Check if plugin version matches running version
When registering a plugin, we check if the request version matches the
self-reported version from the plugin. If these do not match, we log a
warning.
This uncovered a few missing pieces for getting the database version
code fully working.
We added an environment variable that helps us unit test the running
version behavior as well, but only for approle, postgresql, and consul
plugins.
Return 400 on plugin not found or version mismatch
Populate the running SHA256 of plugins in the mount and auth tables (#17217)
Add plugin version to GRPC interface
Added a version interface in the sdk/logical so that it can be shared between all plugin types, and then wired it up to RunningVersion in the mounts, auth list, and database systems.
I've tested that this works with auth, database, and secrets plugin types, with the following logic to populate RunningVersion:
If a plugin has a PluginVersion() method implemented, then that is used
If not, and the plugin is built into the Vault binary, then the go.mod version is used
Otherwise, the it will be the empty string.
My apologies for the length of this PR.
* Placeholder backend should be external
We use a placeholder backend (previously a framework.Backend) before a
GRPC plugin is lazy-loaded. This makes us later think the plugin is a
builtin plugin.
So we added a `placeholderBackend` type that overrides the
`IsExternal()` method so that later we know that the plugin is external,
and don't give it a default builtin version.
Tom Proctor