1. Iterating Faster with Docker + Cascade
John David Garza
Cascade User Conference • October 2017

2. Introduction Who am I? What do I do? Cascade Users since 2014
The University of Texas at San Antonio
What do I do?
Joined 2015
University Webmaster
Communications and Marketing
Cascade Users since 2014
University is very decentralized
Lots of environments
Lots of websites

3. Show & Tell Demo Local Development Docker + Cascade Docker + Lucee
Smaller contexts
Docker + Lucee
Replicating existing sites/infrastructure
Docker + Wordpress
Over 25% of the web!
Switch to safari and show currently running containers
Lucee for coldfusion development
Local alerts development
Docker cascade
Mailcatcher?

4. Today’s Agenda Introduction Show and Tell Demo (why docker)
Prerequisites
What is Docker and Why Use It
Learn by Example
Demo 1 – beginner (tomcat + docker)
Demo 2 – intermediate (mysql + docker)
Demo 3 – advanced (cascade + docker)
Wrap-Up/More Resources

5. Prerequisites This talk will be technical heavy Familiar with Linux?
Server Administration?
Comfortable with the command line?
Familiar with Java application servers (tomcat)
Have you ever installed/configured cascade?
Code for this presentation is available on bitbucket (git)
prerequisites
this talk will be technical heavy
familiar with server administration? VMs? (This will help with understanding the concepts)
familiar with linux? ++ (1 shell script, several configuration files)
comfortable with the command line? ++ (demos are in git and easily accessible with a text reader)
familiar with standard relational databases? (oracle, mysql, mssql)
familiar with configuring java application servers? (wildfly, tomcat)
have you ever deployed cascade? +++
i'll be demoing with this mac, but steps should be easily reproducible on a windows pc and linux pc
what is docker? [docker vs VM image] [
"software container platform"
"Docker automates the repetitive tasks of setting up and configuring development environments"

6. Docker: What is it? “lightweight VMs”
what-docker
“Docker automates the repetitive tasks of setting up and configuring development environments”
Docker > Containers > Images
what is docker? [docker vs VM image] [
"software container platform"
"Docker automates the repetitive tasks of setting up and configuring development environments”
I like using the paraphrase: "lightweight VM"
Docker has it roots in cgroups and LinuX Container (LXC) which started back in 2008
2013 Docker emerged as container management tool which used LXC to implement containers
Containers are described by a Dockerfile, this file tells docker how to build a container, what files are needed, what packages may need to be installed, etc. Docker utilizes a Docker Registry [ which makes it easy for anyone to share their container recipes (Dockerfiles)
what problem does it solve? (why?)
"works on my computer"
screenshot of onacid
i already deal with this for s, why would i want to deal with it in my development environment?
lighter than VMs
screenshot of waiting for windows to load in VMware?
VMs don't scale well:
decentralized university === lots of different environments:
IIS, Apache, Nginx
HTML, ColdFusion, PHP, ASP, Java
mysql, mssql, oracle
consistent, reproducible deployments
full stack portability

7. Docker: What is it? Beginning Concepts Container Dockerfile Registry
Images
Dockerfile
Registry
what problem does it solve? (why?)
"works on my computer"
screenshot of onacid
i already deal with this for s, why would i want to deal with it in my development environment?
lighter than VMs
screenshot of waiting for windows to load in VMware?
VMs don't scale well:
decentralized university === lots of different environments:
IIS, Apache, Nginx
HTML, ColdFusion, PHP, ASP, Java
mysql, mssql, oracle
consistent, reproducible deployments
full stack portability

8. Learn By Examples / Demos

9. Describe steps to install app Leverage Docker Hub
Demo 1 Docker + tomcat
Dockerfile
Start from a base image
Describe steps to install app
Leverage Docker Hub
Registry where Dockerfiles are published
hub.docker.com/_/tomcat/
Demo – 01 – Running tomcat in Docker
Docker operates by using a Dockerfile
This file tells docker how to build the container you want to run
Think of it as a cookbook, recipe, that docker will follow if it was to build a new machine for you to run your application
For any given application, this involves
Starting FROM a base image, think of this as a fresh server with a brand new linux distro installed on it
Then we use RUN to tell docker which commands to run to get our application installed
Screenshot on the right is the official Open JDK java Dockerfile published on Docker Hub
Utilizes Alpine Linux as the base image (super small distro ~30mb)
We’ll use the official tomcat builds to effectively skip most of these installation steps and start with an image ready to run tomcat so we can get on with running our application

10. We can use an official repository to build tomcat
Demo 1 Docker + tomcat
We can use an official repository to build tomcat
We’ll supply our own context.xml but more on that later
Our Dockerfile will now be really short
We start FROM the official tomcat dockerfile repository with the 8-alpine tag, this tell docker to start by first downloading the container that builds a container with open jdk and tomcat 8
We can use the COPY command to replace files in the container with files we have on our host machine, in this case, maybe we want to give tomcat our own version of context.xml
(this is one of the files that is required to be customized with database connection info when running cascade, but more on that in a bit)
We can build this container with this dockerfile directly using the docker build command, but then we’d just have a vanilla install of tomcat
We would still have to package our own web app and then use the tomcat manager to deploy it to tomcat, let’s have docker do that for us!

