# Data Transformation : Create Dynamic field using ruby for array

**URL:** <https://discuss.elastic.co/t/data-transformation-create-dynamic-field-using-ruby-for-array/312249>\
**Category:** Logstash\
**Created:** [August 17, 2022, 6:15am UTC](https://discuss.elastic.co/t/data-transformation-create-dynamic-field-using-ruby-for-array/312249 "2022-08-17T06:15:37Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![priyankamondalhcl](https://avatars.discourse-cdn.com/v4/letter/p/57b2e6/32.png) [@priyankamondalhcl](https://discuss.elastic.co/u/priyankamondalhcl)\
**Post date:** [August 17, 2022, 6:15am UTC](https://discuss.elastic.co/t/data-transformation-create-dynamic-field-using-ruby-for-array/312249/1 "2022-08-17T06:15:37Z")

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Hi Team,

Hope you doing well!  
I am facing problem in creating dynamic field for an array in logstash.  
The list of array is below:  
[{"usage\_start\_time": "2022-08-07T22:00:00Z",  
"usage\_end\_time": "2022-08-07T23:00:00Z",  
"labels": [{  
{  
"key": "env",  
"value": "Prod"  
}, {  
"key": "nodeID",  
"value": "abcd"  
}]  
}]

I need to create [Labels][key] as a new field and [Labels][value] as the field-value. Now, this array length can be different for different event, also the key is not fixed.  
Expected output for this message:  
[{  
"usage\_start\_time": "2022-08-07T22:00:00Z",  
"usage\_end\_time": "2022-08-07T23:00:00Z",  
"env": "prod",  
"nodeID":"abcd"  
}]  
Please help me here, Let me know if any details I need to provide.

---

<div class="post-metadata">

**Author:** ![Badger](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/badger/32/25190_2.png) [@Badger](https://discuss.elastic.co/u/Badger)\
**Post date:** [August 17, 2022, 3:41pm UTC](https://discuss.elastic.co/t/data-transformation-create-dynamic-field-using-ruby-for-array/312249/2 "2022-08-17T15:41:34Z")

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See [this](https://discuss.elastic.co/t/solved-split-filter-question-a-k-a-flatten-json-sub-array/130481/12) thread.

---

<div class="post-metadata">

**Author:** ![priyankamondalhcl](https://avatars.discourse-cdn.com/v4/letter/p/57b2e6/32.png) [@priyankamondalhcl](https://discuss.elastic.co/u/priyankamondalhcl)\
**Post date:** [August 18, 2022, 8:11am UTC](https://discuss.elastic.co/t/data-transformation-create-dynamic-field-using-ruby-for-array/312249/3 "2022-08-18T08:11:25Z")

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Thanks @Badger , it was really easy 🙂

ruby {  
code =\> '  
event.get("Labels").each do |item|  
k = item["key"]  
v = item["value"]  
event.set(k,v)  
end  
'  
}

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [September 15, 2022, 8:11am UTC](https://discuss.elastic.co/t/data-transformation-create-dynamic-field-using-ruby-for-array/312249/4 "2022-09-15T08:11:57Z")

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