## Summary
Update the `RouteID` to use the `policy.ID` if it is set. This makes it
so that updated routes use a stable identifier between updates so if the
envoy control plane is updated before the authorize service's internal
definitions (or vice-versa) the authorize service will still be able to
match the route.
The current behavior results in a 404 if envoy passes the old route id.
The new behavior will result in inconsistency, but it should be quickly
remedied. To help with debugging 4 new fields were added to the
authorize check log. The `route-id` and `route-checksum` as the
authorize sees it and the `envoy-route-id` and `envoy-route-checksum` as
envoy sees it.
I also updated the way we send updates to envoy to try and model their
recommended approach:
> In general, to avoid traffic drop, sequencing of updates should follow
a make before break model, wherein:
>
> - CDS updates (if any) must always be pushed first.
> - EDS updates (if any) must arrive after CDS updates for the
respective clusters.
> - LDS updates must arrive after corresponding CDS/EDS updates.
> - RDS updates related to the newly added listeners must arrive after
CDS/EDS/LDS updates.
> - VHDS updates (if any) related to the newly added RouteConfigurations
must arrive after RDS updates.
> - Stale CDS clusters and related EDS endpoints (ones no longer being
referenced) can then be removed.
This should help avoid 404s when configuration is being updated.
## Related issues
-
[ENG-2386](https://linear.app/pomerium/issue/ENG-2386/large-number-of-routes-leads-to-404s-and-slowness)
## Checklist
- [x] reference any related issues
- [x] updated unit tests
- [x] add appropriate label (`enhancement`, `bug`, `breaking`,
`dependencies`, `ci`)
- [x] ready for review
* Optimize policy iterators (go1.23)
This modifies (*Options).GetAllPolicies() to use a go 1.23 iterator
instead of copying all policies on every call, which can be extremely
expensive. All existing usages of this function were updated as
necessary.
Additionally, a new (*Options).NumPolicies() method was added which
quickly computes the number of policies that would be given by
GetAllPolicies(), since there were several usages where only the
number of policies was needed.
* Fix race condition when assigning default envoy opts to a policy
* proxy: support re-proxying request from envoy for kubernetes
* encrypt policy id for reproxy, implement tls options
* add comment, use hmac
* use httputil handler and error
* remove reproxy headers on all incoming request
* only allow re-proxying for kubernetes, strip headers
* fix tests