11. Demo 1 Docker + tomcat
File structure and resulting cli for docker to get us up and running
We have a simple web app here, called “publish”, it’s a very small web application, with a single index.html file
Important things to note:
- this file and parent directory lives on our host machine (this laptop)
- we will utilize a docker volume to share this local directory with our docker container
- this will allow us to have access to this web app folder after we’ve “launched” our container

12. Docker build -t my-tomcat
Demo 1 Docker + tomcat
Docker build -t my-tomcat
This will tell docker to create a new container and name it “my-tomcat”
Then you can run this container by name
Docker run … my-tomcat
Will still need the –it, –p and –v arguments
We will see a better way to do this in demo 3
Instead, we can use docker build to create a new container with our local dockerfile
-t names the container so we can do:
Docker run …. <container_name>

13. Demo 1 Docker + tomcat
Demo slide of tomcat running locally with the copied publish

14. ENV – environment variables Strategy for defining configuration
Demo 2 Docker + mysql
ENV – environment variables
Strategy for defining configuration
Demo 2 - Persisting data
Containers are meant to be stateless, transient, ephemeral
-v in last demo
When we want to container to persist data, we utilize data volumes
hub.docker.com/r/mysql/mysql-server/
Official builds often use environment variables as a shorter way of configuring your container without having to use the COPY command to replace files
- remember that changes to the file structure of your container will require an extra image being added to your container being built
- environment variables offer a shortcut around this
This is a strategy that is often used in local development with docker, but security should strongly be considered when using this in a test or production environment
To get our

15. Demo 2 Docker + mysql
File structure and resulting cli for docker to get us up and running
We have a simple web app here, called “publish”, it’s a very small web application, with a single index.html file
Important things to note:
- this file and parent directory lives on our host machine (this laptop)
- we will utilize a docker volume to share this local directory with our docker container
- this will allow us to have access to this web app folder after we’ve “launched” our container

16. docker build –t my-mysql docker run –it –p 3302:3306
Demo 2 Docker + mysql
docker build –t my-mysql
docker run –it –p 3302:3306
-v $(pwd)/mysql-data:/var/lib/mysql
my-tomcat
Breakdown of our tomcat.sh bash script
docker run: we are telling docker to run this container
-it : actually two arguments, -I is for interactive, which means this container will utilize the CLI’s standard input/output (STDIN/STDOUT/STDERR), -t will tell docker to use a pseudo-tty for this container
- this will allow us to stop the container much like we would stop any other process
-p: 8080:8080: Here we are mapping the container’s port 8080 with our host’s (laptop) port 8080, resulting into tomcat being accessible from our browser at
Tomcat:8-alpine
**this will only run the Dockerfile in the docker hub registry, nothing special here**

17. Demo 2 Docker + mysql Breakdown of our tomcat.sh bash script
docker run: we are telling docker to run this container
-it : actually two arguments, -I is for interactive, which means this container will utilize the CLI’s standard input/output (STDIN/STDOUT/STDERR), -t will tell docker to use a pseudo-tty for this container
- this will allow us to stop the container much like we would stop any other process
-p: 8080:8080: Here we are mapping the container’s port 8080 with our host’s (laptop) port 8080, resulting into tomcat being accessible from our browser at
-v: this is our volume mapping command
we are telling docker to create a volume container with our current directory/webapps and mount it to the /usr/local/tomcat/webapps directory inside the container
instead of seeing the regular default tomcat webapps folder that tomcat comes with in an vanilla install, tomcat will instead see our webapps folder with the publish webapp
tomcat:8-alpine: here we are telling it which repository/container to build

