skywalking-logger

skywalking-logger

Ships a structured access-log entry for each request to an Apache SkyWalking OAP (Observability Analysis Platform) HTTP endpoint. Entries are buffered by a batch processor and POSTed in the background as a JSON array to <endpoint_addr>/v3/logs. The node passes the context through unchanged, so place it in the response pipeline after the upstream node.

Configuration

Key	Type	Default	Description
endpoint_addr	string	— (required)	SkyWalking OAP HTTP base, e.g. http://127.0.0.1:12800.
service_name	string	featherbit	SkyWalking service name reported on each log item.
service_instance_name	string	featherbit Instance Name	SkyWalking service instance name.
ssl_verify	bool	true	Verify the OAP TLS certificate.
timeout	int (seconds)	3	Per-flush HTTP timeout.
log_format	object	—	Custom name -> "$var template" map. When set, it replaces the default entry.
include_req_body / include_resp_body	bool	false	Include the (lossy UTF-8) request/response body in the default entry.

endpoint_addr is required or config load fails. Batch-processor keys (batch_max_size, inactive_timeout, buffer_duration, max_retry_count, retry_delay, max_pending_entries) are also accepted.

- id: skywalking-log
  type: skywalking-logger
  config:
    endpoint_addr: http://127.0.0.1:12800
    service_name: my-gateway
    service_instance_name: gw-1

Behavior

For each request the node builds a log entry (the shared default entry, or a log_format custom entry) and wraps it in a SkyWalking LogData item:

{
  "service": "<service_name>",
  "serviceInstance": "<service_instance_name>",
  "endpoint": "<request path>",
  "timestamp": 1700000000000,
  "body": { "json": { "json": "<the entry, JSON-encoded as a string>" } }
}

Items are buffered and the batch is POSTed as a JSON array to <endpoint_addr>/v3/logs. The node is a pure passthrough: it never modifies the context and only its success port is taken. Delivery is best-effort — a full queue drops items with a warning and failed flushes are retried per the batch config.

Behavior notes

• featherbit does not thread trace propagation into the log entry, so no traceContext is attached to items.
• A millisecond timestamp (SkyWalking's LogData.timestamp) is stamped at build time. The entry is embedded under body.json.json.