This document summarizes a presentation about using Docker for development. It discusses installing Docker, running a "Hello World" Docker image, building a custom Python Docker image, and composing a more complex Docker application with PHP, MySQL, and Apache. The benefits of Docker like lightweight containers, easy environment setup, and scalability are highlighted. Some challenges with scaling and orchestration are also mentioned, along with solutions like Docker Swarm and Kubernetes.

1. learning:
with Thomas @ Search Investment Group
Slides & codes: http://bit.ly/thomasdocker

2. Ref: 8 surprising facts about real docker adoption

3. Ref: Docker Customers, StackShare

4. Virtual Machines Docker

5. Benefits
● Lightweight
● Experiment and use whatever technology fits best
● Having multiple versions of tools without crashing
(Java, Python 2 & 3, etc)
● Automated deployment
● Quickly and accurately set up environments for DEV, UAT, etc.
● Scale easily

6. Today’s Demo
● Install Docker
● Download and run a Hello World Docker image
● Compose our own Hello World Docker Image
● Compose our own Docker Image that contains a PHP-MySQL
application

7. Install Docker (MacOS)
https://www.docker.com/products/

8. Install Docker (Windows)

9. Hello World
Hello-world container

10. Docker Store

11. Find the Image

12. Hello World
$ docker --version
Docker version 1.13.0, build 49bf474
$ docker pull hello-world
Using default tag: latest
latest: Pulling from library/hello-world
78445dd45222: Pull complete
Digest: sha256:c5515758d4c5e1e838e9cd307f6c6a0d620b5e07e6f927b07d05f6d12a1ac8d7
$ docker run hello-world
Hello from Docker!
(...)
Ref for our “SSL Deep Inspection”:
Docker behind proxy that changes
ssl certificate

13. Basic Docker Commands
$ docker images
(list the images you pulled)
$ docker ps
(list the running containers)
$ docker ps -a
(list all containers, including exited)
$ docker [command] --help
(check the documentation)
$ docker rmi [image ID]
(remove the image by the associated ID
- you don’t have to type in full ID!)
$ docker stop [container ID]
(stop the running container by the ID)
$ docker rm [container ID]
(stop and remove the container from the
ps -a list)
$ docker ps -aq | xargs docker rm
(stop and remove all containers)

14. Build our own Hello World
Python container
Our hello-world container

15. Hello World in Python
$ echo 'print("Hello from Thomas")' > app.py
$ cat app.py
print("Hello from Thomas")
$ python app.py
Hello from Thomas

16. Docker Store

17. Dockerfile & docker-compose.yml
$ vi Dockerfile
FROM python
MAINTAINER Thomas Tong <hello@thomastong.me>
COPY app.py app.py
CMD python app.py
$ vi docker-compose.yml
helloworld:
build: .
Describes the necessary
steps to build the container
Describes the container in
its running state
(environment variables,
dependencies to others
containers, etc)
Ref: Docker Compose vs. Dockerfile

18. Compose a Docker Image
$ ls
Dockerfile app.py
docker-compose.yml
$ docker-compose build
Building helloworld
Step 1/4 : FROM python
latest: Pulling from library/python
5040bd298390: Pull complete
fce5728aad85: Pull complete
76610ec20bf5: Pull complete
52f3db4b5710: Pull complete
45b2a7e03e44: Pull complete
75ef15b2048b: Pull complete
e41da2f0bac3: Pull complete
Digest:
sha256:cba517218b4342514e000557e6e9100018f980cda866420
ff61bfa9628ced1dc
Status: Downloaded newer image for python:latest
---> 775dae9b960e
Step 2/4 : MAINTAINER Thomas Tong
<hello@thomastong.me>
---> Running in b257c26e3b5e
---> b6a9ca588053
Removing intermediate container b257c26e3b5e
Step 3/4 : COPY app.py app.py
---> c30eb29c8920
Removing intermediate container 5c74e320839d
Step 4/4 : CMD python app.py
---> Running in 5c2295d819ad
---> b54de6654b62
Removing intermediate container 5c2295d819ad
Successfully built b54de6654b62

19. Run the Docker Image
$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
2helloworld_helloworld latest b54de6654b62 7 minutes ago 687 MB
python latest 775dae9b960e 7 minutes ago 687 MB
$ docker run [image name/ID]
Hello from Thomas
$ docker-compose up
Creating 2helloworld_helloworld_1
Attaching to 2helloworld_helloworld_1
helloworld_1 | Hello from Thomas
2helloworld_helloworld_1 exited with code 0
You can only use this after
building the image
Build and start according
to the Dockerfile and
docker-compose.yml, good
for development

20. Apache httpd + PHP + MySQL
PHP httpd
Our site
MySQL

21. Sample App - Feed Moby Dock
Credits: Originally done in Flask by acloud.guru, rewritten in PHP
Feed button and fed count
Random message
from database

22. Docker Store

23. Docker Store

24. Docker Store
“latest” tag is used by default

25. Our Files
$ ls -R
Dockerfile docker-compose.yml
./cert:
server.crt server.csr server.key
./conf:
000-default.conf apache2.conf default-ssl.conf php.ini
./database:
seed.sql
./public:
(...)
Docker image config files
HTTPS Cert
Apache and PHP
config files
SQL to create DB
Our Web App files

