Add alerts endpoint

[aleksandra-galara]

It implements (#98).

Signed-off-by: Aleksandra Galara a.galara@samsung.com

[aleksandra-galara]

Payload example:

{
  "alerts": [
    {
      "id": "prometheus-alert-nodeclocknotsynchronising-node-192.168.122.250:9100",
      "origin": "prometheus",
      "properties": {
        "name": "NodeClockNotSynchronising",
        "kind": "node",
        "instance": "192.168.122.250:9100",
        "namespace": "{}",
        "message": "Clock on 192.168.122.250:9100 is not synchronising. Ensure NTP is configured on this host.",
        "severity": "warning"
      }
    },
    {
      "id": "prometheus-alert-kubecontainerwaiting-pod-test-1595997840-l848n-default",
      "origin": "prometheus",
      "properties": {
        "name": "KubeContainerWaiting",
        "kind": "pod",
        "instance": "test-1595997840-l848n",
        "namespace": "default",
        "message": "Pod default/test-1595997840-l848n container hello has been in waiting state for longer than 1 hour.",
        "severity": "warning"
      }
    }
  ]
}

[aleksandra-galara]

As for now, the payload looks like that:

[
  {
    "id": "prometheus-alert-nodeclocknotsynchronising-node-192.168.122.250:9100",
    "origin": "prometheus",
    "name": "NodeClockNotSynchronising",
    "message": "Clock on 192.168.122.250:9100 is not synchronising. Ensure NTP is configured on this host.",
    "severity": "warning",
    "source": {
      "origin": "kubernetes",
      "kind": "node",
      "properties": {
        "name": "192.168.122.250:9100",
        "namespace": "{}"
      }
    },
    "created_at": "1595996122",
    "updated_at": "1595996122"
  },
  {
    "id": "prometheus-alert-kubepodcrashlooping-pod-zabbix-server-rkw4p-zabbix",
    "origin": "prometheus",
    "name": "KubePodCrashLooping",
    "message": "Pod zabbix/zabbix-server-rkw4p (zabbix-server) is restarting 0.43 times / 5 minutes.",
    "severity": "critical",
    "source": {
      "origin": "kubernetes",
      "kind": "pod",
      "properties": {
        "name": "zabbix-server-rkw4p",
        "namespace": "zabbix"
      }
    },
    "created_at": "1595996124",
    "updated_at": "1596021884"
  }
]