Strings Processor Plugin
The strings
plugin maps certain go string functions onto measurement, tag, and field values. Values can be modified in place or stored in another key.
Implemented functions are:
- lowercase
- uppercase
- trim
- trim_left
- trim_right
- trim_prefix
- trim_suffix
- replace
Please note that in this implementation these are processed in the order that they appear above.
Specify the measurement
, tag
or field
that you want processed in each section and optionally a dest
if you want the result stored in a new tag or field. You can specify lots of transformations on data with a single strings processor.
If you'd like to apply the change to every tag
, field
, or measurement
, use the value "" for each respective field. Note that the dest
field will be ignored if "" is used
Configuration:
[[processors.strings]]
# [[processors.strings.uppercase]]
# tag = "method"
# [[processors.strings.lowercase]]
# field = "uri_stem"
# dest = "uri_stem_normalised"
## Convert a tag value to lowercase
# [[processors.strings.trim]]
# field = "message"
# [[processors.strings.trim_left]]
# field = "message"
# cutset = "\t"
# [[processors.strings.trim_right]]
# field = "message"
# cutset = "\r\n"
# [[processors.strings.trim_prefix]]
# field = "my_value"
# prefix = "my_"
# [[processors.strings.trim_suffix]]
# field = "read_count"
# suffix = "_count"
# [[processors.strings.replace]]
# measurement = "*"
# old = ":"
# new = "_"
Trim, TrimLeft, TrimRight
The trim
, trim_left
, and trim_right
functions take an optional parameter: cutset
. This value is a string containing the characters to remove from the value.
TrimPrefix, TrimSuffix
The trim_prefix
and trim_suffix
functions remote the given prefix
or suffix
respectively from the string.
Replace
The replace
function does a substring replacement across the entire
string to allow for different conventions between various input and output
plugins. Some example usages are eliminating disallowed characters in
field names or replacing separators between different separators.
Can also be used to eliminate unneeded chars that were in metrics.
If the entire name would be deleted, it will refuse to perform
the operation and keep the old name.
Example
Config
[[processors.strings]]
[[processors.strings.lowercase]]
field = "uri-stem"
[[processors.strings.trim_prefix]]
field = "uri_stem"
prefix = "/api/"
[[processors.strings.uppercase]]
field = "cs-host"
dest = "cs-host_normalised"
Input
iis_log,method=get,uri_stem=/API/HealthCheck cs-host="MIXEDCASE_host",referrer="-",ident="-",http_version=1.1,agent="UserAgent",resp_bytes=270i 1519652321000000000
Output
iis_log,method=get,uri_stem=healthcheck cs-host="MIXEDCASE_host",cs-host_normalised="MIXEDCASE_HOST",referrer="-",ident="-",http_version=1.1,agent="UserAgent",resp_bytes=270i 1519652321000000000