If you try to upgrade salt-minions from the salt-master, in most cases salt-master would probably lose access to the minions.
If the access is lost, you would have to log in to each host and restart the salt-minion service manually to make it communicate back with the salt-master.
This problem is caused by the salt-minion service that often doesn’t restart after update.
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In this article i’ll show how to safely update salt-minions from the salt-master without loosing communication.
First of all it is required to upgrade salt-master.
Upgrade order: According to documentation, the master should always be upgraded first, as the backward compatibility for minions running newer versions of salt than their masters is not guaranteed.
Upgrade salt-master on CentOS, RHEL, etc.:
$ sudo yum update salt-master
Upgrade salt-master on Debian, Ubuntu, Linux Mint, etc.:
$ sudo apt-get update salt-master
To find out the current version of the salt-master, run:
$ salt-master --version
For the moment there is no a normal way to upgrade salt-minions from the salt-master and not to lose communication between them.
But you can create a salt-state, that will send a special shell command to the salt-minion and execute it in the background.
This shell command will update and restart the salt-minion service using the locally executed
After the salt-minion is restarted, communication with the salt-master would be successfully recovered.
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At the same time the below state beforehand checks if a new version of the salt-minion packaged is available to avoid useless restart of the salt-minion service.
Create the following state on the salt-master and apply it to the salt-minions to upgrade them safely:
Upgrade Salt-Minion: cmd.run: - name: | exec 0>&- # close stdin exec 1>&- # close stdout exec 2>&- # close stderr nohup /bin/sh -c 'salt-call --local pkg.install salt-minion && salt-call --local service.restart salt-minion' & - onlyif: "[[ $(salt-call --local pkg.upgrade_available salt-minion 2>&1) == *'True'* ]]"
To find out the current version of your salt-minions from the salt-master, run:
$ sudo salt '*' test.version
9 Replies to “HowTo: Upgrade Salt-Minions and Don’t Lose Them”
Спасибо, за статью. Помогло.
Не работает, состояние применяется, но не обновляет
– name: |
exec 0>&- # close stdin
exec 1>&- # close stdout
exec 2>&- # close stderr
nohup /bin/sh -c ‘salt-call –local pkg.install salt-minion only_upgrade=True && salt-call –local service.restart salt-minion’ &
Will the same works for windows as well?
@kk12345 for sure not as the commands used are *nix commands.
My idea is to remotely schedule a job a few seconds in the future here.
I had to invert the `onlyif `bash conditional expression (`[[ $(salt-call –local…` to `![[ $(salt-call –local…`). When I ran the expression as written in Bash, it was returning 0 for success, but it appears that Salt was evaluating that return code 0 as False, making the `onlyif` statement False in turn. Negating the expression made it work like a charm.
Show current version (automatically compared against master version):
Very helpful. I had to remove the quotes around the onlyif command for it to actually work. Fails: – onlyif: “[[ … ]]” Succeeds: – onlyif: [[ … ]] Not sure if others had a different experience but it seemed to always return False when quoted as if it was trying to run the entire string as a single command.