/cephadm/troubleshooting.rst
@@ -102,3 +102,49 @@ Manually running containers
 Cephadm writes small wrappers that run a containers. Refer to
 ``/var/lib/ceph/<cluster-fsid>/<service-name>/unit.run`` for the
 container execution command.
+
+
+ssh errors
+----------
+
+Error message::
+
+  xxxxxx.gateway_bootstrap.HostNotFound: -F /tmp/cephadm-conf-kbqvkrkw root@10.10.1.2
+  raise OrchestratorError('Failed to connect to %s (%s).  Check that the host is reachable and accepts  connections using the cephadm SSH key' % (host, addr)) from
+  orchestrator._interface.OrchestratorError: Failed to connect to 10.10.1.2 (10.10.1.2).  Check that the host is reachable and accepts connections using the cephadm SSH key
+
+Things users can do:
+
+1. Ensure cephadm has an SSH identity key::
+      
+     [root@mon1~]# cephadm shell -- ceph config-key get mgr/cephadm/ssh_identity_key > key
+     INFO:cephadm:Inferring fsid f8edc08a-7f17-11ea-8707-000c2915dd98
+     INFO:cephadm:Using recent ceph image docker.io/ceph/ceph:v15 obtained 'mgr/cephadm/ssh_identity_key'
+     [root@mon1 ~] # chmod 0600 key
+
+ If this fails, cephadm doesn't have a key. Fix this by running the following command::
+   
+     [root@mon1 ~]# cephadm shell -- ceph cephadm generate-ssh-key
+
+ or::
+   
+     [root@mon1 ~]# cat key | cephadm shell -- ceph cephadm set-ssk-key -i -
+
+2. Ensure that the ssh config is correct::
+   
+     [root@mon1 ~]# cephadm shell -- ceph cephadm get-ssh-config > config
+
+3. Verify that we can connect to the host::
+    
+     [root@mon1 ~]# ssh -F config -i key root@mon1
+
+4. There is a limitation right now: the ssh user is always `root`.
+
+
+
+Verifying that the Public Key is Listed in the authorized_keys file
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+To verify that the public key is in the authorized_keys file, run the following commands::
+
+     [root@mon1 ~]# cephadm shell -- ceph config-key get mgr/cephadm/ssh_identity_pub > key.pub
+     [root@mon1 ~]# grep "`cat key.pub`"  /root/.ssh/authorized_keys