Access logging

Configuration

Access logs are configured as part of the HTTP connection manager config, TCP Proxy, UDP Proxy or Thrift Proxy.

v3 API reference

Format Rules

Access log formats contain command operators that extract the relevant data and insert it. They support two formats: “format strings” and “format dictionaries”. In both cases, the command operators are used to extract the relevant data, which is then inserted into the specified log format. Only one access log format may be specified at a time.

Format Strings

Format strings are plain strings, specified using the format key. They may contain either command operators or other characters interpreted as a plain string. The access log formatter does not make any assumptions about a new line separator, so one has to specified as part of the format string. See the default format for an example.

Default Format String

If custom format string is not specified, Envoy uses the following default format:

[%START_TIME%] "%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)%" "%UPSTREAM_HOST%"\n

Example of the default Envoy access log format:

[2016-04-15T20:17:00.310Z] "POST /api/v1/locations HTTP/2" 204 - 154 0 226 100 "10.0.35.28"
"nsq2http" "cc21d9b0-cf5c-432b-8c7e-98aeb7988cd2" "locations" "tcp://10.0.2.1:80"

Format Dictionaries

Format dictionaries are dictionaries that specify a structured access log output format, specified using the json_format or typed_json_format keys. This allows logs to be output in a structured format such as JSON. Similar to format strings, command operators are evaluated and their values inserted into the format dictionary to construct the log output.

For example, with the following format provided in the configuration as json_format:

{
  "config": {
    "json_format": {
        "protocol": "%PROTOCOL%",
        "duration": "%DURATION%",
        "my_custom_header": "%REQ(MY_CUSTOM_HEADER)%"
    }
  }
}

The following JSON object would be written to the log file:

{"protocol": "HTTP/1.1", "duration": "123", "my_custom_header": "value_of_MY_CUSTOM_HEADER"}

This allows you to specify a custom key for each command operator.

The typed_json_format differs from json_format in that values are rendered as JSON numbers, booleans, and nested objects or lists where applicable. In the example, the request duration would be rendered as the number 123.

Format dictionaries have the following restrictions:

The dictionary must map strings to strings (specifically, strings to command operators). Nesting is supported.
When using the typed_json_format command operators will only produce typed output if the command operator is the only string that appears in the dictionary value. For example, "%DURATION%" will log a numeric duration value, but "%DURATION%.0" will log a string value.

Note

When using the typed_json_format, integer values that exceed \(2^{53}\) will be represented with reduced precision as they must be converted to floating point numbers.

Command Operators

Command operators are used to extract values that will be inserted into the access logs. The same operators are used by different types of access logs (such as HTTP and TCP). Some fields may have slightly different meanings, depending on what type of log it is. Differences are noted.

Note that if a value is not set/empty, the logs will contain a - character or, for JSON logs, the string "-". For typed JSON logs unset values are represented as null values and empty strings are rendered as "". omit_empty_values option could be used to omit empty values entirely.

Unless otherwise noted, command operators produce string outputs for typed JSON logs.

The following command operators are supported:

%START_TIME%

HTTP/THRIFT: Request start time including milliseconds.
TCP: Downstream connection start time including milliseconds.
UDP: UDP proxy session start time including milliseconds.

START_TIME can be customized using a format string. In addition to that, START_TIME also accepts following specifiers:

Specifier	Explanation
`%s`	The number of seconds since the Epoch
`%f`, `%[1-9]f`	Fractional seconds digits, default is 9 digits (nanosecond)
`%f`, `%[1-9]f`	`%3f` millisecond (3 digits) `%6f` microsecond (6 digits) `%9f` nanosecond (9 digits)

Examples of formatting START_TIME is as follows:

%START_TIME(%Y/%m/%dT%H:%M:%S%z)%

%START_TIME(%s)%

# To include millisecond fraction of the second (.000 ... .999). E.g. 1527590590.528.
%START_TIME(%s.%3f)%

%START_TIME(%s.%6f)%

%START_TIME(%s.%9f)%

In typed JSON logs, START_TIME is always rendered as a string.

%EMIT_TIME%

The time when log entry is emitted including milliseconds.

EMIT_TIME can be customized using a format string. See START_TIME for additional format specifiers and examples.

%REQUEST_HEADERS_BYTES%

HTTP: Uncompressed bytes of request headers.
TCP/UDP: Not implemented (0).

%BYTES_RECEIVED%

HTTP/THRIFT: Body bytes received.
TCP: Downstream bytes received on connection.
UDP: Not implemented (0).

Renders a numeric value in typed JSON logs.

%BYTES_RETRANSMITTED%

HTTP/3 (QUIC): Body bytes retransmitted.
HTTP/1 and HTTP/2: Not implemented (0).
TCP/UDP: Not implemented (0).

Renders a numeric value in typed JSON logs.

%PACKETS_RETRANSMITTED%

HTTP/3 (QUIC): Number of packets retransmitted.
HTTP/1 and HTTP/2: Not implemented (0).
TCP/UDP: Not implemented (0).

Renders a numeric value in typed JSON logs.

%PROTOCOL%

HTTP: Protocol. Currently either HTTP/1.1 HTTP/2 or HTTP/3.
TCP/UDP: Not implemented (“-“).

