»audit Stanza

Placementaudit

The audit stanza configures the Nomad agent to configure Audit logging behavior. Audit logging is an Enterprise-only feature.

audit {
  enabled = true
}

When enabled, each HTTP request made to a nomad agent (client or server) will generate two audit log entries. These two entries correspond to a stage, OperationReceived and OperationComplete. Audit logging will generate a OperationReceived event before the request is processed. An OperationComplete event will be sent after the request has been processed, but before the response body is returned to the end user.

By default, with a minimally configured audit stanza (audit { enabled = true }) The following default sink will be added with no filters.

  sink "audit" {
    type               = "file"
    delivery_guarantee = "enforced"
    format             = "json"
    path               = "/[data_dir]/audit/audit.log"
  }

The sink will create an audit.log file located within the defined data_dir directory inside an audit directory. delivery_guarantee will be set to "enforced" meaning that all requests must successfully be written to the sink in order for HTTP requests to successfully complete.

»audit Parameters

  • enabled (bool: false) - Specifies if audit logging should be enabled. When enabled, audit logging will occur for every request, unless it is filtered by a filter.

  • sink (sink: default) - Configures a sink for audit logs to be sent to.

  • filter (filter: nil) - Configures a filter to exclude matching events from being sent to audit logging sinks.

»sink Stanza

The sink stanza is used to make audit logging sinks for events to be sent to. Currently only a single sink is supported.

The key of the stanza corresponds to the name of the sink which is used for logging purposes

  sink "audit" {
    type               = "file"
    delivery_guarantee = "enforced"
    format             = "json"
    path               = "/var/lib/nomad/audit/audit.log"
    rotate_bytes       = 100
    rotate_duration    = "24h"
    rotate_max_files   = 10
  }

»sink Parameters

  • type (string: "file", required) - Specifies the type of sink to create. Currently only "file" type is supported.

  • delivery_guarantee (string: "enforced", required) - Specifies the delivery guarantee that will be made for each audit log entry. Available options are "enforced" and "best-effort". "enforced" will hault request execution if the audit log event fails to be written to it's sink. "best-effort" will not hault request execution, meaning a request could potentially be un-audited.

  • format (string: "json", required) - Specifies the output format to be sent to a sink. Currently only "json" format is supported.

  • path (string: "[data_dir]/audit/audit.log") - Specifies the path and file name to use for the audit log. By default Nomad will use it's configured data_dir for a combined path of /data_dir/audit/audit.log. If rotate_bytes or rotate_duration are set file rotation will occur. In this case the filename will be post-fixed with a timestamp "filename-{timestamp}.log"

  • rotate_bytes (int: 0) - Specifies the number of bytes that should be written to an audit log before it needs to be rotated. Unless specified, there is no limit to the number of bytes that can be written to a log file.

  • rotate_duration (duration: "24h") - Specifies the maximum duration a audit log should be written to before it needs to be rotated. Must be a duration value such as 30s.

  • rotate_max_files (int: 0) - Specifies the maximum number of older audit log file archives to keep. If 0 no files are ever deleted.

»filter Stanza

The filter stanza is used to create filters to filter out matching events from being written to the audit log. By default, all events will be sent to an audit log for all stages (OperationReceived and OperationComplete). Filters are useful for operators who want to limit the performance impact of audit logging as well as reducing the amount of events generated.

endpoints, stages, and operations support globbed pattern matching.

# Filter all requests and all stages for /ui/ and /v1/agent/health
filter "default" {
  type       = "HTTPEvent"
  endpoints  = ["/ui/", "/v1/agent/health"]
  stages     = ["*"]
  operations = ["*"]
}

# Filter OperationReceived GET requests for all endpoints
filter "OperationReceived GETs" {
  type       = "HTTPEvent"
  endpoints  = ["*"]
  stages     = ["OperationReceived"]
  operations = ["GET"]
}

»filter Parameters

  • type (string: "HTTPEvent", required) - Specifies the type of filter to create. Currently only HTTPEvent is supported.

