MongoDB Docker image

This repository contains Dockerfiles for MongoDB images for general usage and OpenShift. Users can choose between RHEL and CentOS based images.

Environment variables

The image recognizes the following environment variables that you can set during initialization by passing -e VAR=VALUE to the Docker run command.

Variable name Description
MONGODB_ADMIN_PASSWORD Password for the admin user

Optionally you can provide settings for user with 'readWrite' role.

Variable name Description
MONGODB_USER User name for MONGODB account to be created
MONGODB_PASSWORD Password for the user account
MONGODB_DATABASE Database name

The following environment variables influence the MongoDB configuration file. They are all optional.

Variable name Description Default
MONGODB_QUIET Runs MongoDB in a quiet mode that attempts to limit the amount of output. true

You can also set the following mount points by passing the -v /host:/container flag to Docker.

Volume mount point Description
/var/lib/mongodb/data MongoDB data directory

Notice: When mouting a directory from the host into the container, ensure that the mounted directory has the appropriate permissions and that the owner and group of the directory matches the user UID or name which is running inside the container.

Usage

For this, we will assume that you are using the centos/mongodb-32-centos7 image. If you want to set only the mandatory environment variables and store the database in the /home/user/database directory on the host filesystem, execute the following command:

$ docker run -d -e MONGODB_USER=<user> -e MONGODB_PASSWORD=<password> -e MONGODB_DATABASE=<database> -e MONGODB_ADMIN_PASSWORD=<admin_password> -v /home/user/database:/var/lib/mongodb/data centos/mongodb-32-centos7

If you are initializing the database and it's the first time you are using the specified shared volume, the database will be created with two users: admin and MONGODB_USER. After that the MongoDB daemon will be started. If you are re-attaching the volume to another container, the creation of the database user and admin user will be skipped and only the MongoDB daemon will be started.

Custom configuration file

It is allowed to use custom configuration file for mongod server. Providing a custom configuration file supercedes the individual configuration environment variable values.

To use custom configuration file in container it has to be mounted into /etc/mongod.conf. For example to use configuration file stored in /home/user directory use this option for docker run command: -v /home/user/mongod.conf:/etc/mongod.conf:Z.

Notice: Custom config file does not affect name of replica set. It has to be set in MONGODB_REPLICA_NAME environment variable.

MongoDB admin user

The admin user name is set to admin and you have to to specify the password by setting the MONGODB_ADMIN_PASSWORD environment variable. This process is done upon database initialization.

Changing passwords

Since passwords are part of the image configuration, the only supported method to change passwords for the database user (MONGODB_USER) and admin user is by changing the environment variables MONGODB_PASSWORD and MONGODB_ADMIN_PASSWORD, respectively.

Changing database passwords directly in MongoDB will cause a mismatch between the values stored in the variables and the actual passwords. Whenever a database container starts it will reset the passwords to the values stored in the environment variables.