In typed JSON logs, PROTOCOL will render the string "-" if the protocol is not available (e.g. in TCP logs).

%UPSTREAM_PROTOCOL%

HTTP: Upstream protocol. Currently either HTTP/1.1 HTTP/2 or HTTP/3.
TCP/UDP: Not implemented (“-“).

In typed JSON logs, UPSTREAM_PROTOCOL will render the string "-" if the protocol is not available (e.g. in TCP logs).

%RESPONSE_CODE%

HTTP

HTTP response code. Note that a response code of ‘0’ means that the server never sent the beginning of a response. This generally means that the (downstream) client disconnected.

Note that in the case of 100-continue responses, only the response code of the final headers will be logged. If a 100-continue is followed by a 200, the logged response will be 200. If a 100-continue results in a disconnect, the 100 will be logged.

TCP/UDP

Not implemented (“-“).

Renders a numeric value in typed JSON logs.

%RESPONSE_CODE_DETAILS%

HTTP: HTTP response code details provides additional information about the response code, such as who set it (the upstream or envoy) and why.
TCP/UDP: Not implemented (“-“)

%CONNECTION_TERMINATION_DETAILS%

HTTP and TCP: Connection termination details may provide additional information about why the connection was terminated by Envoy for L4 reasons.

%RESPONSE_HEADERS_BYTES%

HTTP: Uncompressed bytes of response headers.
TCP/UDP: Not implemented (0).

%RESPONSE_TRAILERS_BYTES%

HTTP: Uncompressed bytes of response trailers.
TCP/UDP: Not implemented (0).

%BYTES_SENT%

HTTP/THRIFT: Body bytes sent. For WebSocket connection it will also include response header bytes.
TCP: Downstream bytes sent on connection.
UDP: Not implemented (0).

%UPSTREAM_REQUEST_ATTEMPT_COUNT%

HTTP: Number of times the request is attempted upstream. Note that an attempt count of ‘0’ means that the request was never attempted upstream.
TCP: Number of times the connection request is attempted upstream. Note that an attempt count of ‘0’ means that the connection request was never attempted upstream.
UDP: Not implemented (0).

Renders a numeric value in typed JSON logs.

%UPSTREAM_WIRE_BYTES_SENT%

HTTP: Total number of bytes sent to the upstream by the http stream.
TCP: Total number of bytes sent to the upstream by the tcp proxy.
UDP: Not implemented (0).

%UPSTREAM_WIRE_BYTES_RECEIVED%

HTTP: Total number of bytes received from the upstream by the http stream.
TCP: Total number of bytes received from the upstream by the tcp proxy.
UDP: Not implemented (0).

%UPSTREAM_HEADER_BYTES_SENT%

HTTP: Number of header bytes sent to the upstream by the http stream.
TCP/UDP: Not implemented (0).

%UPSTREAM_HEADER_BYTES_RECEIVED%

HTTP: Number of header bytes received from the upstream by the http stream.
TCP/UDP: Not implemented (0).

%DOWNSTREAM_WIRE_BYTES_SENT%

HTTP: Total number of bytes sent to the downstream by the http stream.
TCP: Total number of bytes sent to the downstream by the tcp proxy.
UDP: Not implemented (0).

%DOWNSTREAM_WIRE_BYTES_RECEIVED%

HTTP: Total number of bytes received from the downstream by the http stream. Envoy over counts sizes of received HTTP/1.1 pipelined requests by adding up bytes of requests in the pipeline to the one currently being processed.
TCP: Total number of bytes received from the downstream by the tcp proxy.
UDP: Not implemented (0).

%DOWNSTREAM_HEADER_BYTES_SENT%

HTTP: Number of header bytes sent to the downstream by the http stream.
TCP/UDP: Not implemented (0).

%DOWNSTREAM_HEADER_BYTES_RECEIVED%

HTTP: Number of header bytes received from the downstream by the http stream.
TCP/UDP: Not implemented (0).

Renders a numeric value in typed JSON logs.

%DURATION%

HTTP/THRIFT: Total duration in milliseconds of the request from the start time to the last byte out.
TCP: Total duration in milliseconds of the downstream connection.
UDP: Not implemented (0).

Renders a numeric value in typed JSON logs.

%COMMON_DURATION(START:END:PRECISION)%

HTTP

Total duration between the START time point and the END time point in specific PRECISION. The START and END time points are specified by the following values (NOTE: all values here are case-sensitive):

DS_RX_BEG: The time point of the downstream request receiving begin.
DS_RX_END: The time point of the downstream request receiving end.
US_TX_BEG: The time point of the upstream request sending begin.
US_TX_END: The time point of the upstream request sending end.
US_RX_BEG: The time point of the upstream response receiving begin.
US_RX_END: The time point of the upstream response receiving end.
DS_TX_BEG: The time point of the downstream response sending begin.
DS_TX_END: The time point of the downstream response sending end.
Dynamic value: Other values will be treated as custom time points that are set by named keys.

The PRECISION is specified by the following values (NOTE: all values here are case-sensitive):

ms: Millisecond precision.
us: Microsecond precision.
ns: Nanosecond precision.

TCP/UDP

Not implemented (“-“).

%REQUEST_DURATION%

HTTP: Total duration in milliseconds of the request from the start time to the last byte of the request received from the downstream.
TCP/UDP: Not implemented (“-“).

