MongoDB: Remove an arbiter from a replica set

This isn’t really a straight forward task. From what I know in 1.7 there is a command but that is development only. So I’m running 1.6 and to see the config for my replica set I run

rs.conf();

I get the following output

> rs.conf();
{
        "_id" : "core",
        "version" : 3,
        "members" : [
                {
                        "_id" : 0,
                        "host" : "mongo1.domain.com:27017"
                },
                {
                        "_id" : 1,
                        "host" : "mongo2.domain.com"
                },
                {
                        "_id" : 2,
                        "host" : "mgmt1.domain.com",
                        "arbiterOnly" : true
                }
        ]
}

Now I have two members to my replica set plus my arbiter. So I want to remove that so I can add another one. So I run the following

> use admin;
> cfg = rs.conf();
> cfg.members.splice(2,1);
> cfg['version'] = 4
> db.runCommand({replSetReconfig: cfg});

Then it will be removed. You can see my version was at 3 so I upped it to 4 so mongo will know there was a change. Now if I check the config I get the following

> rs.conf()
{
        "_id" : "core",
        "version" : 4,
        "members" : [
                {
                        "_id" : 0,
                        "host" : "mongo1.domain.com:27017"
                },
                {
                        "_id" : 1,
                        "host" : "mongo2.domain.com"
                }
        ]
}

Install Chromium on Fedora

This is an easy one

Create the following file

/etc/yum.repos.d/chromium.repo

With the following contents

[fedora-chromium]
name=Chromium web browser and deps
baseurl=http://repos.fedorapeople.org/repos/spot/chromium/fedora-$releasever/$basearch/
enabled=1
gpgcheck=0

Then run the following

yum update
yum install chromium

Change get_absolute_url for the user object in Django

I completely overlooked this in the docs. So if you are here you either didn’t look in the docs or overlooked it also.

I was doing something like this

return (user.get_absolute_url(), (), {})

Now that sends the user to

/user/username/

I wanted the user to go to

/u/username/

So in your settings.py file just do this

ABSOLUTE_URL_OVERRIDES = {
    'auth.user': lambda o: "/u/%s/" % o.username,
}

Gitosis with wildcard support

At OpenSky I wanted a way to put config files into git. I started using gitosis for the git server. This was all great but for each new server I had to add the following

servers/host.domain.com

Now that just stinks if you want to do it for a lot of servers. By default gitosis does not support wildcards. So we can’t use servers/* and anything pushing to git@ip:servers/hostn.domain.com.git would be accepted. I found the following patch online. I then forked gitosis to on GitHub to support this and updated the README file. So you can follow it there.

http://github.com/mzupan/gitosis

Bash: Turn a string into an array

I needed to turn a string into an array to loop through it. It is pretty simple

SOLR_CORES="core1,core2,core3"
declare -a CORES
CORES=(`echo $SOLR_CORES | tr ',' ' '`)       

for CORE in ${CORES[@]}
do
    stuff here
done

MongoDB Nagios plugin created

I have created a MongoDB plugin for Nagios. I also put it in a GitHub project so if you want to make changes you can easily fork the project and push changes right to my project

http://github.com/mzupan/nagios-plugin-mongodb