The process of setting up an I2P update server, complete with I2P torrents for updates, is surprisingly straightforward, but there isn't really a document where every step is laid out from end-to-end. Having done it a couple times, I suppose I'm the apt person to write such a document, with the proposed target being a dev build that you host yourself or for a small audience of testers.

What you need to get started

An I2P router installed on your system.
python3, pip3 and bash for generating the news feeds
virtualenv or docker to isolate the feed generator dependencies(optional but a good idea)
git for obtaining software from the internet in source form

# If you're on Debian or Ubuntu linux, this will satisfy the dependencies:
sudo apt-get install python \
    python-dev \
    python-virtualenv \
    libxml2-dev \
    libxslt1-dev

In other systems, you'll need to determine the similar steps to install this software.

Setting up your Signing Keys

In order to distribute updates, you should set up signing keys in order to authenticate the downloads. It's also important in order to carry out the whole process, end-to-end, in order to understand how it all works. In order to generate your plugin signing keys, use the following steps:

Download the helper script. This wraps around some of the key generation options to make them easier to use. The helper script is available at this link and can be viewed on my github.
Generate your newsfeed signing keys by running the following command from the directory where you downloaded i2pk.

./i2pk -p $HOME/.i2p-plugin-keys \
    -s you@mail.i2p \
    -t RSA_SHA512_4096 \
    -n newssigner \
    -c router generate_keys
cp ~/i2p/certificates/router/you_at_mail.i2p ~/i2p/certificates/news/you_at_mail.i2p

And you're all done. Your new signing keys are ready to use for both news and router updates on your own system. These updates will not work for people who do not choose to trust your keys.

Setting up a News Server

Next, you'll need to set up a News Server. In I2P, a News Server is a hidden server which serves up XML files in signed, zipped bundles. You sign these bundles with the keys we generated in the previous step.

`docker` and `virtualenv`

It is highly recommended that you isolate the python dependencies you need using either docker or virtualenv, depending on your preference.

To get started, clone the news server software.

git clone https://github.com/i2p/i2p.newsxml

Next, you'll need to set up the news server software. If you got all the dependencies from "What you need to get started" you should be able to run the following commands:

If you want to use `virtualenv`

Using virtualenv is recommended for anyone who wants to build newsfeeds on their system.

# This is the "official" way
./setup_venv.sh
. env/bin/activate
pip install .

If you want to use `docker`

docker is also capable of isolating these dependencies and can be used instead of virtualenv.

# Docker handles things automatically by wrapping up the official steps in a container
The container has all the dependencies managed automatically, you do not need to do anything.

If you want to use neither

As long as you aren't using the newsfeed package from python anywhere else, you should also be able to just pip install the dependencies. This is the least stable way to do things and only recommended if you host your newsfeed in a dedicated VM.

# This is usually not a very good idea
pip install .

After you've done that, you're adequately configured to build news feeds. However, you still aren't set up to serve the news feeds to people. Since we're not ready to do that for real yet, to practice, let's build the existing feeds, and copy them over to your web server.

Configuring the newsfeed generator

The newsfeed generator can use a configuration file, called etc/su3.vars.custom, which you should edit.

# Install dir
I2P=/home/you/i2p
# private key keystore
KS=/home/you/.i2p-plugin-keys/newssigner-su3-keystore.ks
# signer
SIGNER=you@mail.i2p

If you're using docker, you should use etc/su3.vars.custom.docker instead, and omit the $HOME directory from the config lines.

# Install dir
I2P=/i2p
# private key keystore
KS=/.i2p-plugin-keys/newssigner-su3-keystore.ks
# signer
SIGNER=you@mail.i2p

If you used `pip` or `virtualenv` in the last step

If you used pip or virtualenv to set up your feed generator, then you need to generate the feeds and .su3 bundles first, then manually copy them to the web server you want to use. In this case we're going to assume the one that comes with I2P, but basically any web server will works. The first step will generate the ./build directory and all the files that you need to serve. After it runs, take a moment to examine the contents of ./build. After the second command runs, the feeds can be previewed at http://localhost:7658.

