jschoubben
e5243cd753
The keycloak check was written while keycloak was the module being
worked on, which is how a check ends up proving one thing about one
file. It now runs over every example that requires something, and asks
the two questions that matter for all of them: that no ${bound:...}
reached the machine as a value, and that anything named PASSWORD is
still a hole only the host can fill.
The first is the one worth having. A placeholder written through is read
as a value by whatever parses the file — a connection to a host called
"${bound:postgres-database:at}" — and the failure names neither the
module nor the mesh.
Modules whose requirements nothing in the examples answers are logged
and passed over, because that is a fact about the example set rather
than about them.
examples
Things that run, kept here because a contract is easier to read as working code than as prose.
Nothing here is part of the control plane. The control plane decides and never touches a machine (README); everything in this directory runs on a machine and touches it. These are reference implementations of contracts the control plane defines, and a real one ships with the module that ships the software it configures.
postgres-provisioner |
the last step of a credential: reads what the mesh delivered and makes PostgreSQL accept it |
Running the provisioner
--watch reconciles now and again whenever what the mesh delivered changes. That is what lets it
be a module: an ordinary long-running service the host supervises, rather than something that has
to be invoked after every declaration by a timer or a unit wired to a file.
It polls rather than watching the filesystem, because the host writes atomically — the file is replaced, so a watch on the path stops seeing anything after the first replacement. A watcher that silently stops working is worse than a poll.
Credentials are compared by digest and never by content. This runs for as long as the machine is up, and a secret does not belong in a long-lived variable when a hash answers the same question.