logs.md

Logs

Logging

Logging Levels

The recognized values for logging are: error, warn, info, debug, and trace. For a more detailed explanation of logging in Chef Habitat, see the Supervisor Log Configuration Reference and the Supervisor Log Key documentation.

Basic Logging

To turn on and examine the services debug logging in your Habitat installation:

1. Edit the sudo /hab/svc/builder-api/user.toml file

2. On the first line, change the log_level from error to debug

   log_level="debug,tokio_core=error,tokio_reactor=error,zmq=error,hyper=error"

3. Save and close the file

4. Restart Habitat with sudo systemctl restart hab-sup.

5. Use journalctl -fu hab-sup to view the logs.

6. Reset /hab/svc/builder-api/user.toml file to the default log_level=error and restart the services with sudo systemctl restart hab-sup to restore error-level logging.

RUST_LOG

1. Use RUST_LOG=debug RUST_BACKTRACE=1 to see an individual command's debug and backtrace.

   # Linux/MacOS
   # replace "hab sup run" with your command
   env RUST_LOG=debug RUST_BACKTRACE=1 hab sup run

2. Edit the sudo /hab/svc/builder-api/user.toml file

3. On the second line, change:

   RUST_LOG=debug RUST_BACKTRACE=1

Log Rotation

The builder-api-proxy service will log (via Nginx) all access and errors to log files in your service directory. Since these files may get large, you may want to add a log rotation script. Below is a sample logrotate file that you can use as an example for your needs:

```bash
/hab/svc/builder-api-proxy/logs/host.access.log
/hab/svc/builder-api-proxy/logs/host.error.log
{
        rotate 7
        daily
        missingok
        notifempty
        delaycompress
        compress
        postrotate
                /bin/kill -USR1 `cat /hab/svc/builder-api-proxy/var/pid 2>/dev/null` 2>/dev/null || true
        endscript
}
```