18. Tying it all together Items you will need
Demo 3 Docker + cascade
Tying it all together
Items you will need
Local development license from Hannon Hill
Cascade SQL seed script
Setting-up-the-database-MySQL-
Cascade Downloaded
Breakdown of our tomcat.sh bash script
docker run: we are telling docker to run this container
-it : actually two arguments, -I is for interactive, which means this container will utilize the CLI’s standard input/output (STDIN/STDOUT/STDERR), -t will tell docker to use a pseudo-tty for this container
- this will allow us to stop the container much like we would stop any other process
-p: 8080:8080: Here we are mapping the container’s port 8080 with our host’s (laptop) port 8080, resulting into tomcat being accessible from our browser at
-v: this is our volume mapping command
we are telling docker to create a volume container with our current directory/webapps and mount it to the /usr/local/tomcat/webapps directory inside the container
instead of seeing the regular default tomcat webapps folder that tomcat comes with in an vanilla install, tomcat will instead see our webapps folder with the publish webapp
tomcat:8-alpine: here we are telling it which repository/container to build

19. cascade.sql in mysql directory
Demo 3 Docker + cascade
context.xml
Modified per cascade instructions
help.hannonhill.com/hc/en-us/articles/ Installation-using-the-ZIP-file-
cascade.sql in mysql directory
COPY ./cascade.sql /docker-entrypoint- initdb.d/db.sql
ROOT added to tomcat/webapps directory
This is ROOT.zip downloaded from hannonhill.com
docker-compose.yml - ???
We are pretty much using the previous examples without change
The context.xml I hinted at in our first demo is just the cascade configured context.xml file
ROOT in tomcat/webapps is the cascade we downloaded from hannonhill.com, we don’t need to make any modifications to this directory
And last but not least, docker-compose.yml

20. Updated tomcat Dockerfile New COPY addition
Demo 3 Docker + cascade
Updated tomcat Dockerfile
New COPY addition
Our Dockerfile will now be really short
We start FROM the official tomcat dockerfile repository with the 8-alpine tag, this tell docker to start by first downloading the container that builds a container with open jdk and tomcat 8
We can use the COPY command to replace files in the container with files we have on our host machine, in this case, maybe we want to give tomcat our own version of context.xml
(this is one of the files that is required to be customized with database connection info when running cascade, but more on that in a bit)
We can build this container with this dockerfile directly using the docker build command, but then we’d just have a vanilla install of tomcat
We would still have to package our own web app and then use the tomcat manager to deploy it to tomcat, let’s have docker do that for us!

21. Demo 3 Docker + cascade
What is docker compose?
Containers should follow the single responsibility rule
Compose is a tool for defining and running multi-container Docker applications
Allows us to also describe our runtime arguments (-v, -p, etc)
The last thing we want to do is make one big Dockerfile describing our mysql and tomcat application.
Since containers are cheap, we can separate our concerns and define each application block in it’s own container
Compose is a tool for defining and running multi-container Docker applications
We can then use docker compose commands to bring up or down our entire application stack (or even parts of the stack)
Things to note here:
The service names have meaning, we can instruct docker compose to bring up a single service using these names
docker-compose up tomcat
Or just to build when we make changes: docker-compose build tomcat
These names are just used by docker-compose, docker will generate a container specific name
Links: this sets up service discovery, this is the real magic
Using link: mysql:mysql in the tomcat service tells docker to make sure the tomcat container can talk with our mysql container using the name “mysql”
This allows us to setup our database connection to cascade inside our context.xml using the host address: mysql

22. docker-compose build docker-compose up Demo 3 Docker + cascade
Breakdown of our tomcat.sh bash script
docker run: we are telling docker to run this container
-it : actually two arguments, -I is for interactive, which means this container will utilize the CLI’s standard input/output (STDIN/STDOUT/STDERR), -t will tell docker to use a pseudo-tty for this container
- this will allow us to stop the container much like we would stop any other process
-p: 8080:8080: Here we are mapping the container’s port 8080 with our host’s (laptop) port 8080, resulting into tomcat being accessible from our browser at
Tomcat:8-alpine
**this will only run the Dockerfile in the docker hub registry, nothing special here**

23. To run out last demo we need only to run: docker-compose up
Demo 3 Docker + cascade
To run out last demo we need only to run:
docker-compose up

24. Wrap-Up / More Resources

25. Where do we go from here? Dockerize one or your environments!
Docker Hub is your friend
Official Docker Newsletter
Docker Captains Network
Dockercon on YouTube
Today’s demos
Best next steps is to try it yourself!
- My initial steps was utilizing docker to replicate our wordpress setup, but I first just started with nginx and php for locallly testing some php files
- Searching for a reading other people’s dockerfiles is the best way to use docker hub
Docker puts out a weekly newsletter, not just highlighting their latest developments, but often featuring HOWTO tutorials and blog posts from the community
Also gives a good calendar on upcoming meetups
Docker’s evangelists are called Docker Captains. They are usually very prolific on the web, sharing their own projects via blog posts and videos
For the past couple of years, DockerCon, the yearly convention held by Docker livestream on youtube and are also a great place to learn

26. Questions?
and Thanks!