---
layout: docs
page_title: audit Block - Agent Configuration
description: >-
  The "audit" block configures the Nomad agent to configure Audit Logging
  behavior. This is an Enterprise-only feature.
---

# `audit` Block

<Placement groups={['audit']} />

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

```hcl
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 block (`audit { enabled = true }`)
The following default sink will be added with no filters.

```hcl
audit {
  enabled = true
  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` <code>([sink](#sink-block): default)</code> - Configures a sink
  for audit logs to be sent to.

- `filter` <code>(array<[filter](#filter-block)>: [])</code> - Configures a filter
  to exclude matching events from being sent to audit logging sinks.

### `sink` Block

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

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

```hcl
audit {
  enabled = true

  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
    mode               = "0600"
  }
}
```

#### `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
  halt request execution if the audit log event fails to be written to its sink.
  `"best-effort"` will not halt 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.

- `mode` `(string: "0600")` - Specifies the permissions mode for the audit log
   files using octal notation.

- `path` `(string: "[data_dir]/audit/audit.log")` - Specifies the path and file
  name to use for the audit log. By default Nomad will use its configured
  [`data_dir`](/nomad/docs/configuration#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` Block

The `filter` block 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][glob] matching.

Query parameters are ignored when evaluating filters.

```hcl
audit {
  enabled = true

  # Filter out all requests and all stages for /v1/metrics
  filter "default" {
    type       = "HTTPEvent"
    endpoints  = ["/v1/metrics"]
    stages     = ["*"]
    operations = ["*"]
  }

  # Filter out requests where endpoint matches globbed pattern
  filter "globbed example" {
    type       = "HTTPEvent"
    endpoints  = ["/v1/evaluation/*/allocations"]
    stages     = ["*"]
    operations = ["*"]
  }

  # Filter out 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.

```json
{
  "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.

```json
{
  "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"
    }
  }
}
```

[glob]: https://github.com/ryanuber/go-glob/blob/master/README.md#example
