1. Enable Automatic Software Updates

One of the most important things to keep your relay secure is to install security updates timely and ideally automatically so you can not forget about it. Follow the instructions to enable automatic software updates for your operating system.

2. Install Tor

Ensure you update the packages database before installing the package, than call apt to install it:

# apk update
# apk add tor

3. Install Lyrebird

# apk add lyrebird

4. Edit your Tor config file

Copy the provided /etc/tor/torrc.sample to /etc/tor/torrc and set the following options:

BridgeRelay 1

# Replace "TODO1" with a Tor port of your choice.
# This port must be externally reachable.
# Avoid port 9001 because it's commonly associated with Tor and censors may be scanning the Internet for this port.
ORPort TODO1

ServerTransportPlugin obfs4 exec /usr/bin/lyrebird

# Replace "TODO2" with an obfs4 port of your choice.
# This port must be externally reachable and must be different from the one specified for ORPort.
# Avoid port 9001 because it's commonly associated with Tor and censors may be scanning the Internet for this port.
ServerTransportListenAddr obfs4 0.0.0.0:TODO2

# Local communication port between Tor and obfs4.  Always set this to "auto".
# "Ext" means "extended", not "external".  Don't try to set a specific port number, nor listen on 0.0.0.0.
ExtORPort auto

# Replace "<address@email.com>" with your email address so we can contact you if there are problems with your bridge.
# This is optional but encouraged.
ContactInfo <address@email.com>

# Pick a nickname that you like for your bridge.  This is optional.
Nickname PickANickname

Don't forget to change the ORPort, ServerTransportListenAddr, ContactInfo, and Nickname options.

Note that both Tor's OR port and its obfs4 port must be reachable. If your bridge is behind a firewall or NAT, make sure to open both ports. You can use our reachability test to see if your obfs4 port is reachable from the Internet.

(Optional) Allow obfs4 binding to privileged ports

If you decide to use a fixed obfs4 port smaller than 1024 (for example 80 or 443), you will need to give the Lyrebird executable CAP_NET_BIND_SERVICE capabilities so it can bind to the port without root privileges.

Install the packages libcap-setcap and libcap-getcap, then do this:

# setcap cap_net_bind_service=+ep /usr/bin/lyrebird

You can query the currently assigned capabilities by running getcap /usr/bin/lyrebird. Should you ever decide to use an unprivileged port, remember to remove the capability with setcap -r /usr/bin/lyrebird.

6. Start Tor

Now start the Tor service.

# rc-service tor start

If the service starts successfully, proceed to the next step.

7. Monitor your logs

To confirm your bridge is running with no issues, you should see something like this, usually in /var/log/tor/notices.log (default) or /var/log/messages (syslog):

[notice] Your Tor server's identity key fingerprint is '<NICKNAME> <FINGERPRINT>'
[notice] Your Tor bridge's hashed identity key fingerprint is '<NICKNAME> <HASHED FINGERPRINT>'
[notice] Registered server transport 'obfs4' at '[::]:46396'
[notice] Tor has successfully opened a circuit. Looks like client functionality is working.
[notice] Bootstrapped 100%: Done
[notice] Now checking whether ORPort <redacted>:3818 is reachable... (this may take up to 20 minutes -- look for log messages indicating success)
[notice] Self-testing indicates your ORPort is reachable from the outside. Excellent. Publishing server descriptor.

8. Final Notes

If you are having trouble setting up your bridge, have a look at our help section. If your bridge is now running, check out the post-install notes.