GCE Credentials added

docs/topics/setup.rst

@@ -9,10 +9,44 @@ be provided in one of following ways:
 3. Configuration file
 
 Procuring access credentials
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-For Azure, Create service principle credentials from the following link : 
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+**Microsoft Azure**
+
+For Microsoft Azure, create service principle credentials following
+instructions from the link below:
 https://docs.microsoft.com/en-us/azure/azure-resource-manager/resource-group-create-service-principal-portal#check-azure-subscription-permissions
 
+**Google**
+
+For Google Compute Engine, create a service account following instructions
+from the link below:
+https://cloud.google.com/iam/docs/creating-managing-service-accounts#creating_a_service_account
+
+Once created, grant the account appropriate permissions for your use through
+roles, and create a key, choosing JSON format, when prompted. These
+credentials can then be used with CloudBridge through the variables shown
+in the sections below.
+
+The JSON credentials file will have a similar form to the example shown
+below, and can either be passed through an absolute path to the file, or
+through a variable containing the JSON dictionary itself.
+
+
+.. code-block:: json
+
+    {
+      "type": "service_account",
+      "project_id": "my-project",
+      "private_key_id": "b12321312441245gerg245245g42c245g254t425",
+      "private_key": "-----BEGIN PRIVATE KEY-----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\nXSrevYvoKCl09yhLNAnKD+QvT/YbshW/jibYXwdj\n-----END PRIVATE KEY-----",
+      "client_email": "service-name@my-project.iam.gserviceaccount.com",
+      "client_id": "13451345134513451345",
+      "auth_uri": "https://accounts.google.com/o/oauth2/auth",
+      "token_uri": "https://oauth2.googleapis.com/token",
+      "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
+      "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/service-name%40my-project.iam.gserviceaccount.com"
+    }
+
 
 Providing access credentials through environment variables
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -39,7 +73,7 @@ OS_PROJECT_NAME      OS_STORAGE_URL
 OS_REGION_NAME       OS_AUTH_TOKEN
 ===================  ==================
 
-**Azure**
+**Microsoft Azure**
 
 Note that managing resources in Azure requires a Resource Group. If a
 Resource Group is not provided as part of the configuration, cloudbridge will
@@ -63,6 +97,19 @@ AZURE_TENANT            AZURE_VM_DEFAULT_USER_NAME
                         AZURE_PUBLIC_KEY_STORAGE_TABLE_NAME
 ======================  ==================
 
+
+**Google**
+
+=======================  ==================
+Mandatory variables      Optional Variables
+=======================  ==================
+GCE_SERVICE_CREDS_FILE   GCE_PROJECT_NAME
+           or            GCE_DEFAULT_ZONE
+GCE_SERVICE_CREDS_DICT   GCE_REGION_NAME
+=======================  ==================
+
+
+
 Once the environment variables are set, you can create a connection as follows:
 
 .. code-block:: python
@@ -138,10 +185,11 @@ Providing access credentials in a file
 CloudBridge can also read credentials from a file on your local file system.
 The file should be placed in one of two locations: ``/etc/cloudbridge.ini`` or
 ``~/.cloudbridge``. Each set of credentials should be delineated with the
-provider ID (e.g., ``openstack``, ``aws``, ``azure``) with the necessary credentials
-being supplied in YAML format. Note that only one set of credentials per
-cloud provider type can be supplied (i.e., via this method, it is not possible
-to provide credentials for two different OpenStack clouds).
+provider ID (e.g., ``openstack``, ``aws``, ``azure``, ``gce``) with the
+necessary credentials being supplied in YAML format. Note that only one set
+of credentials per cloud provider type can be supplied (i.e., via this
+method, it is not possible to provide credentials for two different
+OpenStack clouds).
 
 .. code-block:: bash