Exec source

Collect output from a process running on the host

Configuration

Example configurations

{
  "sources": {
    "my_source_id": {
      "type": "exec",
      "command": [
        "echo"
      ],
      "mode": "scheduled"
    }
  }
}

[sources.my_source_id]
type = "exec"
command = [ "echo" ]
mode = "scheduled"

---
sources:
  my_source_id:
    type: exec
    command:
      - echo
    mode: scheduled

{
  "sources": {
    "my_source_id": {
      "type": "exec",
      "command": [
        "echo"
      ],
      "include_stderr": true,
      "maximum_buffer_size_bytes": 1000000,
      "mode": "scheduled"
    }
  }
}

[sources.my_source_id]
type = "exec"
command = [ "echo" ]
include_stderr = true
maximum_buffer_size_bytes = 1_000_000
mode = "scheduled"

---
sources:
  my_source_id:
    type: exec
    command:
      - echo
    include_stderr: true
    maximum_buffer_size_bytes: 1000000
    mode: scheduled

command

required [string]

The command to run, plus any arguments required.

Array string literal

Examples

[
  "echo",
  "Hello World!"
]

Option	Description
`bytes`	Uses the raw bytes as-is.
`gelf`	Decodes the raw bytes as a GELF message.
`json`	Decodes the raw bytes as JSON.
`native`	Decodes the raw bytes as Vector’s native Protocol Buffers format. This codec is experimental.
`native_json`	Decodes the raw bytes as Vector’s native JSON format. This codec is experimental.
`syslog`	Decodes the raw bytes as a Syslog message. Decodes either as the RFC 3164-style format (“old” style) or the RFC 5424-style format (“new” style, includes structured data).

Framing handles how events are separated when encoded in a raw byte form, where each event is a frame that must be prefixed, or delimited, in a way that marks where an event begins and ends within the byte stream.

framing.character_delimited

required object

Options for the character delimited decoder.

Relevant when: method = "character_delimited"

framing.character_delimited.delimiter

required uint

The character that delimits byte sequences.

framing.character_delimited.max_length

optional uint

The maximum length of the byte buffer.

This length does not include the trailing delimiter.

By default, there is no maximum length enforced. If events are malformed, this can lead to additional resource usage as events continue to be buffered in memory, and can potentially lead to memory exhaustion in extreme cases.

If there is a risk of processing malformed data, such as logs with user-controlled input, consider setting the maximum length to a reasonably large value as a safety net. This ensures that processing is not actually unbounded.

framing.method

required string literal enum

The framing method.

Enum options

Option	Description
`bytes`	Byte frames are passed through as-is according to the underlying I/O boundaries (for example, split between messages or stream segments).
`character_delimited`	Byte frames which are delimited by a chosen character.
`length_delimited`	Byte frames which are prefixed by an unsigned big-endian 32-bit integer indicating the length.
`newline_delimited`	Byte frames which are delimited by a newline character.
`octet_counting`	Byte frames according to the octet counting format.

Examples

"bytes"

"character_delimited"

"length_delimited"

"newline_delimited"

"octet_counting"

framing.newline_delimited

optional object

Options for the newline delimited decoder.

Relevant when: method = "newline_delimited"

framing.newline_delimited.max_length

optional uint

The maximum length of the byte buffer.

This length does not include the trailing delimiter.

framing.octet_counting

optional object

Options for the octet counting decoder.

Relevant when: method = "octet_counting"

framing.octet_counting.max_length

optional uint

The maximum length of the byte buffer.

include_stderr

optional bool

Whether or not the output from stderr should be included when generating events.

default: true

maximum_buffer_size_bytes

optional uint

The maximum buffer size allowed before a log event is generated.

default: 1e+06

mode

required string literal enum

Mode of operation for running the command.

Examples

"scheduled"

"streaming"

Enum options string literal

Option	Description
`scheduled`	The command is run on a schedule.
`streaming`	The command is run until it exits, potentially being restarted.

scheduled

optional object

Configuration options for scheduled commands.

scheduled.exec_interval_secs

optional uint

The interval, in seconds, between scheduled command runs.

