tree: becfba2d2f113f06328a77a42383ca48382b3959 [path history] [tgz]
  1. .gitignore
  2. Makefile
  3. PROD.md
  4. README.md
  5. build_envoy_json
  6. build_envoy_skia_org_release
  7. computed.json
  8. deploy_new_certs.sh
  9. envoy-skia-org/
  10. envoy-starter.json
  11. go/
  12. probersk.json5
skfe/README.md

SKFE - The Skia Frontend

A single unified web frontend for all the Skia properties.


+--------------------------+ | GKE Ingress | +----+------------------+--+ | | | | v v +-------------+ +-------------+ | (envoy) | ... | (envoy) | +------+------+ +------+------+ | | +---+-------------+----------+-----+ v v v +---------+ +---------+ +-----------+ |skia perf| ... |skia gold| |skia alerts| +---------+ +---------+ +-----------+

A single static IP is handled by GKE Ingress which handles SSL and then distributes requests to multiple envoy pods: They, in turn, distribute the calls to the backend as kubernetes sevices. The certs for all Skia properties are handled at the GKE Ingress level, see http://go/skia-ssl-cert for more details.

The configuration for the envoy server comes from envoy-starter.json and metadata annotations on services running in the skia-public k8s cluster.

The generation of the configuration involves three files, two of which are auto-generated:

envoy-starter.json
simple.json
computed.json

The simple.json and computed.json are generated files and are not checked into version control.

The enjoy-starter.json file contains our liveness handling, all redirects, and complicated routes for services like Gold. It is a hand-written file.

The contents of simple.json are generated directly from metadata in kubernetes Services.

We need three pieces of information, the domain name, the target service name, and the port that the service is running on. Consider the following configuration for https://perf.skia.org.

apiVersion: v1
kind: Service
metadata:
  labels:
    app: skiaperf
  name: skiaperf
  annotations:
    beta.cloud.google.com/backend-config: '{"ports": {"8000":"skia-default-backendconfig"}}'
    skia.org.domain: perf.skia.org
spec:
  ports:
    - name: metrics
      port: 20000
    - name: http
      port: 8000
  selector:
    app: skiaperf
  type: NodePort

The parts of the Service spec that are important are the skia.org.domain annotation which specifies the public domain name where this service should be available. It must be a sub-domain of .skia.org. There also must be a .spec.ports with a name of “http” that specifies the port at which the service is available. Along with the name of the service those values are combined to produce the simple.json config file. We then run merge_envoy to merge simple.json and envoy-starter.json into computed.json which is then used in the envoy image. Making this a two step process makes it easier to debug the output of each step, as Envoy configs are very wordy.

Finally update_probers can be run to add all the redirects from envoy-starter.json to probersk.json5.

Pushing

Run

make

To build the computed.json config file which is then reviewed and submitted.

After that file has landed then run:

make push

to push the computed.json file to production.

Admin

You can reach the Envoy admin interface by

kubectl port-forward <envoy-skia-org pod name>  9000:9000

And then visit

http://localhost:9000

The admin interface also provides the metrics endpoint to prometheus.

FAQ

Q: Why not just use GKE Ingress?

A: GKE Ingress is limited to 50 total rules, which we currently exceed.

Q: Why not use TCP Load Balancing and a custom ingress on GKE?

A: GKE Ingress is the only public facing option available to us.