telegraf/plugins/processors/strings

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