If the command takes longer than exec_interval_secs to run, it is killed.

default: 60

streaming

optional object

Configuration options for streaming commands.

streaming.respawn_interval_secs

optional uint

The amount of time, in seconds, before rerunning a streaming command that exited.

default: 5

streaming.respawn_on_exit

optional bool

Whether or not the command should be rerun if the command exits.

default: true

working_directory

optional string literal

The directory in which to run the command.

Outputs

<component_id>

Default output stream of the component. Use this component’s ID as an input to downstream transforms and sinks.

Output Data

Logs

Line

An individual event from exec.

Fields

command required [string]

The command that was run to generate this event.

data_stream optional string literal

The data stream from which the event originated.

Examples

stdout

stderr

host required string literal

The local hostname, equivalent to the gethostname command.

Examples

my-host.local

message required string literal

The raw line, unparsed.

Examples

2019-02-13T19:48:34+00:00 [info] Started GET "/" for 127.0.0.1

pid required uint

The process ID of the command.

Examples

source_type required string literal

The name of the source type.

Examples

exec

timestamp required timestamp

The exact time the event was ingested into Vector.

Examples

2020-10-10T17:07:36.452332Z

Telemetry

Metrics

link

command_executed_total

counter

The total number of times a command has been executed.

component_id

The Vector component ID.

component_kind

The Vector component kind.

component_name

Deprecated, use component_id instead. The value is the same as component_id.

component_type

The Vector component type.

host optional

The hostname of the system Vector is running on.

pid optional

The process ID of the Vector instance.

command_execution_duration_seconds

histogram

The command execution duration in seconds.

component_id

The Vector component ID.

component_kind

The Vector component kind.

component_name

Deprecated, use component_id instead. The value is the same as component_id.

component_type

The Vector component type.

host optional

The hostname of the system Vector is running on.

pid optional

The process ID of the Vector instance.

component_discarded_events_total

counter

The number of events dropped by this component.

component_id

The Vector component ID.

component_kind

The Vector component kind.

component_name

Deprecated, use component_id instead. The value is the same as component_id.

component_type

The Vector component type.

host optional

The hostname of the system Vector is running on.

pid optional

The process ID of the Vector instance.

component_errors_total

counter

The total number of errors encountered by this component.

component_id

The Vector component ID.

component_kind

The Vector component kind.

component_name

Deprecated, use component_id instead. The value is the same as component_id.

component_type

The Vector component type.

error_type

The type of the error

host optional

The hostname of the system Vector is running on.

pid optional

The process ID of the Vector instance.

stage

The stage within the component at which the error occurred.

component_received_bytes_total

counter

The number of raw bytes accepted by this component from source origins.

component_id

The Vector component ID.

component_kind

The Vector component kind.

component_name

Deprecated, use component_id instead. The value is the same as component_id.

component_type

The Vector component type.

container_name optional

The name of the container from which the data originated.

file optional

The file from which the data originated.

host optional

The hostname of the system Vector is running on.

mode optional

The connection mode used by the component.

peer_addr optional

The IP from which the data originated.

peer_path optional

The pathname from which the data originated.

pid optional

The process ID of the Vector instance.

pod_name optional

The name of the pod from which the data originated.

uri optional

The sanitized URI from which the data originated.

component_received_event_bytes_total

counter

The number of event bytes accepted by this component either from tagged origins like file and uri, or cumulatively from other origins.

component_id

The Vector component ID.

component_kind

The Vector component kind.

component_name

Deprecated, use component_id instead. The value is the same as component_id.

component_type

The Vector component type.

container_name optional

The name of the container from which the data originated.

file optional

The file from which the data originated.

host optional

The hostname of the system Vector is running on.

mode optional

The connection mode used by the component.

peer_addr optional

The IP from which the data originated.

peer_path optional

The pathname from which the data originated.

pid optional

The process ID of the Vector instance.

pod_name optional

The name of the pod from which the data originated.

uri optional

The sanitized URI from which the data originated.

component_received_events_count

histogram

A histogram of the number of events passed in each internal batch in Vector’s internal topology.

