Invoking Lambda using an external application

So far, we have seen how to integrate third-party services such as GitHub and Slack with Lambda functions. In this section, we will be looking into yet another simple example where an application is used to invoke a particular Lambda function.

The use case is pretty straightforward--we have a simple Node.js application that accepts any city's name as a parameter and as a response, provides you with the detailed weather conditions of that city. The city name is passed to the Lambda function in the form of an event using SNS. Once the event is provided to the function, it makes a call to an open sourced API called as openweather by passing the city name as a parameter. The API in turn returns the current temperature as well as other miscellaneous weather details of that city. If the current temperature of the city is greater than say 25 degrees, the function automatically sends a customized SNS email to the specific user. Sounds simple? Then let...