adding spec tests

README.md

@@ -1,6 +1,32 @@
 # vmpooler-provider-gce
 
-This is a WIP - do not use yet. Provider for GCE VMs in vmpooler.
+This is a provider for [VMPooler](https://github.com/puppetlabs/vmpooler) allows using GCE to create instances, disks,
+snapshots, or destroy instances for specific pools.
 
-Vm has a label 'pool' that represent the VMpooler OS/pool it is part of
-Boot disk had a label 'vm' that represent the vm_name it is attached to
+## Usage
+
+Include this gem in the same Gemfile that you use to install VMPooler itself and then define one or more pools with the `provider` key set to `gce`. VMPooler will take care of the rest.
+See what configuration is needed for this provider in the [example file](https://github.com/puppetlabs/vmpooler-provider-gce/blob/main/vmpooler.yaml.example).
+
+Examples of deploying VMPooler with extra providers can be found in the [puppetlabs/vmpooler-deployment](https://github.com/puppetlabs/vmpooler-deployment) repository.
+
+GCE authorization is handled via a service account (or personal account) private key (json format) and can be configured via
+
+1. GOOGLE_APPLICATION_CREDENTIALS environment variable eg GOOGLE_APPLICATION_CREDENTIALS=/my/home/directory/my_account_key.json
+
+
+### Labels
+This provider adds labels to all resources that are managed
+
+|resource|labels|note|
+|---|---|---|
+|instance|pool=$pool_name|for example pool=pool1|
+|disk|vm=$vm_name, pool=$pool_name|for example vm=foo-bar and pool=pool1|
+|snapshot|snapshot_name=$snapshot_name, vm=$vm_name| for example snapshot_name=snap1, vm=foo-bar|
+
+Also see the usage of vmpooler's optional purge_unconfigured_resources, which is used to delete any resource found that
+do not have the pool label, and can be configured to allow a specific list of unconfigured pool names. 
+
+## License
+
+vmpooler-provider-gce is distributed under the [Apache License, Version 2.0](http://www.apache.org/licenses/LICENSE-2.0.html). See the [LICENSE](LICENSE) file for more details.