HTTP probe paths are urlencoded when requests reach containers

[emaildanwilson]

/area API

What version of Knative?

any version
0.11.x

Expected Behavior

If an http probe is defined with a path containing query parameters, the request should reach the workload as it is defined just like it does on a Kubernetes pod.

for example:

path: /?type=healthcheck
port: 8080

should reach the container as http://:8080/?type=healthcheck

Actual Behavior

instead it reaches the container as http://:8080/%3Ftype%3Dhealthcheck

Steps to Reproduce the Problem

This ksvc fails the health probe because httpbin does not url decode before matching the route.
The GUNICORN_CMD_ARGS environment variable configures logging of requests so it's easy to see what queue-proxy is sending to the container.

apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: httpbin
  namespace: default
spec:
  template:
    metadata:
    spec:
      containers:
      - env:
        - name: GUNICORN_CMD_ARGS
          value: '--capture-output --error-logfile - --access-logfile - --access-logformat
            ''%(h)s %(t)s %(r)s %(s)s Host: %({Host}i)s}'''
        image: kennethreitz/httpbin
        name: httpbin
        ports:
        - containerPort: 80
          name: http1
        readinessProbe:
          failureThreshold: 5
          httpGet:
            path: /headers?p1=123&p2=456
            port: 80
            scheme: HTTP
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 1

I believe this is because the probe is created from url.String() which uses url.EscapedPath().

[nak3]

Thank you for your report! This bug should be fixed in the next release v1.12 via #14267

[nak3]

Closing as dup of #14267