Add variables in prometheus alerts

Change-Id: I1765fc6aa4a8c3da25330f19bb043ddbf548b9ad

linux/meta/prometheus.yml

@@ -1,44 +1,52 @@
-{% raw %}
 server:
   alert:
     AvgCPUUsageIdle:
-      if: 'avg_over_time(cpu_usage_idle{cpu="cpu-total"}[5m]) < 10'
+      if: avg_over_time(cpu_usage_idle{cpu="cpu-total"}[5m]) < {{ prometheus_server.get('alert', {}).get('AvgCPUUsageIdle', {}).get('var', {}).get('threshold', 10) }}
+      {% raw %}
       labels:
         severity: warning
         service: system
       annotations:
         summary: 'Avarage CPU usage (idle) for node {{ $labels.host }} is low'
         description: 'Avarage CPU usage (idle) for node {{ $labels.host }} is low {{ $value }}'
+      {% endraw %}
     PredictLinearDiskFree:
       if: 'predict_linear(disk_free[1h], 8*3600) < 0'
+      {% raw %}
       labels:
         severity: warning
         service: system
       annotations:
         summary: 'Disk space ({{ $labels.path }}) is filling on {{ $labels.host }}'
         description: 'Disk space ({{ $labels.path }}) will be full in 8h on {{ $labels.host }}'
+      {% endraw %}
     PredictLinearDiskInodesFree:
       if: 'predict_linear(disk_inodes_free[1h], 8*3600) < 0'
+      {% raw %}
       labels:
         severity: warning
         service: system
       annotations:
         summary: 'Disk inodes ({{ $labels.path }}) are filling on {{ $labels.host }}'
         description: 'Disk inodes ({{ $labels.path }}) will be full in 8h on {{ $labels.host }}'
+      {% endraw %}
     AvgMemAvailablePercent:
-      if: 'avg_over_time(mem_available_percent[5m]) < 10'
+      if: avg_over_time(mem_available_percent[5m]) < {{ prometheus_server.get('alert', {}).get('AvgMemAvailablePercent', {}).get('var', {}).get('threshold', 10) }}
+      {% raw %}
       labels:
         severity: warning
         service: system
       annotations:
         summary: 'Free memory is low on {{ $labels.host }}'
         description: 'Free memory percent for node {{ $labels.host }} is low {{ $value }}'
+      {% endraw %}
     SystemLoad5:
-      if: 'system_load5 / system_n_cpus > 3'
+      if: system_load5 / system_n_cpus > {{ prometheus_server.get('alert', {}).get('SystemLoad5', {}).get('var', {}).get('threshold', 3) }}
+      {% raw %}
       labels:
         severity: warning
         service: system
       annotations:
         summary: 'High system load (5m) on {{ $labels.host }}'
         description: 'High system load (5m) on node {{ $labels.host }}'
-{% endraw %}
+      {% endraw %}