Skipper Ingress Controller support is added with
https://github.com/weaveworks/flagger/pull/670.
This commit add the documentation and links to mention
Skipper is now an available option.
Currently only Canary deployments are supported.
Add e2e-skipper* files for test setup
It does the following things:
* install Skipper ingress with Kustomize
* load Flagger image onto the local cluster
* install Flagger and Prometheus in the flagger-system namespace
This allows a user to annotate a specific ConfigMap or Secret to be disabled/ignored via the
configTracking logic that tracks config changes makes configuration copies for the primary Deploy
Closes#435
Te be able to distinct Skipper routes we need to combine the Canary data to generate the Skipper metric label.
"request-success-rate" and "request-duration" queries are implemented and tested that provide those obersvations from Skipper metrics
* Takes into account how Skipper renders the paths accordingly and reformats the quieries.
Router implementation for zalan.do/Skipper Ingress -
An HTTP router and reverse proxy for service composition, including use cases like Kubernetes Ingress
https://github.com/zalando/skipper/
* The concept is to define routes with specific weights via the skipper specific annotation predicate of "zalando.org/backend-weights".
* A new "canary ingress" is created that has higher "weight" thus receiving all traffic, which distributes progressively
* After the canary process is finished, this ingress is disabled via the "False()" annotation predicate to route traffic again back to the apex Ingress.
There are certain Skipper principles which are taken into account:
```
Skipper Principles:
* if only one backend has a weight, only one backend will get 100% traffic
* if two of three or more backends have a weight, only those two should get traffic.
* if two backends don't have any weight, it's undefined and right now they get equal amount of traffic.
* weights can be int or float, but always treated as a ratio.
Implementation:
* apex Ingress is immutable
* new canary Ingress contains two paths for primary and canary service
* canary Ingress manages weights on primary & canary service, hence no traffic to apex service
```
