Drop empty tag values from metrics

InfluxDB throws an error when trying to store a list of tags where one
or more have an empty value.

1 files changed, 8 insertions, 0 deletions

diff --git a/spec/workers/metrics_worker_spec.rb b/spec/workers/metrics_worker_spec.rb
index f5650494c7c..2acd0f8ba30 100644
--- a/spec/workers/metrics_worker_spec.rb
+++ b/spec/workers/metrics_worker_spec.rb
@@ -30,6 +30,14 @@ describe MetricsWorker do
 
       expect(metrics).to eq([{ values: {}, tags: { 'foo' => 'bar\\=' } }])
     end
+
+    it 'drops empty tags' do
+      metrics = worker.prepare_metrics([
+        { 'values' => {}, 'tags' => { 'cats' => '', 'dogs' => nil }}
+      ])
+
+      expect(metrics).to eq([{ values: {}, tags: {} }])
+    end
   end
 
   describe '#escape_value' do