Adding support for multiple vsphere providers

Refactoring the vmpooler.yaml format to support multiple providers.
The second level key under :providers: is a unique key name that
represents a provider that can be refered in the pool's parameter
called provider. The code is still backward compatible to support
the :vsphere: and :dummy: keys but in reality if you have more than
one vsphere configuration you would give them a different name. For
example :vsphere-pdx: and :vsphere-bfs: and the actual provider
class would be specified as a parameter called 'provider_class'.
See tests and examples for more information.

README.md

@@ -58,7 +58,7 @@ The following YAML configuration sets up two pools, `debian-7-i386` and `debian-
     provider: vsphere
 ```
 
-See the provided YAML configuration example, [vmpooler.yaml.example](vmpooler.yaml.example), for additional configuration options and parameters.
+See the provided YAML configuration example, [vmpooler.yaml.example](vmpooler.yaml.example), for additional configuration options and parameters or for supporting multiple providers.
 
 ### Running via Docker
 

lib/vmpooler/pool_manager.rb

@@ -694,14 +694,20 @@ module Vmpooler
       raise
     end
 
-    def create_provider_object(config, logger, metrics, provider_name, options)
+    # create a provider object based on the providers/*.rb class that implements providers/base.rb
-      case provider_name
+    # provider_class: needs to match a provider class in providers/*.rb ie Vmpooler::PoolManager::Provider::X
+    # provider_name: should be a unique provider name
+    #
+    # returns an object Vmpooler::PoolManager::Provider::*
+    # or raises an error if the class does not exist
+    def create_provider_object(config, logger, metrics, provider_class, provider_name, options)
+      case provider_class
       when 'vsphere'
         Vmpooler::PoolManager::Provider::VSphere.new(config, logger, metrics, provider_name, options)
       when 'dummy'
         Vmpooler::PoolManager::Provider::Dummy.new(config, logger, metrics, provider_name, options)
       else
-        raise("Provider '#{provider_name}' is unknown")
+        raise("Provider '#{provider_class}' is unknown for pool with provider '#{provider_name}'")
       end
     end
 
@@ -731,8 +737,28 @@ module Vmpooler
       # Create the providers
       $config[:pools].each do |pool|
         provider_name = pool['provider']
+        # The provider_class parameter can be defined in the provider's data eg
+        #:providers:
+        # :vsphere:
+        #  provider_class: 'vsphere'
+        # :another-vsphere:
+        #  provider_class: 'vsphere'
+        # the above would create two providers/vsphere.rb class objects named 'vsphere' and 'another-vsphere'
+        # each pools would then define which provider definition to use: vsphere or another-vsphere
+        #
+        # if provider_class is not defined it will try to use the provider_name as the class, this is to be
+        # backwards compatible for example when there is only one provider listed
+        # :providers:
+        #  :dummy:
+        #   filename: 'db.txs'
+        # the above example would create an object based on the class providers/dummy.rb
+        if $config[:providers].nil? || $config[:providers][provider_name.to_sym].nil? || $config[:providers][provider_name.to_sym]['provider_class'].nil?
+          provider_class = provider_name
+        else
+          provider_class = $config[:providers][provider_name.to_sym]['provider_class']
+        end
         begin
-          $providers[provider_name] = create_provider_object($config, $logger, $metrics, provider_name, {}) if $providers[provider_name].nil?
+          $providers[provider_name] = create_provider_object($config, $logger, $metrics, provider_class, provider_name, {}) if $providers[provider_name].nil?
         rescue => err
           $logger.log('s', "Error while creating provider for pool #{pool['name']}: #{err}")
           raise

lib/vmpooler/providers/vsphere.rb

@@ -35,6 +35,7 @@ module Vmpooler
           end
         end
 
+        # name of the provider class
         def name
           'vsphere'
         end

spec/unit/pool_manager_spec.rb

@@ -1754,7 +1754,7 @@ EOT
         it 'should call create_provider_object idempotently' do
