bin/client fails to connect when called via ansible.builtin.shell

[Ralf Steppacher <ra...@steppacher.name>]

Hello all,

I am trying to provision Karaf using Ansible (on localhost). All is good 
until I first try to use the bin/client script to interact with the 
local Karaf server. For some reason all interactions, no matter what I 
try, end with the error "Closed". However, I can run the client script 
successfully on the command line. I ran the client with full trace logs 
(-v -l 4) with Ansible and on the command line and diffed the output. 
Apart from session IDs, timestamps, and encrypted content on the wire 
the logs look identical as far as I can see until we reach this line:

[main] DEBUG org.apache.sshd.client.session.ClientSessionImpl - 
createExecChannel([ClientSessionImpl[karaf@localhost/127.0.0.1:8101], 
ls, 0, null])[null] created id={} - PTY={}

After which the client continues to process the ls​ command if called on 
the command line and immediately closes the connection when called via 
Ansible:

525 [Thread-2] DEBUG org.apache.sshd.client.channel.ChannelExec - 
close(ChannelExec[id=0, 
recipient=-1]-ClientSessionImpl[karaf@localhost/127.0.0.1:8101]) Closing 
immediately
525 [Thread-2] DEBUG org.apache.sshd.client.channel.ChannelExec - 
close(ChannelExec[id=0, 
recipient=-1]-ClientSessionImpl[karaf@localhost/127.0.0.1:8101]) prevent 
sending EOF
525 [main] DEBUG org.apache.sshd.client.channel.ChannelExec - 
open(ChannelExec[id=0, 
recipient=-1]-ClientSessionImpl[karaf@localhost/127.0.0.1:8101]) Send 
SSH_MSG_CHANNEL_OPEN - type=session
525 [Thread-2] DEBUG org.apache.sshd.common.channel.Window - Closing 
Window[client/local](ChannelExec[id=0, 
recipient=-1]-ClientSessionImpl[karaf@localhost/127.0.0.1:8101])
525 [main] DEBUG org.apache.sshd.client.channel.ChannelExec - 
writePacket(ChannelExec[id=0, 
recipient=-1]-ClientSessionImpl[karaf@localhost/127.0.0.1:8101]) 
Discarding output packet because channel state=Immediate
525 [Thread-2] DEBUG org.apache.sshd.common.channel.Window - Closing 
Window[client/remote](ChannelExec[id=0, 
recipient=-1]-ClientSessionImpl[karaf@localhost/127.0.0.1:8101])
[..]

All output is on level DEBUG or TRACE. No error is reported.

The Ansible task is as simple as they come:

- name: Use Karaf Client
   shell: "./client -v -l 4 ls"
   args:
     chdir: "{{ karaf_install_symlink }}/bin"

The karaf server log shows the connection, and a while later logs an 
authentication timeout, presumably because the client left the 
conversation dangling.

2022-01-04T20:53:13,178 | INFO  | 
sshd-SshServer[315a8514](port=8101)-nio2-thread-2 | ServerSessionImpl 
             | 43 - org.apache.sshd.osgi - 2.5.1 | Session 
karaf@/127.0.0.1:33910 authenticated
2022-01-04T20:55:12,564 | INFO  | 
sshd-SshServer[315a8514](port=8101)-timer-thread-1 | ServerSessionImpl 
              | 43 - org.apache.sshd.osgi - 2.5.1 | 
Disconnecting(ServerSessionImpl[null@/127.0.0.1:33908]): 
SSH2_DISCONNECT_PROTOCOL_ERROR - Detected AuthTimeout after 
120181/120000 ms.
2022-01-04T20:55:12,566 | WARN  | 
sshd-SshServer[315a8514](port=8101)-nio2-thread-2 | ServerSessionImpl 
             | 43 - org.apache.sshd.osgi - 2.5.1 | 
disconnect(ServerSessionImpl[null@/127.0.0.1:33908]) operation failed 
(IOException) for reason=SSH2_DISCONNECT_PROTOCOL_ERROR [Detected 
AuthTimeout after 120181/120000 ms.]: Broken pipe

Where would I have to tweak the setup to make the karaf client work 
through Ansible?


Thanks!
Ralf