ARO-RP/docs/instancemetadata.md

Documentation is a work in progress.

# aro deploy

## Run via ADO

Environment is picked up from instance metadata endpoint, no env vars are required to be set.

## Run via Ev2

Ev2 will run `aro deploy` in ACI which cannot access instance metadata endpoint (169.254.169.254).  We have all the info needed already so we make it available via environment variables.  In addition, a variable indicating we're running in Ev2 is required to ensure current non-Ev2 behavior is not impacted.

Environment variables you **must** set:
* AZURE_EV2: any value other than empty string
* AZURE_ENVIRONMENT: the cloud environment name from go-autorest environment names
* AZURE_SUBSCRIPTION_ID: the target subscription ID
* AZURE_TENANT_ID: the target tenant ID
* LOCATION: the target location
* RESOURCEGROUP: the target resource group name

Environment variables you may **optionally** set:
* HOSTNAME_OVERRIDE: in case default behavior doesn't give a value we want for hostname, pass in an override here.  This can happen when running `aro deploy` inside an Azure Conainer Instance (ACI) where the hostname is not meaningful and we wish to use the host's hostname.
Support creating InstanceMetadata from env In Ev2 deployments the deployer is running in Azure Container Instance (ACI) and does _not_ have access to the instance metadata we have used to date. But we have the info to populate env vars. This PR adds a path to use env vars when AZURE_EV2 is set to non-empty value. Includes pkg/util/env to enable testing with mocks. 2021-06-04 15:22:25 +03:00			`Documentation is a work in progress.`

			`# aro deploy`

			`## Run via ADO`

			`Environment is picked up from instance metadata endpoint, no env vars are required to be set.`

			`## Run via Ev2`

			Ev2 will run `aro deploy` in ACI which cannot access instance metadata endpoint (169.254.169.254). We have all the info needed already so we make it available via environment variables. In addition, a variable indicating we're running in Ev2 is required to ensure current non-Ev2 behavior is not impacted.

			`Environment variables you must set:`
			`* AZURE_EV2: any value other than empty string`
			`* AZURE_ENVIRONMENT: the cloud environment name from go-autorest environment names`
			`* AZURE_SUBSCRIPTION_ID: the target subscription ID`
			`* AZURE_TENANT_ID: the target tenant ID`
			`* LOCATION: the target location`
			`* RESOURCEGROUP: the target resource group name`

			`Environment variables you may optionally set:`
Feedback from review Updated mock to simplify things. Updated unit tests to be more robust. 2021-06-08 15:45:59 +03:00			* HOSTNAME_OVERRIDE: in case default behavior doesn't give a value we want for hostname, pass in an override here. This can happen when running `aro deploy` inside an Azure Conainer Instance (ACI) where the hostname is not meaningful and we wish to use the host's hostname.