Renders a numeric value in typed JSON logs.

%REQUEST_TX_DURATION%

HTTP: Total duration in milliseconds of the request from the start time to the last byte sent upstream.
TCP/UDP: Not implemented (“-“).

Renders a numeric value in typed JSON logs.

%RESPONSE_DURATION%

HTTP: Total duration in milliseconds of the request from the start time to the first byte read from the upstream host.
TCP/UDP: Not implemented (“-“).

Renders a numeric value in typed JSON logs.

%ROUNDTRIP_DURATION%

HTTP/3 (QUIC): Total duration in milliseconds of the request from the start time to receiving the final ack from the downstream.
HTTP/1 and HTTP/2: Not implemented (“-“).
TCP/UDP: Not implemented (“-“).

Renders a numeric value in typed JSON logs.

%RESPONSE_TX_DURATION%

HTTP: Total duration in milliseconds of the request from the first byte read from the upstream host to the last byte sent downstream.
TCP/UDP: Not implemented (“-“).

Renders a numeric value in typed JSON logs.

%DOWNSTREAM_HANDSHAKE_DURATION%

HTTP: Not implemented (“-“).
TCP: Total duration in milliseconds from the start of the connection to the TLS handshake being completed.
UDP: Not implemented (“-“).

Renders a numeric value in typed JSON logs.

%UPSTREAM_CONNECTION_POOL_READY_DURATION%

HTTP/TCP: Total duration in milliseconds from when the upstream request was created to when the connection pool is ready.
UDP: Not implemented (“-“).

Renders a numeric value in typed JSON logs.

%RESPONSE_FLAGS% / %RESPONSE_FLAGS_LONG%: Additional details about the response or connection, if any. For TCP connections, the response codes mentioned in the descriptions do not apply. %RESPONSE_FLAGS% will output a short string. %RESPONSE_FLAGS_LONG% will output a Pascal case string. Possible values are:

HTTP and TCP

Long name	Short name	Description
NoHealthyUpstream	UH	No healthy upstream hosts in upstream cluster in addition to 503 response code.
UpstreamConnectionFailure	UF	Upstream connection failure in addition to 503 response code.
UpstreamOverflow	UO	Upstream overflow (circuit breaking) in addition to 503 response code.
NoRouteFound	NR	No route configured for a given request in addition to 404 response code or no matching filter chain for a downstream connection.
UpstreamRetryLimitExceeded	URX	The request was rejected because the upstream retry limit (HTTP) or maximum connect attempts (TCP) was reached.
NoClusterFound	NC	Upstream cluster not found.
DurationTimeout	DT	When a request or connection exceeded max_connection_duration or max_downstream_connection_duration.

HTTP only

Long name	Short name	Description
DownstreamConnectionTermination	DC	Downstream connection termination.
FailedLocalHealthCheck	LH	Local service failed health check request in addition to 503 response code.
UpstreamRequestTimeout	UT	Upstream request timeout in addition to 504 response code.
LocalReset	LR	Connection local reset in addition to 503 response code.
UpstreamRemoteReset	UR	Upstream remote reset in addition to 503 response code.
UpstreamConnectionTermination	UC	Upstream connection termination in addition to 503 response code.
DelayInjected	DI	The request processing was delayed for a period specified via fault injection.
FaultInjected	FI	The request was aborted with a response code specified via fault injection.
RateLimited	RL	The request was ratelimited locally by the HTTP rate limit filter in addition to 429 response code.
UnauthorizedExternalService	UAEX	The request was denied by the external authorization service.
RateLimitServiceError	RLSE	The request was rejected because there was an error in rate limit service.
InvalidEnvoyRequestHeaders	IH	The request was rejected because it set an invalid value for a strictly-checked header in addition to 400 response code.
StreamIdleTimeout	SI	Stream idle timeout in addition to 408 or 504 response code.
DownstreamProtocolError	DPE	The downstream request had an HTTP protocol error.
UpstreamProtocolError	UPE	The upstream response had an HTTP protocol error.
UpstreamMaxStreamDurationReached	UMSDR	The upstream request reached max stream duration.
ResponseFromCacheFilter	RFCF	The response was served from an Envoy cache filter.
NoFilterConfigFound	NFCF	The request is terminated because filter configuration was not received within the permitted warming deadline.
OverloadManagerTerminated	OM	Overload Manager terminated the request.
DnsResolutionFailed	DF	The request was terminated due to DNS resolution failure.
DropOverload	DO	The request was terminated in addition to 503 response code due to drop_overloads.

UDP

Not implemented (“-“).

%ROUTE_NAME%

HTTP/TCP: Name of the route.
UDP: Not implemented (“-“).

%VIRTUAL_CLUSTER_NAME%

HTTP*/gRPC: Name of the matched Virtual Cluster (if any).
TCP/UDP: Not implemented (“-“)

%UPSTREAM_HOST%: Main address of upstream host (e.g., ip:port for TCP connections).

