Flask Docker Lab – Lesson 2

Lesson 2 – Setting up the dev environment

Lesson Overview

In this lesson, we will set up a Linux machine in AWS EC2 that will work like a developer’s desktop. On that machine, we will download, modify, and test code locally using docker containers.

Lesson

1. If you don’t already have a non-root, administrators AWS IAM user,
   • See http://docs.aws.amazon.com/IAM/latest/UserGuide/getting-started_create-admin-group.html for instructions and log in as that user (not root)
2. Create EC2 Admin Role to be used by our EC2 developer desktop
   • IAM > Roles > Create Role
   • Click Link – Select the service that will use this role – “EC2”
   • Click Link – Select your use case – “EC2” (top choice)
   • Push Button – Next: Permissions
   • Check Box – “AdministratorAccess”
   • Push Button – Next Review
   • Set – Role name – “EC2Admin”
   • Push Button – Create Role
3. Deploy AWS Linux AMI to EC2
   • AWS Console > EC2 > Instances
   • Select Region > **Oregon** (the lab is built for **us-west-2**)
   • Push Button – Launch Instances
   • Select Tab – Community AMIs
   • Search – **ami-50e19028**
   • Push Button – Select (next to image called: flask_docker_lab/developer_desktop-1525870042)
   • Check Box – **t2.large** (it costs about $0.09/hour to have a 8GB RAM desktop)
   • Push Button – Next: Configure Instance Details
   • IAM Role – Select – “EC2Admin” role we just created
   • Push Button – Next: Add Add storage
   • Push Button – Next: Add Tags
   • Push Button – Next: Configure Security Group
   • Update SSH rule – Add Rule – Type: “ssh”, Port “22”, Source: **”My IP”**
   • Push Button – Add Rule – Type: “Custom TCP Rule”, Port “5901”, Source: “My IP”, Description: “VNC”
   • Push Button – Review and Launch
   • Push Button – Launch
   • Keypair – create without keypair (we wont need it for this desktop)
   • Check Box – I acknowledge
   • Push Button – Launch Instance
   • Push Button – View Instance
   • Copy IPv4 Public IP address to clipboard
4. Wait a few minutes, then connect to AWS EC2 instance with VNC
   • OPTION A – Install Chrome VNC viewer extension
     • To install: go to chrome vnc viewer > Install
     • To launch: Chrome > Apps > VNC Viewer
     • Connect to : EC2 public_ip port: 5901 (ex 54.245.171.175:5901)
     • password is `dockerlab`
   • *OPTION B* – Via VNC Client (faster)
     • Download & Install the VNC viewer
     • Connect to EC2 public_ip port: 5901 (ex 54.245.171.175:5901)
     • password will be `dockerlab`
     • To improve the display –
     • right click on title bar > Properties
     • Set – Options Tab > Picture Quality – Medium
     • Click OK
5. Reset the linux user password and test AWS cli connectivity.
   • Open a terminal window Start > System Tools > LxTerminal
   • Make sure your aws cli is authorized to access your AWS account
   • aws s3 ls
   • This should list out any S3 buckets you have without error.
   • If your AWS IAM role is configured incorrectly, you will get an error
   • EXAMPLE OF ERROR:

     $ aws s3 ls 
     Unable to locate credentials. 
     You can configure credentials by running "aws configure".

6. Open Firefox in the VNC window and open this blog
   • Start > Internet > Firefox Web Browser
7. Go to Github and Fork the flask_docker_lab repository
   • Go to: https://github.com/cloudshiftstrategies/flask_docker_lab
   • Signin (or Signup to create a new user) – remember your username!
   • Click “Fork” on the top right of the page
   • This will create a copy of the flask_docker_lab code in your personal
   • github account
8. Link our travis-ci.org account to our github account.
   • login to [travis-ci.org](https://travis-ci.org/) with your github credentials
   • Authorize Travis-ci to communicate with github
   • Click on Your Name in top right > Accounts
   • Flick the switch next to the forked flask_docker_lab to enable travis builds
9. Clone your forked copy of the code
   • From your personal copy of the flask_docker_lab repository
   • click Clone or download
   • copy the repository url (https://github.com/${USER}/flask_docker_lab.git)
   • From a terminal in the developer desktop
     • (substitute user info below with your github username):   git clone https://github.com/YOUR_GITHUB_USERNAME/flask_docker_lab.git

       $ git clone http://github.com/peterb154/flask_docker_lab.git
       Cloning into 'flask_docker_lab'...
       remote: Counting objects: 239, done.
       remote: Compressing objects: 100% (191/191), done.
       remote: Total 239 (delta 66), reused 208 (delta 35), pack-reused 0
       Receiving objects: 100% (239/239), 409.02 KiB | 0 bytes/s, done.
       Resolving deltas: 100% (66/66), done.
       Checking connectivity... done.

10. Launch the code with docker-compose

    cd flask_docker_lab
    docker-compose build
    docker-compose up -d

11. Check out the app
    • From a browser inside of EC2 instance, go to
    • http://localhost:5000
12. Tweak the code using Atom
    1. Open atom ide by clicking Start > Programing > Atom
    2. Note: Be patient, it will take 30+ seconds to open Atom for the first time
    3. Navigate to flask_docker_lab > app > config.py – edit SITE_TITLE
    4. Hit CTRL-S to save changes
    5. Validate the the changes are in effect on our local docker image
    6. 

Lesson 2 Summary

In this lesson, we completed the following tasks:

1. Created an admin user in AWS console (never work as root)
2. Create an IAM role for an EC2 instance
3. Provisioned a developer’s Linux desktop into EC2
4. Connected to that desktop via VNC
5. Validated aws CLI & API connectivity using the role
6. Forked out project code from peterb154/flask_docker_lab
7. Connected travis-ci to our github flask_docker_lab project
8. Cloned our project code to the developers workstation
9. Launched a local docker container to run the code
10. Validated that the application runs on the local machine
11. Made the site our own, and validated the local changes

In Lesson 3 we’ll configure AWS infrastructure to host the application and configure travis-ci to be our continuous integration server.