All About Logs

Tips and Tricks

Logs go stderr

The stacks-node binary output logs to stderr (vs. stdout). To easily capture / pipe / filter logs (e.g. using tools like tee), redirect stderr to stdout. In bash, this is accomplished with 2>&1, like so:

$ stacks-node start --config follower.toml 2>&1 | tee info-logs.txt`

Enabling debug logs

By default, the log level is set to INFO. To enable debug logging, set the environment variable STACKS_LOG_DEBUG=1.

$ STACKS_LOG_DEBUG=1 stacks-node start --config follower.toml 2>&1 | tee info-logs.txt`

To set the log-level to TRACE, set STACKS_LOG_TRACE=1 instead.

Output logs in JSON

First, you must compile stacks-node with the slog_json feature enabled, like so:

$ cargo build -F slog_json -p stacks-node --bin stacks-node

Once enabled, set the environment variable STACKS_LOG_JSON=1:

$ STACKS_LOG_JSON=1  stacks-node check-config --config follower.toml 2>&1 | jq .
{
  "msg": "stacks-node 0.1.0 (chore/logs:a93c2867d+, debug build, macos [aarch64])",
  "level": "INFO",
  "ts": "2023-06-02T16:54:04.377153Z",
  "thread": "main",
  "line": 82,
  "file": "testnet/stacks-node/src/main.rs"
}