cs-dora-demo

Demo for the for csm's and others to simulate the customer experience getting started with LaunchDarkly. This assumes some knowledge of git and github as a place to store and update code, but tries to walk through the python setup with some specificity.

Disclosure - the instrucitons for running this have been written using macOS and python10 as a reference point, this may result in some mismatch is trying to build on a windows/linux machine or with other software.

Overview

1. Get your environment set up
2. Get your code running WITHOUT a flags
3. Get your code running WITH a flag
4. Expand

Access Needed

• If you are on mac, make sure you have access to git. Else run xcode-select --install
• You will need launchDarkly github access and the ability to pull down the local repo
  • https://github.com/cgreenld/csm-dora-demo is the link
  • SSO access to github is required through Okta
• An editor, I recommend Visual Studio Code for this
  • https://code.visualstudio.com/download
  • once instlled look for the extensions tab on the left hand side. Here add the python extension to vscode, this will make developement and management easier
  • There is also an extension for LaunchDarkly that I would recommend adding as well
    • to full utalize this, you will need to add an environment key. I would do this after completing the inital run and flagging.
• Virtualized Environment Intro: https://towardsdatascience.com/virtual-environments-104c62d48c54
• Python Installed
• NOTE: Tech stacks vary from company to company, not everyone will use python or flask. However, these tools will help you quickly get to the core of our product - the flag.

Running the code

• It is normal to run into issues here, especially the first time. Don't be afraid to reference the channel: cs-dev-sandbox

• You will want an up to date python version, the following is a gernal template for the steps to get started. See references for more info

  • Install python 3 (I am using python 3.10 to set this up first)
  • install brew and pyenv
  • validate by running python --version and you should see a python 3 version out put

• once you have python set up, you will want to create a "virtual environemtn" this is like a folder you python code can run in

  • cd into the doraProject folder
  • python -m venv venv
    • create the environment
  • source venv/bin/activate
    • activate the environment
    • at this point you should see something like "python 3.10.1 ('venv':venv) in the lower left hand side of your screen
    • if you are seeing unrelated errors, try another env through vscode
    • https://techinscribed.com/python-virtual-environment-in-vscode/ in case you get stuck
  • pip install [your library here]
  • NOTE: a good way to try and verify this set up, before pip installing everything, is to try and run the code. You should see an error referencing a module missing, pip install that module, then run again to see if the error is still there. This will allow you to validate your flow.

• Environment is activated and libraries are installed, you can hit play in the upper right hand corner with the dorah.py open. This will run your dorah.py

  • pay attention to the output in the terminal below, this will give you a url to see you locally hosted app running!

• References:

  • https://medium.com/@jtpaasch/the-right-way-to-use-virtual-environments-1bc255a0cba7
  • https://opensource.com/article/20/4/pyenv
  • https://www.macworld.co.uk/how-to/python-coding-mac-3635912/
  • https://code.visualstudio.com/docs/python/environments
  • https://mnzel.medium.com/how-to-activate-python-venv-on-a-mac-a8fa1c3cb511

Let's add a Flag and make sure it is initalized

• For reference
  • You will be using the python SDK: https://docs.launchdarkly.com/sdk/server-side/python
• Open dorah.py
  • stop the code if it is still running (ctrl + C)
  • You will find a few comments
    • inline comments are denoted in python with a "#"
    • Multiline comments are denoted with a """ at the beginning and end
  • These will have the string STEP #: [Instructions] with some context on what is going on
  • This will let you know what lines to uncomment, and what the python code is doing to interact with Launchdarkly
  • let's run the code again once you have added LaunchDarkly back into the mix, keep an eye on the terminal to verify implimenenation!
• YOU HAVE GATHERED A FLAG!!
  • congratulations, now it is up to you to find some funcationality to turn on and off, maybe change where a link takes you based on a flag???

Advanced Topics

• Python management
  • https://medium.com/@jtpaasch/the-right-way-to-use-virtual-environments-1bc255a0cba7
  • requirments.txt is what is going to keep track of the things we need to run this code
  • this venv will allows us to manage that more or less in a containted space