Agrammon

The simulation model

Ammonia volatilisation is a significant source of nitrogen (N) loss in agriculture. Almost one-third of the N load of farmyard manure is lost this way, resulting in both a financial loss as well as diminished productivity for the farmer. At the same time, ammonia emissions are detrimental to the environment, in particular to natural ecosystems.

The simulation model Agrammon allows ammonia emissions to be calculated, and shows how changes in structure and production methods at the farm level affect emissions.

The model was developed by the Swiss College of Agriculture (SHL) and the companies Bonjour Engineering GmbH and Oetiker+Partner AG, with support from the Federal Office for the Environment (FOEN).

Please see the Agrammon website for more details.

Port to Raku

This is a port of the existing Agrammon web application to Raku. It was finished by Christmas.

Development setup

You'll need to:

1. Install rakudo and zef.
2. Install the Raku dependencies — this also installs the pinned patched Cro builds (see below): make deps (equivalently: ./install-patched-deps.sh && zef install --deps-only .).
3. Install typst for PDF export — a single static binary from https://github.com/typst/typst/releases; optionally ghostscript for PDF stream re-compression. Point General.typst in the YAML config at it.

Patched Cro dependencies (temporary)

Two upstream Cro fixes Agrammon needs are merged but not yet released, so zef install --deps-only . on its own would pull the stock (unfixed) builds. install-patched-deps.sh — run by make deps / make install-modules, the Docker build, and make deploy-deps — installs them first, pinned to their merge commits, so the stock builds are not pulled over them:

• Cro::HTTP — Cro::HTTP::Middleware::Conditional never completes its per-connection early-responses Supplier, leaking RSS on every request through any before/after route block or token-auth middleware. Fix merged: croservices/cro-http#214.
• Cro::OpenAPI::RoutesFromDefinition — under Cro::HTTP::Router 0.8.12+ the OpenAPI route include crashes with "No such method 'name'". Fix merged: croservices/cro-openapi-routes-from-definition#15.

Once each fix is released to the Raku ecosystem, drop its line from install-patched-deps.sh and rely on normal zef resolution (plus the META6.json version bound).

Running tests

Run tests using prove6 -l t/. If missing prove6, you can install it with zef install App::Prove6.

To only run unit tests, set AGRAMMON_UNIT_TEST=1 in the environment. The integration tests currently have quite some setup dependencies; this should be addressed in the future.

Database setup (PostgreSQL)

Install or use existing PostgreSQL database server:

CREATE GROUP agrammon_user; CREATE USER agrammon; ALTER GROUP agrammon_user ADD USER agrammon; CREATE DATABASE agrammon OWNER agrammon;

Load a database dump (auto creation not yet implemented)

Installation Web App

apt install libnsl-dev

Install npm and jq from your distro and then run

mkdir -p public # first time only ./bootstrap ./configure ./make

Point your config file to the Agrammon database. Adapt runWeb.sh to point to your config file and model.

./runWeb.sh

and point your browser to the shown URL (defaults to localhost:20000)

REST Api

The Agrammon model can be accessed via a REST interface, for details see the online documentation