ldap-matter/Docker

Mattermost-LDAP - Docker module

Summary

This repository provides necessary ressources to build the Docker image for Mattermost-LDAP module. This Docker image is usefull to try Mattermost-LDAP in a PoC or a demo, and is production ready.

Description

The Mattermost-LDAP module can be use with Nginx or Apache/httpd. Both implementation are available in this repository. Images in this directory are used by Docker compose implementation, for more information, see section "Docker Compose setup" in the main README.md.

Mattermost-LDAP use a database to store tokens and users id. The Mattermost-LDAP Docker implementation is based on the official PostgreSQL server image automatically configured with the init script init_postgres.sh mounted in the init.db folder. The script is available in init_db folder.

Architecture

The Oauth container exposes port 80 and PostgreSQL container exposes port 5432. The user interacts with the Oauth server and the tokens generated by it are stored in the database. In addition, when a user logs in, his ID is stored with a unique ID. This behavior is necessary for authentication with Mattermost. The figure above illustrates interraction between Oauth server, Postgres database and Mattermost.

Image Build

You can build docker images by hand or directly use the Docker compose, which will build image automiatically. See section "Docker Compose setup" in the main README.md, for more information. To build images by hand, follow instructions below.

First, install docker-ce on your host server :

• For CentOS/RHEL : https://docs.docker.com/install/linux/docker-ce/centos/
• For Fedora : https://docs.docker.com/install/linux/docker-ce/fedora/
• For Debian : https://docs.docker.com/install/linux/docker-ce/debian/
• For Ubuntu : https://docs.docker.com/install/linux/docker-ce/ubuntu/

Then, clone this repository on your host and go in Docker directory :

git clone
cd Mattermost-LDAP/Docker

Mattermost-LDAP is available in an embedded version which uses an Apache server image (mattermostldap), and in a lightweight version for Nginx (php-ldap-pgsql) which is only an PHP image configured to enable necessary modules.

To build mattermostldap image use the docker build command :

docker build -t mattermostldap mattermostldap/

Once built, the image is available in the Docker daemon and be used to create container with docker run. To view available images you can use :

docker images list

Note : It is recommended to use Podman on CentOS 8 and Fedora. For more information about Podman, see official documentation : https://podman.io/getting-started/

Configuration

Some image parameters can be changed, by specifying the desired parameters in container's environment variable, when you create a container to adapt it to your configuration. To apply custom parameters, they must be added to the container execution line with the --env (or -e) option followed by the parameter name and the desired value (-e = ). For more details, refer to the examples in the Usage section.

LDAP

Parameter	Description	Default value
ldap_host	URL or IP to connect LDAP server	ldap://ldap.company.com/
ldap_port	Port used to connect LDAP server	389
ldap_version	LDAP version or protocol version used by LDAP server	3
ldap_start_tls	LDAP over STARTTLS	false
ldap_search_attribute	Attribute used to identify a user on the LDAP	uid
ldap_filter	Additional filter for LDAP search	objectClass=*
ldap_base_dn	The base directory name of your LDAP server	ou=People,o=Company
ldap_bind_dn	The LDAP Directory Name of an service account to allow LDAP search
ldap_bind_pass	The password associated to the service account to allow LDAP search

Database

Parameter	Description	Default value
db_host	Hostname or IP address of the Postgres container (database)	127.0.0.1
db_port	The port of your database to connect	5432
db_type	Database type to adapt PDO. Should be pgsql for Postgres container	pgsql
db_user	User who manages oauth database	oauth
db_pass	User's password to manage oauth database	oauth_secure-pass
db_name	Database name for oauth server	oauth_db

Client

Parameter	Description	Default value
client_id	Token client ID shared with mattermost	123456789
client_secret	Token client Secret shared with mattermost	987654321
redirect_uri	The callback address where oauth will send tokens to Mattermost	http://mattermost.company.com/signup/gitlab/complete
grant_types	The type of authentification use by Mattermost	authorization_code
scope	The scope of authentification use by Mattermost	api
user_id	The username of the user who create the Mattermost client in Oauth

Note : Configuration is more detailed in the main README.md.

Usage

The easiest way to use these images is to use the associated Docker compose file, located in the root of this repository. Alternatively, you can run only Mattermost-LDAP image, but you need an external database.

Once built, the mattermostldap image can be used to build a container running the oauth server of the Mattermost-LDAP module. The image contains a default configuration specified in the configuration section. To run a container from the mattermostldap image:

docker run -d mattermostldap --name oauth

To adapt the parameters of the image, you just need to specify custom parameters in environment variables of the container at its start. For example, to configure the LDAP server, use the following command:

docker run -d mattermostldap --name oauth -e ldap_host="ldap.company.com" -e ldap_port=389

To delete the oauth container, you can use :

docker rm oauth

Improvement

In order to allow a dynamic configuration of the Mattermost-LDAP module, the choice has been made to pass the parameters by environmental variables to the container. However, this method exposes all user-defined settings to all processes in the container. As a result, passwords and security tokens are exposed throughout the container and can easily be recovered by any process running in the container, including a user shell.

Unfortunately, this is the simplest method to avoid defining static parameters in the image, forcing a recompilation of the image each time a value is changed. While waiting for a more secure solution, it is highly recommended to secure access to the container.