Copy values processor
The copy_values processor copies values within an event and is a mutate event processor.
Configuration
You can configure the copy_values processor with the following options.
| Option | Required | Type | Description |
|---|---|---|---|
entries | Yes | entry | A list of entries to be copied in an event. See entry for more information. |
from_list | No | String | The key for the list of objects to be copied. |
to_list | No | String | The key for the new list to be added. |
overwrite_if_to_list_exists | No | Boolean | When set to true, the existing value is overwritten if the key specified by to_list already exists in the event. Default is false. |
entry
For each entry, you can configure the following options.
| Option | Required | Type | Description |
|---|---|---|---|
from_key | Yes | String | The key for the entry to be copied. |
to_key | Yes | String | The key for the new entry to be added. |
overwrite_if_to_key_exists | No | Boolean | When set to true, the existing value is overwritten if the key already exists in the event. Default is false. |
copy_when | No | String | Specifies a condition for performing the copy_values operation using a Data Prepper expression. If specified, the copy_values operation will only run when the expression evaluates to true. |
Usage
The following examples show you how to use the copy_values processor.
Example: Copy values and skip existing fields
The following example shows you how to configure the processor to copy values and skip existing fields:
...
processor:
- copy_values:
entries:
- from_key: "message1"
to_key: "message2"
- from_key: "message1"
to_key: "message3"
...
When the input event contains the following data:
{"message1": "hello", "message2": "bye"}
The processor copies “message1” to “message3” but not to “message2” because “message2” already exists. The processed event contains the following data:
{"message1": "hello", "message2": "bye", "message3": "hello"}
Example: Copy values with overwrites
The following example shows you how to configure the processor to copy values:
...
processor:
- copy_values:
entries:
- from_key: "message1"
to_key: "message2"
overwrite_if_to_key_exists: true
- from_key: "message1"
to_key: "message3"
...
When the input event contains the following data:
{"message1": "hello", "message2": "bye"}
The processor copies “message1” to both “message2” and “message3”, overwriting the existing value in “message2”. The processed event contains the following data:
{"message1": "hello", "message2": "hello", "message3": "hello"}
Example: Selectively copy values between two lists of objects
The following example shows you how to configure the processor to copy values between lists:
...
processor:
- copy_values:
from_list: mylist
to_list: newlist
entries:
- from_key: name
to_key: fruit_name
...
When the input event contains the following data:
{
"mylist": [
{"name": "apple", "color": "red"},
{"name": "orange", "color": "orange"}
]
}
The processed event contains a newlist with selectively copied fields:
{
"newlist": [
{"fruit_name": "apple"},
{"fruit_name": "orange"}
],
"mylist": [
{"name": "apple", "color": "red"},
{"name": "orange", "color": "orange"}
]
}