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Aleph is a tool for indexing large amounts of both documents (PDF, Word, HTML) and structured (CSV, XLS, SQL) data for easy browsing and search. It is built with investigative reporting as a primary use case. Aleph allows cross-referencing mentions of well-known entities (such as people and companies) against watchlists, e.g. from prior research or public datasets.

Install the development environment

As a first step, check out the source code of Aleph from GitHub:

git clone
cd aleph/

Also, please execute the following command to allow ElasticSearch to map its memory:

sysctl -w vm.max_map_count=262144

Then enable the use of pdb by adding the next lines into the file, under the api service configuration.

stdin_open: true
tty: true

With the settings in place, you can use make all to set everything up and launch the web service. This is equivalent to the following steps:

  • make build to build the docker images for the application and relevant services.
  • make upgrade to run the latest database migrations and create/update the search index.
  • make web to run the web-based API server and the user interface.
  • In a separate shell, run make worker to start a worker. If you do not start a worker, background jobs (for example ingesting new documents) won’t be processed.

Open http://localhost:8080/ in your browser to visit the web frontend.

  • Create a shell to do the operations with make shell.
  • Create the main user within that shell running
    aleph createuser --name="demo" \
        --admin \
        --password=demo \
  • Load some sample data by running aleph crawldir /aleph/contrib/testdata

Debugging the code

To debug the code, you can create pdb breakpoints in the code you cloned, and run the actions that trigger the breakpoint. To be able to act on it, you need to be attached to the api by running:

docker attach aleph_api_1

You don't need to reload the page for it to load the changes, it does it dynamically.


Problems accessing redis locally

If you're with the VPN connected, turn it off.

PDB behaves weird

Sometimes you have two traces at the same time, so each time you run a PDB command it jumps from pdb trace. Quite confusing. Try to c the one you don't want so that you're left with the one you want. Or put the pdb trace in a conditional that only matches one of both threads.


Last update: 2022-11-24