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local.file_match

local.file_match discovers files on the local filesystem using glob patterns and the doublestar library.

Usage

alloy
local.file_match "LABEL" {
  path_targets = [{"__path__" = DOUBLESTAR_PATH}]
}

Arguments

The following arguments are supported:

NameTypeDescriptionDefaultRequired
path_targetslist(map(string))Targets to expand; looks for glob patterns on the __path__ and __path_exclude__ keys.yes
sync_perioddurationHow often to sync filesystem and targets."10s"no

path_targets uses doublestar style paths.

  • /tmp/**/*.log will match all subfolders of tmp and include any files that end in *.log.
  • /tmp/apache/*.log will match only files in /tmp/apache/ that end in *.log.
  • /tmp/** will match all subfolders of tmp, tmp itself, and all files.

Exported fields

The following fields are exported and can be referenced by other components:

NameTypeDescription
targetslist(map(string))The set of targets discovered from the filesystem.

Each target includes the following labels:

  • __path__: Absolute path to the file.

Component health

local.file_match is only reported as unhealthy when given an invalid configuration. In those cases, exported fields retain their last healthy values.

Debug information

local.file_match does not expose any component-specific debug information.

Debug metrics

local.file_match does not expose any component-specific debug metrics.

Examples

Send /tmp/logs/*.log files to Loki

This example discovers all files and folders under /tmp/logs. The absolute paths are used by loki.source.file.files targets.

alloy
local.file_match "tmp" {
  path_targets = [{"__path__" = "/tmp/logs/**/*.log"}]
}

loki.source.file "files" {
  targets    = local.file_match.tmp.targets
  forward_to = [loki.write.endpoint.receiver]
}

loki.write "endpoint" {
  endpoint {
      url = LOKI_URL
      basic_auth {
          username = USERNAME
          password = PASSWORD
      }
  }
}

Replace the following:

  • LOKI_URL: The URL of the Loki server to send logs to.
  • USERNAME: The username to use for authentication to the Loki API.
  • PASSWORD: The password to use for authentication to the Loki API.

Send Kubernetes pod logs to Loki

This example finds all the logs on pods and monitors them.

alloy
discovery.kubernetes "k8s" {
  role = "pod"
}

discovery.relabel "k8s" {
  targets = discovery.kubernetes.k8s.targets

  rule {
    source_labels = ["__meta_kubernetes_namespace", "__meta_kubernetes_pod_label_name"]
    target_label  = "job"
    separator     = "/"
  }

  rule {
    source_labels = ["__meta_kubernetes_pod_uid", "__meta_kubernetes_pod_container_name"]
    target_label  = "__path__"
    separator     = "/"
    replacement   = "/var/log/pods/*$1/*.log"
  }
}

local.file_match "pods" {
  path_targets = discovery.relabel.k8s.output
}

loki.source.file "pods" {
  targets = local.file_match.pods.targets
  forward_to = [loki.write.endpoint.receiver]
}

loki.write "endpoint" {
  endpoint {
      url = LOKI_URL
      basic_auth {
          username = USERNAME
          password = PASSWORD
      }
  }
}

Replace the following:

  • LOKI_URL: The URL of the Loki server to send logs to.
  • USERNAME: The username to use for authentication to the Loki API.
  • PASSWORD: The password to use for authentication to the Loki API.

Compatible components

local.file_match can accept arguments from the following components:

local.file_match has exports that can be consumed by the following components:

Note

Connecting some components may not be sensible or components may require further configuration to make the connection work correctly. Refer to the linked documentation for more details.