Zero Downtime using eureka and zuul .

Blue-green deployment is a technique that reduces downtime and risk by running two identical production environments called Blue and Green.

At any time, only one of the environments is live, with the live environment serving all production traffic. For this example, Blue is currently live and Green is idle.

The component of this example are :

• Service Edge : A service based on Zuul that perform load balancing and reverse proxy .
• Service Registry : A service based on Eureka that receive all the topology of our component .
• Service Dashboard : A simple API that expose a single endpoint /echo
• User load simulator : A simulator for high traffic of user calling the /echo endpoint . This component is based on Gatling .

Compile and generate docker images .

mvn clean install 

Results

[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO] 
[INFO] blue-green-deployement/parent ...................... SUCCESS [  0.285 s]
[INFO] blue-green-deployement/admin-service ............... SUCCESS [ 14.875 s]
[INFO] blue-green-deployement/dashboard-service ........... SUCCESS [  4.823 s]
[INFO] blue-green-deployement/discovery-service ........... SUCCESS [ 12.346 s]
[INFO] blue-green-deployement/edge-service ................ SUCCESS [  5.815 s]
[INFO] blue-green-deployement/perf-simulator .............. SUCCESS [  4.894 s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------

START ALL THE PLATEFORME

docker-compose up -d 

➜ docker-compose ps 
      Name                     Command               State           Ports         
-----------------------------------------------------------------------------------
admin-service       java -Djava.security.egd=f ...   Up      0.0.0.0:9009->9009/tcp
dashboard-service   java -Djava.security.egd=f ...   Up                            
discovery-service   java -Djava.security.egd=f ...   Up      0.0.0.0:8761->8761/tcp
edge-service        java -Djava.security.egd=f ...   Up      0.0.0.0:9999->9999/tcp
weave-scope         /home/weave/entrypoint.sh  ...   Up      0.0.0.0:4040->4040/tcp

SCALE DASHBOARD SERVICE

docker-compose scale dashboard-service=2

Run gatling simulator on the echo endpoint :

cd mvn gatling:execute -Dgatling.simulationClass=ma.octo.simulations.BlueGreenSimulation

Get Service discovery

curl -XGET -H "Accept: application/json" http://localhost:8761/eureka/apps/ | jq '.applications.application[2].instance[] | {app :.app, instanceId: .instanceId} '
curl PUT http://localhost:8761/eureka/apps/DASHBOARD-SERVICE/372c66090d74:dashboard-service:9001/status?value=OUT_OF_SERVICE

START NEW VERSION

docker run  --network=bluegreendeployement_default -it -e EUREKA_INSTANCE_INITIAL-STATUS=OUT_OF_SERVICE -e SPRING_PROFILES_ACTIVE=docker -e ECHO=new --link discovery-service  -d --name dashboard-service-blue octo/dashboard-service

VERIFY IT

Manual or automated Tasks

ACTIVATE IT AND DESACTIVATE OLD

curl -XPUT http://localhost:8761/eureka/apps/DASHBOARD-SERVICE/a68965be2fa8:dashboard-service:9001/status?value=UP
curl -XPUT http://localhost:8761/eureka/apps/DASHBOARD-SERVICE/e38190ec6297:dashboard-service:9001/status?value=OUT_OF_SERVICE

Remove old

docker rm -f bluegreendeployement_dashboard-service_2

Start New version

docker run  --network=bluegreendeployement_default -it -e SPRING_PROFILES_ACTIVE=docker -e ECHO=new --link discovery-service  -d --name dashboard-service-blue octo/dashboard-service