SystemD and Gollum Wiki

I want to set up my Gollum wiki server to be started/stopped/rebooted via SystemD.   Using SystemD I also want it to restart if it should crash.

@reboot and tmux

My current simple solution is using cron @reboot with a simple tmux script.  All of this is all on an Ubuntu 16.04 server.

Most folks don't know that cron supports the ability to run a command on reboot.

With that in mind I set up a quick, temporary, method to start gollum using cron and tmux until I got around to replacing it with a systemD script.

So here is what I currently have set up.

First the script

> vi tmux_gollum_commands.sh

#!/bin/bash #Kill the prior session if exists tmux kill-session -t gollum-wiki tmux new -d -s gollum-wiki tmux send-keys 'cd ~/10x13.wiki' C-m tmux send-keys 'gollum --config gollum-custom/config/config.rb --emoji --css --template-dir gollum-custom/templates' C-m

This simple script starts up a tmux session, tmux is a tool similar to screen, then just starts gollum in it.

This allows me to attach to the tmux session and see what is going on.

> tmux attach -t gollum-wiki

Now I can attach to the tmux session and watch the gollum logs pass by.

To get out of this session press crtl+a then d

Now for the cronjob

> sudo vi /etc/crontab

Here I added a simple @reboot line

@reboot patman /home/patman/tmux_gollum_commands.sh

This @reboot is nice in the since that it will run my script and start up gollum on a reboot.  But it's not so nice in other areas.  It will not recover from a failure.    The script is simple enough and I can rerun it which will kill the current tmux session if it exists and create a new one.   That OK, but I would rather have a systemD script for starting and restarting it.    Also I do not have any logging?

I am going to use systemD to fix all those issues.

Create a Gollum user and move stuff

I want to create a user called gollum who will be used to run the the gollum wiki.

First let me kill my wiki and remove the @reboot from my cronjob

> tmux kill-session -t gollum-wiki

Then comment out the crontab

> sudo vi /etc/crontab

Create a Gollum user which will be used to run the gollum wiki.   Also unlock the user

> sudo useradd gollum -r -m -s /bin/bash   > sudo password gollum   > sudo usermod -U gollum

Normally I would set a user like this to not have a shell by using /bin/false.  But I can't do that in this case as I want my git repo to have a hook that will ssh to this machine as gollum and force a pull when the git repo is updated.

My current gollum wiki is set up to auto sync with a remote git repo (back and forth see http://www.whiteboardcoder.com/2017/04/gollum-auto-sync-to-remote-git-repo.html [1] )

So I need to set that up.  First I need to login as the gollum user and create ssh keys.  I can log in as the gollum user if I am already on the machine and set which shell I want to use.

> sudo su gollum   > cd

> ssh-keygen -t rsa -b 4096

Now I need to copy the .ssh/id_rsa.pub information and put add it the ~/.ssh/authorized_keys on my git server

> cat .ssh/id_rsa.pub

Also because of the way I have it set up my git repo needs to have ssh access back to my gollum server (since it updates the gollum wiki when it is pushed to)

From the git server

> cat .ssh/id_rsa.pub

Then add that to the ~/.ssh/authorized_keys on the gollum server

Confirm that is working…

(from gollum to git server)

> ssh git@git-server

Now from git to Gollum server

> ssh gollum@192.168.0.77

Perfect that is all working

Move repo and update hooks

Now I need to move stuff around and update hooks I made earlier

First I am going to clone my wiki repo as a the gollum user  (this is not my actual IP address)

> git clone git@127.0.0.1:/gitstuff/10x13.wiki

Now let me tweak it

> cd 10x13.wiki

Set a few configs

> git config push.default simple   > git config user.name "Gollum Wiki"   > git config user.email gollum@10x13.com

Now I need to reset my hooks on the gollum server and on my git server.

From the gollum server create the .git/hooks/post-commit  (remember hooks are not part of a git repo itself)

> vi .git/hooks/post-commit

Place the following in it.

