Istio provides an alternative way to control ingress traffic into the cluster. In addition, it allows to finetune the traffic inside the cluster and provides a huge repertoire of load balancing and routing mechanisms.

Currently, only the Gerrit replica chart allows using istio out of the box.

Install istio

An example configuration based on the default profile provided by istio can be found under ./istio/src/. Some values will have to be adapted to the respective system. These are marked by comments tagged with TO_BE_CHANGED. To install istio with this configuration, run:

kubectl apply -f istio/istio-system-namespace.yaml
istioctl install -f istio/gerrit.profile.yaml

To install Gerrit using istio for networking, the namespace running Gerrit has to be configured to enable sidecar injection, by setting the istio-injection: enabled label. An example for such a namespace can be found at ./istio/namespace.yaml.

Uninstall istio

To uninstall istio, run:

istioctl uninstall -f istio/gerrit.profile.yaml

Restricting access to a list of allowed IPs

In development setups, it might be wanted to allow access to the setup only from specified IPs. This can be done by patching the spec.loadBalancerSourceRanges value of the service used for the IngressGateway. A patch doing that can be uncommented in istio/gerrit.profile.yaml.