Letsencrypt auto-renew cronjob failing

Question

I'm running a script provided by rehmatworks to install a LetsEncrypt certificate, which (in addition to the initial install) sets up a monthly cronjob to auto renew. Everything installs fine, however, the cron job is failing, and I can't seem to figure out why.

Here is the cron job (from root 'crontab -e'):

@monthly "sudo service nginx-sp stop && yes | letsencrypt --standalone renew &>/dev/null && service nginx-sp start && service nginx-sp reload"

Which fails with a not found error:

/bin/sh: 1: sudo service nginx-sp stop && yes | letsencrypt --standalone renew &>/dev/null && service nginx-sp start && service nginx-sp reload: not found

Running directly from the command line work fine, however:

sudo service nginx-sp stop && yes | letsencrypt --standalone renew &>/dev/null && service nginx-sp start && service nginx-sp reload

Any ideas why this works from command line, but not via cron?

Answer 1

Try to specify the entire path to the binaries that you're using. I guess they aren't found since the $HOME variable or $PATH should be different to the root and user.

If what I said is the problem, the source of it must be the location of letsencrypt binary, probably not found by root

Answer 2

This is already reported as issue to script provider:

https://github.com/rehmatworks/serverpilot-letsencrypt/issues/8

So you should wait for an answer there. It is not easy to give you a quality answer if we do not know the total background of the system, looks like some special environment.

Update: Issue is solved now by Scriptowner on Github, please checkout the Github. rehmatworks commented 12 hours ago

Solution: Please reclone the script and you will be able to do much more with great ease.

sorry
chris

Answer 3

Update: rehmatworks has since updated the original script to address this issue.

Thanks to @steeldriver comments above, I've learned that the main problem is:

• The crontab should be run using 'bash' (not the default 'sh'), because:
  • &>/dev/null is bash syntax ('sh' would be >/dev/null 2>&1).
  • sh does not recognize commands in quotation marks (produces 'not found' error).
• The crontab should define the default PATH variables.
• If the crontab is run under root, then don't need to use 'sudo' (although probably doesn't hurt).

To edit the root crontask, use sudo crontab -e -u root. Final looks like this:

SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin

@monthly service nginx-sp stop && yes | letsencrypt --standalone renew &>/dev/null && service nginx-sp start && service nginx-sp reload
#

So far, seems like it works (but please confirm by reviewing logs).

Note: Not tested, but in terms of fixing the original install script, without having to define the shell environment separately, it's possible you could wrap the cron command in a bash subshell to make sure it gets run in bash (per askubuntu SE answer):

bash -c "bashcommand"