Posts about sysadmin
Setup SAR on Alpine Linux
There are several good articles on setting up SAR
for debian (sar on ubuntu/debian) and redhat systems but I could find few on Alpine (perhaps because it is simple).
In any event, here's my process for setting up sar to run periodically via cron to track server stats.
Install
Install with: apk add sysstat
Setup
Not a lot of setup is required, you may want to review the /etc/sysconfig/sysstat
file for options.
Running Via cron
Create a cron task as you like to kick off sar periodically, the following will run sar every 2 minutes.
# Run sar to gather stats */2 * * * * /usr/lib/sa/sa1 1 1 # Additional run at 23:59 to rotate the statistics file 59 23 * * * /usr/lib/sa/sa1 60 2
Logs
Alpine's sysstats logs are in /var/log/sa
Use sendmail over mail
mail (from mailutils) is a common sysadmin tool for sending system mail, however, it brings in unneeded/undesired packages (e.g. mysql/mariadb tools). sendmail is much lighter and can usually get the job done.
Typical mail Scenario
The following cron entry runs deborphan every Monday at 14:33, emailing the results to the drad user.
33 14 * * Mon deborphan --guess-all | mail -s "Weekly deborphan Report" drad
Using sendmail Instead
sendmail does not have a -s (subject parameter). You need to preface your message with "Subject: {your subject}" followed by a new line and then the body such as follows:
33 14 * * Mon ( echo "Subject: Weekly deborphan Report"; echo; deborphan --guess-all ) | /usr/sbin/sendmail drad
The sendmail route is a little more verbose but gets the job done and now you do not need mailutils!
Summary
mail (mailutils) is a common and useful mail tool but depends on several packages which may not be desirable. You can fully replace mail with sendmail to avoid the dependencies and yet provide the same system mail functionality.