What does this PR do?

This PR introduces a new feature for (java) micronaut, spring, quarkus, (js) react, express, vue and (PHP) laravel detectors regarding port values set as env vars inside a dockerfile.

More detailed, after the check for locally set env vars (into the operating system), if there is no port value detected, we also check if those env vars are set inside a dockerfile. This dockerfile should be located inside the root dir or one level down.

In order to create this functionality we have created utils.GetValidPortsFromEnvDockerfile(path, []string{envVarNames}) which will try to get valid port numbers defined inside a dockerfile. Also the EnvVar struct is created:

type EnvVar struct {
	Name  string
	Value string
}

Additionally, for express.js detector we have updated the logic, so in case we have a port definition with OR operator we will return both values (env var and default). So for:

// env var PORT = 3000
var PORT = process.env.PORT || 8080
// Alizer should return []int{3000, 8080}

The necessary updates to the documentation are also included to this PR and along with this new feature we have created multiple test cases for existing and new code.

Which issue(s) does this PR fix

Fixes devfile/api#1223

PR acceptance criteria

Testing and documentation do not need to be complete in order for this PR to be approved. We just need to ensure tracking issues are opened.

• Unit/Functional tests

• Documentation

How to test changes / Special notes to the reviewer