# Logstash undefined local variable
**URL:** https://discuss.elastic.co/t/logstash-undefined-local-variable/135243
**Category:** Logstash
**Created:** [June 9, 2018, 9:58pm UTC](https://discuss.elastic.co/t/logstash-undefined-local-variable/135243 "2018-06-09T21:58:57Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@camjoex](https://discuss.elastic.co/u/camjoex)
#### Post date: [June 9, 2018, 9:58pm UTC](https://discuss.elastic.co/t/logstash-undefined-local-variable/135243/1 "2018-06-09T21:58:57Z")
Hello
I'm trying to transform timestamp to specific format YYYY-MM and occured some trouble.
I want to convert timestamp date to format YYYY-MM in specific string crea.
Here my test
echo "1524227744"|logstash -e 'filter {date { match =\> ["message", "UNIX"] target =\> crea }}' -e 'filter {ruby {code =\> "event.set('newfield', event.get('crea').strftime('%Y-%m').to\_i)" }}'
Settings: Default pipeline workers: 4
Pipeline main started
Ruby exception occurred: undefined local variable or method `crea' for #LogStash::Filters::Ruby:0x54686cb7 {:level=\>:error}
{
"message" =\> "1524227744",
"@version" =\> "1",
"@timestamp" =\> "2018-06-09T22:40:16.838Z",
"type" =\> "stdin",
"host" =\> "tech",
"tags" =\> [
[0] "\_rubyexception"
]
}
Pipeline main has been shutdown
stopping pipeline {:id=\>"main"}
Not working.
Any help to troubleshoot
Thank you
---
### Author:  [@Badger](https://discuss.elastic.co/u/Badger)
#### Post date: [June 10, 2018, 1:30am UTC](https://discuss.elastic.co/t/logstash-undefined-local-variable/135243/2 "2018-06-10T01:30:58Z")
> [@camjoex](#):
>
> -e 'filter {ruby {code =\> "event.set('newfield', event.get('crea').strftime('%Y-%m').to\_i)" }}'
You are using single-quotes to quote a string that contains both single-quotes and double-quotes. You could insert 4 spaces before that line to preserve the quoting. But it would be easier to put the filters in a file and use -f.
---
### Author:  [@camjoex](https://discuss.elastic.co/u/camjoex)
#### Post date: [June 10, 2018, 10:09pm UTC](https://discuss.elastic.co/t/logstash-undefined-local-variable/135243/3 "2018-06-10T22:09:53Z")
@Badger Thank you for your feed back
but i have the same issue.
waly@tech:/etc/logstash/conf.d$ echo "1524227744"|logstash -e 'filter {date { match =\> ["message", "UNIX"] target =\> crea }}'
Settings: Default pipeline workers: 4
Pipeline main started
{
"message" =\> "1524227744",
"@version" =\> "1",
"@timestamp" =\> "2018-06-10T22:06:53.655Z",
"type" =\> "stdin",
"host" =\> "tech",
"crea" =\> "2018-04-20T12:35:44.000Z"
}
The first filter is well but when i add ruby code it failed
echo "1524227744"|logstash -e 'filter {date { match =\> ["message", "UNIX"] target =\> crea }}' -e 'filter {ruby {code =\> "event.set('newfield', event.get('crea').strftime('%Y-%m').to\_i)" }}'
Settings: Default pipeline workers: 4
SyntaxError: (ruby filter code):1: unknown type of %string
@codeblock = lambda { |event| event.set(newfield, event.get(crea).strftime(%Y-%m).to\_i) }
^
eval at org/jruby/RubyKernel.java:1079
register at /opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-filter-ruby-2.0.5/lib/logstash/filters/ruby.rb:29
start\_workers at /opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-2.3.4-java/lib/logstash/pipeline.rb:182
each at org/jruby/RubyArray.java:1613
start\_workers at /opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-2.3.4-java/lib/logstash/pipeline.rb:182
run at /opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-2.3.4-java/lib/logstash/pipeline.rb:136
start\_pipeline at /opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-2.3.4-java/lib/logstash/agent.rb
I'm not undertand your feedback with the use of single-quote
Could you help for comprehension ?
---
### Author:  [@Badger](https://discuss.elastic.co/u/Badger)
#### Post date: [June 10, 2018, 10:42pm UTC](https://discuss.elastic.co/t/logstash-undefined-local-variable/135243/4 "2018-06-10T22:42:27Z")
What I meant was that if you put this into a file called foo.conf
```auto
input { stdin {} }
filter {
date { match => ["message", "UNIX"] target => "crea" }
ruby {code => "event.set('newfield', event.get('crea').strftime('%Y-%m').to_i)" }
}
output { stdout { codec => rubydebug } }
```
Then the command
```
echo 1524227744 | /usr/share/logstash/bin/logstash -f foo.conf
```
will result in
```auto
"message" => "1524227744",
"tags" => [
[0] "_rubyexception"
],
"crea" => 2018-04-20T12:35:44.000Z,
```
Note that crea is a timestamp. However, a Logstash timestamp does not have a strftime method.
Ruby exception occurred: undefined method `strftime' for 2018-04-20T12:35:44.000Z:LogStash::Timestamp
You might be better off not using a date filter and just doing the strptime in a Ruby filter to get a datetime that does have a strftime.
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 8, 2018, 10:42pm UTC](https://discuss.elastic.co/t/logstash-undefined-local-variable/135243/5 "2018-07-08T22:42:31Z")
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