Perform docker prune if thin pool is exceeded (#23)

* Perform docker prune if thin pool is exceeded

* Check message correctly

* rename method

* Add tests for pool exception handling

* Raise after retry

* Remove parantheses

* Expect specific exception

lib/fastlane/plugin/mango/helper/docker_commander.rb

@@ -6,7 +6,9 @@ module Helper
     module DockerCommander
 
       def self.pull_image(docker_image_name:)
-        Actions.sh("docker pull #{docker_image_name}")
+        handle_thin_pool_exception do
+          Actions.sh("docker pull #{docker_image_name}")
+        end
       end
 
       def self.start_container(emulator_args:, docker_name:, docker_image:)
@@ -19,7 +21,9 @@ def self.start_container(emulator_args:, docker_name:, docker_image:)
         # Action.sh returns all output that the command produced but we are only
         # interested in the last line, since it contains the id of the created container.
         UI.important("Attaching #{ENV['PWD']} to the docker container")
-        Actions.sh("docker run -v $PWD:/root/tests --privileged -t -d #{emulator_args} #{docker_name} #{docker_image}").chomp
+        handle_thin_pool_exception do
+          Actions.sh("docker run -v $PWD:/root/tests --privileged -t -d #{emulator_args} #{docker_name} #{docker_image}").chomp
+        end
       end
 
       def self.stop_container(container_name:)
@@ -36,10 +40,27 @@ def self.disconnect_network_bridge(container_name:)
         # Do nothing if the network bridge is already gone
       end
 
+      def self.prune
+        Action.sh('docker system prune -f')
+      end
+
+      def self.handle_thin_pool_exception(&block)
+        begin
+          block.call
+        rescue FastlaneCore::Interface::FastlaneShellError => exception
+          retry_counter = retry_counter.to_i + 1
+          if exception.message =~ /Create more free space in thin pool/ && retry_counter < 2
+            prune
+            retry
+          else
+            raise exception
+          end
+        end
+      end
+
       def self.docker_exec(command:, container_name:)
         Actions.sh("docker exec -i #{container_name} bash -l -c \"#{command}\"") if container_name
       end
-
     end
   end
-end
+end

spec/docker_commander_spec.rb

@@ -62,6 +62,38 @@
     end
   end
 
+  describe '#handle_thin_pool_exception' do
+    it 'Raises when exception message is not related to thin pool' do
+      expect {
+        @docker_commander.handle_thin_pool_exception do
+          raise FastlaneCore::Interface::FastlaneShellError, 'some message'
+        end
+      }.to raise_error(FastlaneCore::Interface::FastlaneShellError, 'some message')
+    end
+
+    it 'Retries the command when the message is related to thin pool and raise if it fails after retry' do
+      expect(Fastlane::Actions).to receive(:sh).twice.with('test')
+
+      expect {
+        @docker_commander.handle_thin_pool_exception do
+          Fastlane::Actions.sh('test')
+          raise FastlaneCore::Interface::FastlaneShellError, 'Create more free space in thin pool or ...'
+        end
+      }.to raise_exception(FastlaneCore::Interface::FastlaneShellError)
+    end
+
+    it 'Calls prune just once when the message is related to thin pool and raise if initial command fails' do
+      expect(@docker_commander).to receive(:prune).once
+
+      expect {
+        @docker_commander.handle_thin_pool_exception do
+          raise FastlaneCore::Interface::FastlaneShellError, 'Create more free space in thin pool or ...'
+        end
+      }.to raise_exception(FastlaneCore::Interface::FastlaneShellError)
+    end
+
+  end
+
   describe '#docker_exec' do
     it 'executes commands inside docker if container name is specified' do
       expect(Fastlane::Actions).to receive(:sh).with("docker exec -i my_container bash -l -c \"do stuff\"")
@@ -73,4 +105,5 @@
       @docker_commander.docker_exec(command: 'do stuff', container_name: nil)
     end
   end
+
 end