This is a simple Mantil project template that will demonstrate a few Mantil concepts. It has a single Lambda function that holds a list of programming excuses (strings). API has methods for:
- getting number of items in the list
- clearing list
- loading into list from some URL
- getting random item from the list.
The first concept to show is the use of environment variables. In this case we will use
a project-wide environment variable. They can be also set at the individual stage
level which is a way to configure the same Lambda function to work differently in
different stages.
In our case we will use an environment variable to set
preload_url
which will be used during Lambda function cold start to load the initial list of
excuses. If preload_url is not set application will start with an empty list of
excuses.
The second concept is integration between UI and API. The project has a simple web page which will show random excuses, and on each click call API to get a new random excuse.
This example is created with Mantil. To download Mantil CLI on Mac or Linux use Homebrew
brew tap mantil-io/mantil
brew install mantil
or check direct download links.
To deploy this application you will need an AWS account.
Note: If this is the first time you are using Mantil you will need to install Mantil Node on your AWS account. For detailed instructions please follow the setup guide
mantil aws install
mantil new command has a flag --from for creating a new project from existing
template.
We will use this set of commands to create a project from a template, create new stage and deploy a project to the stage.
mantil new my-excuses --from https://github.com/mantil-io/template-excuses
cd my-excuses
mantil deploy
After that we can load the project web page at URL:
open $(mantil env --url)
The web page should look like:
Click on the excuse text to get a new random text.
Let's call some API methods:
mantil invoke excuses/count
mantil invoke excuses/random
We can use equivalent curl methods:
curl -X POST $(mantil env -u)/excuses/count
curl -X POST $(mantil env -u)/excuses/random
Explore the mantil logs command. It will show logs from the Lambda function
execution. The first form will show all logs. Second only REPORT lines.
mantil logs excuses
mantil logs excuses --filter-pattern "REPORT"
To clear current list execute:
mantil invoke excuses/clear
and check:
➜ mantil invoke excuses/random
Error: 500 Internal Server Error
X-Api-Error: no excuses
To load new list of excuses:
mantil invoke excuses/load --data '{"URL": "https://gist.githubusercontent.com/orf/db8eb0aaddeea92dfcab/raw/5e9a8958fce65b1fe8f9bbaadeb87c207e5da848/gistfile1.txt"}'
Some URLs for loading excuses lists:
index.html page from project /public folder is available at root URL. You can get the root URL by:
mantil env --url
or open in the browser with this terminal command:
open $(mantil env --url)
If you have jq (JSON processor), this is a useful one-liner to be ready when some manager comes into the room:
watch -t -n 5 'curl -s -X POST $(mantil env -u)/excuses/random | jq -r .Excuse'
Try to remove preload_url from config/environment.yml. After deploy function will always start with an empty list.
Run tests with:
mantil test
Explore test/excuses_test.go file to get the feeling of how to use integration tests in Mantil.
Remove created stage with:
mantil stage destroy development
After that all resources created in the AWS account are removed. You can delete this test project folder.
cd ..
rm -rf my-excuses