Description:
Installations of EDA might require to make outgoing connections through an http proxy.

• As user I want to import a project (http git) through an http_proxy
• As user I want to be able to configure an http proxy for my DE's

Implementation proposal:
DE's:
Most of libraries and applications supports the http_proxy and no_proxy environment variables, allowing the user to define these variables in the decision environments would cover most of cases. If the source plugin needs to define this value explicitily it can be managed as well through extra_vars or environment variables. So, regardless of this specific usecase, the solution seems to allow users to define custom environment variables for their activations/decision environments. In this case, the API and the UI must implement it.

PROJECTS:
Currently EDA runs git binary in the worker, the http proxy can be configured directly when executing the command or setting the environment variable http_proxy which is honored by git command.

Option 1: Take the value from the system environment. This would require the user to configure the proxy in the system or the installer could do it.

Option 2: The proxy can be defined at the ui when creating the project

Option 3: The proxy can be configured in the application settings.

I recommend a combination of option 1 and 3, since the http proxy usually has a global scope, if the installation requires a proxy, it would require it for every outgoing connection, but EDA should honor as well the http_proxy environment variable if it is defined in the system as widely adopted convention.

Honoring the XXX_proxy environment variables also affects the podman client.

Related discussions:
https://redhat-internal.slack.com/archives/C037PLP36M7/p1688557919966329
https://redhat-internal.slack.com/archives/C037PLP36M7/p1688596003611579