Jaxe - The J[son] [Pick]axe

jaxe parses new line delimited json on stdin and outputs a color human readable string on stdout.

jaxe supports basic filtering with a simple language. Certain json values can be omited or extracted. Invalid json can be displayed in a different color or omitted.

Examples

Considering the following newline delimited json log line:

$ cat example.log | jq
{
  "logger": "c.a.l.h.logging.RequestLoggingActor",
  "http_stime": "43",
  "http_method": "PUT",
  "http_path": "/api/v1/user",
  "at": "2022-03-24T08:56:20.576Z",
  "http_service_name": "reposerver",
  "msg": "http request",
  "http_status": "204",
  "level": "INFO"
}

Piping that line to jaxe will output:

I|2022-03-24T08:56:20.576Z|http_method=PUT http_path=/api/v1/user http_service_name=reposerver http_status=204 http_stime=43 logger=c.a.l.h.logging.RequestLoggingActor msg=http request

The output is colorized unless you use -n/--no-colors:

non json lines will be printed verbatim unless -j/--no-omit-json is used.

Often you have fields you don't care about, you can set JAXE_OMIT or use -o/to filter those fields out:

$ export JAXE_OMIT="logger,http_service_name"
$ cat example.log | jaxe
I|2022-03-24T08:56:20.576Z|http_method=PUT http_path=/api/v1/user http_status=204 http_stime=43 msg=http request

A DSL can be used to filter log lines, using -f/--filter or JAXE_FILTER:

$ cat example.log | jaxe --filter 'http_status==404'
$
$ cat example.log | jaxe --filter 'http_status==204'
I|2022-03-24T08:56:20.576Z|http_method=PUT http_path=/api/v1/user http_status=204 http_stime=43 msg=http request
$
$ cat example.log | jaxe --filter 'and(contains(msg,"http request"), not(contains(msg,"username")))'

You can extract only certains values from the json:

$ cat example.log | jaxe --extract http_method,http_status,msg
I|2022-03-24T08:56:20.576Z|http_method=PUT http_status=204 msg=http request 

Filtering DSL

The following DSL can be used with -f/--filter to filter lines. . can be used to refer to values nested in json objects.

Syntax	Example
.	nested.key
equals/not equals ==, !=	mykey0.otherkey == myvalue
and(exp)/or(exp)	and(http_status == 200, http_method != GET)
not(exp)	not(and(http_status == 200, http_method != GET))
contains(key, str)	contains(mykey, somestr)
exists(key)	exists(mykey)

Configuration

JAXE_OMIT and JAXE_FILTER can be set the same was as -o/--omit and -f/--filter.

JQ Support

jaxe has experimental jq expressions support. If compiled with --features jq, and the cli flag --jq is used, --filter will accept jq expressions to be used as filters, for example:

$ cat example.log | jaxe --jq --filter '.http_status == "204"'
I|2022-03-24T08:56:20.576Z|http_method=PUT http_path=/api/v1/user http_service_name=reposerver http_status=204 http_stime=43 logger=c.a.l.h.logging.RequestLoggingActor msg=http request

Usage

jaxe 0.1.0
A j[son] [pick]axe!

USAGE:
    jaxe [FLAGS] [OPTIONS]

FLAGS:
    -h, --help            Prints help information
    -n, --no-colors       Disable colors
    -j, --no-omit-json    Do not print non-json lines
    -V, --version         Prints version information

OPTIONS:
    -e, --extract <extract>     Fields to extract, default to extracting all fields [default: []]
    -f, --filter <filter>...    Filter by. See parse language
    -l, --level <level>...      level keys. The first of these keys in the json line will be used as the level of the
                                log line and formatted at the start of the line
    -o, --omit <omit>           Fields to omit [default: []]
    -t, --time <time>...        Time keys. The first of these keys in the json line will be used as the date of the log
                                line and formatted after the level

Install

From source

cargo install --path .

Downloaded Release

Binaries can be downloaded for the releases tab: https://github.com/simao/jaxe/releases

AUR

Use jaxe-bin. For example with yay:

yay -S jaxe-bin