Fixing doc for Spanner Kustomize overlay (GoogleCloudPlatform#1178)

* Fixing doc for Spanner Kustomize overlay

* link to the associated blog

* split spanner instance versus database provisioning for more clarity

Author: mathieu-benoit

Diff for: kustomize/README.md

@@ -73,6 +73,8 @@ Here is the list of the variations available as Kustomize components that you co
   - Enables Monitoring (Stats), Tracing, Profiler, and Debugger for various services within Online Boutique. The code removes the existing environment variables (`DISABLE_STATS`, `DISABLE_TRACING`, `DISABLE_PROFILER`, `DISABLE_DEBUGGER`) from appropriate YAML config files.
 - [**Integrate with Memorystore (redis)**](components/memorystore)
   - The default Online Boutique deployment uses the in-cluster `redis` database for storing the contents of its shopping cart. The Memorystore deployment variation overrides the default database with its own Memorystore (redis) database. These changes directly affect `cartservice`.
+- [**Integrate with Spanner**](components/spanner)
+  - The default Online Boutique deployment uses the in-cluster `redis` database for storing the contents of its shopping cart. The Spanner deployment variation overrides the default database with its own Spanner database. These changes directly affect `cartservice`.
 - [**Secure with Network Policies**](components/network-policies)
   - Deploy fine granular `NetworkPolicies` for Online Boutique.
 - [**Create Kubernetes Service Accounts**](components/service-accounts)

Diff for: kustomize/components/spanner/README.md

@@ -5,23 +5,29 @@ Using a fully managed database service outside your GKE cluster (such as [Google
 
 ## Provision a Spanner database
 
-To provision a Spanner database you can follow the following instructions:
+To provision a Spanner instance you can follow the following instructions:
 ```bash
 gcloud services enable spanner.googleapis.com
 
 SPANNER_REGION_CONFIG="<your-spanner-region-config-name>" # e.g. "regional-us-east5"
 SPANNER_INSTANCE_NAME=onlineboutique
-SPANNER_DATABASE_NAME=carts
 
 gcloud spanner instances create ${SPANNER_INSTANCE_NAME} \
-    --config ${SPANNER_REGION_CONFIG}
+    --description="online boutique shopping cart" \
+    --config ${SPANNER_REGION_CONFIG} \
+    --instance-type free-instance
+```
+_Note: With latest version of `gcloud` we are creating a free Spanner instance._
+
+To provision a Spanner database you can follow the following instructions:
+```bash
+SPANNER_DATABASE_NAME=carts
 
 gcloud spanner databases create ${SPANNER_DATABASE_NAME} \
     --instance ${SPANNER_INSTANCE_NAME} \
     --database-dialect GOOGLE_STANDARD_SQL \
-    --ddl-file ./src/cartservice/ddl/CartItems.ddl
+    --ddl "CREATE TABLE CartItems (userId STRING(1024), productId STRING(1024), quantity INT64) PRIMARY KEY (userId, productId); CREATE INDEX CartItemsByUserId ON CartItems(userId);"
 ```
-_Note: With latest version of `gcloud` you can create a free Spanner instance by leveraging the `--instance-type free-instance` parameter._
 
 ## Grant the `cartservice`'s service account access to the Spanner database
 
@@ -78,9 +84,13 @@ sed -i "s/SPANNER_DB_USER_GSA_ID/${SPANNER_DB_USER_GSA_ID}/g" components/spanner
 
 You can locally render these manifests by running `kubectl kustomize .` as well as deploying them by running `kubectl apply -k .`.
 
-## Note on Spanner connection environmental variables
+## Note on Spanner connection environment variables
 
 The following environment variables will be used by the `cartservice`, if present:
 - `SPANNER_INSTANCE`: defaults to `onlineboutique`, unless specified.
 - `SPANNER_DATABASE`: defaults to `carts`, unless specified.
-- `SPANNER_CONNECTION_STRING`: defaults to `projects/${SPANNER_PROJECT}/instances/${SPANNER_INSTANCE}/databases/${SPANNER_DATABASE}`. If this variable is defined explicitly, all other environmental variables will be ignored.
+- `SPANNER_CONNECTION_STRING`: defaults to `projects/${SPANNER_PROJECT}/instances/${SPANNER_INSTANCE}/databases/${SPANNER_DATABASE}`. If this variable is defined explicitly, all other environment variables will be ignored.
+
+## Resources
+
+- [Use Google Cloud Spanner with the Online Boutique sample apps](https://medium.com/google-cloud/f7248e077339)