Add lines & bytes read to promtail dashboard.

Signed-off-by: Tom Wilkie <tom.wilkie@gmail.com>

production/loki-mixin/dashboards.libsonnet

@@ -146,12 +146,31 @@ local utils = import "mixin-utils/utils.libsonnet";
           utils.latencyRecordingRulePanel('cortex_gw_request_duration_seconds', [utils.selector.eq('job', '$namespace/cortex-gw')], extra_selectors=[utils.selector.eq('cluster', '$cluster')])
         )
       ),
+
       'promtail.json':
         g.dashboard('Loki / Promtail')
         .addTemplate('cluster', 'kube_pod_container_info{image=~".*promtail.*"}', 'cluster')
         .addTemplate('namespace', 'kube_pod_container_info{image=~".*promtail.*"}', 'namespace')
         .addRow(
-          g.row('promtail Reqs')
+          g.row('IO')
+          .addPanel(
+            g.panel('Bps') +
+            g.queryPanel(
+              'sum(rate(promtail_read_bytes_total{cluster="$cluster", job="$namespace/promtail"}[1m]))',
+              'logs read',
+            ) +
+            { yaxes: g.yaxes('Bps') },
+           )
+           .addPanel(
+            g.panel('Lines') +
+             g.queryPanel(
+              'sum(rate(promtail_read_lines_total{cluster="$cluster", job="$namespace/promtail"}[1m]))',
+              'lines read',
+            ),
+          )
+        )
+        .addRow(
+          g.row('Requests')
           .addPanel(
             g.panel('QPS') +
             g.qpsPanel('promtail_request_duration_seconds_count{cluster="$cluster", job="$namespace/promtail"}')