Store logs in /var/log

[zrhoffman]

This PR

• changes configuration to log Traffic Router to /var/log/traffic_router instead of /opt/traffic_router/var/log
• changes configuration to log Traffic Monitor to /var/log/traffic_monitor instead of /opt/traffic_monitor/var/log
• changes configuration to log Traffic Stats to /var/log/traffic_stats instead of /opt/traffic_stats/var/log

so that the logs are on a different partition than the application itself.

---

Which Traffic Control components are affected by this PR?

• Documentation
• Traffic Monitor
• Traffic Router
• Traffic Stats
• CDN in a Box
• Automation - Ansible roles
• unknown

What is the best way to verify this PR?

If this is a bugfix, which Traffic Control versions contained the bug?

PR submission checklist

• This PR has tests
• This PR has documentation
• This PR has a CHANGELOG.md entry
• This PR DOES NOT FIX A SERIOUS SECURITY VULNERABILITY (see the Apache Software Foundation's security guidelines for details)

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 65.77%. Comparing base (26a2f6a) to head (900cf16).
Report is 6 commits behind head on master.

❗ Current head 900cf16 differs from pull request most recent head 72834a2. Consider uploading reports for the commit 72834a2 to get more accurate results

Additional details and impacted files

@@            Coverage Diff            @@
##             master    #7979   +/-   ##
=========================================
  Coverage     65.77%   65.77%           
  Complexity       98       98           
=========================================
  Files           327      327           
  Lines         13010    13010           
  Branches        998      998           
=========================================
  Hits           8557     8557           
  Misses         4091     4091           
  Partials        362      362           

Flag	Coverage Δ
traffic_router_unit	29.03% <ø> (ø)

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[ntheanh201]

+1 this idea, it would be better for the logs agent's permissions

[jagan-parthiban]

After running Dev CIAB on the PR code, couldn't find the log files either at /opt/traffic_router/var or /var/log/. Also couldn't find the log file in TM container as well.

/opt/traffic_router/var # 
/opt/traffic_router/var # ls -l
total 0
drwxr-x---    4 root     root           128 Apr  4 05:19 auto-zones
/opt/traffic_router/var # cd /var/log/
/var/log # ls -l
total 0

[zrhoffman]

After running Dev CIAB on the PR code, couldn't find the log files either at /opt/traffic_router/var or /var/log/.

The TR logs show up for me in /var/log/traffic_router.

[root@trafficrouter traffic_router]# ls -l
total 76
-rw-r--r-- 1 root root     0 Apr 10 18:52 access.log
-rw-r--r-- 1 root root 73560 Apr 10 18:55 traffic_router.log
[root@trafficrouter traffic_router]# tail -f access.log

They also show up for docker-compose logs -f trafficrouter.

Also couldn't find the log file in TM container as well.

The TM logs are printed to stdout only with no files

trafficcontrol/infrastructure/cdn-in-a-box/traffic_monitor/traffic_monitor.cfg

Lines 8 to 13 in 900cf16

	"log_location_access": "$TM_LOG_ACCESS",
	"log_location_event": "$TM_LOG_EVENT",
	"log_location_error": "$TM_LOG_ERROR",
	"log_location_warning": "$TM_LOG_WARNING",
	"log_location_info": "$TM_LOG_INFO",
	"log_location_debug": "$TM_LOG_DEBUG",

trafficcontrol/infrastructure/cdn-in-a-box/variables.env

Lines 76 to 81 in 900cf16

	TM_LOG_ACCESS=stdout
	TM_LOG_EVENT=stdout
	TM_LOG_ERROR=stdout
	TM_LOG_WARNING=stdout
	TM_LOG_INFO=stdout
	TM_LOG_DEBUG=stdout