Validate volumes provided in the service configuration file

lib/cove/configuration/contracts/service_contract.rb

@@ -18,6 +18,13 @@ class ServiceContract < Dry::Validation::Contract
                   required(:target).filled(:integer)
                 end
               end
+              optional(:mounts).value(:array).each do
+                hash do
+                  required(:type).value(eql?: "volume")
+                  required(:source).filled(:string)
+                  required(:target).filled(:string)
+                end
+              end
             end
           end
         end

lib/cove/configuration/service.rb

@@ -64,7 +64,7 @@ def validate!
 
       def formatted_roles
         config["roles"].map do |role_name, role_config|
-          {name: role_name, container_count: role_config["container_count"], ingress: role_config["ingress"]}.compact
+          {name: role_name, container_count: role_config["container_count"], ingress: role_config["ingress"], mounts: role_config["mounts"]}.compact
         end
       end
     end

spec/cove/configuration/contracts/service_contract_spec.rb

@@ -126,5 +126,41 @@
         expect(result.success?).to eq(false)
       end
     end
+
+    context "mounts" do
+      it "succeeds when mounts are included" do
+        contract = Cove::Configuration::Contracts::ServiceContract.new
+        result = contract.call(service_name: "a", image: "b", roles: [{name: "web", mounts: [{type: "volume", source: "my-awesome-volume", target: "/data"}]}])
+        expect(result.success?).to eq(true)
+      end
+
+      it "fails when type is invalid" do
+        contract = Cove::Configuration::Contracts::ServiceContract.new
+        result = contract.call(service_name: "a", image: "b", roles: [{name: "web", mounts: [{type: "foo", source: "my-awesome-volume", target: "/data"}]}])
+        expect(result.errors[:roles][0][:mounts][0][:type]).to be_present
+        expect(result.success?).to eq(false)
+      end
+
+      it "fails when type is not included" do
+        contract = Cove::Configuration::Contracts::ServiceContract.new
+        result = contract.call(service_name: "a", image: "b", roles: [{name: "web", mounts: [{source: "my-awesome-volume", target: "/data"}]}])
+        expect(result.errors[:roles][0][:mounts][0][:type]).to be_present
+        expect(result.success?).to eq(false)
+      end
+
+      it "fails when source is not included" do
+        contract = Cove::Configuration::Contracts::ServiceContract.new
+        result = contract.call(service_name: "a", image: "b", roles: [{name: "web", mounts: [{type: "volume", target: "/data"}]}])
+        expect(result.errors[:roles][0][:mounts][0][:source]).to be_present
+        expect(result.success?).to eq(false)
+      end
+
+      it "fails when target is not included" do
+        contract = Cove::Configuration::Contracts::ServiceContract.new
+        result = contract.call(service_name: "a", image: "b", roles: [{name: "web", mounts: [{type: "volume", source: "my-awesome-volume"}]}])
+        expect(result.errors[:roles][0][:mounts][0][:target]).to be_present
+        expect(result.success?).to eq(false)
+      end
+    end
   end
 end