Logging
Logging overview for Saurron.
Log level and format
Saurron’s log verbosity and output format are controlled with --log-level and --log-format. See Configuration — Logging for the full reference.
RUST_LOG
RUST_LOG is an environment variable read by Saurron at startup that lets you set log levels on a per-crate or per-module basis. It uses the same syntax as the tracing-subscriber EnvFilter and is evaluated in addition to --log-level / SAURRON_LOG_LEVEL.
Directive syntax
A RUST_LOG value is a comma-separated list of directives. Each directive is one of:
- A bare level (
info,debug,warn,error,trace) — sets the global floor. target=level— sets the level for a specific crate or module.target[span]=level— sets the level for events inside a specific span (advanced).
More specific directives take priority over less specific ones. Directives in RUST_LOG take priority over the --log-level / SAURRON_LOG_LEVEL setting.
Common examples
Suppress verbose output from HTTP and Docker client libraries while keeping Saurron at debug:
RUST_LOG=saurron=debug,reqwest=warn,bollard=warn saurron
Raise the global level to warn but keep Saurron’s own update cycle at info:
RUST_LOG=warn,saurron::update=info saurron
Show trace-level output only for registry interactions:
RUST_LOG=saurron=info,saurron::registry=trace saurron
Saurron module targets
| Target | What it covers |
|---|---|
saurron | All Saurron events (catch-all) |
saurron::update | Update cycle: freshness checks, pull, restart, rollback |
saurron::registry | Registry HTTP requests and manifest parsing |
saurron::docker | Docker daemon calls |
saurron::http | HTTP API request handling |
saurron::scheduler | Scheduled cycle dispatch |
saurron::access | HTTP access log events (one per request) |
saurron::audit | Audit log events (one per update or rollback) |
Third-party crate targets you may want to quiet: bollard, reqwest, hyper, tokio.