Note that this is separate than sink-level batching. It is mostly useful for low level debugging performance issues in Vector due to small internal batches.

component_id

The Vector component ID.

component_kind

The Vector component kind.

component_name

Deprecated, use component_id instead. The value is the same as component_id.

component_type

The Vector component type.

container_name optional

The name of the container from which the data originated.

file optional

The file from which the data originated.

host optional

The hostname of the system Vector is running on.

mode optional

The connection mode used by the component.

peer_addr optional

The IP from which the data originated.

peer_path optional

The pathname from which the data originated.

pid optional

The process ID of the Vector instance.

pod_name optional

The name of the pod from which the data originated.

uri optional

The sanitized URI from which the data originated.

component_received_events_total

counter

The number of events accepted by this component either from tagged origins like file and uri, or cumulatively from other origins.

component_id

The Vector component ID.

component_kind

The Vector component kind.

component_name

Deprecated, use component_id instead. The value is the same as component_id.

component_type

The Vector component type.

container_name optional

The name of the container from which the data originated.

file optional

The file from which the data originated.

host optional

The hostname of the system Vector is running on.

mode optional

The connection mode used by the component.

peer_addr optional

The IP from which the data originated.

peer_path optional

The pathname from which the data originated.

pid optional

The process ID of the Vector instance.

pod_name optional

The name of the pod from which the data originated.

uri optional

The sanitized URI from which the data originated.

component_sent_event_bytes_total

counter

The total number of event bytes emitted by this component.

component_id

The Vector component ID.

component_kind

The Vector component kind.

component_name

Deprecated, use component_id instead. The value is the same as component_id.

component_type

The Vector component type.

host optional

The hostname of the system Vector is running on.

output optional

The specific output of the component.

pid optional

The process ID of the Vector instance.

component_sent_events_total

counter

The total number of events emitted by this component.

component_id

The Vector component ID.

component_kind

The Vector component kind.

component_name

Deprecated, use component_id instead. The value is the same as component_id.

component_type

The Vector component type.

host optional

The hostname of the system Vector is running on.

output optional

The specific output of the component.

pid optional

The process ID of the Vector instance.

source_lag_time_seconds

histogram

The difference between the timestamp recorded in each event and the time when it was ingested, expressed as fractional seconds.

component_id

The Vector component ID.

component_kind

The Vector component kind.

component_name

Deprecated, use component_id instead. The value is the same as component_id.

component_type

The Vector component type.

host optional

The hostname of the system Vector is running on.

pid optional

The process ID of the Vector instance.

Examples

Exec line

Given this event...

64 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=0.060 ms

...and this configuration...

[sources.my_source_id]
type = "exec"

---
sources:
  my_source_id:
    type: exec

{
  "sources": {
    "my_source_id": {
      "type": "exec"
    }
  }
}

...this Vector event is produced:

{
  "data_stream": "stdout",
  "host": "my-host.local",
  "message": "64 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=0.060 ms",
  "pid": 5678,
  "source_type": "exec",
  "timestamp": "2020-03-13T20:45:38.119Z"
}

How it works

Context

By default, the exec source augments events with helpful context keys.

Line Delimiters

Each line is read until a new line delimiter, the 0xA byte, is found or the end of the maximum_buffer_size_bytes is reached.

Shutting Down

When Vector begins shutting down (typically due to a SIGTERM), this source will signal to the child process to terminate, if it is running, to shut down.

On *nix platforms, Vector will issue a SIGTERM to the child process, allowing it to gracefully shutdown, and the source will continue reading until the process exits or Vector’s shutdown grace period expires. The duration of the grace period can be configured using --graceful-shutdown-limit-secs.

On Windows, the subprocess will be issued a SIGKILL and terminate abruptly. In the future we hope to support graceful shutdown of Windows processes as well.

State

This component is stateless, meaning its behavior is consistent across each input.