Add credentials.template and support custom INVENTORY

Testers may override the inventory and vars-file using the environment
variables 'INVENTORY' and 'VARS_FILE'.

test/integration/Makefile

+INVENTORY ?= inventory
+VARS_FILE ?= integration_config.yml
+
 all: non_destructive destructive check_mode test_hash
 
 non_destructive:
-	ansible-playbook non_destructive.yml -i inventory -e @integration_config.yml -v $(TEST_FLAGS)
+	ansible-playbook non_destructive.yml -i $(INVENTORY) -e @$(VARS_FILE) -v $(TEST_FLAGS)
 
 destructive:
-	ansible-playbook destructive.yml -i inventory -e @integration_config.yml -v $(TEST_FLAGS)
+	ansible-playbook destructive.yml -i $(INVENTORY) -e @$(VARS_FILE) -v $(TEST_FLAGS)
 
 check_mode:
-	ansible-playbook check_mode.yml -i inventory -e @integration_config.yml -v --check $(TEST_FLAGS)
+	ansible-playbook check_mode.yml -i $(INVENTORY) -e @$(VARS_FILE) -v --check $(TEST_FLAGS)
 
 test_hash:
-	ANSIBLE_HASH_BEHAVIOUR=replace ansible-playbook test_hash.yml -i inventory -v -e '{"test_hash":{"extra_args":"this is an extra arg"}}'
-	ANSIBLE_HASH_BEHAVIOUR=merge ansible-playbook test_hash.yml -i inventory -v -e '{"test_hash":{"extra_args":"this is an extra arg"}}'
+	ANSIBLE_HASH_BEHAVIOUR=replace ansible-playbook test_hash.yml -i $(INVENTORY) -v -e '{"test_hash":{"extra_args":"this is an extra arg"}}'
+	ANSIBLE_HASH_BEHAVIOUR=merge ansible-playbook test_hash.yml -i $(INVENTORY) -v -e '{"test_hash":{"extra_args":"this is an extra arg"}}'
 
 cloud: amazon rackspace
 
@@ -25,17 +28,17 @@ rackspace_cleanup:
 	@#python cleanup_rax.py -y
 
 credentials.yml:
-	@echo "No credentials.yml file found.  A file named 'credentials.yml' is needed to provide credentials needed to run cloud tests."
+	@echo "No credentials.yml file found.  A file named 'credentials.yml' is needed to provide credentials needed to run cloud tests.  See sample 'credentials.template' file."
 	@exit 1
 
 amazon: credentials.yml
-	ansible-playbook amazon.yml -i inventory -e @integration_config.yml -e @credentials.yml -v $(TEST_FLAGS) ; \
+	ansible-playbook amazon.yml -i $(INVENTORY) -e @$(VARS_FILE) -e @credentials.yml -v $(TEST_FLAGS) ; \
     RC=$$? ; \
     make amazon_cleanup ; \
     exit $$RC;
 
 rackspace: credentials.yml
-	ansible-playbook rackspace.yml -i inventory -e @integration_config.yml -e @credentials.yml -v $(TEST_FLAGS) ; \
+	ansible-playbook rackspace.yml -i $(INVENTORY) -e @$(VARS_FILE) -e @credentials.yml -v $(TEST_FLAGS) ; \
     RC=$$? ; \
     make rackspace_cleanup ; \
     exit $$RC;

test/integration/credentials.template

+---
+# AWS Credentials
+ec2_access_key: FIXME
+ec2_secret_key: FIXME
+
+# GITHUB Credentials
+github_ssh_private_key: "{{ lookup('env','HOME') }}/.ssh/id_rsa"