Configurer Discourse pour utiliser un serveur PostgreSQL séparé

[Discourse]

Supposons que vous utilisiez AWS RDS, ou un serveur PostgreSQL existant géré ailleurs. Il est assez simple de faire en sorte que Discourse utilise une telle configuration, sans avoir besoin d’accorder des privilèges de superutilisateur à quoi que ce soit que Discourse exécute lui-même. Voici comment.

Prérequis

Discourse exige que la version majeure de PostgreSQL corresponde à celle que nous livrons dans nos images docker ; si vous essayez d’exécuter sur une version plus récente ou plus ancienne, cela pourrait fonctionner, mais nous ne le garantissons pas, et si quelque chose casse à l’avenir, vous gardez les deux morceaux. Nous exigeons également certaines extensions qui sont distribuées dans le paquet postgresql-contrib (ou son équivalent). Vous aurez également besoin de l’extension pgvector (paquet postgresql-<version>-pgvector), requise par le plugin Discourse AI qui est livré avec le cœur de Discourse.

Générez un mot de passe aléatoire pour la connexion (20+ caractères). Dans ce guide, nous utiliserons s3kr1t comme espace réservé.

Configuration de la base de données

En tant que superutilisateur de la base de données, exécutez ce qui suit :

CREATE USER discourse PASSWORD 's3kr1t';
CREATE DATABASE discourse OWNER discourse;
\c discourse
CREATE EXTENSION hstore;
CREATE EXTENSION pg_trgm;
CREATE EXTENSION unaccent;
CREATE EXTENSION vector;

C’est tout ce qui doit être fait pour préparer la base de données à être utilisée par Discourse.

Configuration de Discourse

Configurez Discourse de la manière habituelle, puis modifiez containers/app.yml comme suit :

1. Supprimez la ligne - "templates/postgres.template.yml" sous la clé de niveau supérieur templates (vers le haut du fichier) ;

2. Sous la clé de niveau supérieur env, définissez ce qui suit :

    DISCOURSE_DB_USERNAME: discourse
    DISCOURSE_DB_PASSWORD: s3kr1t
    DISCOURSE_DB_HOST: <IP ou nom d'hôte>
    DISCOURSE_DB_NAME: discourse
   

3. Vous devez également définir ce qui suit si votre base de données n’utilise pas le port par défaut (5432) :

   DISCOURSE_DB_PORT: <port>
   DISCOURSE_DB_BACKUP_PORT: <port>
   

4. Reconstruisez avec ./launcher rebuild app, et vous devriez être prêt à partir.

[alexweej (Alexander “Weej” Jones)]

There is an additional setting, DISCOURSE_DB_PORT, which can, naturally, configure the TCP port number. @mpalmer please update the post?

Thanks

[mpalmer (Matt Palmer)]

This isn’t supposed to be a comprehensive description of every possible way you can configure your database connection, rather it’s a quick howto to make things a bit easier.

[alexweej (Alexander “Weej” Jones)]

Is there somewhere more authoritative for this documentation? I even tried (unsuccessfully) to track down the source code for this…!

Thanks

[mpalmer (Matt Palmer)]

The discourse_docker repo is where all that lives.

[alexweej (Alexander “Weej” Jones)]

Thanks for the pointer, I’m embarrassed to admit I’ve gone through almost an entire setup without realising the wealth of documentation on that page.

That said, the only reference to DISCOURSE_DB_PORT is in web.template.yml: https://github.com/discourse/discourse_docker/search?utf8=✓&q=DISCOURSE_DB_PORT&type=

[mpalmer (Matt Palmer)]

Yes, it could probably stand to be promoted into the default “web_only” template, with a suitably explanatory comment. PRs welcome!

[Ivan_Rapekas]

Hi, first thanks for this guide. I try to setup external postgresql on the same machine, where docker installed. Do I need to bind port of my external postgresql 5432 to docker? Could anybody assist how to do it, using Discourse configuration file?

[mpalmer (Matt Palmer)]

Your question doesn’t make any sense. You don’t bind external listening ports to Docker.

[Ivan_Rapekas]

I follow the instruction a the top. First I set up an ordinary docker, it works. Then I want to switch the application to external postgres. When I rebuild the app, I get an error

Is the server running on host "127.0.0.1" and accepting TCP/IP connections on port 5432?

My server has not a FQDN yet, I use 127.0.0.1 as a DB host. The database is listening on 127.0.0.1:5432, I am able to connect with psql. Where am I wrong? I tried to play with pg_hba.conf but no success, of course.

[Ivan_Rapekas]

Hi guys, possible of my personal server configuration or what else… But I found a solution by running a docker in hosted mode (not bridged as default):

/var/discourse/launcher rebuild app --docker-args --net=host --skip-mac-address

After that the discourse engine could connect to external postgres database, run at 127.0.0.1:5432. Default bridged mode does not allow docker to access ports listening at the host without tricks.

Hope this might help somebody.

[davedogs]

When I run ./launcher rebuild app, I get this error PG::ConnectionBad: timeout expired during the bundle exec rake db:migrate. Has anyone comes across this issue? I can successfully access the database with a postgres client.

[jpsayshello (Jaimin)]

I have not tried this yet.
Here it is suggested to remove web.template.yml but i see bunch of other stuff happening in discourse_docker/templates/web.template.yml at master · discourse/discourse_docker · GitHub

What about that ?

[schleifer (Andrew Schleifer)]

@jpsayshello

Here it is suggested to remove web.template.yml

No it doesn’t. 

@mpalmer

Remove the line - "templates/postgres.template.yml"

[Tango]

Can you take the same approach for Redis?

remove “templates/redis.template.yml” & add a line in the app.yml file for DISCOURSE_REDIS_HOST

Thanks in advance

Todd

[itsbhanusharma (Bhanu Sharma)]

Is there an obvious benefit that I’m maybe missing?

(I assume running redis on a separate machine will just add unwanted latency if nothing else)

[Tango]

Just that its managed & 1 less thing to worry about

[itsbhanusharma (Bhanu Sharma)]

You don’t have to worry about redis that ships with discourse. I haven’t seen it failing on me in the last 1 year of self hosting discourse.

[Tango]

Thanks @itsbhanusharma,

Do you know what the process would be even if I did?

This article, albeit a little old says to add

DISCOURSE_REDIS_HOST

which is the same format as the article you so kindly mentioned, so that all makes sense.

Just not sure where to put it (maybe underneath other changes made to the app.yml file or maybe in the "templates/redis.template.yml")

and also

what if any lines or files need to be deleted

Thanks

Todd

[itsbhanusharma (Bhanu Sharma)]

That variable should go into the file where you declared postgres variables. Just be warned that exposing redis for a production environment is lethal. (Because of poor security practices of redis itself)