           # Even though there are two pools using the vsphere provider (the default), it should only
           # create the provider object once.
-          expect(subject).to receive(:create_provider_object).with(Object, Object, Object, 'vsphere', Object).and_return(vsphere_provider)
+          expect(subject).to receive(:create_provider_object).with(Object, Object, Object, 'vsphere', 'vsphere', Object).and_return(vsphere_provider)
 
           subject.execute!(1,0)
         end
@@ -1774,6 +1774,50 @@ EOT
       end
     end
 
+    context 'creating multiple vsphere Providers' do
+      let(:vsphere_provider) { double('vsphere_provider') }
+      let(:vsphere_provider2) { double('vsphere_provider') }
+      let(:provider1) { Vmpooler::PoolManager::Provider::Base.new(config, logger, metrics, 'vsphere', provider_options) }
+      let(:provider2) { Vmpooler::PoolManager::Provider::Base.new(config, logger, metrics, 'secondvsphere', provider_options) }
+      let(:config) {
+        YAML.load(<<-EOT
+---
+:providers:
+  :vsphere:
+    server: 'blah1'
+    provider_class: 'vsphere'
+  :secondvsphere:
+    server: 'blah2'
+    provider_class: 'vsphere'
+:pools:
+  - name: #{pool}
+    provider: 'vsphere'
+  - name: 'secondpool'
+    provider: 'secondvsphere'
+EOT
+        )}
+
+      it 'should call create_provider_object twice' do
+        # The two pools use a different provider name, but each provider_class is vsphere
+        expect(subject).to receive(:create_provider_object).with(Object, Object, Object, "vsphere", "vsphere", Object).and_return(vsphere_provider)
+        expect(subject).to receive(:create_provider_object).with(Object, Object, Object, "vsphere", "secondvsphere", Object).and_return(vsphere_provider2)
+        subject.execute!(1,0)
+      end
+
+      it 'should have vsphere providers with different servers' do
+        allow(subject).to receive(:get_provider_for_pool).with(pool).and_return(provider1)
+        result = subject.get_provider_for_pool(pool)
+        allow(provider1).to receive(:provider_config).and_call_original
+        expect(result.provider_config['server']).to eq('blah1')
+
+        allow(subject).to receive(:get_provider_for_pool).with('secondpool').and_return(provider2)
+        result = subject.get_provider_for_pool('secondpool')
+        allow(provider1).to receive(:provider_config).and_call_original
+        expect(result.provider_config['server']).to eq('blah2')
+        subject.execute!(1,0)
+      end
+    end
+
     context 'modify configuration on startup' do
       context 'move vSphere configuration to providers location' do
         let(:config) {

vmpooler.yaml.example

@@ -32,6 +32,11 @@
 #   - insecure
 #     Whether to ignore any HTTPS negotiation errors (e.g. untrusted self-signed certificates)
 #     (optional: default true)
+#
+#   - provider_class
+#     For multiple providers, specify one of the supported backing services (vsphere or dummy)
+#     (optional: will default to it's parent :key: name eg. 'vsphere')
+#
 # Example:
 
   :vsphere:
@@ -39,6 +44,23 @@
     username: 'vmpooler'
     password: 'swimsw1msw!m'
 
+# If you want to support more than one provider with different parameters (server, username or passwords) you have to specify the
+# backing service in the provider_class configuration parameter for example 'vsphere' or 'dummy'. Each pool can specify
+# the provider to use.
+#
+# Multiple providers example:
+
+  :vsphere-pdx:
+    server: 'vsphere.pdx.company.com'
+    username: 'vmpooler-pdx'
+    password: 'swimsw1msw!m'
+    provider_class: 'vsphere'
+  :vsphere-bfs:
+    server: 'vsphere.bfs.company.com'
+    username: 'vmpooler-bfs'
+    password: 'swimsw1msw!m'
+    provider_class: 'vsphere'
+
 # :dummy:
 #
 # The dummy backing service is a simple text file service that can be used
@@ -417,6 +439,8 @@
 #     The name of the VM provider which manage this pool.  This should match
 #     a name in the :providers: section above e.g. vsphere
 #     (required; will default to vsphere for backwards compatibility)
+#     If you have more than one provider, this is where you would choose which
+#     one to use for this pool
 #
 #   - clone_target
 #     Per-pool option to override the global 'clone_target' cluster.