Table of Contents

Admin API Audit Log

Kong Enterprise provides a granular logging facility on its Admin API. This allows cluster administrators to keep detailed track of changes made to the cluster configuration throughout its lifetime, aiding in compliance efforts and providing valuable data points during forensic investigations. Generated audit log trails are Workspace- and RBAC-aware, providing Kong operators a deep and wide look into changes happening within the cluster.

Back to TOC

Getting Started

Audit logging is disabled by default. It is configured via the Kong configuration:

# via Kong configuration file, e.g., kong.conf
audit_log = on # audit logging is enabled
audit_log = off # audit logging is disabled
# or via environmental variables
$ export KONG_AUDIT_LOG=on
$ export KONG_AUDIT_LOG=off

As with other Kong configurations, changes take effect on kong reload or kong restart.

Back to TOC

Request Audits

Generating and Viewing Audit Logs

Audit logging provides granular details of each HTTP request that was handled by Kong’s Admin API. Audit log data is written to Kong’s back database. As a result, request audit logs are available via the Admin API (in addition to via direct database query). For example, consider a query to the Admin API to the /status endpoint:

vagrant@ubuntu-xenial:/kong$ http :8001/status
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Connection: keep-alive
Content-Type: application/json; charset=utf-8
Date: Tue, 13 Nov 2018 17:32:47 GMT
Server: kong/0.34-enterprise-edition
Transfer-Encoding: chunked
X-Kong-Admin-Request-ID: ZuUfPfnxNn7D2OTU6Xi4zCnQkavzMUNM

{
    "database": {
        "reachable": true
    }, 
    "server": {
        "connections_accepted": 1, 
        "connections_active": 1, 
        "connections_handled": 1, 
        "connections_reading": 0, 
        "connections_waiting": 0, 
        "connections_writing": 1, 
        "total_requests": 1
    }
}

The above interaction with the Admin API would generate a correlating entry in the audit log table—querying the audit log via the Admin API returns the details of of the interaction above:

$ http :8001/audit/requests
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Connection: keep-alive
Content-Type: application/json; charset=utf-8
Date: Tue, 13 Nov 2018 17:35:24 GMT
Server: kong/0.34-enterprise-edition
Transfer-Encoding: chunked
X-Kong-Admin-Request-ID: VXgMG1Y3rZKbjrzVYlSdLNPw8asVwhET

{
    "data": [
        {
            "client_ip": "127.0.0.1", 
            "expire": 1544722367698, 
            "method": "GET", 
            "path": "/status", 
            "request_id": "ZuUfPfnxNn7D2OTU6Xi4zCnQkavzMUNM", 
            "request_timestamp": 1542130367699, 
            "status": 200, 
            "workspace": "0da4afe7-44ad-4e81-a953-5d2923ce68ae"
        }
    ], 
    "total": 1
}

Note the value of the request_id field. This is tied to the X-Kong-Admin-Request-ID response header received in the first transaction. This allows close association of client requests and audit log records within the Kong cluster.

Because every audit log entry is made available via Kong’s Admin API, it is possible to transport audit log entries into existing logging warehouses, SIEM solutions, or other remote services for duplication and inspection.

Back to TOC

Workspaces and RBAC

Audit log entries are written with an awareness of the requested Workspace, and the RBAC user (if present). When RBAC is enforced, the RBAC user’s UUID will be written to the rbac_user_id field in the audit log entry:

{
    "data": [
        {
            "client_ip": "127.0.0.1", 
            "expire": 1544722999857, 
            "method": "GET", 
            "path": "/status", 
            "rbac_user_id": "2e959b45-0053-41cc-9c2c-5458d0964331", 
            "request_id": "QUtUa3RMbRLxomqcL68ilOjjl68h56xr", 
            "request_timestamp": 1542130999858, 
            "status": 200, 
            "workspace": "0da4afe7-44ad-4e81-a953-5d2923ce68ae"
        }
    ], 
    "total": 1
}

Note also the presence of the workspace field. This is the UUID of the Workspace with which the request was associated.

