This new version of utils implements the transformation of our polygons
to a Cartesian plane. In other words, it converts them from being
defined in spherical degrees to metres.
For the API this means our simplification will be slightly more
accurate.
We observe high memory usage since we bumped it (along with other
things) and because it only appears on the API and not on the workers
the hypothesis is that Werkzeug is responsible for it.
See https://github.com/alphagov/notifications-utils/pull/878 for
details.
Changes we had to make for our app and tests to work correctly
after the dependency updates:
1. Update emergency alerts polygons test because we changed
how exact we are with locations of the points on the map.
2. Use Flask's g object to set additional request attributes
So far we have been storing them in _request_ctx_stack which is
an innard for Flask's request context.
Because of major update to Werkzeug dependency, which Flask relies
on, the way we were using it stopped working, so we had a new
way to set those values.
The way we set those values now, by using g object, seems to also
be favoured in Flask documentation:
https://flask.palletsprojects.com/en/1.1.x/reqcontext/#how-the-context-works
We haven't bumped the test version for a while.
Also bumped the version of Flask and itsdangerous.
In order to fix flask warnings I needed to changed how the blueprints were registerd.
SMS.
This is not a catch all for international SMS, the rules are quite
complex and still not completely understood. We are talking with our
provider who maybe able to sort this out for us. But in the meantime,
this should solve for the case that we understand.
The maximum content count of a broadcast varies depending on its
encoding, so we can’t simply validate it against a schema. This commit
moves to using the validation from `notifications-utils`, and raising a
custom error response.
One of our dependencies has a dependency on cryptography, which has
recently released version 3.4.
This version introduced a circular import error
(pyca/cryptography#5756) which was fixed in
3.4.1.
However, 3.4.1 has a different error where it fails because it cannot
find a rust compiler.
The suggested
solutions are:
Install a newer version of pip which will install a pre-compiled
cryptography wheel OR
Have rust installed and available on our PATH so that it can be used
to build the package.
Since we can't change the buildpack's pip version and we cannot install
rust ourselves, the only we're left with is to avoid upgrading to 3.4 -
at least until PaaS updates their python buildpacks.
We’re going to let people pass in fairly complex polygons, but:
- we don’t want to store massive polygons
- we don’t want to pass the CBCs massive polygons
So this commit adds a step to simplify the polygons before storing them.
We think it’s best for us to do this because:
- writing code to do polygon simplification is non-trivial, and we don’t
want to make all potential integrators do it
- the simplification we’ve developed is domain-specific to emergency
alerting, so should throw away less information than
There’s a bit more detail about how we simplify polygons in
https://github.com/alphagov/notifications-admin/pull/3590/files
This gives us some extra confidence that there aren’t any problems with
the data we’re getting from the other service. It doesn’t address any
specific problems we’ve seen, rather it seems like a sensible precaution
to take.
Other systems we’re working with won’t easily be adapted to emit JSON
instead of CAP, so it’s less work for us to do that conversion.
This commit adds to code to parse the XML and turn it into a dict that
we can work with, including converting the polygon string into native
Python lists.
