MeshAccessLog
With the MeshAccessLog policy you can easily set up access logs on every data plane proxy in a mesh.
This policy uses a new policy matching algorithm. Do not combine with TrafficLog.
This guide assumes you have already configured your observability tools to work with Kuma. If you haven’t, see the observability docs.
targetRef
support matrix
To learn more about the information in this table, see the matching docs.
Configuration
Format
Kuma gives you full control over the format of the access logs.
The shape of a single log record is defined by a template string that uses command operators to extract and format data about a TCP
connection or an HTTP
request.
For example:
%START_TIME% %KUMA_SOURCE_SERVICE% => %KUMA_DESTINATION_SERVICE% %DURATION%
%START_TIME%
and %KUMA_SOURCE_SERVICE%
are examples of available command operators.
All command operators defined by Envoy are supported, along with additional command operators defined by Kuma:
Command Operator | Description |
---|---|
%KUMA_MESH% |
Name of the mesh in which traffic is flowing. |
%KUMA_SOURCE_SERVICE% |
Name of a service that is the source of traffic. |
%KUMA_DESTINATION_SERVICE% |
Name of a service that is the destination of traffic. |
%KUMA_SOURCE_ADDRESS_WITHOUT_PORT% |
Address of a Dataplane that is the source of traffic. |
%KUMA_TRAFFIC_DIRECTION% |
Direction of the traffic, INBOUND , OUTBOUND , or UNSPECIFIED . |
All additional access log command operators are valid to use with both TCP
and HTTP
traffic.
Internally, Kuma determines traffic protocol based on the value of kuma.io/protocol
tag on the inbound
interface of a destination
Dataplane
.
There are two types of format
, plain
and json
.
Plain accepts a string with command operators and produces a string output.
JSON accepts a list of key-value pairs that produces a valid JSON object.
It is up to the user to decide which format type to use. Some system will automatically parse JSON logs and allow you to filter and query based on available keys.
If a command operator is specific to HTTP
traffic, such as %REQ(X?Y):Z%
or %RESP(X?Y):Z%
, in the case of TCP traffic it will be replaced by a symbol “-
” for plain
and a null
value for json
.
You can set the format.omitEmptyValues
boolean option to change this to ""
for plain
and
omit them entirely for json
.
Plain
The default format string for TCP
traffic is:
[%START_TIME%] %RESPONSE_FLAGS% %KUMA_MESH% %KUMA_SOURCE_ADDRESS_WITHOUT_PORT%(%KUMA_SOURCE_SERVICE%)->%UPSTREAM_HOST%(%KUMA_DESTINATION_SERVICE%) took %DURATION%ms, sent %BYTES_SENT% bytes, received: %BYTES_RECEIVED% bytes
The default format string for HTTP
traffic is:
[%START_TIME%] %KUMA_MESH% "%REQ(:METHOD)% %REQ(X-ENVOY-ORIGINAL-PATH?:PATH)% %PROTOCOL%" %RESPONSE_CODE% %RESPONSE_FLAGS% %BYTES_RECEIVED% %BYTES_SENT% %DURATION% %RESP(X-ENVOY-UPSTREAM-SERVICE-TIME)% "%REQ(X-FORWARDED-FOR)%" "%REQ(USER-AGENT)%" "%REQ(X-REQUEST-ID)%" "%REQ(:AUTHORITY)%" "%KUMA_SOURCE_SERVICE%" "%KUMA_DESTINATION_SERVICE%" "%KUMA_SOURCE_ADDRESS_WITHOUT_PORT%" "%UPSTREAM_HOST%"
Example configuration:
format:
type: Plain
plain: '[%START_TIME%] %BYTES_RECEIVED%'
Example output:
[2016-04-15T20:17:00.310Z] 154
JSON
Example configuration:
format:
type: Json
json:
- key: "start_time"
value: "%START_TIME%"
- key: "bytes_received"
value: "%BYTES_RECEIVED%"
Example output:
{
"start_time": "2016-04-15T20:17:00.310Z",
"bytes_received": "154"
}
TCP configuration with default fields:
format:
type: Json
json:
- key: "start_time"
value: "%START_TIME%"
- key: "response_flags"
