This adds a new very tiny memdb table and corresponding raft operation
for updating a very small effective map[string]string collection of
"system metadata". This can persistently record a fact about the Consul
state machine itself.
The first use of this feature will come in a later PR.
* Create Topology Tab with foundational layout and styling
* Create Toplogy Metrics component with dynamic SVG
* Add ember-render-modifiers addon
* Implement Topology Metrics comp and fix up styling
* Create topology endpoint with tests
* Move arrow drawing to index.js file
* Add topology to show controller
* Fix up conditional wrapper, tabs positioning, links, and styling
* Group upstreams by dc and fix up styling
* Create service/health-percentage helper
* Add health check percentages to upstreams and downstreams
* Basic Layout
* Upgrade @hashicorp/consul-api-double to v5.2.3
* Renamed endpoint to be service-topology
* Refactor styling
* Update to only show Topology tab when Connect is enabled
* Fix bug and changes from review notes
* Remove unused functions that are replaced with SVG markers
* Refactor to resuse svg-curve helper
* Use the render-template helper for the metrics link
* Add topology default null to services show route
* Removed unused ID
* Fix up tests broken by redirect to /topology
This new package provides a client agent implementation of an interface
for fetching the health of services.
This approach has a number of benefits:
1. It provides a much more explicit interface. Instead of everything
dependency on `RPC()` and `Cache.Get()` for many unrelated things
they can depend on a type that are named according to the behaviour
it provides.
2. It gives us a single place to vary the behaviour and migrate to
a new form of RPC (gRPC). The current implementation has two options
(cache, or direct RPC), and in the future we will have more.
It is also a great opporunity to start adding `context.Context` args
to these operations, which in the future will allow us to cancel
the operations.
3. As a concequence of the first, in the Server agent where we make
these calls we can replace the current in-memory RPC calls with
a thin adapter for the real method. This removes the `net/rpc`
machinery from the call in places where it is not needed.
This new package is quite small right now, but I think we can expect it
to grow to a more reasonable size as other RPC calls are replaced.
This change also happens to replace two very similar implementations with
a single implementation.
Reduce Jitter to one function
Rename NewRetryWaiter
Fix a bug in calculateWait where maxWait was applied before jitter, which would make it
possible to wait longer than maxWait.
The fields are only ever read by Waiter, and
setting the fields makes the calling code read much better without
having to create a bunch of constants that only ever get used once.
