MongoDB

How to install MongoDB

	Note:
	Manual configuration required

MongoDB 5.0+ requires the AVX CPU instruction set

lscpu |grep avx

Install Official Repository

Use ExtraRepositories from here

https://wiki.koozali.org/Extrarepositories

Note that versions are available from 4.0/1/2/3/4 -> 5.0 -> 6.0

Please check which versions are deprecated - they should not be used.

https://www.mongodb.com/support-policy/lifecycles

As of July 2022 the oldest supported version is 4.2 until April 2023

yum install smeserver-extrarepositories-mongodb

signal-event yum-modify

Install your chosen version:

yum --enablerepo=mongodb4.2 install mongodb-org 

If refuses to install because of no GPG Key you can change GPGCheck above from Yes to No and try yum install... again or

rpm --import https://www.mongodb.org/static/pgp/server-4.0.asc

Or

 yum --enablerepo=mongodb4.2 install mongodb-org --nogpgcheck

Starting Mongo

	Warning:
	Please check additional notes below before trying this section

	Warning:
	Complete work in progress - here be Dragons!

We need a db config entry for SME to recognise it:

config set mongod service status enabled access private

We will need a file

mkdir -p /usr/lib/systemd/system/mongod.service.d

nano /usr/lib/systemd/system/mongod.service.d/50koozali.conf

Something like:

[Unit]
After=network.target network.service wan.service
[Install]
WantedBy=sme-server.target

Configuration File

Minimal config I use for Rocket.Chat

grep '^[[:blank:]]*[^[:blank:]#;]' /etc/mongod.conf

systemLog:
 verbosity: 0
 destination: file
 logAppend: true
 path: /var/log/mongodb/mongod.log
storage:
 dbPath: /var/lib/mongo
 journal:
   enabled: true
processManagement:
 fork: true  # fork and run in background
 pidFilePath: /var/run/mongodb/mongod.pid  # location of pidfile
 timeZoneInfo: /usr/share/zoneinfo
net:
 port: 27017
 bindIp: 127.0.0.1  # Enter 0.0.0.0,:: to bind to all IPv4 and IPv6 addresses or, alternatively, use the net.bindIpAll setting.

1. Enable replication for Rocket.Chat

replication:
 replSetName: rs0

Once started you need to initialise the replicaset. Make sure to exit from the mongo instance and run from the cli:

mongo --eval "printjson(rs.initiate())"

You should now have a working mongoDB good enough to use with Rocket.Chat

Other settings

nano /etc/security/limits.conf

These settings are automatically added during installation

@mongod       soft        nproc      unlimited
@mongod       hard      nproc        unlimited
@mongod       soft       nofile      64000
@mongod       hard      nofile      64000

Adding a user

https://www.linode.com/docs/guides/install-mongodb-on-centos-7/

use admin

db.createUser(
 {
   user: "admin",
   pwd: "admin123",
   roles: [ { role: "userAdminAnyDatabase", db: "admin" } ]
 }
)

show users

We can then set Mongo to force authentication when connecting.

nano /usr/lib/systemd/system/mongod.service.d/50koozali.conf

Add:

[Service]
Environment="OPTIONS=--auth -f /etc/mongod.conf"

Restart Mongo

systemctl restart mongod 

You should now need a password to login.

Templating mongod.conf

This is possible but we need to create a new file so we do not overwrite the original - otherwise yum/rpm will complain.

Something like /etc/mongod/mongod.conf

Template fragments in

/etc/e-smith/templates/etc/mongod/mongod.conf

We can then amend the systemd overrride

nano /usr/lib/systemd/system/mongod.service.d/50koozali.conf

Add this:

[Service]
Environment="OPTIONS=-f /etc/mongod/mongod.conf"

Dump and restore

Samples - YMMV.

Quick little script to dump the Rocket.Chat collection:

#!bin/bash
echo "Dump with Users/Roles"
mongodump --dumpDbUsersAndRoles -d rocketchat -o /root/backup/rocketchatmongo
echo "dump all"
mongodump -d rocketchat -o /root/backup/rocketchatmongo-all

	Warning:
	Do not restore between versions!!

If you export from a version eg 4.0 then restore to that version. Do not try and restore 4.0 to 4.2 or higher.

Then change your repo, and then upgrade mongo.

To restore:

mongorestore /root/backup/rocketchatmongo-all

Backup with system

With credit to Daniel Berteaud

Action script to dump the mongo DB on pre-backup event

mkdir -p /home/e-smith/db/mongo

cat <<_EOF > /etc/e-smith/events/actions/mongodb-dump
#!/bin/bash -e
/usr/bin/mongodump --quiet --out /home/e-smith/db/mongo/
_EOF

chmod +x /etc/e-smith/events/actions/mongodb-dump
cd /etc/e-smith/events/pre-backup
ln -s ../actions/mongodb-dump ./S60mongodb-dump

Vaporise or reinitialise the database

	Warning:
	This will totally and utterly vaporise your data. Got a backup?? You have been warned

Remove the directory contents:

rm -rf /var/lib/mongo/*

Or remove the entire directory and recreate it with the correct ownership:

rm -rf /var/lib/mongo
mkdir -p /var/lib/mongo
chown -R mongod:mongod /var/lib/mongo

If you have a replicaset set in /etc/mongod.conf make sure you initiate it:

mongo --eval "printjson(rs.initiate())"

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