value: "%RESPONSE_FLAGS%"
- key: "kuma_mesh"
value: "%KUMA_MESH%"
- key: "kuma_source_address_without_port"
value: "%KUMA_SOURCE_ADDRESS_WITHOUT_PORT%"
- key: "kuma_source_service"
value: "%KUMA_SOURCE_SERVICE%"
- key: "upstream_host"
value: "%UPSTREAM_HOST%"
- key: "kuma_destination_service"
value: "%KUMA_DESTINATION_SERVICE%"
- key: "duration_ms"
value: "%DURATION%"
- key: "bytes_sent"
value: "%BYTES_SENT%"
- key: "bytes_received"
value: "%BYTES_RECEIVED%"
HTTP configuration with default fields:
format:
type: Json
json:
- key: "start_time"
value: "%START_TIME%"
- key: "kuma_mesh"
value: "%KUMA_MESH%"
- key: 'method'
value: '"%REQ(:METHOD)%'
- key: "path"
value: "%REQ(X-ENVOY-ORIGINAL-PATH?:PATH)%"
- key: 'protocol'
value: '%PROTOCOL%'
- key: "response_code"
value: "%RESPONSE_CODE%"
- key: "response_flags"
value: "%RESPONSE_FLAGS%"
- key: "bytes_received"
value: "%BYTES_RECEIVED%"
- key: "bytes_sent"
value: "%BYTES_SENT%"
- key: "duration_ms"
value: "%DURATION%"
- key: "upstream_service_time"
value: "%RESP(X-ENVOY-UPSTREAM-SERVICE-TIME)%"
- key: 'x_forwarded_for'
value: '"%REQ(X-FORWARDED-FOR)%"'
- key: 'user_agent'
value: '"%REQ(USER-AGENT)%"'
- key: 'request_id'
value: '"%REQ(X-REQUEST-ID)%"'
- key: 'authority'
value: '"%REQ(:AUTHORITY)%"'
- key: "kuma_source_service"
value: "%KUMA_SOURCE_SERVICE%"
- key: "kuma_destination_service"
value: "%KUMA_DESTINATION_SERVICE%"
- key: "kuma_source_address_without_port"
value: "%KUMA_SOURCE_ADDRESS_WITHOUT_PORT%"
- key: "upstream_host"
value: "%UPSTREAM_HOST%"
Backends
A backend determines where the logs end up.
TCP
A TCP backend streams logs to a server via TCP protocol. You can configure a TCP backend with an address:
backends:
- type: Tcp
tcp:
address: 127.0.0.1:5000
File
A file backend streams logs to a text file. You can configure a file backend with a path:
backends:
- type: File
file:
path: /dev/stdout
OpenTelemetry
An OpenTelemetry (OTel) backend sends data to an OpenTelemetry server. You can configure an OpenTelemetry backend with an endpoint, attributes (which contain additional information about the log) and body (can be a string message, including multi-line, or it can be a structured data). Attributes and endpoints can use placeholders described in the format section.
backends:
- type: OpenTelemetry
openTelemetry:
endpoint: otel-collector:4317
body:
kvlistValue:
values:
- key: "mesh"
value:
stringValue: "%KUMA_MESH%"
attributes:
- key: "start_time"
value: "%START_TIME%"
Body
Body is of type any (defined here) and can be one of the following forms:
body:
stringValue: "%KUMA_MESH%"
body:
boolValue: true
body:
intValue: 123
body:
doubleValue: 1.2
body:
bytesValue: aGVsbG8=
body:
arrayValue:
values:
- stringValue: "%KUMA_MESH%"
body:
kvlistValue:
values:
- key: "mesh"
value:
stringValue: "%KUMA_MESH%"
Examples
Log outgoing traffic from specific frontend version to a backend service
Logging to multiple backends
This configuration logs to three backends: TCP, file and OpenTelemetry.
Log all incoming and outgoing traffic
Logging traffic going outside the Mesh
To target ExternalServices
, use MeshService
as the targetRef
kind with name
set to
the kuma.io/service
value.
To target other non-mesh traffic, i.e. passthrough traffic, use Mesh
as the targetRef
kind. In this case, %KUMA_DESTINATION_SERVICE%
is set to external
.
Select a built-in gateway
You can select a built-in gateway using the kuma.io/service
value. A current limitation is that traffic routed from a gateway to a service is logged by that gateway as having destination "*"
.