docker-wireguard-pia

A Docker container for using WireGuard with PIA.

Requirements

Ideally the host must already support WireGuard. Pre 5.6 kernels may need to have the module manually installed. If this is not possible, then a userspace implementation can be enabled using the WG_USERSPACE environment variable.
An active PIA subscription.

Config

The following ENV vars are required:

ENV Var	Function
`LOC=swiss`	Location id to connect to. Available server location ids are listed here. Example values include `us_california`, `ca_ontario`, and `swiss`. If left empty the container will print out all currently available location ids and exit. Multiple ids can be listed, separated by either a space or a comma, and are used as fallback if the initial endpoint registration fails.
`USER=xxxxxxxx`	PIA username
`PASS=xxxxxxxx`	PIA password

The rest are optional:

ENV Var	Function
`LOCAL_NETWORK=192.168.1.0/24`	Whether to route and allow input/output traffic to the LAN. LAN access is blocked by default if not specified. Multiple ranges can be specified, separated by a comma or space. Note that there may be DNS issues if this overlaps with PIA's default DNS servers (`10.0.0.243` and `10.0.0.242` as of July 2022). Custom DNS servers can be defined using `VPNDNS` (see below) if this is an issue.
`KEEPALIVE=25`	If defined, PersistentKeepalive will be set to this in the WireGuard config.
`MTU=1420`	This can be used to override `wg-quick`'s automatic MTU setting on the Wireguard interface if needed. By default this remains unset (ie. let `wg-quick` choose).
`VPNDNS=8.8.8.8, 8.8.4.4`	Use these DNS servers in the WireGuard config. PIA's DNS servers will be used if not specified. Use 0 to disable making any changes to the default container DNS settings. (Note: Using any DNS servers other than PIA's may lead to DNS queries being leaked outside the VPN connection.)
`PORT_FORWARDING=0/1`	Whether to enable port forwarding. Requires a supported server. Defaults to 0 if not specified.
`PORT_FILE=/pia-shared/port.dat`	The forwarded port number is dumped here for possible access by scripts in other containers. By default this is `/pia-shared/port.dat`.
`PORT_FILE_CLEANUP=0/1`	Remove the file containing the forwarded port number on exit. Defaults to 0 if not specified.
`PORT_PERSIST=0/1`	Set to 1 to attempt to keep the same port forwarded when the container is restarted. The port number may persist for up to two months. Defaults to 0 (always acquire a new port number) if not specified.
`PORT_SCRIPT=/path/to/script.sh`	A mounted custom script can be run inside the container once a port is successfully forwarded if needed. The forwarded port number is passed as the first command line argument. By default this remains unset. See issue #26 for more info.
`FIREWALL=0/1`	Whether to block non-WireGuard traffic. Defaults to 1 if not specified.
`EXIT_ON_FATAL=0/1`	There is no error recovery logic at this stage. If something goes wrong we simply go to sleep. By default the container will continue running until manually stopped. Set this to 1 to force the container to exit when an error occurs. Exiting on an error may not be desirable behaviour if other containers are sharing the connection.
`WG_USERSPACE=0/1`	If the host OS or host Linux kernel does not support WireGuard (certain NAS systems), a userspace implementation (wireguard-go) can be enabled. Defaults to 0 if not specified.
`USER_FILE=/run/secrets/pia-username` `PASS_FILE=/run/secrets/pia-password`	PIA credentials can also be read in from existing files (eg for use with Docker secrets)
`PIA_IP=x.x.x.x` `PIA_CN=hostname401` `PIA_PORT=1337`	Connect to a specific server by manually setting all three of these. This will override whatever `LOC` is set to.
`FWD_IFACE` `PF_DEST_IP`	If needed, the container can be used as a gateway for other containers or devices by setting these. See issue #20 for more info. Note that these are for a specific use case, and in many cases using Docker's `--net=container:xyz` or docker-compose's `network_mode: service:xyz` instead, and leaving these vars unset, would be an easier way of accessing the VPN and forwarded port from other containers.
`NFTABLES=0/1`	Alpine uses `iptables-legacy` by defualt. If needed, `iptables-nft` can be used instead by setting this to 1. Defaults to 0 if not specified. See issue #37.
`PRE_UP` `POST_UP` `PRE_DOWN` `POST_DOWN`	Custom commands and/or scripts can be run at certain stages if needed. See below for more info.

Scripting

Custom commands and/or scripts can be run at certain stages of the container's life-cycle by setting the PRE_UP, POST_UP, PRE_DOWN, and POST_DOWN env vars. PRE_UP is run prior to generating the WireGuard config, POST_UP is run after the WireGuard interface is brought up, and PRE_DOWN and POST_DOWN are run before and after the interface is brought down again when the container exits.

In addition, scripts mounted in /pia/scripts named pre-up.sh, post-up.sh, pre-down.sh and post-down.sh will be run at the appropriate stage if present. See issue #33 for more info.

Notes

Based on what was found in the source code to the PIA desktop app.
As of Sep 2020, PIA have released scripts for using WireGuard outside of their app.
Only tested on a Debian Buster host. May or may not work as expected on other hosts.
PIA username/password is only used on the first run. A persistent auth token is generated and will be re-used for future runs.
Persistent data is stored in /pia.
IPv4 only. IPv6 traffic is blocked unless using FIREWALL=0 but you may want to disable IPv6 on the container anyway.
An example docker-compose.yml is included. Some more working examples can be found here.
Other containers can share the VPN connection using Docker's --net=container:xyz or docker-compose's network_mode: service:xyz.
Standalone Bash scripts are available for use outside of Docker.
The userspace implementation through wireguard-go is very stable but lacks in performance. Looking into supporting (boringtun) might be beneficial.

Credits

Some bits and pieces and ideas have been borrowed from the following:

chrisbensch / docker-wireguard-pia