Cumbersome Installation

Once MongoDB is installed, Rocket.Chat follows: As with InspIRCd and Mattermost, the Rocket.Chat developers don't provide packages for SUSE, Red Hat, or Debian/Ubuntu. Again, the installation is via tarball, which you need to unpack on the target system in a directory of your choice. MongoDB is launched by simply calling node: It has no init script or systemd unit file. Therefore, you need to create your own if you want to start Rocket.Chat automatically.

In the installation guide, the developers point out that manual installation isn't, in their opinion, the best and fastest way to get a Rocket.Chat instance up and running. Instead, they recommend the use of hosting platforms like Sandstorm [9] or Heroku [10]. However, that would wipe out the advantage of a self-hosted system and control over your data. Although Docker containers are available as a middle ground, many administrators dislike these black boxes because they must rely completely on the benevolence of the container's authors and their willingness to provide updates for the containers as needed (e.g., for security reasons).

Decent UI, Handy Features

A look at the feature list reveals that Rocket.Chat is clearly guided by Slack. Whether the connection is made from a web browser or the native desktop app, Rocket.Chat's graphical interface is pleasant and unobtrusive. Standard features such as the automatic preview display for posted links work perfectly (Figure 5). Rocket.Chat stores files uploaded for sharing with other chat participants permanently on the server. As with Mattermost, you should have enough disk space available.

Figure 5: Rocket.Chat is another alternative to Slack and has an automatic URL preview.

A Separate API

Rocket.Chat provides its own API that follows the REST principle. For example, according to the public Rocket.Chat documentation, it is possible to log on to the API with user access and to query all unread messages from a specific channel. However, the API has another purpose: Rocket.Chat implements the same functions with its API as Mattermost does with webhooks.

GitHub, GitLab, Jira, and Confluence can therefore be used to access the Rocket.Chat API by URL for certain events. The commit message for a change in GitLab thus ends up directly in the chat channel of the developers involved, if so desired. If you don't want to write the integration yourself, you can use Hubot [11], which makes sure that GitLab and GitHub directories are correctly integrated into Rocket.Chat.

In addition to the API, Rocket.Chat provides a plugin interface that can be used to expand the service at will. For example, the ScreenShare extension can export your display to another user directly from Rocket.Chat. Rocket.Chat provides appropriate plugins for Chrome and Firefox in the respective extension stores.

If you want to operate more than one Rocket.Chat installation, you will appreciate the federation feature, which can be used to link several servers to form a network. Federation also offers gateway features for IRC, Slack, Skype, and Asterisk. Installing the OAuth extension for Rocket.Chat keeps the user databases of all servers in sync.