#!/bin/bash #Simple push to origin master git push origin master

Make it executable

> chmod a+x .git/hooks/post-commit

Now to the git server.  I need to update the hook there.  (this is a hook I made in another post http://www.whiteboardcoder.com/2017/04/gollum-auto-sync-to-remote-git-repo.html [1] )

> vi hooks/post-receive

I just needed to update the user

#!/bin/bash #Set user to login to gollum server as USER="gollum" GOLLUM_ADDR="192.168.0.77" GOLLUM_DIR="~/10x13.wiki" #First check to see if the Commited SHA on the GOLLUM server and here are a match LOCAL_SHA=$(git rev-parse --verify HEAD) GOLLUM_SHA=$(ssh $USER@$GOLLUM_ADDR "cd $GOLLUM_DIR; git rev-parse --verify HEAD") #If they do not match then GOLLUM server needs to do a pull if [ $LOCAL_SHA != $GOLLUM_SHA ]; then   ssh $USER@$GOLLUM_ADDR "cd $GOLLUM_DIR; git pull origin master" fi

Before I head on I am going to run a few local test to make sure the hooks are working correctly.  Like running gollum by hand and making sure the hook is pushing up.

Make a simple change on the gollum server add it to git and commit it. (Should auto push it)

> git add --all   > git commit -m "simple change"

Then check it by running

> git log -n 1

On gollum and git server

Cool I have a match!

Now test it the other wau

Cloning the repo to my local machine

> git clone git@127.0.0.1:/gitstuff/10x13.wiki

Now let me tweak it

> cd 10x13.wiki

Make a simple change and add it, commit it and push it up

> git add --all   > git commit -m "Git repo to gollum test"   > git push

Then check it by running

> git log -n 1

On gollum and git server

Wahoo worked

SystemD script

Now create a systemd script

> sudo vi /lib/systemd/system/gollum.service

And place the following in it.

[Unit] Description=Gollum Server Requires=network.target After=network.target ConditionPathExists=/home/gollum/10x13.wiki [Service] Type=simple PIDFile=/var/run/gollum.pid User=gollum Group=gollum WorkingDirectory=/home/gollum/10x13.wiki ExecStart=/usr/local/bin/gollum [Install] WantedBy=multi-user.target Alias=gollum.service

Make it executable, enable it, and start it.

> sudo chmod a+x /lib/systemd/system/gollum.service   > sudo systemctl enable gollum.service   > sudo systemctl start gollum

 

Wahoo working

But I am not getting my custom settings yet.

Custom start up script

In the wiki make a simple start up script

> mkdir bin   > vi bin/gollum.sh

And put the following in it.

#!/bin/bash CONFIG="gollum-custom/config/config.rb" TEMPLATE_DIR="gollum-custom/templates" gollum --config $CONFIG --emoji --css --template-dir $TEMPLATE_DIR

Then make it executable

> chmod u+x bin/gollum.sh

Now update the systemd service

> sudo vi /lib/systemd/system/gollum.service

And place the following in it.

[Unit] Description=Gollum Server Requires=network.target After=network.target ConditionPathExists=/home/gollum/10x13.wiki [Service] Type=simple PIDFile=/var/run/gollum.pid User=gollum Group=gollum WorkingDirectory=/home/gollum/10x13.wiki ExecStart=/home/gollum/10x13.wiki/bin/gollum.sh [Install] WantedBy=multi-user.target Alias=gollum.service

Just update the ExecStart

Since the service has been updated it needs to be reloaded

> sudo systemctl daemon-reload

Now restart

> sudo systemctl restart gollum.service

Working !

SystemD Recovery

What about recovery?  If Gollum crashes I want it to Autorestart

Let me kill the process (simulate a crash)

> sudo ps -Af | grep gollum | grep emoji

> sudo kill 2604

How do I fix this?

