STEP-BY-STEP.md

Mesh Arena

This is a step-by-step guide to run the demo.

Slides

This demo was presented at DevopsDday in the Velodrome, Marseilles' famous stadium, and then at RivieraDev 2019. Check the slides, in French (a bit outdated) or in English.

Pre-requisite

• Kubernetes or OpenShift cluster running (ex: minikube 0.27+ / minishift)
• Istio with Kiali installed

Example of Istio + Kiali install:

istioctl install --set profile=demo
kubectl apply -f https://raw.githubusercontent.com/istio/istio/release-1.10/samples/addons/prometheus.yaml
kubectl apply -f https://raw.githubusercontent.com/istio/istio/release-1.10/samples/addons/kiali.yaml
kubectl apply -f https://raw.githubusercontent.com/istio/istio/release-1.10/samples/addons/jaeger.yaml
istioctl dashboard kiali

Get the yml files locally

• Clone this repo locally, cd to it.

git clone git@github.com:jotak/demo-mesh-arena.git
cd demo-mesh-arena

For OpenShift users, you may have to grant extended permissions for Istio, logged as admin:

oc new-project mesh-arena
oc adm policy add-scc-to-user privileged -z default

Jaeger

Tracing data generated from microservices and Istio can be viewed in Jaeger by port-forwarding jaeger-query service.

istioctl dashboard jaeger
make jaeger-service

AI service generates trace named new_game for each game. This way we are able to trace player's movement on the stadium.

The other interesting trace is from ui service called on-start it captures all initialization steps performed at the beginning of the game.

Deploy microservice UI

kubectl label namespace default istio-injection=enabled
make scen-init-ui

Deploy stadium, ball, 2x2 players

make scen-init-rest

or, one by one:

make scen-init-stadium
make scen-init-ball
make scen-init-ai

Kiali TIP

In Kiali Graph, we may want to disable the Service Node display (because it hides some workload-to-workload relations) and also turn on Traffic Animation (because it's prettier!).

Second ball

make scen-add-ball

In this state, the usual K8S load balancer is in use. Players can't seem to decide whether to go to first or second ball. The round-robin algorithm makes them change their target on every request.

Kiali TIP

In Kiali Graph, double-click on ball app (the rectangle) to better visualize this 50-50 distribution. Also, you can type `app=ui OR app=stadium` in the Hide box to reduce noise.

Ponderate ball v1 and v2

make scen-75-25

Players know a little bit better where to go, but still unsure.

Kiali TIP

In Kiali Graph, distribution will be slowly moving close to 75/25.

Messi / Mbappé

make scen-add-players

Two new players.

Each his ball

make scen-by-source-label

Now they know. Clean state.

Kiali TIP

This is how it should looks like: 100% to a ball.

Reset

make scen-reset

Burst ball (500 errors) with shadowing

make scen-add-burst
make scen-mirroring

A new ball, v2 is deployed "for fake": all requests sent to v1 are duplicated to v2. But the players don't "know" about that: from their PoV their requests are for v1 only. They don't get responses from v2.

The new ball sometimes (randomly) returns errors. When it does so, it turns red.

Kiali TIP

In Kiali Graph, when you double-click on ball app, Kiali displays metrics emitted by balls => so there's incoming traffic to v2.

But if you double-click on ai app, Kiali displays metrics emitted by AI => there's no outgoing traffic to ball v2.

Remove shadowing, put circuit breaking

make scen-outlier

CB is configured to evict failing workload for 10s upon error. Then it's put back into the LB pool, and will be evicted again, and again, and again.

When a ball receives no request, it turns darker. So it's grey when it's evicted by the circuit breaker.

Kiali TIP

In Kiali Graph, double-click on ball app. You will see some low proportion of requests from ai to ball-v2, corresponding to the time when it's put back in LB pool.

To clean up everything

make undeploy