%UPSTREAM_HOST_NAME%: Upstream host name (e.g., DNS name). If no DNS name is available, the main address of the upstream host (e.g., ip:port for TCP connections) will be used.
%UPSTREAM_CLUSTER%: Upstream cluster to which the upstream host belongs to. alt_stat_name will be used if provided.
%UPSTREAM_LOCAL_ADDRESS%: Local address of the upstream connection. If the address is an IP address it includes both address and port.
%UPSTREAM_LOCAL_ADDRESS_WITHOUT_PORT%: Local address of the upstream connection, without any port component. IP addresses are the only address type with a port component.
%UPSTREAM_LOCAL_PORT%: Local port of the upstream connection. IP addresses are the only address type with a port component.

%UPSTREAM_REMOTE_ADDRESS%: Remote address of the upstream connection. If the address is an IP address it includes both address and port. Identical to the UPSTREAM_HOST value if the upstream host only has one address and connection is established successfully.
%UPSTREAM_REMOTE_ADDRESS_WITHOUT_PORT%: Remote address of the upstream connection, without any port component. IP addresses are the only address type with a port component.
%UPSTREAM_REMOTE_PORT%: Remote port of the upstream connection. IP addresses are the only address type with a port component.

%UPSTREAM_TRANSPORT_FAILURE_REASON%

HTTP: If upstream connection failed due to transport socket (e.g. TLS handshake), provides the failure reason from the transport socket. The format of this field depends on the configured upstream transport socket. Common TLS failures are in TLS trouble shooting.
TCP/UDP: Not implemented (“-“)

%DOWNSTREAM_TRANSPORT_FAILURE_REASON%

HTTP/TCP: If downstream connection failed due to transport socket (e.g. TLS handshake), provides the failure reason from the transport socket. The format of this field depends on the configured downstream transport socket. Common TLS failures are in TLS trouble shooting. Note: it only works in listener access config, and the HTTP or TCP access logs would observe empty values.
UDP: Not implemented (“-“)

%DOWNSTREAM_REMOTE_ADDRESS%

Remote address of the downstream connection. If the address is an IP address it includes both address and port.

Note

This may not be the physical remote address of the peer if the address has been inferred from Proxy Protocol filter or x-forwarded-for.

%DOWNSTREAM_REMOTE_ADDRESS_WITHOUT_PORT%

Remote address of the downstream connection, without any port component. IP addresses are the only address type with a port component.

Note

This may not be the physical remote address of the peer if the address has been inferred from Proxy Protocol filter or x-forwarded-for.

%DOWNSTREAM_REMOTE_PORT%

Remote port of the downstream connection. IP addresses are the only address type with a port component.

Note

This may not be the physical remote address of the peer if the address has been inferred from Proxy Protocol filter or x-forwarded-for.

%DOWNSTREAM_DIRECT_REMOTE_ADDRESS%

Direct remote address of the downstream connection. If the address is an IP address it includes both address and port.

Note

This is always the physical remote address of the peer even if the downstream remote address has been inferred from Proxy Protocol filter or x-forwarded-for.

%DOWNSTREAM_DIRECT_REMOTE_ADDRESS_WITHOUT_PORT%

Direct remote address of the downstream connection, without any port component. IP addresses are the only address type with a port component.

Note

This is always the physical remote address of the peer even if the downstream remote address has been inferred from Proxy Protocol filter or x-forwarded-for.

%DOWNSTREAM_DIRECT_REMOTE_PORT%

Direct remote port of the downstream connection. IP addresses are the only address type with a port component.

Note

This is always the physical remote address of the peer even if the downstream remote address has been inferred from Proxy Protocol filter or x-forwarded-for.

%DOWNSTREAM_LOCAL_ADDRESS%

Local address of the downstream connection. If the address is an IP address it includes both address and port.

If the original connection was redirected by iptables REDIRECT, this represents the original destination address restored by the Original Destination Filter using SO_ORIGINAL_DST socket option. If the original connection was redirected by iptables TPROXY, and the listener’s transparent option was set to true, this represents the original destination address and port.

Note

This may not be the physical remote address of the peer if the address has been inferred from Proxy Protocol filter or x-forwarded-for.

%DOWNSTREAM_LOCAL_ADDRESS_WITHOUT_PORT%

Local address of the downstream connection, without any port component. IP addresses are the only address type with a port component.

%DOWNSTREAM_LOCAL_PORT%

Local port of the downstream connection. IP addresses are the only address type with a port component.

%CONNECTION_ID%: An identifier for the downstream connection. It can be used to cross-reference TCP access logs across multiple log sinks, or to cross-reference timer-based reports for the same connection. The identifier is unique with high likelihood within an execution, but can duplicate across multiple instances or between restarts.

%UPSTREAM_CONNECTION_ID%: An identifier for the upstream connection. It can be used to cross-reference TCP access logs across multiple log sinks, or to cross-reference timer-based reports for the same connection. The identifier is unique with high likelihood within an execution, but can duplicate across multiple instances or between restarts.

%STREAM_ID%: An identifier for the stream (HTTP request, long-live HTTP2 stream, TCP connection, etc.). It can be used to cross-reference TCP access logs across multiple log sinks, or to cross-reference timer-based reports for the same connection. Different with %CONNECTION_ID%, the identifier should be unique across multiple instances or between restarts. And it’s value should be same with %REQ(X-REQUEST-ID)% for HTTP request. This should be used to replace %CONNECTION_ID% and %REQ(X-REQUEST-ID)% in most cases.
%GRPC_STATUS(X)%: gRPC status code formatted according to the optional parameter X, which can be CAMEL_STRING, SNAKE_STRING and NUMBER. For example, if the grpc status is INVALID_ARGUMENT (represented by number 3), the formatter will return InvalidArgument for CAMEL_STRING, INVALID_ARGUMENT for SNAKE_STRING and 3 for NUMBER. If X isn’t provided, CAMEL_STRING will be used.
%GRPC_STATUS_NUMBER%: gRPC status code.

