local.file.md

---

title: local.file

---

local.file

local.file exposes the contents of a file on disk to other components. The file will be watched for changes so that its latest content is always exposed.

The most common use of local.file is to load secrets (e.g., API keys) from files.

Multiple local.file components can be specified by giving them different labels.

Usage

local.file "LABEL" {
  filename = FILE_NAME
}

Arguments

The following arguments are supported:

Name	Type	Description	Default	Required
filename	string	Path of the file on disk to watch		yes
detector	string	Which file change detector to use (fsnotify, poll)	"fsnotify"	no
poll_frequency	duration	How often to poll for file changes	"1m"	no
is_secret	bool	Marks the file as containing a [secret][]	false	no

[secret]: {{< relref "../../config-language/expressions/types_and_values.md#secrets" >}}

{{< docs/shared lookup="flow/reference/components/local-file-arguments-text.md" source="agent" >}}

Exported fields

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

Name	Type	Description
content	string or secret	The contents of the file from the most recent read

The content field will have the secret type only if the is_secret argument was true.

Component health

local.file will be reported as healthy whenever if the watched file was read successfully.

Failing to read the file whenever an update is detected (or after the poll period elapses) will cause the component to be reported as unhealthy. When unhealthy, exported fields will be kept at the last healthy value. The read error will be exposed as a log message and in the debug information for the component.

Debug information

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

Debug metrics

• agent_local_file_timestamp_last_accessed_unix_seconds (gauge): The timestamp, in Unix seconds, that the file was last successfully accessed.

Example

local.file "secret_key" {
  filename  = "/var/secrets/password.txt"
  is_secret = true
}