Add limitador tracing-endpoint command

[adam-cattermole]

Changes

A new --tracing-endpoint command was added to limitador in Kuadrant/limitador#261. I have used a struct to match the spec in Authorino (eventually to contain an Insecure boolean once limitador supports TLS tracing endpoint).

docker run --rm -t quay.io/kuadrant/limitador:latest limitador-server --help

Rate Limiting Server

Usage: limitador-server [OPTIONS] <LIMITS_FILE> [STORAGE]

STORAGES:
  memory        Counters are held in Limitador (ephemeral)
  disk          Counters are held on disk (persistent)
  redis         Uses Redis to store counters
  redis_cached  Uses Redis to store counters, with an in-memory cache

Arguments:
  <LIMITS_FILE>  The limit file to use

Options:
  -b, --rls-ip <ip>
          The IP to listen on for RLS [default: 0.0.0.0]
  -p, --rls-port <port>
          The port to listen on for RLS [default: 8081]
  -B, --http-ip <http_ip>
          The IP to listen on for HTTP [default: 0.0.0.0]
  -P, --http-port <http_port>
          The port to listen on for HTTP [default: 8080]
  -l, --limit-name-in-labels
          Include the Limit Name in prometheus label
      --tracing-endpoint <tracing_endpoint>
          The host for the tracing service [default: ]
  -v...
          Sets the level of verbosity
      --validate
          Validates the LIMITS_FILE and exits
  -H, --rate-limit-headers <rate_limit_headers>
          Enables rate limit response headers [default: NONE] [possible values: NONE, DRAFT_VERSION_03]
      --grpc-reflection-service
          Enables gRPC server reflection service
  -h, --help
          Print help
  -V, --version
          Print version

Verification Steps

Deploy cluster:

make local-setup

Create limitador CR with .spec.tracing.endpoint set:

kubectl apply -f - <<EOF
---
apiVersion: limitador.kuadrant.io/v1alpha1
kind: Limitador
metadata:
  name: limitador
spec:
  listener:
    http:
      port: 8080
    grpc:
      port: 8081
  tracing:
    endpoint: rpc://tracing-endpoint:4317
  limits:
    - conditions: ["get_toy == 'yes'"]
      max_value: 2
      namespace: toystore-app
      seconds: 30
      variables: []
EOF

Wait for deployment:

kubectl wait --timeout=300s --for=condition=Ready limitador limitador

Check limitador deployment command:

kubectl get deployment/limitador-limitador  -o yaml | yq '.spec.template.spec.containers[0].command'

- limitador-server
- --tracing-endpoint
- rpc://tracing-endpoint:4317
- --http-port
- "8080"
- --rls-port
- "8081"
- /home/limitador/etc/limitador-config.yaml
- memory

[codecov-commenter]

Codecov Report

Merging #130 (e7ae162) into main (c4802c5) will decrease coverage by 1.09%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #130      +/-   ##
==========================================
- Coverage   86.03%   84.94%   -1.09%     
==========================================
  Files          19       19              
  Lines         988      990       +2     
==========================================
- Hits          850      841       -9     
- Misses         91       97       +6     
- Partials       47       52       +5     

Flag	Coverage Δ
integration	78.88% <0.00%> (-1.89%)	⬇️
unit	66.81% <100.00%> (+0.10%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
api/v1alpha1 (u)	100.00% <ø> (ø)
pkg/helpers (u)	83.87% <ø> (ø)
pkg/log (u)	94.73% <ø> (ø)
pkg/reconcilers (u)	74.67% <ø> (ø)
pkg/limitador (u)	98.74% <100.00%> (+<0.01%)	⬆️
controllers (i)	74.32% <ø> (-3.72%)	⬇️
pkg/upgrades	88.88% <ø> (ø)

Files	Coverage Δ
api/v1alpha1/limitador_types.go	100.00% <ø> (ø)
pkg/limitador/deployment_options.go	100.00% <100.00%> (ø)

... and 2 files with indirect coverage changes

[adam-cattermole]

cc @david-martin

[eguzki]

Just one comment/question, but LGTM as it is now

[eguzki]

Should endpoint be optional or required?

spec.tracing is optional, but spec.tracing.endpoint?

[adam-cattermole]

Yeah that's a good point actually, if the tracing struct is provided the endpoint should be required I guess

[eguzki]

Should we add come documentation regarding tracing?? Any requirement on the tracing backend side?? Opentelemetry compatible service?

[adam-cattermole]

Yep I think I should definitely add some docs about configuring here, I'll add a follow up commit with that change

[adam-cattermole]

@eguzki - I'm going to merge this if you're happy with the latest changes