Dev/Tracker

This article describes how to set up your own tracker just like the official Archive Team tracker just like the open-source core of the official Archive Team tracker.
Note: A virtual machine appliance is available at ArchiveTeam/archiveteam-dev-env which contains a ready-to-use tracker. A docker container is also at this fork of the tracker (unofficial).
Installation will cover:
* Environment: Ubuntu/Debian
* Languages:
** Python
** Ruby
** JavaScript
* Web: 
** Nginx
** Phusion Passenger
** Redis
** Node.js
* Tools:
** Screen
** Rsync
** Git
** Wget
** regular expressions
== The Tracker ==
The Tracker manages what items are claimed by users that run the Seesaw client. It also shows a pretty leaderboard.
Let's create a dedicated account to run the web server and tracker:
 sudo adduser --system --group --shell /bin/bash tracker
=== Redis ===
Redis is database stored in memory. So, item names should be engineered to be memory efficient. Redis saves its database periodically into a file located at /var/lib/redis/6379/dump.rdb. It is safe to copy the file, e.g., for backups.
To install Redis, you may follow these quickstart instructions, but we'll show you how.
These steps are from the quickstart guide:
 wget http://download.redis.io/redis-stable.tar.gz
 tar xvzf redis-stable.tar.gz
 cd redis-stable
 make
Now install the server:
 sudo make install
 cd utils
 sudo ./install_server.sh
Note, by default, it runs as root. Let's stop it and make it run under www-data:
 sudo invoke-rc.d redis_6379 stop
 sudo adduser --system --group www-data
 sudo chown -R www-data:www-data /var/lib/redis/6379/
 sudo chown -R www-data:www-data /var/log/redis_6379.log
Edit the config file /etc/redis/6379.conf with the options like:
 bind 127.0.0.1
 pidfile /var/run/shm/redis_6379.pid
Now tell the start up script to run it as www-data:
 sudo nano /etc/init.d/redis_6379
Change the EXEC and CLIEXEC variables to use sudo -u www-data -g www-data:
 EXEC="sudo -u www-data -g www-data /usr/local/bin/redis-server"
 CLIEXEC="sudo -u www-data -g www-data /usr/local/bin/redis-cli"
 PIDFILE=/var/run/shm/redis_6379.pid
To avoid catastrophe with background saves failing on fork() (Redis needs lots of memory), run:
 sudo sysctl vm.overcommit_memory=1
The above setting will be lost after reboot. Add this line to /etc/sysctl.conf:
 vm.overcommit_memory=1
The log file will get big so we need a logrotate config. Create one at /etc/logrotate.d/redis with the config:
 /var/log/redis_*.log {
 daily
 rotate 10
 copytruncate
 delaycompress
 compress
 notifempty
 missingok
 size 10M
 }
Start up Redis again using:
 sudo invoke-rc.d redis_6379 start
=== Nginx with Passenger ===
Nginx is a web server. Phusion Passenger is a module within Nginx that runs Rails applications.
There is a guide on how to install Nginx with Passenger, the following instructions are similar.
Log in as tracker:
 sudo -u tracker -i
We'll use RVM to install Ruby libraries:
 curl -L get.rvm.io | bash -s stable
 source ~/.rvm/scripts/rvm
 rvm requirements
A list of things needed to be installed will be shown. Log out of the tracker account, install them, and log back into the tracker account.
Install Ruby and Bundler:
 rvm install 2.2.2
 rvm rubygems current
 gem install bundler
Install Passenger:
 gem install passenger
Install Nginx. This command will download, compile, and install a basic Nginx server.:
 passenger-install-nginx-module
Use the following prefix for Nginx installation:
 /home/tracker/nginx/
Change the location of the tracker software (to be installed later). Edit nginx/conf/nginx.conf. Use the lines under the "location /" option:
 root /home/tracker/universal-tracker/public;
 passenger_enabled on;
 client_max_body_size 15M;
The logs will get big so we'll use logrotate. Save this into /home/tracker/logrotate.conf:
 /home/tracker/nginx/logs/error.log
 /home/tracker/nginx/logs/access.log {
 daily
 rotate 10
 copytruncate
 delaycompress
 compress
 notifempty
 missingok
 size 10M
 }
To call logrotate, we'll add an entry using crontab:
 crontab -e
Now add the following line:
 @daily /usr/sbin/logrotate --state /home/tracker/.logrotate.state /home/tracker/logrotate.conf
Log out of the tracker account at this point.
Let's create an Upstart configuration file to start up Nginx. Save this into /etc/init/nginx-tracker.conf:
 description "nginx http daemon"
 
 start on runlevel [2]
 stop on runlevel [016]
 
 setuid tracker
 setgid tracker
 
 console output
 
 exec /home/tracker/nginx/sbin/nginx -c /home/tracker/nginx/conf/nginx.conf -g "daemon off;"
Or, if you use Systemd, put this into /lib/systemd/system/nginx-tracker.service:
 [Unit]
 Description="nginx http daemon"
 
