caddy/dist/init/linux-systemd/README.md
W-Mark Kubacki da8ae9e511
systemd: Run caddy with even less privileges and more confined
The exemplary unit file for systemd is intentionally redundant at times, for
example dropping privileges which an unprivileged user "www-data" did not have
in the first place: To aid as fallback in case the file gets copied and an
operator setting UID to 0 (which reportedly happened in the past).
2016-05-12 15:11:43 +02:00

79 lines
3 KiB
Markdown
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# systemd unit for caddy
Please do not hesitate to ask if you have any questions.
## Quickstart
The provided unit file assumes that you want to run caddy as `www-data` and group `www-data`,
both having UID and GID 33 here.
Adjust this to your liking according to the preferences of you Linux distribution!
```bash
groupadd -g 33 www-data
useradd \
-g www-data --no-user-group \
--home-dir /var/www --no-create-home \
--shell /usr/sbin/nologin \
--system --uid 33 www-data
mkdir /etc/caddy
chown -R root:www-data /etc/caddy
mkdir /etc/ssl/caddy
chown -R www-data:root /etc/ssl/caddy
chmod 0770 /etc/ssl/caddy
```
- Install the unit configuration file: `cp caddy.service /etc/systemd/system/`
- Reload the systemd daemon: `systemctl daemon-reload`
- Make sure to [configure](#configuration) the service unit before starting caddy.
- Start caddy: `systemctl start caddy.service`
- Enable the service (automatically start on boot): `systemctl enable caddy.service`
- A folder `.caddy` will be created inside the home directory of the user that runs caddy;
you can change that by providing an environment variable `HOME`,
i.e. `Environment=HOME=/var/lib/caddy` will result in `/var/lib/caddy/.caddy`.
## Configuration
- Do not edit the systemd unit file directly. Instead, use systemd's builtin tools:
- `systemctl edit caddy.service` to make user-local modifications
- `systemctl edit --full caddy.service` for system-wide ones
- In most cases it is enough to override the `ExecStart` directive.
- systemd needs absolute paths, therefore make sure that the path to caddy is correct.
- example:
```ini
[Service]
; an empty value clears the original (and preceding) settings
ExecStart=
ExecStart=/usr/bin/caddy -conf="/etc/caddy/myCaddy.conf" -agree -email="my@mail.address"
```
- To view the resulting configuration use `systemctl cat caddy`
- Double check permissions of your *document root* path.
The user caddy runs as needs to have access to it. For example:
```bash
# caddy would run as www-data:www-data
# serving, in this example: /var/www
sudo -u www-data -g www-data -s \
ls -hlAS /var/www
```
## Tips
- Use `log stdout` and `errors stderr` in your Caddyfile to utilize `journalctl`.
- `journalctl` is systemd's log query tool.
- Let's say you want all the log entries since the last boot, beginning from the last entry:
`journalctl --reverse --boot --unit caddy.service`
- To follow caddy's log output: `journalctl -fu caddy.service`
- Send a signal to a service unit's main PID, e.g. have caddy reload its config:
`systemctl kill --signal=USR1 caddy.service`
- If you have more files that start with `caddy` like a `caddy.timer`, `caddy.path`, or `caddy.socket` then it is important to append `.service`.
Although if `caddy.service` is all you have, then you can just use `caddy` without any extension, such as in: `systemctl status caddy`
- You can make your other certificates and private key files accessible to a user `www-data` by command `setfacl`, if you must:
```bash
setfacl -m user:www-data:r-- /etc/ssl/private/my.key
```