added stop scripts and comments in terraform example

terraform/demo4-scale-out-lb/run-terraform.sh

@@ -1,5 +1,23 @@
 #!/bin/bash
+
+# initialization of terraform state and download openstack plugin/dependencies
 ./terraform init
+
+# show what will done
 ./terraform plan
+
+# let terraform create the resources specified in .tf file in same directory
 ./terraform apply
-./terraform destroy
+
+# you can also use "terraform apply -auto-approve" to prevent terraform from asking back whether it should proceed
+
+# among the benefits of terraform, is that is deploys the resources rather quick. It identifies dependencies and
+# deploys independent resources in parallel.
+# "terraform graph" creates a dependency graph of the resource specified in the .tf file
+# another benefit of terraform is, that it does the heavy lifting to support the APIs of multiple cloud
+# providers and supports way more features and cloud services than, e.g., libcloud, hence it's quite popular
+#
+# among the drawbacks however is, that it comes with its own definition language and does not offer the full
+# flexibility of a programming language. In this regard, libcloud, boto3, openstack-sdk etc. are way more flexible
+#
+# we discuss different cloud service deployment solutions and their pros/cons in the course

terraform/demo4-scale-out-lb/stop-terraform.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+# let terraform remove the resources specified in .tf file in same directory
+./terraform destroy
+
+# you can also use "terraform destroy -auto-approve" to prevent terraform from asking back whether it should proceed