Grafana dashboard: Loki Dashboard quick search
Description: Loki logs panel with prometheus variables 

Loki Dashboard.

{
  "__inputs": [
    {
      "name": "DS_LOKI",
      "label": "Loki",
      "description": "",
      "type": "datasource",
      "pluginId": "loki",
      "pluginName": "Loki"
    },
    {
      "name": "DS_PROMETHEUS",
      "label": "Prometheus",
      "description": "",
      "type": "datasource",
      "pluginId": "prometheus",
      "pluginName": "Prometheus"
    }
  ],
  "__requires": [
    {
      "type": "grafana",
      "id": "grafana",
      "name": "Grafana",
      "version": "6.7.0"
    },
    {
      "type": "panel",
      "id": "graph",
      "name": "Graph",
      "version": ""
    },
    {
      "type": "panel",
      "id": "logs",
      "name": "Logs",
      "version": ""
    },
    {
      "type": "datasource",
      "id": "loki",
      "name": "Loki",
      "version": "1.0.0"
    },
    {
      "type": "datasource",
      "id": "prometheus",
      "name": "Prometheus",
      "version": "1.0.0"
    },
    {
      "type": "panel",
      "id": "text",
      "name": "Text",
      "version": ""
    }
  ],
  "annotations": {
    "list": [
      {
        "$$hashKey": "object:75",
        "builtIn": 1,
        "datasource": "-- Grafana --",
        "enable": true,
        "hide": true,
        "iconColor": "rgba(0, 211, 255, 1)",
        "name": "Annotations & Alerts",
        "type": "dashboard"
      }
    ]
  },
  "editable": true,
  "gnetId": 18616,
  "graphTooltip": 0,
  "id": null,
  "iteration": 1586288900167,
  "links": [],
  "panels": [
    {
      "aliasColors": {},
      "bars": true,
      "dashLength": 10,
      "dashes": false,
      "datasource": "${DS_LOKI}",
      "fill": 1,
      "fillGradient": 0,
      "gridPos": {
        "h": 3,
        "w": 24,
        "x": 0,
        "y": 0
      },
      "hiddenSeries": false,
      "id": 6,
      "legend": {
        "avg": false,
        "current": false,
        "max": false,
        "min": false,
        "show": false,
        "total": false,
        "values": false
      },
      "lines": false,
      "linewidth": 1,
      "nullPointMode": "null",
      "options": {
        "dataLinks": []
      },
      "percentage": false,
      "pointradius": 2,
      "points": false,
      "renderer": "flot",
      "seriesOverrides": [],
      "spaceLength": 10,
      "stack": false,
      "steppedLine": false,
      "targets": [
        {
          "expr": "sum(count_over_time({namespace=\"$namespace\", instance=~\"$pod\"} |~ \"$search\"[$__interval]))",
          "refId": "A"
        }
      ],
      "thresholds": [],
      "timeFrom": null,
      "timeRegions": [],
      "timeShift": null,
      "title": "",
      "tooltip": {
        "shared": true,
        "sort": 0,
        "value_type": "individual"
      },
      "type": "graph",
      "xaxis": {
        "buckets": null,
        "mode": "time",
        "name": null,
        "show": true,
        "values": []
      },
      "yaxes": [
        {
          "$$hashKey": "object:168",
          "format": "short",
          "label": null,
          "logBase": 1,
          "max": null,
          "min": null,
          "show": false
        },
        {
          "$$hashKey": "object:169",
          "format": "short",
          "label": null,
          "logBase": 1,
          "max": null,
          "min": null,
          "show": false
        }
      ],
      "yaxis": {
        "align": false,
        "alignLevel": null
      }
    },
    {
      "datasource": "${DS_LOKI}",
      "gridPos": {
        "h": 25,
        "w": 24,
        "x": 0,
        "y": 3
      },
      "id": 2,
      "maxDataPoints": "",
      "options": {
        "showLabels": false,
        "showTime": true,
        "sortOrder": "Descending",
        "wrapLogMessage": true
      },
      "targets": [
        {
          "expr": "{namespace=\"$namespace\", instance=~\"$pod\"} |~ \"$search\"",
          "refId": "A"
        }
      ],
      "timeFrom": null,
      "timeShift": null,
      "title": "Logs Panel",
      "type": "logs"
    },
    {
      "content": "<div style=\"text-align:center\"> For Grafana Loki blog example </div>\n\n\n",
      "datasource": null,
      "gridPos": {
        "h": 3,
        "w": 24,
        "x": 0,
        "y": 28
      },
      "id": 4,
      "mode": "html",
      "timeFrom": null,
      "timeShift": null,
      "title": "",
      "transparent": true,
      "type": "text"
    }
  ],
  "schemaVersion": 22,
  "style": "dark",
  "tags": [],
  "templating": {
    "list": [
      {
        "allValue": null,
        "current": {},
        "datasource": "${DS_PROMETHEUS}",
        "definition": "label_values(kube_pod_info, namespace)",
        "hide": 0,
        "includeAll": false,
        "index": -1,
        "label": null,
        "multi": false,
        "name": "namespace",
        "options": [],
        "query": "label_values(kube_pod_info, namespace)",
        "refresh": 1,
        "regex": "",
        "skipUrlSync": false,
        "sort": 0,
        "tagValuesQuery": "",
        "tags": [],
        "tagsQuery": "",
        "type": "query",
        "useTags": false
      },
      {
        "allValue": ".*",
        "current": {},
        "datasource": "${DS_PROMETHEUS}",
        "definition": "label_values(container_network_receive_bytes_total{namespace=~\"$namespace\"},pod)",
        "hide": 0,
        "includeAll": true,
        "index": -1,
        "label": null,
        "multi": true,
        "name": "pod",
        "options": [],
        "query": "label_values(container_network_receive_bytes_total{namespace=~\"$namespace\"},pod)",
        "refresh": 1,
        "regex": "",
        "skipUrlSync": false,
        "sort": 0,
        "tagValuesQuery": "",
        "tags": [],
        "tagsQuery": "",
        "type": "query",
        "useTags": false
      },
      {
        "current": {
          "selected": false,
          "text": "level=warn",
          "value": "level=warn"
        },
        "hide": 0,
        "label": null,
        "name": "search",
        "options": [
          {
            "selected": true,
            "text": "level=warn",
            "value": "level=warn"
          }
        ],
        "query": "level=warn",
        "skipUrlSync": false,
        "type": "textbox"
      }
    ]
  },
  "time": {
    "from": "now-30m",
    "to": "now"
  },
  "timepicker": {
    "refresh_intervals": [
      "5s",
      "10s",
      "30s",
      "1m",
      "5m",
      "15m",
      "30m",
      "1h",
      "2h",
      "1d"
    ]
  },
  "timezone": "",
  "title": "Loki Dashboard quick search",
  "uid": "liz0yRCZz",
  "variables": {
    "list": []
  },
  "version": 1,
  "description": "Loki logs panel with prometheus variables "
}