%REQ(X?Y):Z%

HTTP: An HTTP request header where X is the main HTTP header, Y is the alternative one, and Z is an optional parameter denoting string truncation up to Z characters long. The value is taken from the HTTP request header named X first and if it’s not set, then request header Y is used. If none of the headers are present ‘-’ symbol will be in the log.
TCP/UDP: Not implemented (“-“).

%RESP(X?Y):Z%

HTTP: Same as %REQ(X?Y):Z% but taken from HTTP response headers.
TCP/UDP: Not implemented (“-“).

%TRAILER(X?Y):Z%

HTTP: Same as %REQ(X?Y):Z% but taken from HTTP response trailers.
TCP/UDP: Not implemented (“-“).

%DYNAMIC_METADATA(NAMESPACE:KEY*):Z%

HTTP

Dynamic Metadata info, where NAMESPACE is the filter namespace used when setting the metadata, KEY is an optional lookup key in the namespace with the option of specifying nested keys separated by ‘:’, and Z is an optional parameter denoting string truncation up to Z characters long. Dynamic Metadata can be set by filters using the StreamInfo API: setDynamicMetadata. The data will be logged as a JSON string. For example, for the following dynamic metadata:

com.test.my_filter: {"test_key": "foo", "test_object": {"inner_key": "bar"}}

%DYNAMIC_METADATA(com.test.my_filter)% will log: {"test_key": "foo", "test_object": {"inner_key": "bar"}}
%DYNAMIC_METADATA(com.test.my_filter:test_key)% will log: foo
%DYNAMIC_METADATA(com.test.my_filter:test_object)% will log: {"inner_key": "bar"}
%DYNAMIC_METADATA(com.test.my_filter:test_object:inner_key)% will log: bar
%DYNAMIC_METADATA(com.unknown_filter)% will log: -
%DYNAMIC_METADATA(com.test.my_filter:unknown_key)% will log: -
%DYNAMIC_METADATA(com.test.my_filter):25% will log (truncation at 25 characters): {"test_key": "foo", "test

TCP

Not implemented (“-“).

UDP

For UDP Proxy, when NAMESPACE is set to “udp.proxy.session”, optional KEYs are as follows:

cluster_name: Name of the cluster.
bytes_sent: Total number of downstream bytes sent to the upstream in the session.
bytes_received: Total number of downstream bytes received from the upstream in the session.
errors_sent: Number of errors that have occurred when sending datagrams to the upstream in the session.
datagrams_sent: Number of datagrams sent to the upstream successfully in the session.
datagrams_received: Number of datagrams received from the upstream successfully in the session.

Recommended session access log format for UDP proxy:

[%START_TIME%] %DYNAMIC_METADATA(udp.proxy.session:cluster_name)%
%DYNAMIC_METADATA(udp.proxy.session:bytes_sent)%
%DYNAMIC_METADATA(udp.proxy.session:bytes_received)%
%DYNAMIC_METADATA(udp.proxy.session:errors_sent)%
%DYNAMIC_METADATA(udp.proxy.session:datagrams_sent)%
%DYNAMIC_METADATA(udp.proxy.session:datagrams_received)%\n

when NAMESPACE is set to “udp.proxy.proxy”, optional KEYs are as follows:

bytes_sent: Total number of downstream bytes sent to the upstream in UDP proxy.
bytes_received: Total number of downstream bytes received from the upstream in UDP proxy.
errors_sent: Number of errors that have occurred when sending datagrams to the upstream in UDP proxy.
errors_received: Number of errors that have occurred when receiving datagrams from the upstream in UDP proxy.
datagrams_sent: Number of datagrams sent to the upstream successfully in UDP proxy.
datagrams_received: Number of datagrams received from the upstream successfully in UDP proxy.
no_route: Number of times that no upstream cluster found in UDP proxy.
session_total: Total number of sessions in UDP proxy.
idle_timeout: Number of times that sessions idle timeout occurred in UDP proxy.

Recommended proxy access log format for UDP proxy:

[%START_TIME%]
%DYNAMIC_METADATA(udp.proxy.proxy:bytes_sent)%
%DYNAMIC_METADATA(udp.proxy.proxy:bytes_received)%
%DYNAMIC_METADATA(udp.proxy.proxy:errors_sent)%
%DYNAMIC_METADATA(udp.proxy.proxy:errors_received)%
%DYNAMIC_METADATA(udp.proxy.proxy:datagrams_sent)%
%DYNAMIC_METADATA(udp.proxy.proxy:datagrams_received)%
%DYNAMIC_METADATA(udp.proxy.proxy:session_total)%\n

THRIFT

For Thrift Proxy, NAMESPACE should be always set to “thrift.proxy”, optional KEYs are as follows:

method: Name of the method.
cluster_name: Name of the cluster.
passthrough: Passthrough support for the request and response.
request:transport_type: The transport type of the request.
request:protocol_type: The protocol type of the request.
request:message_type: The message type of the request.
response:transport_type: The transport type of the response.
response:protocol_type: The protocol type of the response.
response:message_type: The message type of the response.
response:reply_type: The reply type of the response.

