krapslog

Visualize a log file with sparklines

When troubleshooting a problem with a production service, I often need to get the general shape of a log file. Are there any spikes? Was the load higher during the incident than it was beforehand? Does anything else stand out? Without tooling to help you, a large log file is little more than a blob of data. This tool is designed to quickly surface key features of the log — and then get out of your way.

Installing

cargo install krapslog

Usage

``` $ krapslog -h [...] Visualize log files using sparklines

USAGE: krapslog [FLAGS] [OPTIONS] [FILE]

FLAGS: -p, --progress Display progress while working. Requires a file. -h, --help Prints help information -V, --version Prints version information

OPTIONS: -f, --filter Only consider lines that contain this value -F, --format Timestamp format to match [default: %d/%b/%Y:%H:%M:%S%.f] -m, --markers Number of time markers to display [default: 0]

ARGS: Log file to analyze ```

Examples

Get the basic shape:

$ krapslog /var/log/haproxy.log ▂▂▂▂▂▁▂▁▁▁▁▂▁▁▁▁▂▂▂▁▁▁▁▁▁▁▁▁▂▂▂▂▂▂▂▂▂▃▂▂▂▃▂▂▂▂▃▃▃▃▃▄▅▅▅▄▅▃▄▃▄▄▅▅▆▇▆▆▆▆▆▆▆▆▇▇▇▇██

Add points in time:

$ krapslog --markers 10 /var/log/haproxy.log Sat Nov 23 14:15:56 Sat Nov 23 13:22:29 | Sat Nov 23 12:29:01 | | Sat Nov 23 11:35:33 | | | Sat Nov 23 10:48:02 | | | | | | | | | ▂▂▂▂▂▁▂▁▁▁▁▂▁▁▁▁▂▂▂▁▁▁▁▁▁▁▁▁▂▂▂▂▂▂▂▂▂▃▂▂▂▃▂▂▂▂▃▃▃▃▃▄▅▅▅▄▅▃▄▃▄▄▅▅▆▇▆▆▆▆▆▆▆▆▇▇▇▇██ | | | | | | | | | Sat Nov 23 09:54:34 | | | Sat Nov 23 09:01:07 | | Sat Nov 23 08:13:36 | Sat Nov 23 07:20:08 Sat Nov 23 06:26:40

Custom date formats

By default, krapslog assumes that log timestamps are in the Common Log Format (CLF), which looks like this: "02/Jan/2006:15:04:05.000" (timezone offset is ignored). However, you can use the format parameter to find timestamps in other formats. The parameter value must use a format that's recognized by strftime.

For example, if your log contains dates that look like "Jan 1, 2020 15:04:05", you can run krapslog as follows:

krapslog --format "%b %d, %Y %H:%M:%S" ...

Currently supported specifiers

| Specifier | Meaning | | --------- | ------- | | %Y | The full proleptic Gregorian year, zero-padded to 4 digits. | | %C | The proleptic Gregorian year divided by 100, zero-padded to 2 digits. | | %y | The proleptic Gregorian year modulo 100, zero-padded to 2 digits. | | %m | Month number (01--12), zero-padded to 2 digits. | | %b | Abbreviated month name. Always 3 letters. | | %B | Full month name. Also accepts corresponding abbreviation in parsing. | | %h | Same as %b. | | %d | Day number (01--31), zero-padded to 2 digits. | | %H | Hour number (00--23), zero-padded to 2 digits. | | %M | Minute number (00--59), zero-padded to 2 digits. | | %S | Second number (00--60), zero-padded to 2 digits. | | %.f | Similar to .%f but left-aligned. These all consume the leading dot. |

Contributing

Please be kind. We're all trying to do our best.

If you find a bug, please open an issue. (Or, better, submit a pull request that fixes it!)

If you'd like see a new feature or would like to add one yourself, please open an issue so that we can discuss it.