Fix DSN

Rebased against upstream, works like a charm on WindRiver.

Airflow deployed, so we can test D2754.

Airflow runs well.

Tweaks after deployment

Connectivity works like a charm for Airflow:

Fix configuration files. Split software and service, so we've the software/config/service order for first run.

s/nbsp/space

About logging, with WARNING, the example given above would be limited to one line:
Can't run command: [Errno 2] No such file or directory: 'notification-push'

Used on Dwellers to test T1809

Still actively maintained.

For reference, xargs behavior isn't consistent amongst OSes:

https://api.nasqueron.org/infra/servers.json

Fix path ; allow Relay to specify optional dependencies.

Relay service has optional dependencies.

Avoid to query Salt twice (we win 4-5 seconds execution time)

Switch from YAML to JSON, as PyYAML isn't installed on role paas-docker

On it, with a graph and topological sorting.

get-containers-list is superseded by D2934

Containers are now defined in docker_containers pillar.

Self-commit as this fixes production issue and @DorianWinty is sleeping. This change has been tested in prod, and has tests for it.

Build is green
See https://ci.nasqueron.org/job/test-notifications-phab/277/ for more details.

Add tests (excepted for the objects without 'data' property, out of scope for this change)

Tests probably needed for that one.

Looks good to me :)

Refactoring of some parts of the script