Recommended access log format for Thrift proxy:

[%START_TIME%] %DYNAMIC_METADATA(thrift.proxy:method)%
%DYNAMIC_METADATA(thrift.proxy:cluster)%
%DYNAMIC_METADATA(thrift.proxy:request:transport_type)%
%DYNAMIC_METADATA(thrift.proxy:request:protocol_type)%
%DYNAMIC_METADATA(thrift.proxy:request:message_type)%
%DYNAMIC_METADATA(thrift.proxy:response:transport_type)%
%DYNAMIC_METADATA(thrift.proxy:response:protocol_type)%
%DYNAMIC_METADATA(thrift.proxy:response:message_type)%
%DYNAMIC_METADATA(thrift.proxy:response:reply_type)%
%BYTES_RECEIVED%
%BYTES_SENT%
%DURATION%
%UPSTREAM_HOST%\n

Note

For typed JSON logs, this operator renders a single value with string, numeric, or boolean type when the referenced key is a simple value. If the referenced key is a struct or list value, a JSON struct or list is rendered. Structs and lists may be nested. In any event, the maximum length is ignored.

Note

DYNAMIC_METADATA command operator will be deprecated in the future in favor of METADATA operator.

%CLUSTER_METADATA(NAMESPACE:KEY*):Z%

HTTP

Upstream cluster Metadata info, where NAMESPACE is the filter namespace used when setting the metadata, KEY is an optional lookup key in the namespace with the option of specifying nested keys separated by ‘:’, and Z is an optional parameter denoting string truncation up to Z characters long. The data will be logged as a JSON string. For example, for the following dynamic metadata:

com.test.my_filter: {"test_key": "foo", "test_object": {"inner_key": "bar"}}

%CLUSTER_METADATA(com.test.my_filter)% will log: {"test_key": "foo", "test_object": {"inner_key": "bar"}}
%CLUSTER_METADATA(com.test.my_filter:test_key)% will log: foo
%CLUSTER_METADATA(com.test.my_filter:test_object)% will log: {"inner_key": "bar"}
%CLUSTER_METADATA(com.test.my_filter:test_object:inner_key)% will log: bar
%CLUSTER_METADATA(com.unknown_filter)% will log: -
%CLUSTER_METADATA(com.test.my_filter:unknown_key)% will log: -
%CLUSTER_METADATA(com.test.my_filter):25% will log (truncation at 25 characters): {"test_key": "foo", "test

TCP/UDP/THRIFT

Not implemented (“-“).

Note

For typed JSON logs, this operator renders a single value with string, numeric, or boolean type when the referenced key is a simple value. If the referenced key is a struct or list value, a JSON struct or list is rendered. Structs and lists may be nested. In any event, the maximum length is ignored.

Note

CLUSTER_METADATA command operator will be deprecated in the future in favor of METADATA operator.

%UPSTREAM_METADATA(NAMESPACE:KEY*):Z%

HTTP/TCP

Upstream host Metadata info, where NAMESPACE is the filter namespace used when setting the metadata, KEY is an optional lookup key in the namespace with the option of specifying nested keys separated by ‘:’, and Z is an optional parameter denoting string truncation up to Z characters long. The data will be logged as a JSON string. For example, for the following upstream host metadata:

com.test.my_filter: {"test_key": "foo", "test_object": {"inner_key": "bar"}}

%UPSTREAM_METADATA(com.test.my_filter)% will log: {"test_key": "foo", "test_object": {"inner_key": "bar"}}
%UPSTREAM_METADATA(com.test.my_filter:test_key)% will log: foo
%UPSTREAM_METADATA(com.test.my_filter:test_object)% will log: {"inner_key": "bar"}
%UPSTREAM_METADATA(com.test.my_filter:test_object:inner_key)% will log: bar
%UPSTREAM_METADATA(com.unknown_filter)% will log: -
%UPSTREAM_METADATA(com.test.my_filter:unknown_key)% will log: -
%UPSTREAM_METADATA(com.test.my_filter):25% will log (truncation at 25 characters): {"test_key": "foo", "test

UDP/THRIFT

Not implemented (“-“).

Note

For typed JSON logs, this operator renders a single value with string, numeric, or boolean type when the referenced key is a simple value. If the referenced key is a struct or list value, a JSON struct or list is rendered. Structs and lists may be nested. In any event, the maximum length is ignored.

Note

UPSTREAM_METADATA command operator will be deprecated in the future in favor of METADATA operator.

%FILTER_STATE(KEY:F:FIELD?):Z%

HTTP: Filter State info, where the KEY is required to look up the filter state object. The serialized proto will be logged as JSON string if possible. If the serialized proto is unknown to Envoy it will be logged as protobuf debug string. Z is an optional parameter denoting string truncation up to Z characters long. F is an optional parameter used to indicate which method FilterState uses for serialization. If ‘PLAIN’ is set, the filter state object will be serialized as an unstructured string. If ‘TYPED’ is set or no F provided, the filter state object will be serialized as an JSON string. If F is set to ‘FIELD’, the filter state object field with the name FIELD will be serialized. FIELD parameter should only be used with F set to ‘FIELD’.
TCP/UDP: Same as HTTP, the filter state is from connection instead of a L7 request.

