Purpose

This project takes a Dropbox share URL, downloads its content, and puts it into an AWS S3 bucket. It then exposes a public URL for the S3 bucket and returns to the user.

The frontend is Slack's slash command.

The backend runs as an AWS lambda function.

Configuration

AWS Lambda

Create a lambda function

I manually created a lambda function first instead of using the deploy.yml to create one. It's possible to automate the lambda function creation, but the deploy.yml wasn't tested that way.

• go to AWS lambda and click "create a lambda function"
• under "select blueprint", select "blank function"
• click "Next"
• In "configure function"

  • name = max

  • runtime = python 2.7

  • handler = max.lambda_handler

  • role = I think this is what I did

    • select "create a custom role"
    • this brings you to another page
    • IAM role = create a new IAM Role
    • role name = fill in the role name, this is the role name to be used in deploy.yml later
    • click "Allow"

  • click "Next"

  • click "create function"

Configure a trigger

• go to the Lambda function page for max
• click on the "triggers tab"
• click "add a trigger"
• click on the dotted box and select "API gateway"
• I think the first time around, you'll have to create a "deployment stage"

Configure the API Gateway

• go to the AWS API Gateway page

• In the left most panel, select APIs -> LambdaMicroService -> Resources

• In the 2nd left most panel,

  • select /max,
  • from the "actions" dropdown,
  • select "create method"
  • select "POST"

• click on "POST", this brings the up the configuration for the "POST" method in the right panel

  • click on "integration request" (right, top)

  • expand "body mapping templates"

  • for "request body passthrough", select "when there are no templates defined"

  • under "content-type", add a mapping template

    • name = aplication/x-www-form-urlencoded, this what slack uses
    • I got a mapping template from https://gist.github.com/ryanray/668022ad2432e38493df to translate the request to json.

• scroll down and click on "save"

• deploy the changes we made to the API gateway

  • In the 2nd left most panel, next to max, click on the "Actions" dropdown,
  • select "Deploy API"

Slack

• Visit https://your_team_name.slack.com/services/new
• in the search bar, look for slash command
• click on "add configuration"
  • command = enter the name of your slash command, for example, /dropbox-download
  • URL = your lambda's URL
  • method = post
  • token = make a note of your token, you'll need it later
  • customize name = this is the name that will show up when the response is sent to you. For example, Dropbox Download
  • click on "Save integration"
• go back to your slack message, now you should be able to type /dropbox-download

Deploy

We use Ansible to automate deploy.

• Use ansible vault to create key.yml

  ansible-vault create key.yml

  It should one line:

  key: your_slack_token

• install python modules pytz and requests if not already installed These packages are needed for the function to run in lambda

  cd max # this is the main directory pip install pytz -t . pip install requests -t . # -t means to install into the given directory

  I have these version:

  pytz (2016.10) requests (2.12.4)

• install boto3 This is needed for Ansible to run locally. This is not needed in lambda as AWS supplies this module.

  pip install boto3

  I have

  boto3 (1.4.4)

• This is not tested, but I suspect the "role" in the "deploy aws" task of the ansible playbook needs to be created ahead of time.

• Deploy to AWS

  ansible-playbook -i localhost deploy.yml

Try out the slash command

• From your slack message, type /dropbox-download and copy/paste the Dropbox share URL.