diff options
Diffstat (limited to 'docs/setup/turn/eturnal.md')
| -rw-r--r-- | docs/setup/turn/eturnal.md | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/docs/setup/turn/eturnal.md b/docs/setup/turn/eturnal.md new file mode 100644 index 0000000000..2e5a45673e --- /dev/null +++ b/docs/setup/turn/eturnal.md @@ -0,0 +1,170 @@ +# eturnal TURN server + +The following sections describe how to install [eturnal](<https://github.com/processone/eturnal>) +(which implements the TURN REST API). + +## `eturnal` setup + +### Initial installation + +The `eturnal` TURN server implementation is available from a variety of sources +such as native package managers, binary packages, installation from source or +[container image](https://eturnal.net/documentation/code/docker.html). They are +all described [here](https://github.com/processone/eturnal#installation). + +Quick-Test instructions in a [Linux Shell](https://github.com/processone/eturnal/blob/master/QUICK-TEST.md) +or with [Docker](https://github.com/processone/eturnal/blob/master/docker-k8s/QUICK-TEST.md) +are available as well. + +### Configuration + +After installation, `eturnal` usually ships a [default configuration file](https://github.com/processone/eturnal/blob/master/config/eturnal.yml) +here: `/etc/eturnal.yml` (and, if not found there, there is a backup file here: +`/opt/eturnal/etc/eturnal.yml`). It uses the (indentation-sensitive!) [YAML](https://en.wikipedia.org/wiki/YAML) +format. The file contains further explanations. + +Here are some hints how to configure eturnal on your [host machine](https://github.com/processone/eturnal#configuration) +or when using e.g. [Docker](https://eturnal.net/documentation/code/docker.html). +You may also further deep dive into the [reference documentation](https://eturnal.net/documentation/). + +`eturnal` runs out of the box with the default configuration. To enable TURN and +to integrate it with your homeserver, some aspects in `eturnal`'s default configuration file +must be edited: + +1. Homeserver's [`turn_shared_secret`](../../usage/configuration/config_documentation.md#turn_shared_secret) + and eturnal's shared `secret` for authentication + + Both need to have the same value. Uncomment and adjust this line in `eturnal`'s + configuration file: + + ```yaml + secret: "long-and-cryptic" # Shared secret, CHANGE THIS. + ``` + + One way to generate a `secret` is with `pwgen`: + + ```sh + pwgen -s 64 1 + ``` + +1. Public IP address + + If your TURN server is behind NAT, the NAT gateway must have an external, + publicly-reachable IP address. `eturnal` tries to autodetect the public IP address, + however, it may also be configured by uncommenting and adjusting this line, so + `eturnal` advertises that address to connecting clients: + + ```yaml + relay_ipv4_addr: "203.0.113.4" # The server's public IPv4 address. + ``` + + If your NAT gateway is reachable over both IPv4 and IPv6, you may + configure `eturnal` to advertise each available address: + + ```yaml + relay_ipv4_addr: "203.0.113.4" # The server's public IPv4 address. + relay_ipv6_addr: "2001:db8::4" # The server's public IPv6 address (optional). + ``` + + When advertising an external IPv6 address, ensure that the firewall and + network settings of the system running your TURN server are configured to + accept IPv6 traffic, and that the TURN server is listening on the local + IPv6 address that is mapped by NAT to the external IPv6 address. + +1. Logging + + If `eturnal` was started by systemd, log files are written into the + `/var/log/eturnal` directory by default. In order to log to the [journal](https://www.freedesktop.org/software/systemd/man/systemd-journald.service.html) + instead, the `log_dir` option can be set to `stdout` in the configuration file. + +1. Security considerations + + Consider your security settings. TURN lets users request a relay which will + connect to arbitrary IP addresses and ports. The following configuration is + suggested as a minimum starting point, [see also the official documentation](https://eturnal.net/documentation/#blacklist): + + ```yaml + ## Reject TURN relaying from/to the following addresses/networks: + blacklist: # This is the default blacklist. + - "127.0.0.0/8" # IPv4 loopback. + - "::1" # IPv6 loopback. + - recommended # Expands to a number of networks recommended to be + # blocked, but includes private networks. Those + # would have to be 'whitelist'ed if eturnal serves + # local clients/peers within such networks. + ``` + + To whitelist IP addresses or specific (private) networks, you need to **add** a + whitelist part into the configuration file, e.g.: + + ```yaml + whitelist: + - "192.168.0.0/16" + - "203.0.113.113" + - "2001:db8::/64" + ``` + + The more specific, the better. + +1. TURNS (TURN via TLS/DTLS) + + Also consider supporting TLS/DTLS. To do this, adjust the following settings + in the `eturnal.yml` configuration file (TLS parts should not be commented anymore): + + ```yaml + listen: + - ip: "::" + port: 3478 + transport: udp + - ip: "::" + port: 3478 + transport: tcp + - ip: "::" + port: 5349 + transport: tls + + ## TLS certificate/key files (must be readable by 'eturnal' user!): + tls_crt_file: /etc/eturnal/tls/crt.pem + tls_key_file: /etc/eturnal/tls/key.pem + ``` + + In this case, replace the `turn:` schemes in homeserver's `turn_uris` settings + with `turns:`. More is described [here](../../usage/configuration/config_documentation.md#turn_uris). + + We recommend that you only try to set up TLS/DTLS once you have set up a + basic installation and got it working. + + NB: If your TLS certificate was provided by Let's Encrypt, TLS/DTLS will + not work with any Matrix client that uses Chromium's WebRTC library. This + currently includes Element Android & iOS; for more details, see their + [respective](https://github.com/vector-im/element-android/issues/1533) + [issues](https://github.com/vector-im/element-ios/issues/2712) as well as the underlying + [WebRTC issue](https://bugs.chromium.org/p/webrtc/issues/detail?id=11710). + Consider using a ZeroSSL certificate for your TURN server as a working alternative. + +1. Firewall + + Ensure your firewall allows traffic into the TURN server on the ports + you've configured it to listen on (By default: 3478 and 5349 for TURN + traffic (remember to allow both TCP and UDP traffic), and ports 49152-65535 + for the UDP relay.) + +1. Reload/ restarting `eturnal` + + Changes in the configuration file require `eturnal` to reload/ restart, this + can be achieved by: + + ```sh + eturnalctl reload + ``` + + `eturnal` performs a configuration check before actually reloading/ restarting + and provides hints, if something is not correctly configured. + +### eturnalctl opterations script + +`eturnal` offers a handy [operations script](https://eturnal.net/documentation/#Operation) +which can be called e.g. to check, whether the service is up, to restart the service, +to query how many active sessions exist, to change logging behaviour and so on. + +Hint: If `eturnalctl` is not part of your `$PATH`, consider either sym-linking it (e.g. ´ln -s /opt/eturnal/bin/eturnalctl /usr/local/bin/eturnalctl´) or call it from the default `eturnal` directory directly: e.g. `/opt/eturnal/bin/eturnalctl info` |