% MONGODB-30-upg(1) Container Image Pages % SoftwareCollections.org % July 18, 2017
This repository contains Dockerfiles for MongoDB images for general usage and OpenShift. Users can choose between RHEL and CentOS based images. The CentOS image is then available on Docker Hub as centos/mongodb-30-upg-centos7.
Notice: This image is supported only for upgrade from MongoDB 2.6 to 3.2.
This container image provides a containerized packaging of the MongoDB mongod daemon and client application. The mongod server daemon accepts connections from clients and provides access to content from MongoDB databases on behalf of the clients. You can find more information on the MongoDB project from the project Web site (https://www.mongodb.com/).
For this, we will assume that you are using the centos/mongodb-30-upg-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-30-upg-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, passwords of users will be changed and
only the MongoDB daemon will be started.
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. (Note you MUST specify all three of these settings)
| 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_PREALLOC |
Enable data file preallocation. | false |
MONGODB_NOPREALLOC |
DEPRECATED - use MONGODB_PREALLOC instead. Disable data file preallocation. |
|
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 mounting 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.
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 user has 'dbAdminAnyDatabase', 'userAdminAnyDatabase', 'readWriteAnyDatabase', 'clusterAdmin' roles (for more information see MongoDB reference).
The user with $MONGODB_USER name is created in database $MONGODB_DATABASE
and you have to to specify the password by setting the MONGODB_PASSWORD
environment variable.
This user has only 'readWrite' role in the database.
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.
This image can be extended using source-to-image.
For example to build customized MongoDB database image my-mongodb-centos7
with configuration in ~/image-configuration/ run:
$ s2i build ~/image-configuration/ centos/mongodb-32-centos7 my-mongodb-centos7
The directory passed to s2i build should contain one or more of the
following directories:
when running run-mongod or run-mongod-replication commands contained
mongod.conf file is used for mongod configuration
- `envsubst` command is run on this file to still allow customization of
the image using environment variables
- custom configuration file does not affect name of replica set - it has
to be set in `MONGODB_REPLICA_NAME` environment variable
- it is not possible to configure SSL using custom configuration file
contained shell scripts (*.sh) are sourced before mongod server is
started
contained shell scripts (*.sh) are sourced when mongod server is
started
- `run-mongod` command doesn't have enabled authentication in this phase
- `run-mongod-replication` command has enabled authentication in this phase
these scripts are skipped if run-mongod-replication is run with already
initialized data directory
Variables that can be used in the scripts provided to s2i:
- `mongo_common_args` -- contains arguments for the `mongod` server (changing
this can break existing customization scripts, e.g. default scripts)
- `$MEMBER_ID` -- contains 'id' of the container. It is defined only in
scripts for replication (`run-mongod-replication` command) and has different
value for each container in a replicaset cluster. Customization scripts are
run by all containers in replicaset - `MEMBER_ID` can be used to write scripts
which are run only by some container.
During s2i build all provided files are copied into /opt/app-root/src
directory in the new image. If some configuration files are present in
destination directory, files with the same name are overwritten. Also only one
file with the same name can be used for customization and user provided files
are preferred over default files in /usr/share/container-scripts/mongodb/-
so it is possible to overwrite them.
Same configuration directory structure can be used to customize the image
every time the image is started using docker run. The directory have to be
mounted into /opt/app-root/src/ in the image (-v ./image-configuration/:/opt/app-root/src/). This overwrites customization
built into the image.
The mongod deamon in the container logs to the standard output, so the log is available in the container log. The log can be examined by running:
docker logs <container>
Dockerfile and other sources for this container image are available on https://github.com/sclorg/mongodb-container. In that repository, Dockerfile for CentOS is called Dockerfile, Dockerfile for RHEL is called Dockerfile.rhel7.