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Migration from Commento

How to migrate to Comentario from Commento

Commento was once a popular open-source commenting system.

It is in fact a predecessor of Comentario, because Comentario 2.x started as a fork to Commento 1.8, reworking the user interface and the internals, but keeping the database structure intact.

The fact that Comentario 2.x database was 100% compatible with Commento made the migration very easy: it was basically a drop-in replacement, which only required adjusting some server parameters. It made also a reverse migration possible.

IMPORTANT: a direct database migration from Commento to Comentario is only possible if you’re staying on the same database, i.e. PostgreSQL (the only option for Commento). Migration from PostgreSQL to SQLite can only be done via export and a subsequent import.

Comentario 3

The version 3 of Comentario is a major step forward: it addresses many inconsistencies and limitations of Commento data model, which slowed down the development of the latter and made solving some issues nearly impossible.

The data model was developed from scratch, and all the constituent components had to be overhauled and rewritten.

We’ve done our best to make the migration transparent, keeping Comentario “plug-n-play.” The database will be automatically migrated on first run.

Contrary to Comentario 2.x, it’s a one-way ticket though; once migrated, the original database will be deleted. The only way to revert that is restoring a back-up copy made prior to migration.

Migration steps

1. Back up your data

VERY IMPORTANT: Always make a backup of your original database!

The migration can fail, go wrong, or wipe the original data. This is especially true due to the quirks of the original Commento data model.

2. Check your backup

ALSO VERY IMPORTANT: Make sure the backup you made can be restored. A non-restorable backup is as useless as a non-existent one.

3. Deploy Comentario

Install Comentario and configure it to connect to the same PostgreSQL database Commento used (or a copy of it).

The database should be automatically migrated on the first run. If everything goes smoothly, the server will just run without any error or warning message in the console.

And if you start it with the -v command-line switch, you should have seen the following lines in the log:

2023/08/20 11:49:38 INFO  persistence Connected to database
2023/08/20 11:49:38 INFO  persistence Discovered 1 database migrations in /comentario/db
2023/08/20 11:49:38 INFO  persistence 0 migrations already installed
2023/08/20 11:49:38 INFO  persistence Successfully installed 1 migrations

4. Appoint a superuser

Comentario introduces the concept of superuser: it’s essentially an instance admin. Only superusers can manage (edit, ban, delete) other users and change configuration parameters. You’ll definitely need at least one for your installation.

There are the following four ways to become a superuser:

  1. Superuser privilege can be granted a user by another superuser. It can only work if you already have a superuser.
  2. The first local user (i.e. one signing up with email and password) registered on the server automatically gets a superuser privilege.
  3. Using the --superuser=<ID-or-email> command-line switch to turn a user into a superuser.
  4. Updating the database directly with a UI tool or the following SQL statement:
update cm_users set is_superuser = true where email = 'YOUR@EMAIL';

Since you’re migrating from Commento, you’d probably already have users, so you’ll need to use the last two options.

5. Update your code snippet

Comentario is embedded on a web page as a web component, and not via a <div> tag like Commento.

In practice, it only means updating the code snippet you place on your web pages, replacing the <div> with <comentario-comments>. You can look the snippet up in the Administration console, under Domain propertiesInstallation, and it looks like this:

<script defer src=""></script>

If you used data-* attributes, you’ll need to change those, too:

  • Firstly, they now have to be put on the <comentario-comments> tag (not on the <script>).
  • Secondly, the data- prefix should be removed.

There’s one exception to the data attributes: data-hide-deleted, which Commento used to hide deleted comments, isn’t supported by Comentario on the page level. Instead, you can switch off the Show deleted comments configuration parameter.