Note

For typed JSON logs, this operator renders a single value with string, numeric, or boolean type when the referenced key is a simple value. If the referenced key is a struct or list value, a JSON struct or list is rendered. Structs and lists may be nested. In any event, the maximum length is ignored

%UPSTREAM_FILTER_STATE(KEY:F:FIELD?):Z%

HTTP

Extracts filter state from upstream components like cluster or transport socket extensions.

Filter State info, where the KEY is required to look up the filter state object. The serialized proto will be logged as JSON string if possible. If the serialized proto is unknown to Envoy it will be logged as protobuf debug string. Z is an optional parameter denoting string truncation up to Z characters long. F is an optional parameter used to indicate which method FilterState uses for serialization. If ‘PLAIN’ is set, the filter state object will be serialized as an unstructured string. If ‘TYPED’ is set or no F provided, the filter state object will be serialized as an JSON string. If F is set to ‘FIELD’, the filter state object field with the name FIELD will be serialized. FIELD parameter should only be used with F set to ‘FIELD’.

TCP/UDP

Not implemented.

Note

This command operator is only available for upstream_log

%REQUESTED_SERVER_NAME%

HTTP/TCP/THRIFT: String value set on ssl connection socket for Server Name Indication (SNI)
UDP: Not implemented (“-“).

%DOWNSTREAM_LOCAL_IP_SAN%

HTTP/TCP/THRIFT: The ip addresses present in the SAN of the local certificate used to establish the downstream TLS connection.
UDP: Not implemented (“-“).

%DOWNSTREAM_PEER_IP_SAN%

HTTP/TCP/THRIFT: The ip addresses present in the SAN of the peer certificate received from the downstream client to establish the TLS connection.
UDP: Not implemented (“-“).

%DOWNSTREAM_LOCAL_DNS_SAN%

HTTP/TCP/THRIFT: The DNS names present in the SAN of the local certificate used to establish the downstream TLS connection.
UDP: Not implemented (“-“).

%DOWNSTREAM_PEER_DNS_SAN%

HTTP/TCP/THRIFT: The DNS names present in the SAN of the peer certificate received from the downstream client to establish the TLS connection.
UDP: Not implemented (“-“).

%DOWNSTREAM_LOCAL_URI_SAN%

HTTP/TCP/THRIFT: The URIs present in the SAN of the local certificate used to establish the downstream TLS connection.
UDP: Not implemented (“-“).

%DOWNSTREAM_PEER_URI_SAN%

HTTP/TCP/THRIFT: The URIs present in the SAN of the peer certificate used to establish the downstream TLS connection.
UDP: Not implemented (“-“).

%DOWNSTREAM_LOCAL_SUBJECT%

HTTP/TCP/THRIFT: The subject present in the local certificate used to establish the downstream TLS connection.
UDP: Not implemented (“-“).

%DOWNSTREAM_PEER_SUBJECT%

HTTP/TCP/THRIFT: The subject present in the peer certificate used to establish the downstream TLS connection.
UDP: Not implemented (“-“).

%DOWNSTREAM_PEER_ISSUER%

HTTP/TCP/THRIFT: The issuer present in the peer certificate used to establish the downstream TLS connection.
UDP: Not implemented (“-“).

%DOWNSTREAM_TLS_SESSION_ID%

HTTP/TCP/THRIFT: The session ID for the established downstream TLS connection.
UDP: Not implemented (0).

%DOWNSTREAM_TLS_CIPHER%

HTTP/TCP/THRIFT: The OpenSSL name for the set of ciphers used to establish the downstream TLS connection.
UDP: Not implemented (“-“).

%DOWNSTREAM_TLS_VERSION%

HTTP/TCP/THRIFT: The TLS version (e.g., TLSv1.2, TLSv1.3) used to establish the downstream TLS connection.
UDP: Not implemented (“-“).

%DOWNSTREAM_PEER_FINGERPRINT_256%

HTTP/TCP/THRIFT: The hex-encoded SHA256 fingerprint of the client certificate used to establish the downstream TLS connection.
UDP: Not implemented (“-“).

%DOWNSTREAM_PEER_FINGERPRINT_1%

HTTP/TCP/THRIFT: The hex-encoded SHA1 fingerprint of the client certificate used to establish the downstream TLS connection.
UDP: Not implemented (“-“).

%DOWNSTREAM_PEER_SERIAL%

HTTP/TCP/THRIFT: The serial number of the client certificate used to establish the downstream TLS connection.
UDP: Not implemented (“-“).

%DOWNSTREAM_PEER_CERT%

HTTP/TCP/THRIFT: The client certificate in the URL-encoded PEM format used to establish the downstream TLS connection.
UDP: Not implemented (“-“).

%DOWNSTREAM_PEER_CERT_V_START%

HTTP/TCP/THRIFT: The validity start date of the client certificate used to establish the downstream TLS connection.
UDP: Not implemented (“-“).

DOWNSTREAM_PEER_CERT_V_START can be customized using a format string. See START_TIME for additional format specifiers and examples.

