Add healthcheck page at /status/health

CHANGELOG.md

@@ -54,6 +54,7 @@
         - Add perl 5.38 support.
         - Add plain text template previews to /_dev/email. #5105
         - Add --exclude option to bin/open311-populate-service-list
+        - Add /status/health page to indicate service health.
     - Performance improvements:
         - Reduce database queries on shortlist page.
         - Provide ResultSet fallback translation in lookup.

perllib/FixMyStreet/App/Controller/Status.pm

@@ -4,6 +4,7 @@ use namespace::autoclean;
 
 use HTTP::Negotiate;
 use JSON::MaybeXS;
+use Try::Tiny;
 
 BEGIN { extends 'Catalyst::Controller'; }
 
@@ -46,7 +47,6 @@ sub index : Path : Args(0) {
         $chosen = 'html' unless $chosen;
     }
 
-    # TODO Perform health checks here
 
     if ($chosen eq 'json') {
         $c->res->content_type('application/json; charset=utf-8');
@@ -68,6 +68,31 @@ sub index : Path : Args(0) {
     return 1;
 }
 
+sub health : Path('health') : Args(0) {
+    my ($self, $c) = @_;
+
+    # Just do a very simple and inexpensive query to confirm DB connectivity
+    my $id = try {
+        $c->model('DB::Problem')->search(undef, {
+            columns => [ "id" ],
+            rows => 1,
+            order_by => { -desc => 'id' },
+        })->first->id;
+    } catch {
+        undef;
+    };
+
+    $c->res->content_type('text/plain; charset=utf-8');
+    $c->res->headers->header('Cache-Control' => 'max-age=0');
+    if ($id) {
+        $c->res->body("OK: $id");
+    } else {
+        $c->response->status("500");
+        $c->res->body("ERROR: Couldn't get last problem ID from DB");
+    }
+}
+
+
 __PACKAGE__->meta->make_immutable;
 
 1;

t/app/controller/status.t

@@ -0,0 +1,28 @@
+use FixMyStreet::TestMech;
+use Test::MockModule;
+
+
+ok( my $mech = FixMyStreet::TestMech->new, 'Created mech object' );
+
+my $surrey = $mech->create_body_ok(2242, 'Surrey County Council');
+(my $report) = $mech->create_problems_for_body(1, $surrey->id, 'Pothole', {
+    category => 'Potholes', cobrand => 'surrey',
+    latitude => 51.293415, longitude => -0.441269, areas => '2242',
+});
+
+
+subtest 'Health page returns 200 when things are OK' => sub {
+    $mech->get_ok('/status/health');
+    is $mech->content, 'OK: ' . $report->id, 'Got correct content for status page';
+    is $mech->res->code, 200, 'Got 200 for status page';
+};
+
+subtest 'Health page returns 500 when things are not OK' => sub {
+    my $rs = Test::MockModule->new('FixMyStreet::DB::ResultSet::Problem');
+    $rs->mock('first', sub { die 'DB error' });
+    $mech->get('/status/health');
+    is $mech->res->code, 500, 'Got 500 for status page';
+};
+
+
+done_testing();