(PUP-10772) Only accept msgpack if gem is installed

Previously the agent always advertised that it accepted the rich data msgpack
format (application/vnd.puppet.rich+msgpack) even if the agent didn't have the
msgpack gem installed locally. If the msgpack gem was installed on the server,
and the server selected the rich data msgpack format, then the agent would fail
to deserialize the catalog.

Now we call the superclass so the msgpack feature constraint is taken into
account. Note the "raw" msgpack format didn't have this issue because it didn't
override the "supported?" method.

Author: joshcooper

lib/puppet/network/formats.rb

@@ -255,7 +255,8 @@ def render(instance)
   end
 
   def supported?(klass)
-    klass == Puppet::Resource::Catalog &&
+    super &&
+      klass == Puppet::Resource::Catalog &&
       Puppet.lookup(:current_environment).rich_data?
   end
 end

spec/unit/http/service/compiler_spec.rb

@@ -131,6 +131,26 @@
       subject.post_catalog(certname, environment: 'production', facts: facts, checksum_type: %w[sha256 sha384])
     end
 
+    it 'does not accept msgpack by default' do
+      stub_request(:post, uri)
+        .with(headers: {'Accept' => 'application/vnd.puppet.rich+json, application/json, text/pson'})
+        .to_return(**catalog_response)
+
+      allow(Puppet.features).to receive(:msgpack?).and_return(false)
+
+      subject.post_catalog(certname, environment: environment, facts: facts)
+    end
+
+    it 'accepts msgpack & rich_json_msgpack if the gem is present' do
+      stub_request(:post, uri)
+        .with(headers: {'Accept' => 'application/vnd.puppet.rich+json, application/json, application/x-msgpack, text/pson'})
+        .to_return(**catalog_response)
+
+      allow(Puppet.features).to receive(:msgpack?).and_return(true)
+
+      subject.post_catalog(certname, environment: environment, facts: facts)
+    end
+
     it 'returns a deserialized catalog' do
       stub_request(:post, uri)
         .to_return(**catalog_response)
@@ -140,6 +160,35 @@
       expect(cat.name).to eq(certname)
     end
 
+    it 'deserializes the catalog from msgpack', if: Puppet.features.msgpack? do
+      body = catalog.to_msgpack
+      formatter = Puppet::Network::FormatHandler.format(:msgpack)
+      catalog_response = { body: body, headers: {'Content-Type' => formatter.mime }}
+
+      stub_request(:post, uri)
+        .to_return(**catalog_response)
+
+      _, cat = subject.post_catalog(certname, environment: 'production', facts: facts)
+      expect(cat).to be_a(Puppet::Resource::Catalog)
+      expect(cat.name).to eq(certname)
+    end
+
+    it 'deserializes the catalog from rich msgpack', if: Puppet.features.msgpack? do
+      body = Puppet.override(rich_data: true) do
+        catalog.to_msgpack
+      end
+
+      formatter = Puppet::Network::FormatHandler.format(:rich_data_msgpack)
+      catalog_response = { body: body, headers: {'Content-Type' => formatter.mime }}
+
+      stub_request(:post, uri)
+        .to_return(**catalog_response)
+
+      _, cat = subject.post_catalog(certname, environment: 'production', facts: facts)
+      expect(cat).to be_a(Puppet::Resource::Catalog)
+      expect(cat.name).to eq(certname)
+    end
+
     it 'returns the request response' do
       stub_request(:post, uri)
         .to_return(**catalog_response)