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Version: 3.4.0

exec

Execute arbitrary commands

Things to note:

  • By default, input data streams through the output process, i.e. works like a shell filter. You cannot have ${field} expansions of the command when streaming, so streaming is switched off. Then the command will be executed once for each input line. With input-field you have to explicitly ask for streaming: true for reasons of backward compatibility.
  • With batched output you will have access to the fields of the first event in the batch

Note: This invokes a shell, which is something we might want to avoid at some point

Field NameDescriptionTypeDefault
batchMaximum number of events in an output batch. If 'document' send on end of documentinteger or the 'document'-
timeoutInterval after which the batch is sent, to keep throughput goinginterval100ms
headerPut a header line before the batchtemplated text-
footerPut a header line after the last line of the batchtemplated text-
use-document-markerEnrich the pipe metadata with a document marker (for document handling in batch mode)boolfalse
input-fieldA field from where data is to be read, meaning JSON is assumedfield-
commandA shell command to be executedstring-
streamingRun the command separately for each eventbooltrue
retryFor operations that could potentially failRetry-

batch

Maximum number of events in an output batch. If 'document' send on end of document

Type: integer or the 'document'

timeout

Interval after which the batch is sent, to keep throughput going

Type: interval

Put a header line before the batch

Type: templated text

Put a header line after the last line of the batch

Type: templated text

use-document-marker

Enrich the pipe metadata with a document marker (for document handling in batch mode)

Type: bool

input-field

A field from where data is to be read, meaning JSON is assumed

Otherwise the whole event is sent

Type: field

Example

input:

{"text":"one","number":1}

action:

exec:
input-field: text
command: cat

output:

one

command

A shell command to be executed

If streaming is set to false (or input-field by default) then there can be field expansions

Type: string

Example

input:

{"text":"one","number":1}

action:

exec:
command: cat

output:

{"text":"one","number":1}

streaming

Run the command separately for each event

Normally, the command runs continuously and events are passed through

Type: bool

Example: streaming must be explicit if input-field is defined

input:

{"msg":"hello dolly"}
{"msg":"we are happy"}

action:

exec:
input-field: msg
streaming: true
command: tr 'h' 'H'

output:

Hello dolly
we are Happy

Example: streaming is implicit if there are field expansions

input:

{"text":"one","number":1}

action:

exec:
command: echo "${text}-${number}"

output:

one-1

retry

For operations that could potentially fail

Type: Retry

Field NameDescriptionTypeDefault
countHow many attempts to make before declaring failureinteger-
pauseHow long to pause before re-tryingduration-
foreverKeep trying until success is declaredboolfalse

count

How many attempts to make before declaring failure

Type: integer

Example

action:

exec:
command: echo 'one two'
retry:
count: 1

output:

{"_raw":"one two"}

pause

How long to pause before re-trying

Accepts human-friendly formats, like 1m (for 1 minute) and 4h (for 4 hours)

Type: duration

Example

action:

exec:
command: echo 'one two'
retry:
count: 6
pause: 10s

output:

{"_raw":"one two"}

forever

Keep trying until success is declared

Accepts human-friendly formats, like 1m (for 1 minute) and 4h (for 4 hours)

Type: bool

Example

action:

exec:
command: echo 'one two'
retry:
forever: true

output:

{"_raw":"one two"}