Add newrelic as an option to the PHP extensions installation

[DrowningElysium]

Is your feature request related to a problem? Please describe.
Hello for our project we use a service called newrelic. This has also been added in our composer.json which makes it so we need to have it locally too. I would love to be able to install this extension in Laradock.

If it can't be supported officially I love to get some instructions on how to add it myself. I wasn't able to find this out by looking at the docker file (I am new to docker).

Additional context
Installation instructions that I got:

echo 'deb http://apt.newrelic.com/debian/ newrelic non-free' | sudo tee /etc/apt/sources.list.d/newrelic.list
wget -O- https://download.newrelic.com/548C16BF.gpg | sudo apt-key add -
sudo apt-get update
sudo apt-get install newrelic-php5
sudo newrelic-install install

Docs about installation:
https://docs.newrelic.com/docs/agents/php-agent/installation/php-agent-installation-ubuntu-debian

Docs about preseeding:
https://docs.newrelic.com/docs/agents/php-agent/installationaphp-agent-installation-ubuntu-debian#preseeding

[DrowningElysium]

What I've tried adding to php-fpm/Dockerfile and workspace/Dockerfile is:

###########################################################################
# NEWRELIC:
###########################################################################

USER root

ARG INSTALL_NEWRELIC=false

RUN if [ ${INSTALL_NEWRELIC} = true ]; then \
 	echo 'deb http://apt.newrelic.com/debian/ newrelic non-free' | sudo tee /etc/apt/sources.list.d/newrelic.list \
	&& wget -O- https://download.newrelic.com/548C16BF.gpg | sudo apt-key add - \
	&& apt-get update -yqq \
	&& DEBIAN_FRONTEND=noninteractive apt-get -y install newrelic-php5 \
;fi

After installation I still get that the extension is not enabled. I've added it to the .env and set it to true.

Edit: I found the issue. I forgot to remove the sudo from the pipe commands.
Also wget can't be used and had to be replaced with curl.
Which results in the following:

###########################################################################
# NEWRELIC:
###########################################################################

USER root

ARG INSTALL_NEWRELIC=false

RUN if [ ${INSTALL_NEWRELIC} = true ]; then \
 	echo 'deb http://apt.newrelic.com/debian/ newrelic non-free' | tee /etc/apt/sources.list.d/newrelic.list \
	&& curl https://download.newrelic.com/548C16BF.gpg | apt-key add - \
	&& apt-get update -yqq \
	&& DEBIAN_FRONTEND=noninteractive apt-get -y install newrelic-php5 \
;fi

[calebanthony]

This is already a PR: #2755

[DrowningElysium]

My bad. I didn't see it at the time. But also there is an issue with the PR. And I am not sure if it is still gonna be fixed or merged.