oryx is running the composer install command by default

[AG-Abhirup]

While Doing the deployment via Azure WebApp’s Deployment Center its brings in a file oryx

Which enable PHP to run the composer.

Refer:

Oryx/doc/runtimes/php.md

Line 71 in 4644e4c

1. Run custom command or script if specified by `PRE_BUILD_COMMAND` or `PRE_BUILD_SCRIPT_PATH`.

The PHP toolset will run when the following conditions are met:

composer.json file exists in the root of the repository.

Files with .php extension in root of repository or in any sub-directories.

Build
We have the composer.json file available in the root folder hence its running the below step

Run php composer.phar install --ignore-platform-reqs --no-interaction if composer file found