Updates docs for azure and pipeline related setup

doc/AzurePipelines.md

@@ -1,13 +1,54 @@
 # Azure Pipelines
 
 ## Pipeline Code
+
 This project uses CI/CD pipelines that are implemented as yaml code.
 They are declared in the following files.
+
 - `azure-pipelines.yml`
 
 These pipelines are divided in parameterized stages that are defined accross several files, all located under [`azure-pipleine/`](../azure-pipeline/).
 The more complex stages are also divided into several steps files, again all located under the azure-pipeline folder.
 
+## Azure setup
+
+### Global resource group
+
+The following needs to be setup in azure before any deployment can be done:
+
+- A resource group named "rg-global-<project_short_name>"
+- A storage account with a container
+  - Make sure all names are properly setup in the provider.tf file
+
+This global resource group is where we will store the terraform state.
+
+### Resource groups for each deployment environment
+
+The pipeline is setup to run as a loop for multiple environments (look at the environments parameter in file [`azure-pipleine/`](../azure-pipeline/environments_loop.yml)). A resource group has to be manually created beforehand for each environment, matching the environment name declared in the main.tf file, `"rg-<environment>-<project_short_name>"`.
+
+## Azure devops setup
+
+### Pipeline Library
+
+You must create a couple of libraries where some variables needed by the pipeline will be stored.
+
+- web-react-skeleton-azure (to store "global" values that won't change between each environment)
+  - ARM_SERVICE_CONNECTION_NAME
+  - PROJECT_SHORT_NAME
+- web-react-skeleton-\<env> (for environment specific values, like the API URL or a Google Analytics key)
+
+### Service connection
+
+Under `Project settings` -> `Pipelines`, go to service connections.
+
+Select `Azure resource manager` and then `Workload Identity federation (automatic)`. Make sure the service connection name matches ARM_SERVICE_CONNECTION_NAME from the library. **Do not select a resource group** (this will allow the service connection to create resources on all resource groups).
+
+## Possible issues
+
+When running the pipeline, if you get the following error:
+
+`Message="The subscription is not registered to use namespace 'Microsoft.Cdn'.`
 
-## Main Pipeline [azure-pipelines.yml](../azure-pipelines.yml)
+You can connect to the cloud shell on the azure portal and run the following command:
 
+`az provider register --namespace Microsoft.Cdn`