Improve error resilience and handling

Timeouts are now handled correctly and the Runner automatically
creates the execution environment if it could not be found in
Poseidon. The runner is deleted locally if Poseidon returns
a bad request error.

spec/lib/runner/strategy/poseidon_spec.rb

@@ -16,11 +16,26 @@ describe Runner::Strategy::Poseidon do
       let(:response_status) { 400 }
 
       it 'raises an error' do
+        allow(Runner).to receive(:destroy).with(runner_id)
         expect { action.call }.to raise_error(Runner::Error::BadRequest, /#{error_message}/)
       end
     end
   end
 
+  # Only #copy_files and #execute_command destroy the runner locally in case
+  # of a BadRequest (400) response.
+  shared_examples 'BadRequest (400) destroys local runner' do
+    context 'when Poseidon returns BadRequest (400)' do
+      let(:response_body) { {message: error_message}.to_json }
+      let(:response_status) { 400 }
+
+      it 'destroys the runner locally' do
+        expect(Runner).to receive(:destroy).with(runner_id)
+        expect { action.call }.to raise_error(Runner::Error::BadRequest)
+      end
+    end
+  end
+
   # All requests handle a Unauthorized (401) response the same way.
   shared_examples 'Unauthorized (401) error handling' do
     context 'when Poseidon returns Unauthorized (401)' do
@@ -193,6 +208,7 @@ describe Runner::Strategy::Poseidon do
     end
 
     include_examples 'BadRequest (400) error handling'
+    include_examples 'BadRequest (400) destroys local runner'
     include_examples 'Unauthorized (401) error handling'
     include_examples 'NotFound (404) error handling'
     include_examples 'InternalServerError (500) error handling'
@@ -247,6 +263,7 @@ describe Runner::Strategy::Poseidon do
     end
 
     include_examples 'BadRequest (400) error handling'
+    include_examples 'BadRequest (400) destroys local runner'
     include_examples 'Unauthorized (401) error handling'
     include_examples 'NotFound (404) error handling'
     include_examples 'InternalServerError (500) error handling'

spec/models/runner_spec.rb

@@ -61,28 +61,81 @@ describe Runner do
     include_examples 'delegates method sends to its strategy', :attach_to_execution, nil
   end
 
-  describe '#request_id' do
-    it 'requests a runner from the runner management when created' do
+  describe 'creation' do
+    let(:user) { FactoryBot.create :external_user }
+    let(:execution_environment) { FactoryBot.create :ruby }
+    let(:create_action) { -> { described_class.create(user: user, execution_environment: execution_environment) } }
+
+    it 'requests a runner id from the runner management' do
       expect(strategy_class).to receive(:request_from_management)
-      described_class.create
+      create_action.call
     end
 
-    it 'sets the runner id when created' do
+    it 'returns a valid runner' do
       allow(strategy_class).to receive(:request_from_management).and_return(runner_id)
-      runner = described_class.create
-      expect(runner.runner_id).to eq(runner_id)
+      expect(create_action.call).to be_valid
     end
 
-    it 'sets the strategy when created' do
+    it 'sets the strategy' do
       allow(strategy_class).to receive(:request_from_management).and_return(runner_id)
-      runner = described_class.create
-      expect(runner.strategy).to be_present
+      strategy = strategy_class.new(runner_id, execution_environment)
+      allow(strategy_class).to receive(:new).with(runner_id, execution_environment).and_return(strategy)
+      runner = create_action.call
+      expect(runner.strategy).to eq(strategy)
     end
 
-    it 'does not call the runner management again when validating the model' do
+    it 'does not call the runner management again while a runner id is set' do
       expect(strategy_class).to receive(:request_from_management).and_return(runner_id).once
-      runner = described_class.create
-      runner.valid?
+      runner = create_action.call
+      runner.update(user: FactoryBot.create(:external_user))
+    end
+  end
+
+  describe '#request_new_id' do
+    let(:runner) { FactoryBot.create :runner }
+
+    context 'when the environment is available in the runner management' do
+      it 'requests the runner management' do
+        expect(strategy_class).to receive(:request_from_management)
+        runner.send(:request_new_id)
+      end
+
+      it 'updates the runner id' do
+        allow(strategy_class).to receive(:request_from_management).and_return(runner_id)
+        runner.send(:request_new_id)
+        expect(runner.runner_id).to eq(runner_id)
+      end
+
+      it 'updates the strategy' do
+        allow(strategy_class).to receive(:request_from_management).and_return(runner_id)
+        strategy = strategy_class.new(runner_id, runner.execution_environment)
+        allow(strategy_class).to receive(:new).with(runner_id, runner.execution_environment).and_return(strategy)
+        runner.send(:request_new_id)
+        expect(runner.strategy).to eq(strategy)
+      end
+    end
+
+    context 'when the environment could not be found in the runner management' do
+      let(:environment_id) { runner.execution_environment.id }
+
+      before { allow(strategy_class).to receive(:request_from_management).and_raise(Runner::Error::NotFound) }
+
+      it 'syncs the execution environment' do
+        expect(strategy_class).to receive(:sync_environment).with(runner.execution_environment)
+        runner.send(:request_new_id)
+      rescue Runner::Error::NotFound
+        # Ignored because this error is expected (see tests below).
+      end
+
+      it 'raises an error when the environment could be synced' do
+        allow(strategy_class).to receive(:sync_environment).with(runner.execution_environment).and_return(true)
+        expect { runner.send(:request_new_id) }.to raise_error(Runner::Error::NotFound, /#{environment_id}.*successfully synced/)
+      end
+
+      it 'raises an error when the environment could not be synced' do
+        allow(strategy_class).to receive(:sync_environment).with(runner.execution_environment).and_return(false)
+        expect { runner.send(:request_new_id) }.to raise_error(Runner::Error::NotFound, /#{environment_id}.*could not be synced/)
+      end
     end
   end