Back to TOC

Limiting Audit Log Generation

It may be desirable to ignore audit log generation for certain Admin API requests, such as innocuous requests to the /status endpoint for healthchecking, or to ignore requests for a given path prefix (e.g., a given Workspace). To this end, the audit_log_ignore_methods and audit_log_ignore_paths configuration options are presented:

audit_log_ignore_methods = GET,OPTIONS # do not generate an audit log entry for GET or OPTIONS HTTP requests
audit_log_ignore_paths = /foo,/status # do not generate an audit log entry for requests that match the strings '/foo' or '/status'

Note that audit_log_ignore_paths values matched via simple string matching; regular expression or anchored searching for ignored paths is not supported at this time.

Back to TOC

Database Audits

Generating and Viewing Audit Logs

In addition to Admin API request data, Kong will generate granular audit log entries for all insertions, updates, and deletions to the cluster database. Database updates audit logs are also associated with Admin API request unique IDs. Consider the following request to create a Consumer:

$ http :8001/consumers username=bob
HTTP/1.1 201 Created
Access-Control-Allow-Origin: *
Connection: keep-alive
Content-Type: application/json; charset=utf-8
Date: Tue, 13 Nov 2018 17:50:18 GMT
Server: kong/0.34-enterprise-edition
Transfer-Encoding: chunked
X-Kong-Admin-Request-ID: 59fpTWlpUtHJ0qnAWBzQRHRDv7i5DwK2

{
    "created_at": 1542131418000, 
    "id": "16787ed7-d805-434a-9cec-5e5a3e5c9e4f", 
    "type": 0, 
    "username": "bob"
}

As seen before, a request audit log is generated with details about the request. Note the presence of the payload field, recorded when the request body is present:

$ http :8001/audit/requests
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Connection: keep-alive
Content-Type: application/json; charset=utf-8
Date: Tue, 13 Nov 2018 17:52:41 GMT
Server: kong/0.34-dev-enterprise-edition
Transfer-Encoding: chunked
X-Kong-Admin-Request-ID: SpPaxLTkDNndzKaYiWuZl3xrxDUIiGRR

{
    "data": [
        {
            "client_ip": "127.0.0.1", 
            "expire": 1544723418013, 
            "method": "POST", 
            "path": "/consumers", 
            "payload": "{\"username\": \"bob\"}", 
            "request_id": "59fpTWlpUtHJ0qnAWBzQRHRDv7i5DwK2", 
            "request_timestamp": 1542131418014, 
            "status": 201, 
            "workspace": "fd51ce6e-59c0-4b6b-b991-aa708a9ff4d2"
        }
    ], 
    "total": 1
}

Additionally, additional audit logs are generated to track the creation of the database entity:

$ http :8001/audit/objects
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Connection: keep-alive
Content-Type: application/json; charset=utf-8
Date: Tue, 13 Nov 2018 17:53:27 GMT
Server: kong/0.34-dev-enterprise-edition
Transfer-Encoding: chunked
X-Kong-Admin-Request-ID: ZKra3QT0d3eJKl96jOUXYueLumo0ck8c

{
    "data": [
        {
            "dao_name": "consumers", 
            "entity": "{\"created_at\":1542131418000,\"id\":\"16787ed7-d805-434a-9cec-5e5a3e5c9e4f\",\"username\":\"bob\",\"type\":0}", 
            "entity_key": "16787ed7-d805-434a-9cec-5e5a3e5c9e4f", 
            "expire": 1544723418009, 
            "id": "7ebabee7-2b09-445d-bc1f-2092c4ddc4be", 
            "operation": "create", 
            "request_id": "59fpTWlpUtHJ0qnAWBzQRHRDv7i5DwK2"
        }, 
  ],
  "total": 1
}

Object audit entries contain information about the entity updated, including the entity body itself, its database primary key, and the type of operation performed (create, update, or delete). Note also the associated request_id field.

Back to TOC

Limiting Audit Log Generation

As with request audit logs, it may be desirable to skip generation of audit logs for certain database tables. This is configurable via the audit_log_ignore_tables Kong config option:

audit_log_ignore_tables = consumers # do not generate database audit logs for changes to the consumers table

Back to TOC

Digital Signatures

To provide nonrepudiation, audit logs may be signed with a private RSA key. When enabled, a lexically sorted representation of each audit log entry is signed by the defined private key; the signature is stored in an additional field within the record itself. The public key should be stored elsewhere and can be used later to validate the signature of the record.

