Ensure that the runner can log duration even without a vm

We expect having a VM where we log duration in the runner, but this
doesn't seem to always be the case. I've noticed several crashes in the
web logs.

If a webhook is delivered while the runner is being destroyed, the
runner's VM may have already been deleted.

model/github_runner.rb

@@ -35,9 +35,12 @@ def display_state
  end
 
  def log_duration(message, duration)
- values = {ubid: ubid, label: label, repository_name: repository_name, duration: duration, vm_ubid: vm.ubid, arch: vm.arch, cores: vm.cores}
- values[:vm_host_ubid] = vm.vm_host.ubid if vm.vm_host
- values[:vm_pool_ubid] = VmPool[vm.pool_id].ubid if vm.pool_id
+ values = {ubid: ubid, label: label, repository_name: repository_name, duration: duration}
+ if vm
+ values.merge!(vm_ubid: vm.ubid, arch: vm.arch, cores: vm.cores)
+ values[:vm_host_ubid] = vm.vm_host.ubid if vm.vm_host
+ values[:vm_pool_ubid] = VmPool[vm.pool_id].ubid if vm.pool_id
+ end
  Clog.emit(message) { {message => values} }
  end
 

spec/model/github_runner_spec.rb

@@ -22,6 +22,12 @@
  github_runner.log_duration("runner_tested", 10)
  end
 
+ it "can log duration when does not have a vm" do
+ expect(github_runner).to receive(:vm).and_return(nil)
+ expect(Clog).to receive(:emit).with("runner_tested").and_call_original
+ github_runner.log_duration("runner_tested", 10)
+ end
+
  it "provisions a spare runner" do
  expect(Prog::Vm::GithubRunner).to receive(:assemble).with(github_runner.installation, repository_name: github_runner.repository_name, label: github_runner.label)
  .and_return(instance_double(Strand, subject: instance_double(described_class)))