updating create cluster to be idempotent

pipeline.yml

@@ -676,6 +676,7 @@ jobs:
   - get: configuration
     trigger: true
     passed: ['create-cluster']
+  - get: env-state-gcp
   - get: pcf-automation-source
   - <<: *interpolate
   - put: cluster-state-gcp
@@ -698,7 +699,7 @@ groups:
   - apply-product-changes
 - name: create-cluster
   jobs:
-  # - terraforming-k8s
+  - terraforming-k8s
   - create-cluster
 - name: destroy
   jobs:

tasks/create-cluster.yml

@@ -27,6 +27,14 @@ run:
     export PKS_PASSWORD="$(om --env env/${ENV_FILE} credentials --product-name pivotal-container-service --credential-reference .properties.uaa_admin_password -f secret)" 
     export PKS_API="$(./jq -r .pks_api_endpoint terraform-output/metadata)"
 
+    echo "checking if cluster exists"
+    set +e
+    ./pks-cli cluster "${CLUSTER_NAME}"
+    if [ $? -eq 0 ]; then
+      echo "cluster exists skipping creation"
+      exit 0  
+    fi
+    set -e
     echo "starting cluster creation"
     ./pks-cli login -a $PKS_API -u admin -p $PKS_PASSWORD -k
     ./pks-cli create-cluster "${CLUSTER_NAME}" -e "${CLUSTER_HOSTNAME}" -p small --wait