* agent: remove agent cache dependency from service mesh leaf certificate management
This extracts the leaf cert management from within the agent cache.
This code was produced by the following process:
1. All tests in agent/cache, agent/cache-types, agent/auto-config,
agent/consul/servercert were run at each stage.
- The tests in agent matching .*Leaf were run at each stage.
- The tests in agent/leafcert were run at each stage after they
existed.
2. The former leaf cert Fetch implementation was extracted into a new
package behind a "fake RPC" endpoint to make it look almost like all
other cache type internals.
3. The old cache type was shimmed to use the fake RPC endpoint and
generally cleaned up.
4. I selectively duplicated all of Get/Notify/NotifyCallback/Prepopulate
from the agent/cache.Cache implementation over into the new package.
This was renamed as leafcert.Manager.
- Code that was irrelevant to the leaf cert type was deleted
(inlining blocking=true, refresh=false)
5. Everything that used the leaf cert cache type (including proxycfg
stuff) was shifted to use the leafcert.Manager instead.
6. agent/cache-types tests were moved and gently replumbed to execute
as-is against a leafcert.Manager.
7. Inspired by some of the locking changes from derek's branch I split
the fat lock into N+1 locks.
8. The waiter chan struct{} was eventually replaced with a
singleflight.Group around cache updates, which was likely the biggest
net structural change.
9. The awkward two layers or logic produced as a byproduct of marrying
the agent cache management code with the leaf cert type code was
slowly coalesced and flattened to remove confusion.
10. The .*Leaf tests from the agent package were copied and made to work
directly against a leafcert.Manager to increase direct coverage.
I have done a best effort attempt to port the previous leaf-cert cache
type's tests over in spirit, as well as to take the e2e-ish tests in the
agent package with Leaf in the test name and copy those into the
agent/leafcert package to get more direct coverage, rather than coverage
tangled up in the agent logic.
There is no net-new test coverage, just coverage that was pushed around
from elsewhere.
Protobuf Refactoring for Multi-Module Cleanliness
This commit includes the following:
Moves all packages that were within proto/ to proto/private
Rewrites imports to account for the packages being moved
Adds in buf.work.yaml to enable buf workspaces
Names the proto-public buf module so that we can override the Go package imports within proto/buf.yaml
Bumps the buf version dependency to 1.14.0 (I was trying out the version to see if it would get around an issue - it didn't but it also doesn't break things and it seemed best to keep up with the toolchain changes)
Why:
In the future we will need to consume other protobuf dependencies such as the Google HTTP annotations for openapi generation or grpc-gateway usage.
There were some recent changes to have our own ratelimiting annotations.
The two combined were not working when I was trying to use them together (attempting to rebase another branch)
Buf workspaces should be the solution to the problem
Buf workspaces means that each module will have generated Go code that embeds proto file names relative to the proto dir and not the top level repo root.
This resulted in proto file name conflicts in the Go global protobuf type registry.
The solution to that was to add in a private/ directory into the path within the proto/ directory.
That then required rewriting all the imports.
Is this safe?
AFAICT yes
The gRPC wire protocol doesn't seem to care about the proto file names (although the Go grpc code does tack on the proto file name as Metadata in the ServiceDesc)
Other than imports, there were no changes to any generated code as a result of this.
Replace two methods with a single one that returns the cert. This moves more
of the logic into the single caller (auto-config).
tlsutil.Configurator is widely used. By keeping it smaller and focused only on storing and
returning TLS config, we make the code easier to follow.
These two methods were more related to auto-config than to tlsutil, so reducing the interface
moves the logic closer to the feature that requires it.
R.B. Boyer