Ahmia index

The Ahmia search engine uses Elasticsearch indexes to save website text.

Installation

• Install Elasticsearch 8
• Install Python3 and pip
• Install the Python packages required, preferably in a virtual environment, with:

pip install -r requirements.txt

Configuration

example.env contains some default values that should work out of the box. Copy this to .env to create your own instance of environment settings:

cp example.env .env

Review the .env file to ensure that it fits your needs. Make any modifications needed there.

Elasticsearch

Default configuration is enough to run index in dev mode. Here is suggestion for a more secure configuration

/etc/security/limits.conf

elasticsearch - nofile unlimited
elasticsearch soft memlock unlimited
elasticsearch hard memlock unlimited

/etc/default/elasticsearch

MAX_OPEN_FILES=unlimited
MAX_LOCKED_MEMORY=unlimited

/etc/elasticsearch/elasticsearch.yml

bootstrap.memory_lock: true

/etc/elasticsearch/jvm.options

-Xms15g
-Xmx15g

Start the service

sudo systemctl start elasticsearch

Give users permissions to use the HTTPS cert

Any user on the system can read the certificate file, which is generally acceptable for a public certificate authority (CA) certificate as it does not contain sensitive private keys.

sudo mkdir -p /usr/local/share/ca-certificates/
sudo cp /etc/elasticsearch/certs/http_ca.crt /usr/local/share/ca-certificates/
sudo chmod 644 /usr/local/share/ca-certificates/http_ca.crt

Init mappings

Please set mappings running for the first time

bash setup_index.sh

Alternatively, you could set up the indices manually, somehow like this:

curl -i --cacert /usr/local/share/ca-certificates/http_ca.crt -u elastic -XPUT \
'https://localhost:9200/tor-2024-01/' \
-H 'Content-Type: application/json' -d "@./mappings_tor.json"

Keep latest-tor aliase pointed to latest monthly indices

This needs to be the first time you deploy and then once per month

python point_to_indexes.py

Filter some abuse sites

bash call_filtering.sh

Crontab

# Execute child abuse text filtering over the index every hour
30 * * * * cd /home/juha/ahmia-index && bash wrap_filtering.sh > ./crontab_filter.log 2>&1
# First of Each Month:
10 04 01 * * cd /home/juha/ahmia-index && python point_to_indexes.py --add > ./add_alias.log 2>&1
# On 6th of Each Month
10 04 06 * * cd /home/juha/ahmia-index && python point_to_indexes.py --rm > ./remove_alias.log 2>&1

Keep Elasticsearch running: autorestart

sudo apt install restartd

# Add the following line to /etc/restartd.conf
elasticsearch "elasticsearch" "echo 'Elasticsearch is not running!' >>/tmp/restartd_restart.out && service elasticsearch restart >> /tmp/restartd_restart.out" "echo 'Elasticsearch is running!' >/tmp/restartd.out"

sudo service restartd restart