-*- mode: org -*- The Guix Data Service processes, stores and provides data about Guix over time. It's written in Guile, stores data in a PostgreSQL database, and provides a web interface and API to browse and access the data. * Overview The aim of the Guix Data Service is to provide a complementary interface to Guix itself, providing a different way of interacting with Guix data, which hopefully enables tools and services that otherwise wouldn't be feasible to write. For example, with the command line tooling or Guile API for Guix, you can quickly and easily access information about packages, and manipulate derivations. However, if you wish to compare two revisions of Guix, or look at the history of the derivations for a package over recent Guix revisions, it could take some time until you have the information you're looking for. However, with the Guix Data Service, this information can be gathered continuously, and stored in a a manor that makes these kind of queries much quicker to answer. By storing data abount multiple Guix revisions in a SQL database (PostgreSQL), it becomes possible to quickly compare the data for different revisions. By configuring the Guix Data Service to listen for changes in the Guix Git repository, the database can be kept up to date. * Local Development There's no one right way of doing local development, but outlined here is a recommended approach. You will need to have: - The Guix package manager, either installed on any GNU/Linux distribution, or be using Guix as a system. - A running PostgreSQL service, version 10 or above is recommended - Git, so you can clone the repository - direnv, to manage environment variables If you have any problems with the instructions here, you can ask for help on the #guix IRC channel on Freenode. You can also email help-guix@gnu.org, please include the step you got to, and the problem you encountered (with the error message if applicable). ** Cloning the repository To clone the Git repository, run the following command: #+BEGIN_SRC shell git clone https://git.savannah.gnu.org/git/guix/data-service.git guix-data-service #+END_SRC ** Getting direnv working direnv is used to update the environment within the shell to contain the dependencies of the Guix Data Service. If you've just installed direnv, check you've hooked it in to your shell https://direnv.net/docs/hook.html . Change in to the =guix-data-service= directory. You should see direnv prompting to trust the =.envrc= file contained within the repository. Check the contents of the =.envrc= file, and if you trust it, run =direnv allow=. ** Setup the database Dumps of the database behind data.guix.gnu.org are available at http://data.guix.gnu.org/dumps, use the following URL to download the latest small dump. http://data.guix.gnu.org/dumps/latest/guix_data_service_small.dump There are multiple ways you can setup the database, the instructions here involve creating a =guix_data_service= user with a password, then connecting to the database over the local network interface. To create the user and database use the scripts from PostgreSQL. The =createuser= command will prompt for a password for the database user, you'll need this at multiple points so it might be useful to keep it simple. #+BEGIN_SRC shell createuser guix_data_service --pwprompt createdb guix_data_service --owner=guix_data_service #+END_SRC You may need to run these commands as the postgres user. To restore the downloaded dump, run =pg_restore=. This command should prompt for a password, at which point enter the password for the database user that you set earlier. #+BEGIN_SRC shell pg_restore --jobs=4 --user=guix_data_service --host=127.0.0.1 --dbname=guix_data_service guix_data_service_small.dump #+END_SRC ** Set the database paramstring To setup the configuration for your local environment, create a file called .local.envrc. To provide the password you've set for the =guix_data_service= user, you'll need to set the =GUIX_DATA_SERVICE_DATABASE_PARAMSTRING= environment variable in this file. Add the following line, replacing THEPASSWORD with the password you set earlier. #+BEGIN_SRC shell export GUIX_DATA_SERVICE_DATABASE_PARAMSTRING="dbname=guix_data_service user=guix_data_service password=THEPASSWORD host=127.0.0.1" #+END_SRC After, run =direnv reload= to update the environment in your shell. ** Building the source files The following three commands will compile the =.go= files and generate the scripts used as entry points to the Guix Data Service. #+BEGIN_SRC shell ./bootstrap.sh ./configure make #+END_SRC ** Run the web server The =guix-data-service= script is the main entry point in to the service, run it from the shell. #+BEGIN_SRC shell guix-data-service #+END_SRC You should now be able to access the Guix Data Service web interface through a web browser using the URL http://localhost:8765/ To automatically restart the Guix Data Service when a change to the code is made, you can use the rerun command: #+BEGIN_SRC shell rerun -d guix-data-service -p "**/*.scm" guix-data-service #+END_SRC ** Checking the setup You now should be ready to do local development. To double check that you can change the code and see those changes, try chaging the "Guix Data Service" text within the index function, in the =(guix-data-service web view html)= module (contained in the =guix-data-service/web/view/html.scm= file). That text appears towards the top of the index page (the page with the path =/=). * Roadmap Ideas for future enhancements to the Guix Data Service, in no particular order. ** WebSub support for subscribing to branches and other changable state ** Link to other sites (Free Software Directory, Wikidata, Debian, ...) ** Track package replacements (grafts) ** Load in derivations related to =guix pull= ** Load in the derivations for system tests within Guix ** Provide data in RDF formats (TTL, XML, ...) ** Provide statistics about Guix over time (with graphs)