Docker Mastery: Section 8 作業阿～！！！ Create a Multi-Service Multi-Node Web App

• section8-67

Udemy

• Docker Mastery: with Kubernetes +Swarm from a Docker Captain

• GitHub: udemy-docker-mastery

• 講師的YouTube

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Assignment: Create Multi-Service App

• Using Docker’s Distrubuted Voting App
• use swarm-app-1 directory in our course repo for requirements
• 1 volume, 2 networks, and 5 servcies needed
• Create the commands needed, spin up services, and test app
• Everything is using Docker Hub images, so no data needed on Swarm
• Like many computer things, this is 1/2 art form and 1/2 science

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Swarm-app-a-1

Goal: create networks, volumes, and services for a web-based “cats vs. dogs” voting app.

Here is a basic diagram of how the 5 services will work:

• All images are on Docker Hub, so you should use editor to craft your commands locally, then paste them into swarm shell (at least that’s how I’d do it)
• a backend and frontend overlay network are needed. Nothing different about them other then that backend will help protect database from the voting web app. (similar to how a VLAN setup might be in traditional architecture)
• The database server should use a named volume for preserving data. Use the new --mount format to do this: --mount type=volume,source=db-data,target=/var/lib/postgresql/data

Services (names below should be service names)

• vote
  • bretfisher/examplevotingapp_vote
  • web front end for users to vote dog/cat
  • ideally published on TCP 80. Container listens on 80
  • on frontend network
  • 2+ replicas of this container
• redis
  • redis:3.2
  • key/value storage for incoming votes
  • no public ports
  • on frontend network
  • 1 replica NOTE VIDEO SAYS TWO BUT ONLY ONE NEEDED
• worker
  • bretfisher/examplevotingapp_worker:java
  • backend processor of redis and storing results in postgres
  • no public ports
  • on frontend and backend networks
  • 1 replica
• db
  • postgres:9.4
  • one named volume needed, pointing to /var/lib/postgresql/data
  • on backend network
  • 1 replica
• result
  • bretfisher/examplevotingapp_result
  • web app that shows results
  • runs on high port since just for admins (lets imagine)
  • so run on a high port of your choosing (I choose 5001), container listens on 80
  • on backend network
  • 1 replica

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作業

• network

root@node1:~# docker network create -d overlay frontend
munnt6ardwyclcym3xr5ud1mq
root@node1:~# docker network create -d overlay backend
k4tt3cmxy3c2mlykvfnlsyh4l

• vote

  • docker service create --name vote -p 80:80 --network frontend --replicas 2 bretfisher/examplevotingapp_vote

  •  root@node1:~# docker service create --name vote -p 80:80 --network frontend --replicas 2 bretfisher/examplevotingapp_vote
     2rfb86fjjeypll7o4v67t7iry
     overall progress: 2 out of 2 tasks
     1/2: running
     2/2: running
     verify: Service converged
    

• redis

  • docker service create --name redis --network frontend redis:3.2

  •  root@node1:~# docker service create --name redis --network frontendredis:3.2
     uytakkvfxkhjrx4emtjlzhrce
     overall progress: 1 out of 1 tasks
     1/1: running   [==================================================>]
     verify: Service converged
    

• worker

  • docker service create --name worker --network backend --network frontend bretfisher/examplevotingapp_worker:java

  •  root@node1:~# docker service create --name worker --network backend --network frontend bretfisher/examplevotingapp_worker:java
     kp3dbsf8u2qu8e0w7gyszf0di
     overall progress: 1 out of 1 tasks
     1/1: running   [==================================================>]
     verify: Service converged
    

• db

  • docker service create --name db --network backend --mount type=volume,source=db-data,target=/var/lib/postgresql/data postgres:9.4

  •  root@node1:~# docker service create --name db --network backend --mount type=volume,source=db-data,target=/var/lib/postgresql/data postgres:9.4
     3kdzx5bf79yjz3o4pba9n7w17
     overall progress: 1 out of 1 tasks
     1/1: running   [==================================================>]
     verify: Service converged
    

• result

  • docker service create --name result --network backend -p 5001:80 bretfisher/examplevotingapp_result

  •  root@node1:~# docker service create --name result --network backend -p 5001:80 bretfisher/examplevotingapp_result
     k7ysp6z5k0seag0u034xlbtq1
     overall progress: 1 out of 1 tasks
     1/1: running   [==================================================>]
     verify: Service converged
    

看整體樣子

• 隨便近一個 IP
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• 看投票結果 隨便一個IP:5001
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• 這作業大概長這樣子

• 架構比對

真的很棒的練習! 感覺功力又大增了!!