Start by building the feeds. Make sure you're in your virtualenv if you're using it, and run the command:

./new.sh

If you used pip or virtualenv then we will also be using the web server that is built into I2P. When this step is complete, the feeds can be previewed at http://localhost:7658.

# Use this command if you're on Debian or Ubuntu a service
sudo -u i2psvc cp -r ./build /var/lib/i2p/i2p-config/eepsite/docroot/news

# Use this command if you're using a "User" install or the `.jar` package
cp -r ./build $HOME/.i2p/eepsite/docroot/news

If you used `docker` in the last step

All you need to do is the following two commands. The first one will generate the ./build directory and all the files that you need to serve. After it runs, take a moment to examine the contents of ./build. The second command takes the build directory and places it in the document root of a light web server, which will serve the built feeds on http://localhost:3000.

The first command generates the feeds and turns them into signed bundles. This will prompt you for a password.

./docker-news.sh

The second command runs the web server and serves the feeds on localhost:3000

./docker-newsxml.sh

Now you're ready to host your news feeds.

Signing your Update

Now you're prepared to build and sign newsfeeds, however, you still need to build and sign the updates themselves. How you build the updates is going to depend on how you build your app, but for the first example we're going to assume you're building an I2P router from the i2p.i2p source. In i2p.i2p there is an ant target that runs the signing command, you can use it with:

ant signed-updater200

When you run this command, you'll be prompted to enter your signing key details. When you see:

-sign-update:
    [input] Enter su3 private signing key store:

When you see:

[input] Enter su3 key name (you@mail.i2p):

Finally, when you see:

[input] Enter su3 key password for you@mail.i2p:

Enter the password for your keystore. You will end up with a signed update file named i2pupdate.su3 in your directory. That is your signed update file, which you will place in your update server in the next step.

There are different kinds of I2P updates now, registered via the UpdatePostProcessor system. You can, for example, make an "Executable" UpdatePostProcessor or a "DMG" UpdatePostProcessor instead. When you generate an .su3 for such a file, you may once again use i2pk to make the process easier. For example, to build an Executable based updater, use:

./i2pk -p $HOME/.i2p-plugin-keys \
    -s you@mail.i2p \
    -t RSA_SHA512_4096 \
    -n newssigner \
    -f EXE \
    -c router sign i2pupdate.exe

Setting up a Download Server

Now you're able to notify your users that there is an update, but you need somewhere to host the actual download. For the purposes of our tutorial, we'll assume you're using the I2P site included with the Java I2P router, but any web server will do. This will serve as a reliable backup distribution point for your I2P updates. Copy i2pupdate.su3 to the document root.

# Use this command if you're on Debian or Ubuntu a service
sudo -u i2psvc mkdir -p /var/lib/i2p/i2p-config/eepsite/docroot/files
sudo -u i2psvc cp ./i2pupdate.su3 /var/lib/i2p/i2p-config/eepsite/docroot/files

# Use this command if you're using a "User" install or the `.jar` package
mkdir -p $HOME/.i2p/eepsite/docroot/files
cp ./i2pupdate.su3 $HOME/.i2p/eepsite/docroot/files

If you don't want to use that, any static file server with an I2P tunnel pointed at it will do. For example, you can use this:

# This is a suggestion for people who want to use docker, for instance
mkdir -p "$HOME/update-server"
cp ./i2pupdate.su3 "$HOME/update-server"
docker run -d \
    -v "$HOME/update-server":/web \
    -p 8080:8080 \
    halverneus/static-file-server:latest

or any other web server you want.

Setting up a Bittorrent Tracker

Strictly speaking you don't need to set up your own tracker, but I think you should. It's easy and reliable to host one using the zzzot plugin on a Java I2P router. zzzot is hosted at http://stats.i2p/ can be installed by pasting the URL below into the Installation from URL field on the Router Plugins page:

http://stats.i2p/i2p/plugins/zzzot.su3

and clicking the Install plugin button.

