Add Terraform module to configure Azure Batch easily

[rchretien]

Summary

Terraform module that encapsulates Azure Batch's configuration with Docker-compatible nodes running a custom Docker image hosted on a private registry.

The usage is indicated as comment in the main.tf file hosted in the root directory.

Future improvement

• Make the number of default nodes dependent on the environment.
• Make the autoscale formula dependent on the environment.

[lsorber]

Thanks for the PR @rchretien! Please find some comments below.

[rchretien]

Here's the new version of the PR.

Providers' requirements are specified in a separate file called versions.tf and different outputs are now indicated (i.e. the pool_id, the login_server of the container registry, as well as the admin username/password) in the outputs.tf file.

The corpus of the module is also regrouped in the root folder.

Normally, the module is usable "as such", although one has to provide his own subscription ID as a parameter of the module (I don't how we can circumvent it).

[lsorber]

The module looks very good, thanks @rchretien! Only some details left now.

[rchretien]

Thanks @lsorber for your comments and for the review!

Here's the new version of the PR.

Every suggestion has been accepted.

I changed a bit my mind based on your comments and have therefore removed anything related to the creation of a private container registry or to the push of a Docker image from the module definition. The information (login_server, username and password) of the container registry (either pre-existing or created in a previous step of a CI/CD pipeline) is now provided as input variables. I think it can now smoothly integrate within a pipeline.

Should I add a README?