 [Service]
 Type=simple
 ExecStart=/home/tracker/nginx/sbin/nginx -c /home/tracker/nginx/conf/nginx.conf -g "daemon off;"
=== Tracker ===
Log in into the tracker account.
Download the Tracker software:
 git clone https://github.com/ArchiveTeam/universal-tracker.git
We'll need to configure the location of Redis. Copy the config file:
 cp universal-tracker/config/redis.json.example universal-tracker/config/redis.json
Add a "production" object into the JSON file. Here is an example:
 {
 "development": {
 "host": "127.0.0.1",
 "port": 6379,
 "db": 13
 },
 "test": {
 "host": "127.0.0.1",
 "port": 6379,
 "db": 14
 },
 "production": {
 "host":"127.0.0.1",
 "port":6379,
 "db": 1
 }
 }
* Now we may need to fix an issue with Passenger forking after the Redis connection has been made. Please see https://github.com/ArchiveTeam/universal-tracker/issues/5 for more information.
* There is also an issue with non-ASCII names. See https://github.com/ArchiveTeam/universal-tracker/issues/7.
Now install the necessary gems:
 cd universal-tracker
 bundle install
Log out of the tracker account at this point.
=== Node.js ===
Node.js is required to run the fancy leaderboard using WebSockets. We'll use NPM to manage the Node.js libraries:
 sudo apt-get install npm
Log into the tracker account.
Now, we manually edit the Node.js program because it has problems:
 cp -R universal-tracker/broadcaster .
 nano broadcaster/server.js
Modify env and trackerConfig variables to something like this:
 var env = {
 tracker_config: {
 redis_pubsub_channel: "tracker-log"
 },
 redis_db: 1
 };
 var trackerConfig = env['tracker_config'];
You also need to modify the "transports" configuration by adding websocket. The new line should look like this:
 io.set("transports", ["websocket", "xhr-polling"]);
Install the Node.js libraries needed:
 npm install
If you get an error while installing hiredis, you may need to provide Debian's "nodejs" as "node". Symlink "node" to the nodejs executable and try again.
Log out of the tracker account at this point.
Create an Upstart file at /etc/init/nodejs-tracker.conf:
 description "tracker nodejs daemon"
 
 start on runlevel [2]
 stop on runlevel [016]
 
 setuid tracker
 setgid tracker
 
 exec node /home/tracker/broadcaster/server.js
Or, for Systemd, put this into /lib/systemd/system/nodejs-tracker.service:
 [Unit]
 Description="tracker nodejs daemon"
 
 [Service]
 Type=forking
 Group=tracker
 User=tracker
 ExecStart=/usr/bin/js /home/tracker/broadcaster/server.js
=== Tracker Setup ===
Start up the Tracker and Broadcaster:
Upstart:
 sudo start nginx-tracker
 sudo start nodejs-tracker
Systemd:
 sudo systemctl start nginx-tracker
 sudo systemctl start nodejs-tracker
You now need to configure the tracker. Open up your web browser and visit http://localhost/global-admin/.
* In Global-Admin→Configuration→Live logging host, specify the public location of the Node.js app. By default, it uses port 8080.
You are now free to manage the tracker.
Notes:
* If you followed this guide, the rsync location is defined as rsync://HOSTNAME/PROJECT_NAME/:downloader/
* The trailing slash within the rsync URL is very important. Without it, files will not be uploaded within the directory.
==== Claims ====
You probably want to have Cron clearing out old claims. The Tracker includes a Ruby script that will do that for you. By default, it removes claims older than 6 hours. You may want to change that for big items by creating a copy of the script for each project.
To set up Cron, login as the tracker account, and run:
 which ruby
Take note of which Ruby executable is used.
Now edit the Cron table:
 crontab -e
Add the following line which runs release-stale.rb every 6 hours:
 0 */6 * * * cd /home/tracker/universal-tracker && WHICH_RUBY scripts/release-stale.rb PROJECT_NAME
==== Logs ====
Since the Tracker stores logs into Redis, it will use up memory quickly. log-drainer.rb continuously writes the logs into a text file:
 mkdir -p /home/tracker/universal-tracker/logs/
 cd /home/tracker/universal-tracker && ruby scripts/log-drainer.rb
Pressing CTRL+C will stop it. Run this within a Screen session.
This crontab entry will compress the log files that haven't been modified in two days:
 @daily find /home/tracker/universal-tracker/logs/ -iname "*.log" -mtime +2 -exec xz {} \;
==== Reducing memory usage ====
The Passenger Ruby module may use up too much memory. You can add the following lines to your nginx config. Add these inside the http block:
 passenger_max_pool_size 2;
 passenger_max_requests 10000;
The first line allows spawning maximum of 2 processes. The second line restarts Passenger after 10,000 requests to free memory caused by memory leaks.