refactor(app): Simplify backend metrics tower layer #3318
+20
−34
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
nb: this is based on #3308. this is a refactor branch aimed at finding a way to simplify the somewhat burdensome types in the metrics middleware's
layer(..)
function.refactor(app): Define layer type aliases
this isn't a "simplification" so much as an outlining of the chunky types in this function signature.
that said... it's subjectively nice to outline the definition of our layers into a
MetricsLayer<T, N>
that we can use as shorthand in the function signature of
layer(..)
.refactor(app): Simplify backend metrics layer bounds
this commit changes the backend-level metrics layer function, so that it invokes
linkerd_app_core::svc::layers()
rather thanlinkerd_app_core::svc::layer::mk()
.this has a nice effect in that it simplifies the bounds of the
layer
function.