sls-logger

sls-logger

Builds one access-log entry per request and hands it to a fire-and-forget batching sink; a background task POSTs batches to Alibaba Cloud Simple Log Service (SLS) using its signed PutLogs REST API. Place it in the response pipeline, after the upstream node. The node passes the context through unchanged and never fails.

Configuration

Key	Type	Default	Description
host	string	—	SLS endpoint, e.g. cn-hangzhou.log.aliyuncs.com. Required.
port	integer	—	Endpoint port, e.g. 443. Required.
project	string	—	SLS project; prefixed to host as the request authority <project>.<host>. Required.
logstore	string	—	Destination logstore. Required.
access_key_id	string	—	RAM access-key id. Required.
access_key_secret	string	—	RAM access-key secret (used to sign each request). Required.
timeout	integer (ms)	5000	Per-flush HTTP deadline.
include_req_body	bool	false	Include the request body in the default entry.
include_resp_body	bool	false	Include the response body in the default entry.
log_format	object	—	Custom flat entry of name -> "$var template".
batch_max_size	integer	1000	Entries per batch before an immediate flush.
inactive_timeout	integer (s)	5	Flush after this much idle time.
buffer_duration	integer (s)	60	Flush when the oldest buffered entry is this old.
max_retry_count	integer	0	Retries after a failed flush.
retry_delay	integer (s)	1	Delay between retries.
max_pending_entries	integer	10000	Queue capacity; entries are dropped (with a warning) when full.

- id: sls-log
  type: sls-logger
  config:
    host: cn-hangzhou.log.aliyuncs.com
    port: 443
    project: my-project
    logstore: gateway
    access_key_id: ${SLS_KEY_ID}
    access_key_secret: ${SLS_KEY_SECRET}

Behavior

Each flush POSTs https://<project>.<host>:<port>/logstores/<logstore>/shards/lb with a JSON body {"__topic__","__source__","__logs__":[…]}. SLS requires string log values, so non-string entry fields are JSON-encoded. The request is signed per the SLS spec: Content-MD5, Date, the sorted x-log-* canonical headers, and the canonical resource are HMAC-SHA1 signed with the access-key secret, base64-encoded, and sent as Authorization: LOG <access_key_id>:<signature>. A non-200 response fails the batch, which is retried per the batch settings.

Behavior notes

featherbit's shared logging infrastructure is HTTP-only — there is no raw TLS/TCP syslog delivery path to the SLS syslog ingress. This node targets the documented SLS PutLogs REST API:

• The batch is POSTed as JSON to /logstores/<logstore>/shards/lb.
• Requests are signed with the SLS HMAC-SHA1 Authorization: LOG <id>:<signature> scheme (with a self-contained MD5 for Content-MD5).

The signing helper and its primitives (MD5, HMAC-SHA1) are unit-tested against fixed vectors.