%DOWNSTREAM_PEER_CERT_V_END%

HTTP/TCP/THRIFT: The validity end date of the client certificate used to establish the downstream TLS connection.
UDP: Not implemented (“-“).

DOWNSTREAM_PEER_CERT_V_END can be customized using a format string. See START_TIME for additional format specifiers and examples.

%UPSTREAM_PEER_SUBJECT%

HTTP/TCP/THRIFT: The subject present in the peer certificate used to establish the upstream TLS connection.
UDP: Not implemented (“-“).

%UPSTREAM_PEER_ISSUER%

HTTP/TCP/THRIFT: The issuer present in the peer certificate used to establish the upstream TLS connection.
UDP: Not implemented (“-“).

%UPSTREAM_TLS_SESSION_ID%

HTTP/TCP/THRIFT: The session ID for the established upstream TLS connection.
UDP: Not implemented (0).

%UPSTREAM_TLS_CIPHER%

HTTP/TCP/THRIFT: The OpenSSL name for the set of ciphers used to establish the upstream TLS connection.
UDP: Not implemented (“-“).

%UPSTREAM_TLS_VERSION%

HTTP/TCP/THRIFT: The TLS version (e.g., TLSv1.2, TLSv1.3) used to establish the upstream TLS connection.
UDP: Not implemented (“-“).

%UPSTREAM_PEER_CERT%

HTTP/TCP/THRIFT: The server certificate in the URL-encoded PEM format used to establish the upstream TLS connection.
UDP: Not implemented (“-“).

%UPSTREAM_PEER_CERT_V_START%

HTTP/TCP/THRIFT: The validity start date of the upstream server certificate used to establish the upstream TLS connection.
UDP: Not implemented (“-“).

UPSTREAM_PEER_CERT_V_START can be customized using a format string. See START_TIME for additional format specifiers and examples.

%UPSTREAM_PEER_CERT_V_END%

HTTP/TCP/THRIFT: The validity end date of the upstream server certificate used to establish the upstream TLS connection.
UDP: Not implemented (“-“).

UPSTREAM_PEER_CERT_V_END can be customized using a format string. See START_TIME for additional format specifiers and examples.

%UPSTREAM_PEER_URI_SAN%

HTTP/TCP/THRIFT: The URIs present in the SAN of the peer certificate used to establish the upstream TLS connection.
UDP: Not implemented (“-“).

%UPSTREAM_PEER_DNS_SAN%

HTTP/TCP/THRIFT: The DNS names present in the SAN of the peer certificate used to establish the upstream TLS connection.
UDP: Not implemented (“-“).

%UPSTREAM_PEER_IP_SAN%

HTTP/TCP/THRIFT: The ip addresses present in the SAN of the peer certificate used to establish the upstream TLS connection.
UDP: Not implemented (“-“).

%UPSTREAM_LOCAL_URI_SAN%

HTTP/TCP/THRIFT: The URIs present in the SAN of the local certificate used to establish the upstream TLS connection.
UDP: Not implemented (“-“).

%UPSTREAM_LOCAL_DNS_SAN%

HTTP/TCP/THRIFT: The DNS names present in the SAN of the local certificate used to establish the upstream TLS connection.
UDP: Not implemented (“-“).

%UPSTREAM_LOCAL_IP_SAN%

HTTP/TCP/THRIFT: The ip addresses present in the SAN of the local certificate used to establish the upstream TLS connection.
UDP: Not implemented (“-“).

%HOSTNAME%

The system hostname.

%LOCAL_REPLY_BODY%

The body text for the requests rejected by the Envoy.

%FILTER_CHAIN_NAME%

The network filter chain name of the downstream connection.

%ACCESS_LOG_TYPE%

The type of the access log, which indicates when the access log was recorded. If a non-supported log (from the list below), uses this substitution string, then the value will be an empty string.

TcpUpstreamConnected - When TCP Proxy filter has successfully established an upstream connection.
TcpPeriodic - On any TCP Proxy filter periodic log record.
TcpConnectionEnd - When a TCP connection is ended on TCP Proxy filter.
DownstreamStart - When HTTP Connection Manager filter receives a new HTTP request.
DownstreamTunnelSuccessfullyEstablished - When the HTTP Connection Manager sends response headers
indicating a successful HTTP tunnel.
DownstreamPeriodic - On any HTTP Connection Manager periodic log record.
DownstreamEnd - When an HTTP stream is ended on HTTP Connection Manager filter.
UpstreamPoolReady - When a new HTTP request is received by the HTTP Router filter.
UpstreamPeriodic - On any HTTP Router filter periodic log record.
UpstreamEnd - When an HTTP request is finished on the HTTP Router filter.
UdpTunnelUpstreamConnected - When UDP Proxy filter has successfully established an upstream connection.
Note: It is only relevant for UDP tunneling over HTTP.
UdpPeriodic - On any UDP Proxy filter periodic log record.
UdpSessionEnd - When a UDP session is ended on UDP Proxy filter.

%ENVIRONMENT(X):Z%

Environment value of environment variable X. If no valid environment variable X, ‘-’ symbol will be used. Z is an optional parameter denoting string truncation up to Z characters long.

%TRACE_ID%

HTTP: The trace ID of the request. If the request does not have a trace ID, this will be an empty string.
TCP/UDP: Not implemented (“-“).