Ashish Pandey

(Business Consultant)

@ashishapy

blog.ashishapy.com

One step towards microservices

Meet-up on 13th March 2016 @ Thoughtworks Pune

Microservices

Services are small - fine-grained to perform a single function.

Services are easy to replace and deploy independently 

One service fails, then the whole application does not have to fail 

Services can be implemented using different programming languagesdatabases, hardware and software environment, depending on what fits best

Service

One service managed by two pizza team

Comes with complexity and new challenges

Microservices ...

https://www.flickr.com/photos/psd/13109673843/

Principles of Microservices

Microservices

Modeled around
business concept
Small autonomous services
Culture of automation
Highly Observable 
Isolate failure
Deploy independently
Decentralize all the things
Hide internal implementation details

Cultural change is the key

Let's start the journey ...

Chapter A:

  • Understanding Docker container technologies
  • Build a service / app with Docker

 

Chapter B:

  • Docker app with DevOps (CI/CD) automated workflow

We try to achieve today...

 The Implementation Breakthrough: 



Continuous Deployment, Microservices, and Containers
It's a quest to deploy often and fast, be fully automatic, accomplish zero-downtime, have the ability to rollback, provide constant reliability across environments, be able to scale effortlessly, and create self-healing systems able to recuperate from failures.

Virtual Machines vs Containers

Container

The underlying technology

  • Namespaces: 

    • The pid namespace
    • The net namespace
    • The ipc namespace
    • The mnt namespace
    • The uts namespace
  • Control groups

  • Union file systems

  • Container format

https://docs.docker.com/

Get Started

  • Install Docker Engine on host machine
  •  
  • For quick start use my Digital Ocean referral: https://m.do.co/c/af7efed41ac1​ . You will get $10 credit, more than enough for the exercise.

Get Started...

  • Run few basic commands:
    • docker info
    • docker images
    • docker ps
    • docker ps -a

Run a software image in a container

  • docker run hello-world
  • docker run -i -t ubuntu /bin/bash

Re-run commands:

  • docker info
  • docker images
  • docker ps
  • docker ps -a
  • docker history <ImageId>

Docker hub

Signup on hub.docker.com

Docker image hosting provider

Docker image & Containers

docker images

Image

Image

https://www.docker.com/

docker commit

  • docker commit command saves changes in a container as a new image.

docker commit [options] [container id] [repository:tag]

Docker Containers

  • Run container from a image: docker run
  • Check running containers: docker ps
  • Check all (Running, Stopped, Paused) containers: docker ps -a
  • Inspect a container: docker inspect

Docker’s architecture

https://www.docker.com/

docker run

  1. Pulls the image

  2. Creates a new container

  3. Allocates a filesystem and mounts a read-write layer

  4. Allocates a network / bridge interface

  5. Sets up an IP address

  6. Executes a process that you specify

  7. Captures and provides application output

https://www.docker.com/

Docker Application

Download Base Image (OS)

Install tools for the app

Download & Install the app

Expose container port to host

1

2

3

4

5

Container default command / Entry point

Demo Node Web App

Node Web Docker App

FROM node:argon

COPY . /usr/src/app & RUN npm install

EXPOSE 8080

1

2

3

4

5

CMD [ "npm", "start" ]

Dockerfile

Dockerfile

A Dockerfile is a configuration file that contains instructions for building a Docker Image

Demo

  1. Login to host machine & check docker command
  2. git clone https://github.com/ashishapy/Demo_DockerCI-CD.git
  3. cd Demo_DockerCI-CD
  4. docker build -t <username>/demo_dockerci-cd .
  5. docker images
  6. docker run -p 80:8080 -d <username>/demo_dockerci-cd
  7. Enter host machine ip address on browser.
  • docker login
  • docker push <username>/demo_dockerci-cd

Push to Docker hub

OOO! 

We have our own image now!

Can we use it to quickly spin node-web-app?

Run own image

docker run -p 80:8080 -d <username>/demo_dockerci-cd

Achievement unlocked!

Successfully completed Docker basics

Chapter - B

Chapter A:

  • Understanding Docker container technologies
  • Build a service / app with Docker

Chapter B:

  • Docker app with DevOps (CI/CD) automated workflow

DevOps (CI/CD) Workflow

Hub

Automated Workflow

Docker
Cloud

DevOps (CI/CD) Workflow

Hub

Automated Workflow

Docker
Cloud

Continuous Integration

Automated Workflow

Hub

Cloud
Docker

Continuous Integration ...

Automated Workflow

Hub

Cloud
Docker

Docker Hub

  1. Link your GitHub account with Docker Hub here.
  2. Go to "Create" -> "Create Automated Build" and create.
  3. Under "Build Settings" of the repo, uncheck "When active, builds will happen automatically on pushes." option & save.
  4. Go to "Build Triggers" section, click on "Activate Trigger" button.
  5. Copy "Trigger URL" generated from previous step.

CircleCI

  1. Signup with CircleCI using your GitHub account.
  2. On CircleCI "Dashboard", click on "Add Projects".
  3. Select your GitHub account then "Build Project" for the repo.
  4. If all is well then it should successfully pass the project.
  5. Go to "Project Settings" -> "Environment Variables" & add environment variable as Name: DOCKER_HUB_TRIGGER; Value: curl -H "Content-Type": application/json" --data '{"build": true}' -X POST <Docker_Hub TRIGGER_URL>
  6. Change circle.yml file to include "deployment" section.
  7. Push the changes to GitHub repo and watch all auto builds.
Hub

Automated Workflow

Docker
Cloud

Story till now ...

Continuous Deployment

Hub

Automated Workflow

Docker
Cloud

Reference Architecture

Service

  • App / Container

Node Cluster

Node

Node

Node

Node

Cloud VM

Cloud VM

Cloud VM

Cloud VM

Docker Cloud

cloud.docker.com

Digital Ocean

Everything have been taken care of by "Docker Cloud"

Check you should have one instance running, created by "Docker Cloud" -> "Node"

Open "Docker Cloud" "Service End Point" on browser

Incremental Change

Push a change to Github, and monitor changes at every step.

Evolving Docker Platform

  • Registry: Docker Hub
  • Clustering: Docker Swarm
  • Orchestration: Docker Compose
  • Deploy, manage, and monitor: Docker Universal Control Plane

Also check Kubernetes by Google  and Apache Mesos to Manage a cluster of Linux containers

Container as a Service (CaaS)

Future of Docker

Docker on Windows

End of Virtual Machines and only Docker Containers. ex. Joyent Triton

Chip-level assists for Containers

Docker With DevOps

By Ashish Pandey

Docker With DevOps

One step towards microservices

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