elasticsearch-to-splunk

Go utility to ship logs from Elasticsearch to Splunk.

With special support for logit.io.

Usage

Source

Use --es-url or the ES_URL environment variable to configure the Elasticsearch source. Should be in the format https://ffffffff-ffff-ffff-ffff-ffffffffffff-es.logit.io.

Use --logit-api-key or the LOGIT_API_KEY environment variable to configure the (Logit specific) Elasticsearch API key. Should be in the format ffffffff-ffff-ffff-ffff-ffffffffffff.

Use --basic-auth-username or the BASIC_AUTH_USERNAME environment variable to configure HTTP basic authentication, along with --basic-auth-password (BASIC_AUTH_PASSWORD).

For Logit Elasticsearch, these variables are available on the Elasticsearch page within a Logit stack's settings.

Destination

Use --splunk-url or the SPLUNK_URL environment variable to configure the Splunk destination. Should be in the format https://instance-name.splunkcloud.com:443/services/collector.

Use --splunk-key or the SPLUNK_KEY environment variable to configure the API key used when sending logs to Splunk.

Content

Use --search-json or the SEARCH_JSON environment variable to configure the query used in Elasticsearch. For instance if your Elasticsearch query is:

{
  "query": {
    "bool": {
      "must": [{
        "exists": { "field": "message" }
      }, {
        "range": {
          "@timestamp": { "gte" : "now-2m/d" }
        }
      }]
    }
  },
  "sort": [
    {
      "@timestamp": {
        "order": "desc"
      }
    }
  ]
}

then you would use:

--search-json '{
  "bool": {
    "must": [{
      "exists":{
        "field": "message"
      }
    }, {
      "range": {
        "@timestamp": {
          "gte": "now-2m/d"
        }
      }
    }
  ]}
}'

i.e. without the query object wrapping the query. You can compact the json by using jq -c.

It is important you specify a range otherwise you will retrieve all documents.

Cadence

Use --search-cadence or the SEARCH_CADENCE environment variable to specify how many seconds to wait in-between queries to Elasticsearch. Defaults to 15.

Deduplication and tuning

You should specify a range in your Elasticsearch query, e.g. in the format now-2m/d to get all logs in the last two minutes.

Logs are deduplicated probabilistically using a bloom filter using the entire content of the document returned by Elasticsearch. This means you could set --search-cadence to 60, logs which have already been seen will not be shipped to Splunk.