Provide parallel_one_host_only via workers config file

docs/WritingTests.asciidoc

@@ -672,8 +672,8 @@ eventually workers can be held back for the cluster.
 It is possible to ensure that all jobs within the same _parallel_ cluster are
 executed on the same worker host. This is useful for connecting the SUTs without
 having to connect the physical worker hosts. Use `PARALLEL_ONE_HOST_ONLY=1` to
-enable this. Note that adding this setting in `workers.ini` has currently *no*
-effect.
+enable this. This setting can be applied as a test variable during the time
+of scheduling as well as in the worker configuration file `workers.ini`.
 
 WARNING: You need to provide enough worker slots on single worker hosts to fit
 an entire cluster. So this feature is mainly intended to workaround situations

etc/openqa/workers.ini

@@ -5,7 +5,10 @@
 [global]
 # space separated list of webuis to connect to (empty defaults to localhost)
 #HOST = http://openqa.example.host
+HOST = http://localhost:9526
 
+# Ensure that Multimachine jobs are scheduled on the same worker host.
+#PARALLEL_ONE_HOST_ONLY = 1
 # Specify a cache directory for assets and tests to sync them automatically via
 # http/rsync; the specified path is just an example but what you would usually
 # use on a normal setup
@@ -83,6 +86,15 @@
 
 # The section ids are the instance of the workers.
 # The key/value pairs will appear in vars.json
+[1]
+WORKER_CLASS = qemu_x86_64_staging,qemu_x86_64,tap
+
+[2]
+WORKER_CLASS = qemu_x86_64_staging,qemu_x86_64,tap
+#PARALLEL_ONE_HOST_ONLY = 1
+[3]
+WORKER_CLASS = qemu_x86_64_staging,qemu_x86_64,tap
+
 #[1]
 #WORKER_CLASS = 64bit-ipmi
 

lib/OpenQA/WebAPI/Controller/API/V1/Worker.pm

@@ -173,18 +173,17 @@ sub create {
     my ($self) = @_;
     my $validation = $self->validation;
     my @validation_params
-      = qw(cpu_arch cpu_modelname cpu_opmode cpu_flags mem_max isotovideo_interface_version websocket_api_version worker_class);
+      = qw(cpu_arch cpu_modelname cpu_opmode cpu_flags mem_max isotovideo_interface_version websocket_api_version worker_class parallel_one_host_only);
     $validation->required($_) for qw(host instance cpu_arch mem_max worker_class);
     $validation->optional($_)
-      for qw(cpu_modelname cpu_opmode cpu_flags isotovideo_interface_version job_id websocket_api_version);
+      for qw(cpu_modelname cpu_opmode cpu_flags isotovideo_interface_version job_id websocket_api_version parallel_one_host_only);
     return $self->reply->validation_error({format => 'json'}) if $validation->has_error;
 
     my $host = $validation->param('host');
     my $instance = $validation->param('instance');
     my $job_ids = $validation->every_param('job_id');
     my $caps = {};
     $caps->{$_} = $validation->param($_) for @validation_params;
-
     my $id;
     try {
         $id = $self->_register($self->schema, $host, $instance, $caps, $job_ids);

lib/OpenQA/Worker.pm

@@ -212,7 +212,7 @@ sub capabilities ($self) {
           = join(',', map { 'qemu_' . $_ } @{$supported_archs_by_cpu_archs{$caps->{cpu_arch}} // [$caps->{cpu_arch}]});
         # TODO: check installed qemu and kvm?
     }
-
+    $caps->{parallel_one_host_only} = $global_settings->{PARALLEL_ONE_HOST_ONLY} if exists $global_settings->{PARALLEL_ONE_HOST_ONLY};
     return $self->{_caps} = $caps;
 }
 

t/24-worker-overall.t

@@ -142,6 +142,16 @@ subtest 'capabilities' => sub {
     # clear cached capabilities
     delete $worker->{_caps};
 
+    subtest 'capabilities include PARALLEL_ONE_HOST_ONLY setting if present' => sub {
+	my $worker2 = OpenQA::Worker->new({instance => 2, verbose => 1});
+        my $capabilities2 = $worker2->capabilities;
+	# ignore keys which are not always present and also not strictly required anyways
+	delete $capabilities->{cpu_flags};
+	delete $capabilities->{cpu_opmode};
+	delete $capabilities->{cpu_modelname};
+        is $capabilities2->{parallel_one_host_only}, 1, 'capabilities contain expected information';
+    };
+
     subtest 'deduce worker class from CPU architecture' => sub {
         delete $global_settings->{WORKER_CLASS};
         $global_settings->{ARCH} = 'aarch64';

t/24-worker-settings.t

@@ -110,6 +110,22 @@ subtest 'instance-specific settings' => sub {
         },
         'global settings (instance 2)'
     ) or diag explain $settings2->global_settings;
+    my $settings3 = OpenQA::Worker::Settings->new(3);
+    is_deeply(
+        $settings3->global_settings,
+        {
+            CRITICAL_LOAD_AVG_THRESHOLD => 40,
+            GLOBAL => 'setting',
+            WORKER_HOSTNAME => '127.0.0.1',
+            WORKER_CLASS => 'qemu_aarch64',
+            LOG_LEVEL => 'test',
+            LOG_DIR => 'log/dir',
+	    PARALLEL_ONE_HOST_ONLY => 1,
+            RETRY_DELAY => 5,
+	    RETRY_DELAY_IF_WEBUI_BUSY => 60,
+        },
+        'global settings (instance 3)'
+    ) or diag explain $settings2->global_settings;
 };
 
 subtest 'settings file with errors' => sub {

t/data/24-worker-overall/workers.ini

@@ -7,3 +7,7 @@ LOG_LEVEL = debug
 
 [1]
 WORKER_CLASS = qemu_i386,qemu_x86_64
+
+[2]
+WORKER_CLASS = qemu_i386,qemu_x86_64
+PARALLEL_ONE_HOST_ONLY = 1

t/data/24-worker-settings/workers.ini

@@ -16,6 +16,10 @@ FOO = bar
 RETRY_DELAY = 10
 RETRY_DELAY_IF_WEBUI_BUSY = 120
 
+[3]
+WORKER_CLASS = qemu_aarch64
+PARALLEL_ONE_HOST_ONLY = 1
+
 [http://localhost:9527]
 HOST_SPECIFIC = setting (localhost)