Expand JSON fields - Log Service - Alibaba Cloud Documentation Center

You can use the processor_json plug-in to expand JSON fields. This topic describes the parameters of the processor_json plug-in. This topic also provides an example on how to configure the plug-in.

Important You can use form configuration to add Logtail plug-ins only if you select Kubernetes - Standard Output in the Import Data section.

Entry point

If you want to use a Logtail plug-in to process logs, you can add a Logtail plug-in configuration when you create or modify a Logtail configuration. For more information, see Entry point.

Usage notes

Important Only Logtail V0.16.28 and later support the processor_json plug-in.

Form configuration

Parameters

Set Processor Type to Expand JSON Field. Then, configure other parameters based on the following table.


Parameter	Description
Original Field	The name of the original field to expand.
JSON Expansion Depth	The depth of JSON expansion. Default value: 0, which indicates that the depth of JSON expansion is unlimited. If the value is n, the depth of JSON expansion is n.
Character to Concatenate Expanded Keys	The character that is used to connect expanded keys. The default value is an underscore (_).
Name Prefix of Expanded Keys	The prefix that is added to the names of expanded keys.
Retain Original Field	Specifies whether to retain the original field in the new log that is obtained after parsing.
Report Original Field Missing Error	Specifies whether to report an error if the raw log does not contain the original field.
Use Name of Original Field as Name Prefix of Expanded Keys	Specifies whether to add the name of the original field as a prefix to all expanded keys.
Retain Raw Logs If Parsing Fails	Specifies whether to retain the raw log if the raw log fails to be parsed.

Configuration example
The following example shows how to expand the JSON field s_key and add j and the name of the original field s_key as a prefix to the expanded keys:
- Raw log
```
"s_key":"{\"k1\":{\"k2\":{\"k3\":{\"k4\":{\"k51\":\"51\",\"k52\":\"52\"},\"k41\":\"41\"}}})"
```
- Logtail plug-in configuration for data processing
- Result
```
"js_key-k1-k2-k3-k4-k51":"51"
"js_key-k1-k2-k3-k4-k52":"52"
"js_key-k1-k2-k3-k41":"41"
```

Editor configuration in JSON

Parameters

Set type to processor_json. Then, configure other parameters in detail based on the following table.


Parameter	Type	Required	Description
SourceKey	String	Yes	The name of the original field to expand.
NoKeyError	Boolean	No	Specifies whether to report an error if the raw log does not contain the original field. Valid values: true: reports an error. This is the default value. false: does not report an error.
ExpandDepth	Int	No	The depth of JSON expansion. Default value: 0, which indicates that the depth of JSON expansion is unlimited. If the value is n, the depth of JSON expansion is n.
ExpandConnector	String	No	The character that is used to connect expanded keys. The default value is an underscore (_).
Prefix	String	No	The prefix that is added to the names of expanded keys.
KeepSource	Boolean	No	Specifies whether to retain the original field in the new log that is obtained after parsing. Valid values: true: retains the original field. This is the default value. false: does not retain the original field.
UseSourceKeyAsPrefix	Boolean	No	Specifies whether to add the name of the original field as a prefix to all expanded keys.
KeepSourceIfParseError	Boolean	No	Specifies whether to retain the raw log if the raw log fails to be parsed. Valid values: true: retains the raw log. This is the default value. false: does not retain the raw log.

Configuration example

The following example shows how to expand the JSON field s_key and add j and the name of the original field s_key as a prefix to the expanded keys:

Raw log

"s_key":"{\"k1\":{\"k2\":{\"k3\":{\"k4\":{\"k51\":\"51\",\"k52\":\"52\"},\"k41\":\"41\"}}})"

Logtail plug-in configuration for data processing

{
  "processors":[
    {
      "type":"processor_json",
      "detail": {
        "SourceKey": "s_key",
        "NoKeyError":true,
        "ExpandDepth":0,
        "ExpandConnector":"-",
        "Prefix":"j",
        "KeepSource": false,
        "UseSourceKeyAsPrefix": true
      }
    }
  ]
}

Result

"js_key-k1-k2-k3-k4-k51":"51"
"js_key-k1-k2-k3-k4-k52":"52"
"js_key-k1-k2-k3-k41":"41"