Using test recordings to populate a development database

One of the more difficult tasks when developing for ManageIQ is when a feature requires some provider specific inventory to be present in your local database when you don’t have access to the provider.

Most providers have something called a “VCR Cassette” to aid in running spec tests without access to a real provider. It is a YAML file which “replays” HTTP calls back to a calling method making it appear that it is interacting with a real native provider.

While this is critical for running specs, we can also make use of this for development by treating it as an offline dump of real inventory data. It is possible to configure VCR in a development environment and use a VCR cassette when running a refresh, thereby creating inventory records in our development database from the data stored in the VCR.

VCR is fairly unforgiving, if any data doesn’t match it will throw an exception and fail the refresh so it is critical to set everything up the same way it would run in spec tests. Specifically, things like provider hostname/port/region and authentication userid/password have to match what is in the VCR cassette or the vcr gem won’t recognize the request.

For this example we’ll use an Amazon provider. We first have to create a “fake” Amazon provider to use for the VCR backed refresh.

vcr_region   = "us-east-1"
vcr_userid   = "AMAZON_CLIENT_ID"
vcr_password = "AMAZON_CLIENT_SECRET"

ems = ManageIQ::Providers::Amazon::CloudManager.create!(
  :name             => "AWS VCR",
  :provider_region  => vcr_region,
  :default_userid   => vcr_userid,
  :default_password => vcr_password,
  :zone             => Zone.default_zone

We can find these values by looking at the amazon provider’s vcr cassette file, src/manageiq/manageiq-providers-amazon/spec/vcr_cassettes/manageiq/providers/amazon/cloud_manager/refresher_inventory_object.yml

We can see that 'us-east-1' is used as the region in the URIs, and in the config/secrets.defaults.yml and spec/factories/ext_management_system.rb files we can see that AMAZON_CLIENT_ID and AMAZON_CLIENT_SECRET are used for the userid and password values for the authentication.

Now that we have our provider record created we can configure VCR and run the refresh:

require "vcr"
VCR.configure do |config|
  config.cassette_library_dir = ManageIQ::Providers::Amazon::Engine.root("spec/vcr_cassettes").to_s
  config.hook_into :webmock
VCR.use_cassette("manageiq/providers/amazon/cloud_manager/refresher_inventory_object") { EmsRefresh.refresh(ems) }

Each provider can have slight variances in the names of their VCR cassettes so it is best to review the spec tests in the provider you are trying to replicate.

Now you should have inventory in your database for this provider: ```ruby

ems.vms.count => 9 ems.miq_templates.count => 243 ems.orchestration_templates.count => 0 ems.cloud_networks.count
=> 5