How to Tail Logs Directly from the Supervisor

Sometimes when a user enters a command in Supervisor CLI, and something goes wrong, it is not obvious what caused the issue, and the user needs to exit Supervisor CLI to review logs.  

To make the navigation easier, Supervisor has a feature to tail logs directly from CLI.

Issue 'tail <process-name>' command directly from Supervisor CLI. The example below shows the tail of the engine process:

[root@atscale-ha-node-01 /]# su atscaler
[atscaler@atscale-ha-node-01 /]$ export PATH=/opt/atscale/versions/2020.3.1.2003/pkg/python3/bin/:$PATH
[atscaler@atscale-ha-node-01 /]$ export LD_LIBRARY_PATH=/opt/atscale/versions/2020.3.1.2003/pkg/python3/lib:/opt/atscale/versions/2020.3.1.2003/pkg/openssl/lib
[atscaler@atscale-ha-node-01 /]$ /opt/atscale/versions/2020.3.1.2003/pkg/python3/bin/supervisorctl -c /opt/atscale/versions/2020.3.1.2003/conf/supervisor/supervisor.conf
agent                                RUNNING   pid 21157, uptime 4 days, 13:33:19
balancer                            RUNNING   pid 21158, uptime 4 days, 13:33:19
coordinator                       RUNNING   pid 21159, uptime 4 days, 13:33:19
database                           RUNNING   pid 21160, uptime 4 days, 13:33:19
engine                               RUNNING   pid 23507, uptime 4 days, 13:31:56
health                               RUNNING   pid 21163, uptime 4 days, 13:33:19
ingress                              RUNNING   pid 21164, uptime 4 days, 13:33:19
modeler                            RUNNING   pid 21169, uptime 4 days, 13:33:19
orchestrator                      RUNNING   pid 21171, uptime 4 days, 13:33:19
supervisor> tail -f engine
==> Press Ctrl-C to exit <==
Id=default, connGroupName=BigQuery Data Warehouse} c.a.e.c.pool.ConnectionManager - Executing initialization statements:
392410896 DEBUG {sourceThread=atscale-akka.actor.default-dispatcher-19, akkaSource=akka://atscale/system/receptionist, sourceActorSystem=atscale, akkaTimestamp=00:59:25.827UTC} a.c.t.i.r.ClusterReceptionist  - ClusterReceptionist [akka.tcp://atscale@atscale-ha-node-01.docker.infra.atscale.com:10507] - Pruning tombstones

Also, atscale_service_control shows the same result.

[atscaler@atscale-ha-node-01 /]$ /opt/atscale/bin/atscale_service_control tail -f engine