MongoDB for OpenShift - Docker images

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

Versions

MongoDB versions currently provided are:

• mongodb-2.4
• mongodb-2.6

RHEL versions currently supported are:

• RHEL7

CentOS versions currently supported are:

• CentOS7

Installation

Choose either the CentOS7 or RHEL7 based image:

• RHEL7 based image

  To build a RHEL7 based image, you need to run Docker build on a properly subscribed RHEL machine.

  $ git clone https://github.com/openshift/mongodb.git
  $ cd mongodb
  $ make build TARGET=rhel7 VERSION=2.4
  

• CentOS7 based image

  This image is available on DockerHub. To download it run:

  $ docker pull openshift/mongodb-24-centos7
  

  To build a MongoDB image from scratch run:

  $ git clone https://github.com/openshift/mongodb.git
  $ cd mongodb
  $ make build VERSION=2.4
  

Notice: By omitting the VERSION parameter, the build/test action will be performed on all provided versions of MongoDB.

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_USER	User name for MONGODB account to be created
MONGODB_PASSWORD	Password for the user account
MONGODB_DATABASE	Database name
MONGODB_ADMIN_PASSWORD	Password for the admin user

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

Variable name	Description	Default
MONGODB_NOPREALLOC	Disable data file preallocation.	true
MONGODB_SMALLFILES	Set MongoDB to use a smaller default data file size.	true
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 openshift/mongodb-24-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 openshift/mongodb-24-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 together with the database administrator user and MongoDB admin 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.

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.

Test

This repository also provides a test framework which checks basic functionality of the MongoDB image.

Users can choose between testing MongoDB based on a RHEL or CentOS image.

• RHEL based image

  To test a RHEL7 based MongoDB image, you need to run the test on a properly subscribed RHEL machine.

  $ cd mongodb
  $ make test TARGET=rhel7 VERSION=2.4
  

• CentOS based image

  $ cd mongodb
  $ make test VERSION=2.4
  

Notice: By omitting the VERSION parameter, the build/test action will be performed on all provided versions of MongoDB.