Debugging
Getting access to custom apps means you get the power to deploy whatever you want. This also means you can easily break your bench if things go wrong. But with ssh access you will also be able to perform some level of debugging to figure out the cause of issues.
Note : Please ONLY use SSH for debugging purposes. The bench setup on Cloud is different from the usual production setup you'll find in self hosted instances. Therefore, you can essentially break your bench by running arbitrary bench commands that change configuration. Eg:
bench setup supervisor
Things NOT to do after SSH
The following is a list of things that can break your smooth flow of operations on Cloud unless you know what you're doing.
-
Install apps in bench. If you do
bench new-app my_awesome_app
OR
bench get-app my_awesome_app
it may seem like it works without issue but the app will only be available for this particular bench version and will not persist across bench updates
-
If you did the above anyway and install the app onto a site, this will prevent you from updating your site. If you do reach this case, simply uninstall the app from your site.
Reading the logs
After ssh-ing into the bench, you will see certain files in the
logs
directory that are of interest
-
web.log
andweb.err.log
. These correspond to the STDOUT and STDERR streams of the web process. These handle the individual web requests to your site. -
worker.log
andworker.err.log
. These correspond to the STDOUT and STDERR streams of the background workers. These run the background jobs.
The above files are usually the areas of interest when you're debugging. But similarly, all the files in the
logs
directory correspond to the processes listed when you do
supervisorctl status
in your bench. Different issues will have you looking at different logs in your bench.
Read logs with the
less
command. To start reading from the bottom, use
less +G
. Vim keybindings work in
less
. Press
q
to quit.
tail
is also a similarly useful command.
tail -f
allows you to read output as it is being written to the file.
Bench
You can use bench commands for debugging.
bench doctor
is a command that shows you the status of background jobs on the machine. When you make code changes to files after ssh, you need to run
bench restart
for the changes to take effect.
Database Queries
You can access the SQL console with
bench mariadb
command. This console is useful to see current status of the database. Eg: You can see running queries with
SHOW PROCESSLIST
command.
Supervisor
Supervisor is the process manager within your bench. In a correctly functioning bench, all the processes should be in
RUNNING
state when you run
supervisorctl status
. You can also use
supervisorctl
commands to start and stop the processes listed.
bench restart
uses the same.
This means there is no
bench start
command that is running your bench. It is similar (not same) to howbench setup production
works