# Install MongoDB Community Edition on Centos 7

By

Charl Cronje

This tutorial installs MongoDB 5.0 Community Edition. To install a different version of MongoDB Community, use the version drop-down menu in the upper-left corner of this page to select the documentation for that version.

Follow these steps to install MongoDB Community Edition using the yum package manager.

Create a /etc/yum.repos.d/mongodb-org-5.0.repo file so that you can install MongoDB directly using yum:

[mongodb-org-5.0]
name=MongoDB Repository
baseurl=https://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/5.0/x86_64/
gpgcheck=1
enabled=1
gpgkey=https://www.mongodb.org/static/pgp/server-5.0.asc

You can also download the .rpm files directly from the MongoDB repository. Downloads are organized by Red Hat / CentOS version (e.g. 7), then MongoDB release version (e.g. 5.0), then architecture (e.g. x86_64).

Prior to MongoDB 5.0, odd-numbered MongoDB release versions, such as 4.3, were development releases. Beginning with MongoDB 5.1, MongoDB has quarterly rapid releases. For more information on the differences between rapid and long-term support releases, see MongoDB Versioning.

sudo yum install -y mongodb-org

By default, MongoDB runs using the mongod user account and uses the following default directories:

• /var/lib/mongo (the data directory)
• /var/log/mongodb (the log directory)

To use a data directory and/or log directory other than the default directories:

Edit the configuration file /etc/mongod.conf and modify the following fields accordingly:

• storage.dbPath to specify a new data directory path (e.g. /some/data/directory)
• systemLog.path to specify a new log file path (e.g. /some/log/directory/mongod.log)
• Ensure that the user running MongoDB has access to the directory or directories:

sudo chown -R mongod:mongod <directory>

If you change the user that runs the MongoDB process, you must give the new user access to these directories.

The current SELinux Policy does not allow the MongoDB process to open and read /proc/net/netstat, which is required for Full Time Diagnostic Data Capture (FTDC). If you intend to run SELinux in enforcing mode, you will need to make the following adjustment to your SELinux policy:

Ensure your system has the checkpolicy package installed:

sudo yum install checkpolicy

Create a custom policy file mongodb_proc_net.te:

cat > mongodb_proc_net.te <<EOF
module mongodb_proc_net 1.0;
require {
        type sysctl_net_t;
        type mongod_t;
        class dir search;
        class file { getattr open read };
}
#============= mongod_t ==============
#!!!! This avc is allowed in the current policy
allow mongod_t sysctl_net_t:dir search;
allow mongod_t sysctl_net_t:file open;
#!!!! This avc is allowed in the current policy
allow mongod_t sysctl_net_t:file { getattr read };
EOF

Once created, compile and load the custom policy module by running these three commands:

- checkmodule -M -m -o mongodb_proc_net.mod mongodb_proc_net.te
- semodule_package -o mongodb_proc_net.pp -m mongodb_proc_net.mod
- sudo semodule -i mongodb_proc_net.pp

Update the SELinux policy to allow the mongod service to use the new directory:

sudo semanage fcontext -a -t <type> </some/MongoDB/directory.*>

where specify one of the following types as appropriate:

mongod_var_lib_t for data directory
mongod_log_t for log file directory
mongod_var_run_t for pid file directory

NOTE Be sure to include the .* at the end of the directory.

Update the SELinux user policy for the new directory:

sudo chcon -Rv -u system_u -t <type> </some/MongoDB/directory>

where specify one of the following types as appropriate:

• mongod_var_lib_t for data directory
• mongod_log_t for log directory
• mongod_var_run_t for pid file directory

Apply the updated SELinux policies to the directory:

sudo restorecon -R -v </some/MongoDB/directory>

You can start the mongod process by issuing the following command:

sudo systemctl start mongod

If you receive an error similar to the following when starting mongod:

Failed to start mongod.service: Unit mongod.service not found.

Run the following command first:

sudo systemctl daemon-reload

Then run the start command above again.

Verify that MongoDB has started successfully. You can verify that the mongod process has started successfully by issuing the following command:

sudo systemctl status mongod

You can optionally ensure that MongoDB will start following a system reboot by issuing the following command:

sudo systemctl enable mongod

As needed, you can stop the mongod process by issuing the following command:

sudo systemctl stop mongod

You can restart the mongod process by issuing the following command:

sudo systemctl restart mongod

You can follow the state of the process for errors or important messages by watching the output in the /var/log/mongodb/mongod.log file.

Start a mongosh session on the same host machine as the mongod. You can run mongosh without any command-line options to connect to a mongod that is running on your localhost with default port 27017.

mongosh

For more information on connecting using mongosh, such as to connect to a mongod instance running on a different host and/or port, see the mongosh documentation.

To help you start using MongoDB, MongoDB provides Getting Started Guides in various driver editions. For the driver documentation, see Start Developing with MongoDB.

To completely remove MongoDB from a system, you must remove the MongoDB applications themselves, the configuration files, and any directories containing data and logs. The following section guides you through the necessary steps.

This process will completely remove MongoDB, its configuration, and all databases. This process is not reversible, so ensure that all of your configuration and data is backed up before proceeding.

Stop the mongod process by issuing the following command:

sudo service mongod stop

Remove any MongoDB packages that you had previously installed.

sudo yum erase $(rpm -qa | grep mongodb-org)

Remove MongoDB databases and log files.

sudo rm -r /var/log/mongodb
sudo rm -r /var/lib/mongo