dendrite/docs/INSTALL.md

Installing Dendrite

Dendrite can be run in one of two configurations:

• Monolith mode: All components run in the same process. In this mode, it is possible to run an in-process NATS Server instead of running a standalone deployment. This will usually be the preferred model for low-to-mid volume deployments, providing the best balance between performance and resource usage.

• Polylith mode: A cluster of individual components running in their own processes, dealing with different aspects of the Matrix protocol (see WIRING.md). Components communicate with each other using internal HTTP APIs and NATS Server. This will almost certainly be the preferred model for very large deployments but scalability comes with a cost. API calls are expensive and therefore a polylith deployment may end up using disproportionately more resources for a smaller number of users compared to a monolith deployment.

In almost all cases, it is recommended to run in monolith mode with PostgreSQL databases.

Regardless of whether you are running in polylith or monolith mode, each Dendrite component that requires storage has its own database connections. Both Postgres and SQLite are supported and can be mixed-and-matched across components as needed in the configuration file.

Be advised that Dendrite is still in development and it's not recommended for use in production environments just yet!

Requirements

Dendrite requires:

• Go 1.16 or higher
• PostgreSQL 12 or higher (if using PostgreSQL databases, not needed for SQLite)

If you want to run a polylith deployment, you also need:

• A standalone NATS Server deployment with JetStream enabled

Building Dendrite

Start by cloning the code:

git clone https://github.com/matrix-org/dendrite
cd dendrite

Then build it:

./build.sh

Install NATS Server

Follow the NATS Server installation instructions and then start your NATS deployment.

JetStream must be enabled, either by passing the -js flag to nats-server, or by specifying the store_dir option in the the jetstream configuration.

Configuration

PostgreSQL database setup

Assuming that PostgreSQL 12 (or later) is installed:

• Create role, choosing a new password when prompted:

  sudo -u postgres createuser -P dendrite
  

At this point you have a choice on whether to run all of the Dendrite components from a single database, or for each component to have its own database. For most deployments, running from a single database will be sufficient, although you may wish to separate them if you plan to split out the databases across multiple machines in the future.

On macOS, omit sudo -u postgres from the below commands.

• If you want to run all Dendrite components from a single database:

    sudo -u postgres createdb -O dendrite dendrite
  

  ... in which case your connection string will look like postgres://user:pass@database/dendrite.

• If you want to run each Dendrite component with its own database:

  for i in mediaapi syncapi roomserver federationapi appservice keyserver userapi_accounts; do
      sudo -u postgres createdb -O dendrite dendrite_$i
  done
  

  ... in which case your connection string will look like postgres://user:pass@database/dendrite_componentname.

SQLite database setup

WARNING: SQLite is suitable for small experimental deployments only and should not be used in production - use PostgreSQL instead for any user-facing federating installation!

Dendrite can use the built-in SQLite database engine for small setups. The SQLite databases do not need to be pre-built - Dendrite will create them automatically at startup.

Server key generation

Each Dendrite installation requires:

• A unique Matrix signing private key
• A valid and trusted TLS certificate and private key

To generate a Matrix signing private key:

./bin/generate-keys --private-key matrix_key.pem

WARNING: Make sure take a safe backup of this key! You will likely need it if you want to reinstall Dendrite, or any other Matrix homeserver, on the same domain name in the future. If you lose this key, you may have trouble joining federated rooms.

For testing, you can generate a self-signed certificate and key, although this will not work for public federation:

./bin/generate-keys --tls-cert server.crt --tls-key server.key

If you have server keys from an older Synapse instance, convert them to Dendrite's PEM format and configure them as old_private_keys in your config.

Configuration file

Create config file, based on dendrite-config.yaml. Call it dendrite.yaml. Things that will need editing include at least:

• The server_name entry to reflect the hostname of your Dendrite server
• The database lines with an updated connection string based on your desired setup, e.g. replacing database with the name of the database:
  • For Postgres: postgres://dendrite:password@localhost/database, e.g.
    • postgres://dendrite:password@localhost/dendrite_userapi_account to connect to PostgreSQL with SSL/TLS
    • postgres://dendrite:password@localhost/dendrite_userapi_account?sslmode=disable to connect to PostgreSQL without SSL/TLS
  • For SQLite on disk: file:component.db or file:///path/to/component.db, e.g. file:userapi_account.db
  • Postgres and SQLite can be mixed and matched on different components as desired.
• Either one of the following in the jetstream configuration section:
  • The addresses option — a list of one or more addresses of an external standalone NATS Server deployment
  • The storage_path — where on the filesystem the built-in NATS server should store durable queues, if using the built-in NATS server

There are other options which may be useful so review them all. In particular, if you are trying to federate from your Dendrite instance into public rooms then configuring key_perspectives (like matrix.org in the sample) can help to improve reliability considerably by allowing your homeserver to fetch public keys for dead homeservers from somewhere else.

WARNING: Dendrite supports running all components from the same database in PostgreSQL mode, but this is NOT a supported configuration with SQLite. When using SQLite, all components MUST use their own database file.

Starting a monolith server

The monolith server can be started as shown below. By default it listens for HTTP connections on port 8008, so you can configure your Matrix client to use http://servername:8008 as the server:

./bin/dendrite-monolith-server

If you set --tls-cert and --tls-key as shown below, it will also listen for HTTPS connections on port 8448:

./bin/dendrite-monolith-server --tls-cert=server.crt --tls-key=server.key

If the jetstream section of the configuration contains no addresses but does contain a store_dir, Dendrite will start up a built-in NATS JetStream node automatically, eliminating the need to run a separate NATS server.

Starting a polylith deployment

The following contains scripts which will run all the required processes in order to point a Matrix client at Dendrite.

nginx (or other reverse proxy)

This is what your clients and federated hosts will talk to. It must forward requests onto the correct API server based on URL:

• /_matrix/client to the client API server
• /_matrix/federation to the federation API server
• /_matrix/key to the federation API server
• /_matrix/media to the media API server

See docs/nginx/polylith-sample.conf for a sample configuration.

Client API server

This is what implements CS API endpoints. Clients talk to this via the proxy in order to send messages, create and join rooms, etc.

./bin/dendrite-polylith-multi --config=dendrite.yaml clientapi

Sync server

This is what implements /sync requests. Clients talk to this via the proxy in order to receive messages.

./bin/dendrite-polylith-multi --config=dendrite.yaml syncapi

Media server

This implements /media requests. Clients talk to this via the proxy in order to upload and retrieve media.

./bin/dendrite-polylith-multi --config=dendrite.yaml mediaapi

Federation API server

This implements the federation API. Servers talk to this via the proxy in order to send transactions. This is only required if you want to support federation.

./bin/dendrite-polylith-multi --config=dendrite.yaml federationapi

Internal components

This refers to components that are not directly spoken to by clients. They are only contacted by other components. This includes the following components.

Room server

This is what implements the room DAG. Clients do not talk to this.

./bin/dendrite-polylith-multi --config=dendrite.yaml roomserver

Appservice server

This sends events from the network to application services running locally. This is only required if you want to support running application services on your homeserver.

./bin/dendrite-polylith-multi --config=dendrite.yaml appservice

Key server

This manages end-to-end encryption keys for users.

./bin/dendrite-polylith-multi --config=dendrite.yaml keyserver

EDU server

This manages processing EDUs such as typing, send-to-device events and presence. Clients do not talk to

./bin/dendrite-polylith-multi --config=dendrite.yaml eduserver

User server

This manages user accounts, device access tokens and user account data, amongst other things.

./bin/dendrite-polylith-multi --config=dendrite.yaml userapi