While trying to get MongoDB working on a Fedora 15 test server I found that there was no way of installing the latest version with SystemD control due to a pre-existing known bug.

To Mongo’s credit there is a file provided in the source under rpm/init.d-mongod, however when it comes to this being used by SystemD, well it just errors.

This was frustrating, but as I was doing it on a VM, I did what any logical person would do. Installed Mongo from the package manager, took a copy of the required SystemD files, reverted to a snapshot, then installed the latest version of Mongo from source.

After this I adapted the mongod.service file to use the correct locations, ensured all the required directories, files and users were present on the system then started the service et voila, working latest version of MongoDB on Fedora 15 with SystemD

the two required files are:
/lib/systemd/system/mongod.service

[Unit]
Description=High-performance, schema-free document-oriented database
After=syslog.target network.target
 
[Service]
Type=forking
User=mongod
Group=mongod
PIDFile=/var/run/mongodb/mongod.pid
EnvironmentFile=/etc/sysconfig/mongod
ExecStart=/usr/local/bin/mongod $OPTIONS run
 
[Install]
WantedBy=multi-user.target

/etc/sysconfig/mongod

Or you can just use the RedHat distro based install script I created:

#!/bin/sh

# MongoDB Version
MONGODB_VER='2.2.2'

# Get all the dependencies up to date
yum -y update
yum -y install scons gcc-c++ glibc-devel

# Get the source
cd /usr/local/src/
wget http://downloads.mongodb.org/src/mongodb-src-r$MONGODB_VER.tar.gz
tar xfz mongodb-src-r$MONGODB_VER.tar.gz
cd mongodb-src-r$MONGODB_VER

# Compile and Install
scons all
scons install

# Create the SystemD dependant files
echo '[Unit]
Description=High-performance, schema-free document-oriented database
After=syslog.target network.target
 
[Service]
Type=forking
User=mongod
Group=mongod
PIDFile=/var/run/mongodb/mongod.pid
EnvironmentFile=/etc/sysconfig/mongod
ExecStart=/usr/local/bin/mongod $OPTIONS run
 
[Install]
WantedBy=multi-user.target' > /lib/systemd/system/mongod.service

echo 'OPTIONS="--quiet -f /etc/mongod.conf"' > /etc/sysconfig/mongod

# Setup the required user and group
useradd -r -U mongod

# Setup the required directories
mkdir -p /var/run/mongodb/
mkdir -p /var/log/mongo/
mkdir -p /var/lib/mongo/
chown mongod:mongod /var/run/mongodb/
chown mongod:mongod /var/log/mongo/
chown mongod:mongod /var/lib/mongo/
chmod 0755 /var/log/mongo/
chmod 0755 /var/run/mongodb/
chmod 0755 /var/lib/mongo

# Start the new service and enable it on boot
systemctl --system daemon-reload
systemctl start mongod.service
systemctl enable mongod.service