systemd_dropin

Manages systemd unit drop-in override files. Creates or removes files under /etc/systemd/system/<unit>.d/ and automatically runs systemctl daemon-reload when changes are made.

Parameters

Parameter	Required	Default	Description
`unit`	Yes	--	Systemd unit name (e.g., `nginx.service`, `docker.service`).
`dropin`	No	`override`	Drop-in file name (without `.conf` extension).
`content`	Yes (for present)	--	Contents of the drop-in file.
`state`	Yes	--	Desired state: `present` or `absent`.

States

present -- Ensure the drop-in file exists with the specified content. Creates the drop-in directory if needed.
absent -- Remove the drop-in file. Cleans up the drop-in directory if empty.

Idempotency

Reads the existing drop-in file and compares against the desired content. If they match, no action is taken. systemctl daemon-reload is only called when the file is actually created, modified, or removed.

Examples

Basic override

resources:
  - name: docker-limits
    type: systemd_dropin
    unit: docker.service
    content: |
      [Service]
      LimitNOFILE=1048576
      LimitNPROC=infinity

Named drop-in

resources:
  - name: nginx-env
    type: systemd_dropin
    unit: nginx.service
    dropin: environment
    content: |
      [Service]
      Environment="NGINX_WORKER_PROCESSES=auto"
      Environment="NGINX_WORKER_CONNECTIONS=4096"

Restart after override

resources:
  - name: docker-limits
    type: systemd_dropin
    unit: docker.service
    content: |
      [Service]
      LimitNOFILE=1048576
    notify: restart-docker

  - name: restart-docker
    type: service
    service: docker
    state: restarted
    subscribes: docker-limits

Remove a drop-in

resources:
  - name: remove-old-override
    type: systemd_dropin
    unit: nginx.service
    dropin: old-tuning
    state: absent

Multiple drop-ins for one unit

resources:
  - name: app-limits
    type: systemd_dropin
    unit: myapp.service
    dropin: limits
    content: |
      [Service]
      LimitNOFILE=65536
      MemoryMax=2G

  - name: app-restart-policy
    type: systemd_dropin
    unit: myapp.service
    dropin: restart
    content: |
      [Service]
      Restart=on-failure
      RestartSec=5

Platform

Linux only (systemd).

Notes

Drop-in files are written to /etc/systemd/system/<unit>.d/<dropin>.conf.
The default drop-in name is override, matching the convention used by systemctl edit.
systemctl daemon-reload runs automatically after any change -- you do not need a separate exec resource for this.
When removing a drop-in with state: absent, the empty .d directory is cleaned up automatically.
Drop-in file permissions are set to 0644 (readable by all, writable by root).