  • endpoints (array<string>: []) - Specifies the list of endpoints to apply the filter to.

  • stages (array<string>: []) - Specifies the list of stages ("OperationReceived", "OperationComplete", "*") to apply the filter to for a matching endpoint.

  • operations (array<string>: []) - Specifies the list of operations to apply the filter to for a matching endpoint. For HTTPEvent types this corresponds to an HTTP verb (GET, PUT, POST, DELETE...).

»Audit Log Format

Below are two audit log entries for a request made to /v1/job/web/summary. The first entry is for the OperationReceived stage. The second entry is for the OperationComplete stage and includes the contents of the OperationReceived stage plus a response key.

{
  "created_at": "2020-03-24T13:09:35.703869927-04:00",
  "event_type": "audit",
  "payload": {
    "id": "8b826146-b264-af15-6526-29cb905145aa",
    "stage": "OperationReceived",
    "type": "audit",
    "timestamp": "2020-03-24T13:09:35.703865005-04:00",
    "version": 1,
    "auth": {
      "accessor_id": "a162f017-bcf7-900c-e22a-a2a8cbbcef53",
      "name": "Bootstrap Token",
      "global": true,
      "create_time": "2020-03-24T17:08:35.086591881Z"
    },
    "request": {
      "id": "02f0ac35-c7e8-0871-5a58-ee9dbc0a70ea",
      "operation": "GET",
      "endpoint": "/v1/job/web/summary",
      "namespace": {
        "id": "default"
      },
      "request_meta": {
        "remote_address": "127.0.0.1:33648",
        "user_agent": "Go-http-client/1.1"
      },
      "node_meta": {
        "ip": "127.0.0.1:4646"
      }
    }
  }
}
{
  "created_at": "2020-03-24T13:09:35.704224536-04:00",
  "event_type": "audit",
  "payload": {
    "id": "8b826146-b264-af15-6526-29cb905145aa",
    "stage": "OperationComplete",
    "type": "audit",
    "timestamp": "2020-03-24T13:09:35.703865005-04:00",
    "version": 1,
    "auth": {
      "accessor_id": "a162f017-bcf7-900c-e22a-a2a8cbbcef53",
      "name": "Bootstrap Token",
      "global": true,
      "create_time": "2020-03-24T17:08:35.086591881Z"
    },
    "request": {
      "id": "02f0ac35-c7e8-0871-5a58-ee9dbc0a70ea",
      "operation": "GET",
      "endpoint": "/v1/job/web/summary",
      "namespace": {
        "id": "default"
      },
      "request_meta": {
        "remote_address": "127.0.0.1:33648",
        "user_agent": "Go-http-client/1.1"
      },
      "node_meta": {
        "ip": "127.0.0.1:4646"
      }
    },
    "response": {
      "status_code": 200
    }
  }
}

If the request returns an error the audit log will reflect the error message.

{
  "created_at": "2020-03-24T13:18:36.121978648-04:00",
  "event_type": "audit",
  "payload": {
    "id": "21c6f97a-fbfb-1090-1e34-34d1ece57cc2",
    "stage": "OperationComplete",
    "type": "audit",
    "timestamp": "2020-03-24T13:18:36.121428628-04:00",
    "version": 1,
    "auth": {
      "accessor_id": "anonymous",
      "name": "Anonymous Token",
      "policies": [
        "anonymous"
      ],
      "create_time": "0001-01-01T00:00:00Z"
    },
    "request": {
      "id": "c696cc9e-962e-18b3-4097-e0a09070f89e",
      "operation": "GET",
      "endpoint": "/v1/jobs?prefix=web",
      "namespace": {
        "id": "default"
      },
      "request_meta": {
        "remote_address": "127.0.0.1:33874",
        "user_agent": "Go-http-client/1.1"
      },
      "node_meta": {
        "ip": "127.0.0.1:4646"
      }
    },
    "response": {
      "status_code": 403,
      "error": "Permission denied"
    }
  }
}