[IT-3523] Document current process for testing AMIs

Document the current manual process used for testing changes to AMIs
used by service catalog products.

Author: ConsoleCatzirl

sceptre/scipool/README.md

@@ -31,6 +31,8 @@ Requirements:
 * Run `pre-commit install` to install the git hook.
 
 ## Testing
+
+### Pre-Commit
 As a pre-deployment step we syntatically validate our sceptre and
 cloudformation yaml files with [pre-commit](https://pre-commit.com).
 
@@ -40,6 +42,30 @@ execute the validations by running `pre-commit run --all-files`.
 Please install pre-commit, once installed the file validations will
 automatically run on every commit.
 
+### Functional Testing
+The process to test the functionality of an AMI and it's integration with our
+Service Catalog products is to first manually create a new AMI, then manually
+upload a new product template to S3, and finally create a test product in
+Service Catalog through a pull request to `organizations-infra`:
+
+1. Make local changes to the packer repo to update or modify the AMI.
+1. Run packer manually with admin credentials for the `itsandbox` account
+  to create a test AMI.
+1. Create an EC2 instance in the `itsandbox` account from the test AMI for any
+  initial system validation.
+1. Make local changes to `service-catalog-library` to update the desired template
+  to reference the test AMI.
+1. Manually upload the test template to S3 in the `itsandbox` account.
+1. Create a pull request for `organizations-infra` to add a new Service Catalog
+  product to `scipool-dev` with 'test' in the name.
+1. Provision the test product from http://sc-dev.sageit.org to validate AMI
+  integration with the product template
+1. Create a pull request for the packer repo to modify the AMI.
+1. Create a pull request for `service-catalog-library` to reference the new AMI.
+1. Create a pull request for `organizations-infra` to remove the test product and
+  update the target product with the new template version.
+1. Delete the manually-created resources from `itsandbox`.
+
 ## Issues
 * https://sagebionetworks.jira.com/projects/IT