docker deployment

current deployment

Build an DEB
Deploy DEB to test env.
Run unit and integration tests
Deploy to each node in production (via chef)

Current deployment

Development ENV could be not same Production ENV and Test

Even if your code is perfect, deployment might fall

More work done on start-up (via chef-boot)

Not FAST!

Slower,error-prone , runtime dependency (chef,apt,pypi)

Chef or Debian repo. could be down

Deployment w/ Docker

Build docker container for application

Dependencies in Dockerfile
Without config/env

Build/Run/Test container with TEST env. (CI tool)
Push docker container image to registry
Pull docker container on each node
"Paramertized containers" using environment variables
Run docker container

Common environment

config

An app’s config is everything that is likely to vary between deploys (staging, production, developer environments, etc).

Resource handles to the database, Memcached, and other backing services
Credentials to external services such as Amazon S3 or Twitter
Per-deploy values such as the canonical hostname for the deploy

Config

"The twelve-factor app stores config in environment variables (often shortened to env vars or env). Env vars are easy to change between deploys without changing any code; unlike config files, there is little chance of them being checked into the code repo accidentally; and unlike custom config files, or other config mechanisms such as Java System Properties, they are a language- and OS-agnostic standard."

From: http://12factor.net/config

"Paramertized containers" using environment variables

FiG : Fast, isolated development environments using Docker

http://orchardup.github.io/fig/

 Dockerfile

FROM orchardup/python:2.7
ADD . /code
WORKDIR /code 
RUN pip install -r requirements.txt

fig.yml

web:
  build: .
  command: python app.py
  ports:
   - "5000:5000"
  volumes:
   - .:/code
  links:
   - redis
redis:
  image: orchardup/redis

FIG : FAST, ISOLATED DEVELOPMENT ENVIRONMENTS USING DOCKER

app.py

from flask import Flask
from redis import Redis
import os
app = Flask(__name__)
redis = Redis(
    host=os.environ.get('REDIS_1_PORT_6379_TCP_ADDR'),
    port=int(os.environ.get('REDIS_1_PORT_6379_TCP_PORT'))
)

@app.route('/')
def hello():
    redis.incr('hits')
    return 'Hello World! I have been seen %s times.' % redis.get('hits')

if __name__ == "__main__":
    app.run(host="0.0.0.0", debug=True)

FIG : FAST, ISOLATED DEVELOPMENT ENVIRONMENTS USING DOCKER

fig.yml (for production?)

web:
  build: .
  command: python app.py
  ports:
   - "5000:5000"
  environment:
   REDIS_1_PORT_6379_TCP_ADDR : 192.168.100.45
   REDIS_1_PORT_6379_TCP_PORT : 6379

Connector agnostic containers

Cross-Host linking using Ambassador Containers

https://docs.docker.com/articles/ambassador_pattern_linking/

Linking containers is only in same host (now)

(consumer) --> (redis-ambassador) ---network---> (redis-ambassador) --> (redis)