fix(k8s-views-namespaces): filter metrics to prevent reporting double…

… cpu/memory

Most queries already use label matcher. The metric reports usage for each
individual image, and the whole pod which will result in incorrect reporting if
not filtered correctly.

Fixes: #60

dashboards/k8s-views-namespaces.json

@@ -143,7 +143,7 @@
           },
           "editorMode": "code",
           "exemplar": false,
-          "expr": "sum(rate(container_cpu_usage_seconds_total{namespace=~\"$namespace\", image!=\"\"}[$__rate_interval])) / sum(machine_cpu_cores)",
+          "expr": "sum(rate(container_cpu_usage_seconds_total{namespace=~\"$namespace\", image=\"\"}[$__rate_interval])) / sum(machine_cpu_cores)",
           "instant": true,
           "interval": "",
           "legendFormat": "",
@@ -214,7 +214,7 @@
             "uid": "${datasource}"
           },
           "exemplar": true,
-          "expr": "sum(container_memory_working_set_bytes{namespace=~\"$namespace\"}) / sum(machine_memory_bytes)",
+          "expr": "sum(container_memory_working_set_bytes{namespace=~\"$namespace\", image=\"\"}) / sum(machine_memory_bytes)",
           "interval": "",
           "legendFormat": "",
           "refId": "A"
@@ -475,7 +475,7 @@
           },
           "editorMode": "code",
           "exemplar": true,
-          "expr": "sum(rate(container_cpu_usage_seconds_total{namespace=~\"$namespace\"}[$__rate_interval]))",
+          "expr": "sum(rate(container_cpu_usage_seconds_total{namespace=~\"$namespace\", image=\"\"}[$__rate_interval]))",
           "interval": "",
           "legendFormat": "Real",
           "range": true,
@@ -574,7 +574,7 @@
           },
           "editorMode": "code",
           "exemplar": true,
-          "expr": "sum(container_memory_working_set_bytes{namespace=~\"$namespace\"})",
+          "expr": "sum(container_memory_working_set_bytes{namespace=~\"$namespace\", image=\"\"})",
           "interval": "",
           "legendFormat": "Real",
           "range": true,