The I2P service is pretty simple to install, simply use the apt repository

Gather the binaries

sudo apt-add-repository ppa:i2p-maintainers/i2p
sudo apt-get update
sudo apt-get install i2p

Once installed we can ensure it is running…

systemctl status i2p.service

Basic config tweeks

Assuming that worked, first thing we will want to do is to familiarize ourselves with the router config. The preferred way to do this is through the router console served on localhost. Since our VM is tiny and we have not installed a desktop thus far, we will do this through lynx (or dillo or seamonkey)

# Pick the browser you want...
# browser="seamonkey"
# browser="dillo"
browser="lynx -cookies"
http_proxy="http://127.0.0.1:4444" \
 no_proxy="127.0.0.1" \
 $browser \
 http://127.0.0.1:7657

First thing I did was to lower the bandwidth by a factor of 3. Since GCE charges for egress (bytes in) you will want to keep track of this and not go overboard. This can be done manually in /var/lib/i2p/i2p-config/router.config, or at the URI http://127.0.0.1:7657

Next I changed I2P to point to my existing lighttpd server instead of spinning up the default Jetty webserver. First find out what clientApp is associated with jetty

sudo egrep "main=.*jetty" /var/lib/i2p/i2p-config/clients.config
# yields clientApp.3.main=net.i2p.jetty.JettyStart

So, Jetty settings are in clientApp number 3. Now to prevent Jetty from loading we change its startOnLoad to false

sudo vi /var/lib/i2p/i2p-config/clients.config
  clientApp.3.startOnLoad=false # find this line and set it accordingly

Now, without jetty, we will want to to change target port the tunnel is using to 80 since that is where our webserver is serving.

Find the tunnel using port 7658 (the default jetty port)

grep 7658 /var/lib/i2p/i2p-config/i2ptunnel.config
# yields tunnel.3.targetPort=7658

So in this test config, our eepsite is described in tunnel 3

sudo vi /var/lib/i2p/i2p-config/i2ptunnel.config
  tunnel.3.targetPort=80 # find this line and set it accordingly

Open Firewall

Finally, once everything is set up, we can open up our incoming ports to participate fully in the network. First determine what port to open

sudo grep -i port /var/lib/i2p/i2p-config/router.config

Although it isn’t clear from the config file, I2P opens both TCP and UDP ports. You need to enable both. See http://127.0.0.1:7657/confignet for more info.

Create a firewall in GCP for our VM to use that port.

gcloud config set compute/zone {zone}
gcloud compute firewall-rules create i2p-server \
 --target-tags=i2p-server \
 --allow=udp:{port},tcp:{port} \
 --source-ranges=0.0.0.0/0
gcloud compute instances add-tags {vm-name} --tags "i2p-server"

Handle hosts file

At this point the lighttpd server is serving up content for both our clearnet webstie and our i2p site (eepsite). The eepsite has one extra requirement which is a hosts.txt file. Usually it is served out of the jetty site, but since we are not using that, we will just make a symlink to the appropriate file. But we will want to ensure we set the permissions appropriately.

sudo systemctl stop lighttpd.service
sudo systemctl stop i2p.service
sudo chown i2psvc:www-data ~i2psvc/i2p-config/eepsite/docroot/hosts.txt
sudo ln -s ~i2psvc/i2p-config/eepsite/docroot/hosts.txt ~www-data/html/hosts.txt
sudo systemctl start lighttpd.service
sudo systemctl start i2p.service

Of course we will want to change our sitebuild.sh file as well to read

#!/bin/bash
docroot="~www-data/html"
sudo -- sh -c "umask 0027; bundle exec jekyll build -d $docroot"
sudo chown -R root:www-data $docroot
sudo chmod -R g+r,o-rwx,g-w $docroot
sudo ln -s ~i2psvc/i2p-config/eepsite/docroot/hosts.txt ~www-data/html/hosts.txt
sudo chown i2psvc:www-data ${docroot}/hosts.txt

Final config tweeks

Finally, if you installed seamonkey in the VM, you can finish the I2P configuration via VNC with the following xterm command

http_proxy="http://127.0.0.1:4444" \
 no_proxy="127.0.0.1" \
 seamonkey http://127.0.0.1:7657

From within Seamonkey…

  • Click ‘Router Console’
  • Click ‘Hidden Service Manager’
  • Click ‘Start’ for the HTTP Server
  • Click the config gear next to your I2P HTTP Server
  • Fill out Name, Description, and pick a ‘.i2p’ hostname
  • Check ‘Automatically start tunnel …’
  • Click ‘Save’
  • Click the config gear next to your I2P HTTP Server (again)
  • Click ‘Add to local addressbook’
  • Click ‘Replace’
  • Click Back navigation
  • Click ‘Add to local addressbook’ (again)
  • Click ‘Published’ (If you want to publish)
  • Click ‘Replace’ (If you want to publish)
  • Exit seamonkey
  • vncserver -kill :1 to stop VNC

Further tasks

  • Set eepsite to autostart
  • Learn how to backup the private keys