Enabling serviced debug logging

You can enable debug messages without restarting serviced.

Enabling all debug messages

To enable debug messages for all of the packages included in serviced, follow these steps:

Log in to the host as root or as a user with superuser privileges.

Toggle debug mode on.

pkill -f -USR1 /opt/serviced/bin/serviced

Display the messages.
```
journalctl -o cat -flu serviced
```

To turn off debug messages, repeat step 2.

Enabling debug messages for specific packages

The serviced daemon is written in Go, and many of the packages included in it use logrus logging. One of the features of logrus is the ability to change the logging level for individual packages without restarting the daemon. The daemon watches a configuration file and adjusts levels when the file changes.

To enable debug messages for serviced packages that use logrus logging, follow these steps:

Log in to the Control Center host as root or as a user with superuser privileges.
Open /opt/serviced/etc/logconfig-server.yaml with a text editor.
Modify the logging for the package or packages that interest you.

For example, to log everything at debug level except RPC requests (which are frequent and might hide useful logs), modify the file as follows:
```
- logger: '*'
  level: debug
- logger: rpc
  level: info
```
For more package names, see the next section.
Save the file, and then exit the text editor.
Display the messages.
```
journalctl -o cat -flu serviced
```

Control Center packages that use logrus logging

The following packages in release 1.5.1 use logrus logging. However, some do not include debug messages, and sometimes, understanding debug messages requires knowledge of the source code.

audit
auth
cli/api
cli/cmd
config
container
coordinator/client
coordinator/client/zookeeper
coordinator/storage
dao/elasticsearch
datastore/elastic
dfs
dfs/docker
dfs/nfs
dfs/ttl
domain
domain/addressassignment
domain/host
domain/hostkey
domain/logfilter
domain/pool
domain/properties
domain/registry
domain/service
domain/serviceconfigfile
domain/servicedefinition
domain/servicetemplate
domain/user
facade
isvcs
metrics
node
proxy
rpc
rpc/agent
rpc/master
rpc/rpcutils
scheduler
scheduler/servicestatemanager
script
servicedversion
shell
stats
utils
utils/iostat
web
zzk
zzk/registry
zzk/service