Be sure to follow the instructions on the FaaS repo to deploy the Faas stack.
Get the CLI
You can install the faas-cli via brew install faas-cli or curl -sSL https://get.openfaas.com | sudo sh.
Build and deploy
Build and deploy your stack using the following commands:
$ faas-cli build -f text-to-speech.yml
$ faas-cli deploy -f text-to-speech.yml
Test
Using curl, you can send a string to the function to generate an MP3 of speech:
$ curl http://localhost:8080/function/text-to-speech \
-d 'This is a test of OpenFaaS text to speech!' > output.mp3
Also, you can optionally provide an X-Language header for a different language:
$ curl http://localhost:8080/function/text-to-speech \
-H 'X-Language: en-uk' \
-d 'This is a test of OpenFaaS text to speech!' > output.mp3
A list of supported languages is here.