26. Dockerfile
FROM php:apache
RUN docker-php-ext-install mysqli
COPY conf/php.ini /usr/local/etc/php/
RUN a2enmod headers
RUN a2enmod rewrite
RUN a2enmod ssl
COPY cert/server.crt /etc/ssl/certs/
COPY cert/server.key /etc/ssl/certs/
COPY conf/000-default.conf /etc/apache2/sites-enabled/
COPY conf/default-ssl.conf /etc/apache2/sites-enabled/
COPY conf/apache2.conf /etc/apache2/
COPY public/ /var/www/html/
COPY .env /var/www/html/
Found in Docker Store PHP image’s description
Run apache commands to set up additional modules
Copy php.ini from image to container’s file system
Ref: Docker Command CMD vs RUN, COPY vs ADD
Copy SSL cert and httpd config files
Copy Web App files

27. docker-compose.yml
example_app_db:
image: mysql
environment:
MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD}
MYSQL_DATABASE: ${MYSQL_DATABASE}
MYSQL_USER: ${MYSQL_USER}
MYSQL_PASSWORD: ${MYSQL_PASSWORD}
ports:
- '3306:3306'
volumes:
- ~/.docker-volumes/exampleapp/mysql/data:/var/lib/mysql
- ./database/seed.sql:/docker-entrypoint-initdb.d/seed.sql
example_app:
build: .
links:
- example_app_db
ports:
- '80:80'
- '443:443'
Variables found in MySQL image descriptionUse MySQL image
Link with MySQL image defined above
Map HTTP and HTTPS ports (local port:container port)
Map local volume to
container volume
and seed SQL file to
init directory
Read .env file with ${VAR_NAME}
Map local port 3306 to container

28. Build and Run
$ vi .env
MYSQL_ROOT_PASSWORD=password
MYSQL_DATABASE=exampleapp
MYSQL_USER=exampleapp
MYSQL_PASSWORD=password
$ docker-compose up
(...)
$ docker ps
CONTAINER ID IMAGE PORTS
bda700bcf1ab 3phpapp_example_app 0.0.0.0:80->80/tcp, 0.0.0.0:443->443/tcp
cf443ee159e7 mysql 0.0.0.0:3306->3306/tcp
Setting up environments with different configs,
you may:
● create multiple docker-compose.yml files
● create multiple .env files and use reference
Check port
mappings here

29. Docker Inspect
$ docker inspect [container ID]
(...)
"Env": [
"MYSQL_ROOT_PASSWORD=password",
"MYSQL_PASSWORD=password",
"MYSQL_USER=exampleapp",
"MYSQL_DATABASE=exampleapp",
(...)
$ docker exec -it [container ID] sh
#
Check whether environment
variables are loaded correctly
Run bash shell in a container
to check its file system

30. Check Seed Database
# mysql -u root -p
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| exampleapp |
| mysql |
| performance_schema |
| sys |
+--------------------+
5 rows in set (0.02 sec)
mysql> use exampleapp
mysql> show tables;
+----------------------+
| Tables_in_exampleapp |
+----------------------+
| Feed |
| Messages |
+----------------------+
2 rows in set (0.00 sec)
mysql> select * from Messages;
+----------------------------------------------+
| message |
+----------------------------------------------+
| Thanks good sir. I am feeling quite healthy! |
| Thanks for the meal buddy. |
| Please stop feeding me. I am getting huge! |
+----------------------------------------------+
3 rows in set (0.00 sec)

31. Try it in https://localhost/
Click the button and hear
from Moby Dock
If you want to redo
this exercise, don’t
forget to remove
database files from
your local machine
(hint: check the yml)

32. What have we Achieved?
● Learnt the skills
○ To download and use Docker images
○ To compose our own Docker image
● Learnt the benefits
○ Lightweight
○ Experiment and use whatever technology fits best
○ Having multiple versions of tools without crashing (Java, Python 2 & 3, etc)
○ Automated deployment
○ Quickly and accurately set up environments for development, UAT, etc.
○ Scale easily
Scale easily? Really?

33. ...or Actually the Same?
● What to do when adding new machines?
● How do containers discover each other?
● What happens if containers die?
● What if the host machine is down?
● What happens if 1 container is using excessive resources?

34. #GIFEE
● GIFEE - Google Infrastructure for Everyone Else
● Google starts over 2 billion containers per week
● Container Orchestration
● Docker Swarm, Kubernetes
● Cluster as a giant computer

35. Modern DevOps Architecture
Git Push Git Hook
Git / Source Ctrl. Jenkins / Continuous Integration Server
Static Tests
Unit Tests
Reporting
Docker Compose
Build
Docker Orchestration Docker Registry
Store
Docker Pull

36. ...and they lived happily ever after.

37. Further Watchings & Readings
● Docker for DevOps - From Development to Production
MOOC by acloud.guru
● Scalable Microservices with Kubernetes
MOOC by Google and Udacity
● Shipping code with Docker + Kubernetes (Cantonese)
Recordings of 20 Jun 2016 Meetup @ OneSky
● ...and remember not to overkill: It’s the Future, It really is the future
Blog by CircleCI

38. learning:
with Thomas @ Search Investment Group
Slides & codes: http://bit.ly/thomasdocker