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Prosody XMPP Docker image

This docker image provides you with a configured Prosody XMPP server. The image is based on debian:bookworm-slim. The server was tested using the Android App Conversations and the Desktop client Gajim. Multiple architectures are supported. I use it on my raspberry pi 4.

While Conversations got everything set-up out-of-the-box, Gajim was used with the following extensions:

• HttpUpload
• Off-The-Record Encryption
• OMEMO (requires python-axolotl to be installed)
• Url Image preview

Table of Contents

• Prosody XMPP Docker image
  • Table of Contents
  • Features
  • Requirements
  • Image Details
    • Ports
    • Directories
      • Data
      • Bundled modules
      • Additionally installed prosody modules
      • Config
      • SSL certificates
        • Folder structure
        • Symlinks
        • Permissions
    • Run
    • Volumes permissions
    • Docker tags
    • Configuration
      • Environment variables
      • DNS
    • Extend
    • Upgrade
  • Test your server

Features

• Secure by default
  • SSL certificate required
  • End-to-end encryption required (using OMEMO or OTR)
• Data storage
  • SQLite message store
  • Configured file upload and image sharing
• Multi-user chat (MUC)

Requirements

• You need a SSL certificate. I recommend LetsEncrypt for that.

Image Details

Ports

The following ports are exposed:

• 5000: proxy65 port used for file sharing
• 5222: c2s port (client to server)
• 5223: c2s legacy ssl port (client to server)
• 5269: s2s port (server to server)
• 5347: XMPP component port
• 5280: BOSH / websocket port
• 5281: Secure BOSH / websocket port

Directories

Data

Path: /usr/local/var/lib/prosody/.

• used for SQLite file
• used for HTTP uploads
• this is exposed as docker volume

Bundled modules

Path: /usr/local/lib/prosody/modules/.

Additionally installed prosody modules

Path: /usr/local/lib/prosody/custom-modules/.

Config

Path: /usr/local/etc/prosody/.

• containing the main config file called prosody.cfg.lua
• containing additional config files within conf.d/

SSL certificates

Path: /usr/local/etc/prosody/certs/.

Uses automatic location to find your certs.

The http_upload module and the legacy_ssl module do not use the same search algorithm for the certificates. See service certificates.

The settings https_ssl and legacy_ssl_ssl in 05-vhost.cfg.lua configures the certificates to certs/domain.tld/fullchain.pem and certs/domain.tld/privkey.pem for legacy_ssl and to certs/DOMAIN_HTTP_UPLOAD/fullchain.pem and certs/DOMAIN_HTTP_UPLOAD/privkey.pem for http_upload where DOMAIN_HTTP_UPLOAD is an environtment variable.

Folder structure

An example certificate folder structure could look like this:

certs
├── conference.domain.tld
│   ├── fullchain.pem
│   └── privkey.pem
├── proxy.domain.tld
│   ├── fullchain.pem
│   └── privkey.pem
├── upload.domain.tld
│   ├── fullchain.pem
│   └── privkey.pem
└── domain.tld
    ├── fullchain.pem
    └── privkey.pem

Thats how Let's encrypt certbot does it out of the box.

Symlinks

certbot creates the structure and uses symlinks to the actual certificates. If you mount them like that prosody somehow does not find them. I copied them to a folder named certs next to my docker-compose.yml and made sure to use the -L flag of cp. This makes cp follow symbolic links when copying from them. For example cp -L src dest.

Permissions

See official documentation for more information. Check Volumes permissions as well.

Run

I recommend using a docker-compose.yml file:

version: '3.7'

services:
  server:
    image: sarasmiseth/prosody:latest
    restart: unless-stopped
    ports:
      - "5000:5000"
      - "5222:5222"
      - "5223:5223"
      - "5269:5269"
      - "5281:5281"
    environment:
      DOMAIN: domain.tld
    volumes:
      - ./certs:/usr/local/etc/prosody/certs
      - ./data:/usr/local/var/lib/prosody

Boot it via: docker compose up -d.

Inspect logs: docker compose logs -f.

Volumes permissions

The prosody user inside the container has the uid=999 and gid=999. If you use the example docker-compose.yml from above make sure, that the ./data folder and the ./certs folder have the correct permissions.

sudo chown 999:999 ./certs
sudo chown 999:999 ./data

Docker tags

https://hub.docker.com/r/sarasmiseth/prosody/tags

Configuration

Environment variables

DNS

You need these DNS record pointing to your server:

• domain.tld
• conference.domain.tld
• proxy.domain.tld
• pubsub.domain.tld
• upload.domain.tld
• A SRV record for _xmpps-client._tcp.domain.tld for port 5223.

where domain.tld is the environment variable DOMAIN.

Extend

There is a helper script that eases installing additional prosody modules: docker-prosody-module-install

It downloads the current prosody-modules repository. The specified modules are copied and its name is added to the modules_enabled variable within conf.d/01-modules.cfg.lua.

There is also docker-prosody-module-copy which copies the specified modules but does not add them to the modules_enabled variable within conf.d/01-modules.cfg.lua.

If you need additional configuration just overwrite the respective cfg.lua file or add new ones.

Upgrade

When migrating from prosody 0.10, you need to update the database once:

docker compose exec server bash
prosodyctl mod_storage_sql upgrade

Test your server

You can test your server with these websites:

• IM Observatory
• XMPP Compliance Tester