Nginx config for scaling matrix synapse server via workers

nginx.conf

# Matrix Synapse workers example config 

# backends
upstream synapse_master {
	server 192.19.18.12:38008;
}

upstream synapse_federation {
	server 192.19.18.12:8083;
}

upstream synapse_client {
	server 192.19.18.12:8084;
}

# map urls to backend
# based on list from 
# https://github.com/matrix-org/synapse/blob/develop/docs/workers.md
map $request_uri $synapse_backend {
	default synapse_master;

	# Sync requests
	~*^/_matrix/client/(r0|v3)/sync$ synapse_client;
	~*^/_matrix/client/(api/v1|r0|v3)/events$ synapse_client;
	~*^/_matrix/client/(api/v1|r0|v3)/initialSync$ synapse_client;
	~*^/_matrix/client/(api/v1|r0|v3)/rooms/[^/]+/initialSync$ synapse_client;

	# Federation requests
	~*^/_matrix/federation/v1/event/ synapse_federation;
	~*^/_matrix/federation/v1/state/ synapse_federation;
	~*^/_matrix/federation/v1/state_ids/ synapse_federation;
	~*^/_matrix/federation/v1/backfill/ synapse_federation;
	~*^/_matrix/federation/v1/get_missing_events/ synapse_federation;
	~*^/_matrix/federation/v1/publicRooms synapse_federation;
	~*^/_matrix/federation/v1/query/ synapse_federation;
	~*^/_matrix/federation/v1/make_join/ synapse_federation;
	~*^/_matrix/federation/v1/make_leave/ synapse_federation;
	~*^/_matrix/federation/(v1|v2)/send_join/ synapse_federation;
	~*^/_matrix/federation/(v1|v2)/send_leave/ synapse_federation;
	~*^/_matrix/federation/(v1|v2)/invite/ synapse_federation;
	~*^/_matrix/federation/v1/event_auth/ synapse_federation;
	~*^/_matrix/federation/v1/exchange_third_party_invite/ synapse_federation;
	~*^/_matrix/federation/v1/user/devices/ synapse_federation;
	~*^/_matrix/key/v2/query synapse_federation;
	~*^/_matrix/federation/v1/hierarchy/ synapse_federation;

	# Inbound federation transaction request
	~*^/_matrix/federation/v1/send/ synapse_federation;

	# Client API requests
	~*^/_matrix/client/(api/v1|r0|v3|unstable)/createRoom$ synapse_client;
	~*^/_matrix/client/(api/v1|r0|v3|unstable)/publicRooms$ synapse_client;
	~*^/_matrix/client/(api/v1|r0|v3|unstable)/rooms/.*/joined_members$ synapse_client;
	~*^/_matrix/client/(api/v1|r0|v3|unstable)/rooms/.*/context/.*$ synapse_client;
	~*^/_matrix/client/(api/v1|r0|v3|unstable)/rooms/.*/members$ synapse_client;
	~*^/_matrix/client/(api/v1|r0|v3|unstable)/rooms/.*/state$ synapse_client;
	~*^/_matrix/client/v1/rooms/.*/hierarchy$ synapse_client;
	~*^/_matrix/client/unstable/org.matrix.msc2716/rooms/.*/batch_send$ synapse_client;
	~*^/_matrix/client/unstable/im.nheko.summary/rooms/.*/summary$ synapse_client;
	~*^/_matrix/client/(r0|v3|unstable)/account/3pid$ synapse_client;
	~*^/_matrix/client/(r0|v3|unstable)/account/whoami$ synapse_client;
	~*^/_matrix/client/(r0|v3|unstable)/devices$ synapse_client;
	~*^/_matrix/client/versions$ synapse_client;
	~*^/_matrix/client/(api/v1|r0|v3|unstable)/voip/turnServer$ synapse_client;
	~*^/_matrix/client/(api/v1|r0|v3|unstable)/rooms/.*/event/ synapse_client;
	~*^/_matrix/client/(api/v1|r0|v3|unstable)/joined_rooms$ synapse_client;
	~*^/_matrix/client/(api/v1|r0|v3|unstable)/search$ synapse_client;

	# Encryption requests
	~*^/_matrix/client/(r0|v3|unstable)/keys/query$ synapse_client;
	~*^/_matrix/client/(r0|v3|unstable)/keys/changes$ synapse_client;
	~*^/_matrix/client/(r0|v3|unstable)/keys/claim$ synapse_client;
	~*^/_matrix/client/(r0|v3|unstable)/room_keys/ synapse_client;

	# Registration/login requests
	~*^/_matrix/client/(api/v1|r0|v3|unstable)/login$ synapse_client;
	~*^/_matrix/client/(r0|v3|unstable)/register$ synapse_client;
	~*^/_matrix/client/v1/register/m.login.registration_token/validity$ synapse_client;

	# Event sending requests
	~*^/_matrix/client/(api/v1|r0|v3|unstable)/rooms/.*/redact synapse_client;
	~*^/_matrix/client/(api/v1|r0|v3|unstable)/rooms/.*/send synapse_client;
	~*^/_matrix/client/(api/v1|r0|v3|unstable)/rooms/.*/state/ synapse_client;
	~*^/_matrix/client/(api/v1|r0|v3|unstable)/rooms/.*/(join|invite|leave|ban|unban|kick)$ synapse_client;
	~*^/_matrix/client/(api/v1|r0|v3|unstable)/join/ synapse_client;
	~*^/_matrix/client/(api/v1|r0|v3|unstable)/profile/ synapse_client;

	# Account data requests
	~*^/_matrix/client/(r0|v3|unstable)/.*/tags synapse_client;
	~*^/_matrix/client/(r0|v3|unstable)/.*/account_data synapse_client;

	# Receipts requests
	#~*^/_matrix/client/(r0|v3|unstable)/rooms/.*/receipt synapse_client;
	#~*^/_matrix/client/(r0|v3|unstable)/rooms/.*/read_markers synapse_client;

	# Presence requests
	~*^/_matrix/client/(api/v1|r0|v3|unstable)/presence/ synapse_client;

	# User directory search requests
	~*^/_matrix/client/(r0|v3|unstable)/user_directory/search$ synapse_client;
}

server {
	listen 443 ssl http2;
	listen [::]:443 ssl http2;
	server_name example.com;

	# SSL
	ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem;
	ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem;
	ssl_trusted_certificate /etc/letsencrypt/live/example.com/chain.pem;

	# security
	#include snippets/security.conf;

	location /_matrix {
		# use whatever backend our map gives us
		proxy_pass http://$synapse_backend;
		include snippets/proxy.conf;
		client_max_body_size 5g;
		# Fuck no
		access_log off;
		log_not_found off;
		add_header Backend-Server $synapse_backend;
	}

	# This is also provided by synapse server
	location /.well-known/matrix/client {
		return 200 '{"m.homeserver": {"base_url": "https://example.com/"}}';
		default_type application/json;
		add_header Access-Control-Allow-Origin *;
		access_log off;
		log_not_found off;
	}

	location /.well-known/matrix/server {
		return 200 '{"m.server": "example.com:443"}';
		default_type application/json;
		add_header Access-Control-Allow-Origin *;
		access_log off;
		log_not_found off;
	}

	# additional config
	#include snippets/general.conf;
}

# HTTP redirect
server {
	listen 80;
	listen [::]:80;

	server_name example.com;

	include snippets/letsencrypt.conf;

	location / {
		return 301 https://example.com$request_uri;
	}
}

@udovichenkoAlexander Thank's for the feedback! nginx variables magic has always been a bit of a confusion point for me. I will try to implement the fixes when I get the time.