Jitsi meet is a free open source video conferencing web application and Mattermost an open source self hostable chat platform. Jitsi can be integrated with various chat platforms like Mattermost and Slack. The below steps describe how we could integrate Jitsi with Mattermost.
Step 1: Download the Jitsi meet plugin from https://integrations.mattermost.com/jitsi-plugin/
Step 2: Move the downloaded plugin file to the plugins directory in Mattermost or login to Mattermost and move to 'Plugin Management' option in 'Plugins' in 'System Console' in Mattermost.
Step 3: Upload the plugins zip file via Mattermost 'Upload Plugin' option.
Step 4: Enable the 'Jitsi Plugin' from the 'Plugin Management' option.
Step 5: Once this is done, You will need to configure the Plugin to either use self-hosting jitsi option or the jitsi meet URL which is the default option.
Step 6: Once the URL is configured, You will be able to start a jitsi meeting by using the slash commands '/'.
For example: To start a meeting with the name DevOpsmeet, You will need to run '/jitsi DevOpsmeet' in Mattermost chat.
Step 7: You will be redirected towards the URL: https://meet.jit.si/DevOpsmeet