jl is a development tool for working with structured JSON logging.
Modern applications quite often use structured logging instead of simple log
messages. This is preferable for computer systems but not for humans. jl will
help development by translating structured message into old-fashioned log lines.
A code snippets says more than a thousand words:
$ myprogram
{"message": "Hello, world!!", "severity": "info"}
{"message": "skipping file", "severity": "warn", "file": "empty.txt"}
$ myprogram | jl
INFO: Hello, world!!
WARNING: skipping file [file=empty.txt]
$ brew install koenbollen/public/jl
$ echo '{"msg": "It works!"}' | jl
It works!$ curl -LO https://github.com/koenbollen/jl/releases/download/v1.4.0/jl_linux_amd64
$ sudo install jl_linux_amd64 /usr/bin/jl && rm jl_linux_amd64
$ echo '{"msg": "It works!"}' | jl
It works!Alternatively you can fetch a binary from the
latest release or install the
latest development version from source: go install github.com/koenbollen/jl@latest (requires Go 1.17+).
Usage:
jl [options] [FILE...]
Options:
-h, --help Show this screen.
--version Show version.
Output Options:
--color Force colorized output
--no-color Don't colorize output
--skip-prefix Skip printing truncated bytes before the JSON
--skip-suffix Skip printing truncated bytes after the JSON
Formatting Options:
--skip-fields Don't output misc json keys as fields
--max-field-length <int> Any field, exceeding the given length (including field name) will be ommitted from output. Use 0 to remove the length limit [default: 30]
--include-fields <fields>, -f <fields> Always include these json keys as fields, no matter the length (comma separated list)
--exclude-fields <fields> Always exclude these json keys (comma separated list)
You can add any option to the JL_OPTS environment variable, ex:
export JL_OPTS="--no-color"
jl tries to dynamically parse the lines to support as many well
known formats as possible.
Is jl not compatible with your structured logging? Please let me
know by creating an issue.