Requirements

• Minikube
• Virtualbox
• Kubernetes
• Docker
• Golang

Description

• We have a set of cowboys.
• Each cowboy has a unique name, health points and damage points.
• Cowboys list is stored in persistent storage (File, Database etc).
• Each cowboy s in it’s own isolated process, workload or replica.
• All communication between cowboys happens via gRPC. Cowboys encounter starts at the same time in parallel. Each cowboys selects random target and shoots.
• Subtract shooter damage points from target health points.
• If target cowboy health points are 0 or lower, then target is dead.
• Cowboys don’t shoot themselves and don’t shoot dead cowboys.
• After the shot shooter sleeps for 1 second.
• Last standing cowboy is the winner.
• Outcome of the shootout is printed out to the centralized log. Every action and winner is logged.
• Kubernetes solution is used.
• Provideed startup and usage instructions in Readme.MD

Start minikube

minikube start
minikube update-context

Set docker registry to minikube

eval $(minikube docker-env)

Build cowboy docker image

docker build -f docker/cowboy/Dockerfile -t cowboy .

Build log docker image

docker build -f docker/log/Dockerfile -t log .

Apply rbac rules to enable pods get list of pods inside cluster

kubectl apply -f rbac.yaml

Run master script to deploy cowboys

go run cmd/master/main.go

Check logs

kubectl exec log-pod -- cat log.txt

Delete all pods

kubectl delete pods --all

Example logs from log pod

k exec log-pod -- cat log.txt

{"Time":"2022-04-29T07:05:14.44638893Z","Msg":"cowboy Bill made a shoot and realized that John was shot with 1 damage"}
{"Time":"2022-04-29T07:05:14.63593824Z","Msg":"cowboy Philip made a shoot and realized that John is dead already"}
{"Time":"2022-04-29T07:05:14.696269113Z","Msg":"John realized that he is dead"}
{"Time":"2022-04-29T07:05:15.456160835Z","Msg":"cowboy Bill made a shoot and realized that Philip was shot with 1 damage"}
{"Time":"2022-04-29T07:05:15.644005933Z","Msg":"cowboy Philip made a shoot and realized that Bill was shot with 2 damage"}
{"Time":"2022-04-29T07:05:16.476270422Z","Msg":"cowboy Bill made a shoot and realized that Philip was shot with 1 damage"}
{"Time":"2022-04-29T07:05:16.654680115Z","Msg":"cowboy Philip made a shoot and realized that Bill was shot with 2 damage"}
{"Time":"2022-04-29T07:05:17.485769444Z","Msg":"cowboy Bill made a shoot and realized that Philip was shot with 1 damage"}
{"Time":"2022-04-29T07:05:17.657985339Z","Msg":"Philip realized that he is dead"}
{"Time":"2022-04-29T07:05:33.527848165Z","Msg":"no alive cowboys. I am Bill the winner!"}

Example logs from cowboy pod

k logs peter

2022/04/29 06:56:31 got target pod 172.17.0.8:50006
2022/04/29 06:56:31 cowboy Peter made a shoot and realized that Philip was shot with 1 damage
2022/04/29 06:56:31 sleep for 1 sec
2022/04/29 06:56:32 got target pod 172.17.0.8:50006
2022/04/29 06:56:32 cowboy Peter made a shoot and realized that Philip was shot with 1 damage
2022/04/29 06:56:32 sleep for 1 sec
2022/04/29 06:56:33 Peter realized that he is dead
2022/04/29 06:56:33 got signal {}, attempting graceful shutdown
2022/04/29 06:56:33 clean shutdown

Commands used to generate protos

protoc --proto_path=api/cowboy --go_out=api/cowboy --go_opt=paths=source_relative --go-grpc_out=api/cowboy --go-grpc_opt=paths=source_relative cowboy.proto
protoc --proto_path=api/log --go_out=api/log --go_opt=paths=source_relative --go-grpc_out=api/log --go-grpc_opt=paths=source_relative log.proto