add external_labels support to promtail ksonnet

production/ksonnet/promtail/promtail.libsonnet

@@ -13,6 +13,7 @@ k {
       scheme: 'https',
       hostname: 'logs-us-west1.grafana.net',
       dataroot: '/var/lib/docker',
+      external_labels: {},
     },
 
 
@@ -37,6 +38,9 @@ k {
     ]),
 
   promtail_config:: {
+    client: {
+      external_labels: $._config.promtail_config.external_labels,
+    },
     scrape_configs: [
       {
         job_name: 'kubernetes-pods',
@@ -205,5 +209,5 @@ k {
     daemonSet.mixin.spec.template.spec.withServiceAccount('promtail') +
     $.util.configVolumeMount('promtail', '/etc/promtail') +
     $.util.hostVolumeMount('varlog', '/var/log', '/var/log') +
-    $.util.hostVolumeMount('varlibdockercontainers', $._config.promtail_config.dataroot + '/containers', '/var/lib/docker/containers', readOnly=true),
+    $.util.hostVolumeMount('varlibdockercontainers', $._config.promtail_config.dataroot + '/containers', $._config.promtail_config.dataroot + '/containers', readOnly=true),
 }