> sudo vi /lib/systemd/system/gollum.service

And place the following in it.

[Unit] Description=Gollum Server Requires=network.target After=network.target ConditionPathExists=/home/gollum/10x13.wiki [Service] Type=simple PIDFile=/var/run/gollum.pid User=gollum Group=gollum WorkingDirectory=/home/gollum/10x13.wiki ExecStart=/home/gollum/10x13.wiki/bin/gollum.sh Restart=always RestartSec=3 [Install] WantedBy=multi-user.target Alias=gollum.service

Reload

> sudo systemctl daemon-reload

Now restart

> sudo systemctl restart gollum.service

Now if I simulate a crash

> sudo ps -Af | grep gollum | grep emoji

> sudo kill 2750

> sudo ps -Af | grep gollum | grep emoji

After three seconds it restart J

Logging and logrotate

The last thing I want to take care of is logging.

Out of the box it looks like its logging to /var/log/syslog

> tail -f /var/log/syslog

Also if I uses systemctl status I see all the logs

> sudo systemctl status gollum.service

Hmmm.

I think the simple answer is to edit the gollum.sh script I made to output to a log.

I need to add gollum user to the syslog group

> sudo usermod -a -G syslog gollum

Edit the script

> vi bin/gollum.sh

#!/bin/bash CONFIG="gollum-custom/config/config.rb" TEMPLATE_DIR="gollum-custom/templates" LOG="/var/log/gollum.log" gollum --config $CONFIG --emoji --css --template-dir $TEMPLATE_DIR >> $LOG 2>&1

Now restart

> sudo systemctl restart gollum.service

Now I can tail the log

> tail -f /var/log/gollum.log

Also systemctl should look cleaner now

> sudo systemctl status gollum.service

Much Better.

Logrotate

To be safe I am going to add a logrotate to rotate this file daily and to keep 30 days worth of files.

> sudo vi /etc/logrotate.d/gollum

And put the following in it.

/var/log/gollum.log {         daily         dateext         dateformat _%Y-%m-%d         missingok         create 640 gollum gollum         rotate 90         compress         notifempty }

Test it

> sudo logrotate -d /etc/logrotate.conf

Looks good.

Another test

> sudo logrotate -vf /etc/logrotate.d/gollum

 

Oh little error need to specify user/group

> sudo vi /etc/logrotate.d/gollum

And put the following in it.

/var/log/gollum.log {         su gollum gollum         daily         dateext         dateformat _%Y-%m-%d         missingok         create 640 gollum gollum         rotate 90         compress         notifempty }

Test again

> sudo logrotate -vf /etc/logrotate.d/gollum

 

Still failed

Oh need gollum syslog

> sudo vi /etc/logrotate.d/gollum

And put the following in it.

/var/log/gollum.log {         su gollum syslog         daily         dateext         dateformat _%Y-%m-%d         missingok         create 640 gollum gollum         rotate 90         compress         notifempty }

Test again

> sudo logrotate -vf /etc/logrotate.d/gollum

But now I am no longer logging to the file.  I think I need to add a thing to the logrotate to restart the gollum (not ideal but it will do)

> sudo vi /etc/logrotate.d/gollum

And put the following in it.

/var/log/gollum.log {         su gollum syslog         daily         dateext         dateformat _%Y-%m-%d         missingok         create 640 gollum syslog         rotate 90         compress         notifempty         postrotate            /bin/systemctl restart gollum.service         endscript }

Test again

> sudo logrotate -vf /etc/logrotate.d/gollum

 

OK I think that got it.

Let me remove all the gollum logs and reboot the box.

> sudo rm /var/log/gollum.log*   > sudo reboot now

Looks good!

OK I think I got it.

References

[1]        Gollum auto sync to remote git repo

http://www.whiteboardcoder.com/2017/04/gollum-auto-sync-to-remote-git-repo.html
Accessed 5/2017