Parses data as JSON. Specify field=@rawstring to parse the rawstring into JSON. It is possible to prefix the names of the extracted fields using the prefix parameter. It is also possible to exclude some of the extracted fields using the exclude parameter, specify exclude=a.b.c to exclude c and all of its descendants or exclude="a.b[*].c" to exclude all c inside the array b. If you need to keep certain descendants of an otherwise excluded path you can use the include parameter.

ParameterTypeRequiredDefaultDescription
exclude[string]false[]Fields that should be excluded from the result, supports dot-pathing and array wildcards. If used with prefix the exclude fields should be prefixed as well.
excludeEmpty[string]falsefalseWhether to exclude if the field is empty
fieldstringtrue@rawstringFields that should be parsed as JSON. [a]
handleNull[string]falsekeepHow to handle null values: keep; empty; discard.
include[string]false[]Fields that should be included even if they had been previously excluded by use of exclude, supports dot-pathing and array wildcards. If used with prefix the include fields should be prefixed as well.
prefixstringfalseblankPrefix the name of the extracted JSON fields with the value of this parameter.
removePrefixes[string]false[]Prefixes that should be removed from the names of the extracted JSON fields, supports dot-pathing. If multiple prefixes are supplied, the longest matching prefix will be used.

[a] If an argument name is not given, field is the default argument.

parseJson() Examples

If the whole event sent to LogScale is JSON like:

javascript
{"service": "userService", "timestamp": "2017-12-18T20:39:35Z", "msg": "user with id=47 logged in"}
logscale
parseJson()
| parseTimestamp(field=timestamp)

If a field in the incoming event contains JSON like:

ini
2017-12-18T20:39:35Z user id=47 logged in details="{"name": "Peter", "email": "peter@test.com", "id":47}"

In the example below the details field is extracted using the kvparse function and then parseJson is used to parse the JSON inside the details field.

logscale
/(?<timestamp>\S+)/
| parseTimestamp(field=timestamp)
| kvParse()
| parseJson(field=details)

It is possible to prefix names of the extracted JSON fields. This can be useful for avoiding collisions with existing fields with the same name. For example the input line:

logscale
added new user details="{"email": "foo@test.com", "name": "Peter"}"

Could be parsed into these fields: , user.name=Peter.

logscale
kvParse()
| parseJson(field=details, prefix="user.")

It is possible to remove prefixes as well. For example the input line:

logscale
details="{"a": { "b": { "c": { "d": "e", "f": "g"}, "h": "i" }, "j": "k" } }"

Would be parsed into these fields: b.c.d=e, b.c.f=g, b.h=i, j=k.

logscale
kvParse()
| parseJson(field=details, removePrefixes=a.)

It is possible to exclude extracted fields. This can be useful for removing sensitive data or e.g. large arrays. For example the input line:

logscale
details="{"a": { "b": { "c": { "d": "e", "f": "g"}, "h": "i" }, "j": "k" } }"

Would be parsed into these fields: a.b.h=i, a.j=k but not e.g. a.b.c.d=e

logscale
kvParse()
| parseJson(field=details, exclude=a.b.c)

It is also possible to exclude extracted fields within arrays. For example the input line:

logscale
details="{"a": { "b": [{ "c": { "d": 1 }, "e": "f" }, { "c": { "d": 2 }, "e": "h" }] } }"

Would be parsed into these fields: a.b[0].e=f, a.b[1].e=h but not e.g. a.b[0].c.d=1.

logscale
kvParse()
| parseJson(field=details, exclude="a.b[*].c")

It is possible to include fields that had previously been excluded. For example the input line:

logscale
details="{"a": { "b": { "c": { "d": 1, "e": 2} } } }"

Would be parsed into these fields: a.b.c.e=2.

logscale
kvParse()
| parseJson(field=details, exclude=a.b.c, include=a.b.c.e)

If includes and excludes are used with prefix, you need to prefix the includes and excludes as well. For example the input line:

logscale
details="{"a": { "b": { "c": { "d": 1, "e": 2} } } }"

Would be parsed into these fields: x.a.b.c.e=2.

logscale
kvParse()
| parseJson(field=details, prefix=x., exclude=x.a.b.c, include=x.a.b.c.e)