132-linkerd-flagger.sh

#########################################################################
# How To Do Canary Deployments In Kubernetes Using Flagger And Linkerd? #
# https://youtu.be/NrytqS43dgw                                          #
#########################################################################

# Referenced videos:
# - What Is Linkerd Kubernetes Service Mesh? Linkerd Tutorial Part 1: https://youtu.be/mDC3KA_6vfg
# - Progressive Delivery Explained - Big Bang (Recreate), Blue-Green, Rolling Updates, Canaries: https://youtu.be/HKkhD6nokC8
# - Service Mesh In Kubernetes Explained: https://youtu.be/cjhb7_uwzDk
# - Argo Rollouts - Canary Deployments Made Easy In Kubernetes: https://youtu.be/84Ky0aPbHvY
# - Kustomize - How to Simplify Kubernetes Configuration Management: https://youtu.be/Twtbg6LFnAg

#########
# Setup #
#########

# Create a Kubernetes cluster with NGINX Ingress

gh repo fork vfarcic/linkerd-demo \
    --clone

cd linkerd-demo

# Replace `[...]` with the Ingress Service IP
export INGRESS_HOST=[...]

cat kustomize/overlays/flagger/ingress.yaml \
    | sed -e "s@host: .*@host: silly-demo.$INGRESS_HOST.nip.io@g" \
    | tee kustomize/overlays/flagger/ingress.yaml

kubectl create namespace production

#############################
# Install And Setup Linkerd #
#############################

# Please watch https://youtu.be/mDC3KA_6vfg if you're not familiar with Linkerd

linkerd install \
    | kubectl apply --filename -

linkerd viz install \
    | kubectl apply --filename -

linkerd check

###################
# Install Flagger #
###################

kubectl apply \
    --kustomize github.com/fluxcd/flagger/kustomize/linkerd

##########################
# Define Canary Resource #
##########################

cd kustomize/overlays/flagger

cat deployment.yaml

cat hpa.yaml

cat ingress.yaml

cat canary.yaml

# Watch https://youtu.be/Twtbg6LFnAg if you are not familiar with Kustomize
kubectl apply --kustomize .

kubectl --namespace production get pods

kubectl --namespace production \
    get canaries

kubectl --namespace production \
    get services

kubectl --namespace production \
    get canaries

kubectl --namespace production \
    describe canary silly-demo

###########################
# Deploy A Canary Release #
###########################

kustomize edit set image \
    vfarcic/silly-demo=vfarcic/silly-demo:1.0.3

kubectl apply --kustomize .

while true; do
    kubectl --namespace production get canaries
    curl http://silly-demo.$INGRESS_HOST.nip.io
    echo ""
    sleep 0.5
done

kubectl --namespace production \
    describe canary silly-demo

############################
# Canary Releases Rollback #
############################

kustomize edit set image \
    vfarcic/silly-demo=vfarcic/silly-demo:1.0.4

kubectl apply --kustomize .

while true; do
    kubectl --namespace production get canaries
    curl http://silly-demo.$INGRESS_HOST.nip.io
    curl http://silly-demo.$INGRESS_HOST.nip.io?fail
    echo ""
    sleep 0.5
done

kubectl --namespace production \
    describe canary silly-demo

######################################################
# Flagger Webhooks, Gating, Alerting, And Monitoring #
######################################################

# Open https://docs.flagger.app/usage/webhooks
# Open https://docs.flagger.app/usage/alerting
# Open https://docs.flagger.app/usage/monitoring

###########
# Destroy #
###########

kustomize edit set image \
    vfarcic/silly-demo=vfarcic/silly-demo:1.0.2

# Destroy the cluster