field_edit

Edits individual fields within columnar or tabular files like /etc/passwd, /etc/group, or CSV-style configs. Targets a specific line by regex, then modifies a specific field by position.

Parameters

Parameter	Required	Default	Description
`path`	Yes	--	Absolute path to the file.
`line_match`	Yes	--	Regex to identify the target line.
`select_field`	Yes	--	1-indexed field number to modify.
`state`	Yes	--	Desired state: `present` or `absent`.
`field_separator`	No	`:`	Character used to split fields.
`field_value`	Yes (for present)	--	The value to set on the selected field.
`field_operation`	No	`set`	Operation to perform: `set`, `append`, `prepend`, or `delete`.
`value_separator`	No	`,`	Separator for multi-value fields (used by append/prepend/delete operations).
`extend_fields`	No	`false`	If `true`, extend the line with empty fields if `select_field` exceeds the current field count.

States

present -- Ensure the specified field has the desired value.
absent -- Remove the value from the specified field (for multi-value fields) or clear the field.

Idempotency

Reads the file, finds the matching line, extracts the target field, and compares it against the desired value and operation. Only writes when the field content would change.

Examples

Set a user's shell in /etc/passwd

resources:
  - name: Set deploy user shell
    type: field_edit
    path: /etc/passwd
    line_match: "^deploy:"
    select_field: "7"
    field_separator: ":"
    field_value: /bin/bash

Append a user to a group in /etc/group

resources:
  - name: Add deploy to docker group
    type: field_edit
    path: /etc/group
    line_match: "^docker:"
    select_field: "4"
    field_separator: ":"
    field_value: deploy
    field_operation: append
    value_separator: ","

Remove a user from a group

resources:
  - name: Remove olduser from docker group
    type: field_edit
    path: /etc/group
    line_match: "^docker:"
    select_field: "4"
    field_separator: ":"
    field_value: olduser
    field_operation: delete
    value_separator: ","

Platform

Cross-platform.

Notes

Field numbering is 1-based (field 1 is the first field).
The extend_fields parameter handles cases where the line has fewer fields than select_field by padding with empty fields.
Operations append/prepend/delete work on multi-value fields separated by value_separator.