Setting Up Log Signing

Generate a private key via the openssl tool:

$ openssl genrsa -out private.pem 2048

Configure Kong to sign audit log records:

audit_log_signing_key = /path/to/private.pem

Audit log entries will now contain a field signature:

{
    "client_ip": "127.0.0.1", 
    "expire": 1544724298663, 
    "method": "GET", 
    "path": "/status", 
    "request_id": "Ka2GeB13RkRIbMwBHw0xqe2EEfY0uZG0", 
    "request_timestamp": 1542132298664, 
    "signature": "ctD8DXJEfuFAVdlYuhay7f4kmcZhfRPjX8Q6HlSJ+67aHjJIzzrlSxWKfmxnJ7WKRvlF7bU8PX/rtu1ytLQwmzW2LpMd/WFt34PKmyOFUByslkxCdfKKNHadZ+FfINzD+JrecFdXNJrSxKKHHTxj8g6vglAcoJMmuSB6cMsAuVUbO+CL6N/WV9RfCquxxkQUfqGoyEA09EeU4uC0xa8gcYAr1FMGcu+TdRbazfBqZayrKxn8iMV/7LUefMgzUrVdC7UFjZORo5Q0wl9U/iQWU5sRGiTo/HTQmU/a7EdyX3c6Wbmg2khYJFzUIkg9JRL/YUla+yfe3AL4KwFSH90xTw==", 
    "status": 200, 
    "workspace": "fd51ce6e-59c0-4b6b-b991-aa708a9ff4d2"
}

Back to TOC

Validating Signatures

Record signatures can be regenerated and verified by openssl or other cryptographic tools to confirm the validity of the signature. Re-generating the signature requires serializing the record into a string format that can be signed. The following is a canonical implementation written in Lua:

local pl_sort = require "pl.tablex".sort

local function serialize(data)
  local p = {}

  for k, v in pl_sort(data) do
    if type(v) == "table" then
      p[#p + 1] = serialize(v)
    else
      p[#p + 1] = v
    end
  end

  return p
end

table.concat(serialize(data), "|")

The contents of the record itself can be fed to this implementation (minus the signature field) in order to derive the value passed to the RSA key signing facility. Note that the signature field within each record is a Base-64 encoded representation of the RSA signature itself.

Back to TOC


Reference

API Reference

List Request Audit Logs

Endpoint
/audit/requests
Response
HTTP 200 OK
{
    "data": [
        {
            "client_ip": "127.0.0.1",
            "expire": 1544722367698,
            "method": "GET", 
            "path": "/status", 
            "request_id": "ZuUfPfnxNn7D2OTU6Xi4zCnQkavzMUNM",
            "request_timestamp": 1542130367699,
            "status": 200, 
            "workspace": "0da4afe7-44ad-4e81-a953-5d2923ce68ae"
        }
    ], 
    "total": 1
}

List Database Audit Logs

Endpoint
/audit/objects
Response
HTTP 200 OK
{
    "data": [
        {
            "dao_name": "consumers",
            "entity": "{\"created_at\":1542131418000,\"id\":\"16787ed7-d805-434a-9cec-5e5a3e5c9e4f\",\"username\":\"bob\",\"type\":0}",
            "entity_key": "16787ed7-d805-434a-9cec-5e5a3e5c9e4f",
            "expire": 1544723418009,
            "id": "7ebabee7-2b09-445d-bc1f-2092c4ddc4be",
            "operation": "create",
            "request_id": "59fpTWlpUtHJ0qnAWBzQRHRDv7i5DwK2"
        },
  ],
  "total": 1
}

Back to TOC

Configuration Reference

audit_log

When enabled, Kong will log information about Admin API access and database row insertions, updates, and deletes.

Default: off


audit_log_ignore_methods

Comma-separated list of HTTP methods that will not generate audit log entries. By default, all HTTP requests will be logged.

Default: none


audit_log_ignore_paths

Comma-separated list of request paths that will not generate audit log entries. By default, all HTTP requests will be logged.

Default: none


audit_log_ignore_tables

Comma-separated list of database tables that will not generate audit log entries. By default, updates to all database tables will be logged (the term “updates” refers to the creation, update, or deletion of a row).

Default: none


audit_log_record_ttl

Length, in seconds, of the TTL for audit log records. Records in the database older than their TTL are automatically purged.

Default: 2592000


audit_log_signing_key

Defines the path to a private RSA signing key that can be used to insert a signature of audit records, adjacent to the record. The corresponding public key should be stored offline, and can be used the validate audit entries in the future. If this value is undefined, no signature will be generated.

Default: none

Back to TOC