Self-Publishing your update

Finally, now that you've got the news server, the news feed generator, the download server, and an updater published, you're ready to create the last thing you need, your custom newsfeed. This will replace the example newsfeed we built earlier. To do this we'll need to generate a torrent of our router update using our open tracker, generate a releases.json file describing where to find the torrent and the update packages, and write a news entry for your router update.

Using the .su3 package you generated in the "Signing your Update" step, generate a .torrent of your update and convert it to a magnet link. Every torrent generator I have tried is capable of generating an I2P torrent, they aren't substantially different from regular torrents for the most part. I often use mktorrent because most package managers have it and because it's pretty easy to automate.

# Using mktorrent
mktorrent --announce="http://yourzzzotopentrackerhasabase32urlthatisprettylong.b32.i2p/a" \
   --web-seed="http://yoursite.i2p/files/i2pupdate.su3" \
   i2pupdate.su3

Load the file named i2pupdate.su3.torrent into I2PSnark without starting it. Copy the i2pupdate.su3 file into the i2psnark directory, then start the torrent from the I2PSnark webUI. The torrent will appear as fully downloaded, and you will be ready to seed. As a last step, copy the "Magnet Link" for your .su3.torrent from the WebUI.

# Use this command if you're on Debian or Ubuntu a service
sudo -u i2psvc cp ./i2pupdate.su3 /var/lib/i2p/i2p-config/i2psnark

# Use this command if you're using a "User" install or the `.jar` package
cp ./i2pupdate.su3 $HOME/.i2p/i2psnark

Next we need to create the releases.json file which will be used to generate part of our newsfeed that informs I2P routers that they need to update, and where to get those updates from. You will need to add this file to your i2p.newsxml checkout. A releases.json file contains: the date the torrent was created, the minimum version required to apply the automatic update, the version that I2P will be updated to, and the download locations. This is a recent example of an releases.json file:

[
  {
    "date": "2022-02-21",
    "version": "1.7.0",
    "minVersion": "0.9.9",
    "minJavaVersion": "1.8",
    "updates": {
      "su3": {
        "torrent": "magnet:?xt=urn:btih:f49db26dd75f61d8d2b4a187bc3d61d71c6dee09&dn=i2pupdate-1.7.0.su3&tr=http://tracker2.postman.i2p/announce.php",
        "url": [
          "http://stats.i2p/i2p/1.7.0/i2pupdate.su3",
          "http://mgp6yzdxeoqds3wucnbhfrdgpjjyqbiqjdwcfezpul3or7bzm4ga.b32.i2p/releases/1.7.0/i2pupdate.su3"
        ]
      }
    }
  }
]

Note the "torrent:" field, where you should place the generated magnet link you copied from the I2PSnark Web UI, and the "url:" field, where you should place the download links to your .su3 files. When you're done editing your releases.json file, copy it to the ./data directory corresponding to it's os/branch in i2p.newsxml.

Now you should create a news entry for your update. Change directory to your i2p.newsxml checkout, run the command:

./create_new_entry.sh

to automatically start editing a new entry in your custom newsfeed. If you're building for a specific OS or branch, then set them in the I2P_OS and I2P_BRANCH environment variables. Check the code comments or the example below for more custom environment arguments.

# This is an example of what I would run
TITLE="Update for Windows Jpackage 1.7.0" AUTHOR=idk EDITOR=mousepad I2P_OS=win I2P_BRANCH=beta ./create_new_entry.sh

Once you have finished editing, your newsfeed is ready to generate and sign.

Now you're ready to build the newsfeed which you will finally be able to use. Return to the step called "Signing your Update" and repeat those steps with your new feeds. Copy them over to your news server. Your updates are now ready to distribute. Keep an eye on your torrent client while the peers go up.

README.md

Hopefully Holistic Guide to I2P Dev Build Update Hosting