costinm / istio-consul

Istio MCP to Consul adapter

Intro

This is a refactoring of the consul registry adapter from Istio 1.x.

Changes:

• use the streaming interface instead of periodic polling, which doesn't scale and results in delay
• implements MCP and XDS EDS protocols - using minimal common code/deps from a separate repository ( istio.io/istio has too many deps). It can be used directly from envoy, or via Pilot.
• simplified/optimized

Limitations

K8S consul syncer is flattening the services. To workaround we could use namespace labels (or fix consul syncer).

Run

By default will look for the local consul agent, on port 8500, and expose an MCP/ADS on 15098. A http debug interface is available on 15099. Command line flags allow setting different values.

It is expected that an Envoy sidecar will add MTLS.

Testing with k8s

consul agent -dev -config-dir=$TOP/src/github.com/costinm/istio-consul/pkg/consul/testdata/config-dir -ui

or

kubectl --namespace consul port-forward $(kubectl -n consul get -l app=consul pod -l component=server \
  -o=jsonpath='{.items[0].metadata.name}') 8500:8500

go run ../../../istio.io/istio/galley/tools/mcpc/main.go \
    --server 127.0.0.1:15098 \
    -sortedCollections istio/networking/v1alpha3/vserviceentries \
    -id testmcp 

TODO

• E2E and integration testing
• load and perf testing
• sync with the K8S synthetic entries on structure
• add service definition - service accounts, etc - via labels or other mechanisms.
• add the docker image and k8s yaml, using sidecar ( see istio-ecosystem/istio-insteller )