|
|
|
# systemd-vaultd
|
|
|
|
|
|
|
|
systemd-vaultd is a proxy between systemd and [vault
|
|
|
|
agent](https://vaultproject.io). It provides a unix socket that can be used in
|
|
|
|
systemd services in the `LoadCredential` option and then waits for vault agent
|
|
|
|
to write these secrets at `/run/systemd-vaultd/<service_name>-<secret_name>`.
|
|
|
|
|
|
|
|
## Systemd's `LoadCredential` option
|
|
|
|
|
|
|
|
Systemd has an option called `LoadCredentials` that allows to provide credentials to a service:
|
|
|
|
|
|
|
|
```conf
|
|
|
|
# myservice.service
|
|
|
|
[Service]
|
|
|
|
ExecStart=/usr/bin/myservice.sh
|
|
|
|
LoadCredential=foobar:/etc/myfoobarcredential.txt
|
|
|
|
```
|
|
|
|
|
|
|
|
In this case systemd will load credential the file `/etc/myfoobarcredential.txt`
|
|
|
|
and provide it to the service at `$CREDENTIAL_PATH/foobar`.
|
|
|
|
|
|
|
|
While vault agent also supports writing these secrets, a service may be started
|
|
|
|
before vault agent was able to retrieve secrets from vault, in which case
|
|
|
|
systemd would fail to start the service.
|
|
|
|
|
|
|
|
Here is where `systemd-vaultd` is put to use: In additional to normal paths,
|
|
|
|
systemd also supports loading credentials from unix sockets.
|
|
|
|
|
|
|
|
With `systemd-vaultd` the service `myservice.service` would look like this:
|
|
|
|
|
|
|
|
```conf
|
|
|
|
[Service]
|
|
|
|
ExecStart=/usr/bin/myservice.sh
|
|
|
|
LoadCredential=foobar:/run/systemd-vaultd/sock
|
|
|
|
```
|
|
|
|
|
|
|
|
vault agent is then expected to write secrets to `/run/systemd-vaultd/`
|
|
|
|
|
|
|
|
```
|
|
|
|
template {
|
|
|
|
contents = "{{ with secret \"secret/my-secret\" }}{{ .Data.data.foo }}{{ end }}"
|
|
|
|
destination = "/run/systemd-vaultd/secrets/myservice.service-foo"
|
|
|
|
}
|
|
|
|
```
|
|
|
|
|
|
|
|
When `myservice` is started, systemd will open a connection to `systemd-vaultd`'s socket.
|
|
|
|
`systemd-vaultd` then either serve the secrets from `/run/systemd-vaultd/secrets/myservice.service-foo`
|
|
|
|
or it waits with inotify on secret directory for vault agent to write the secret.
|
|
|
|
|
|
|
|
## Installation
|
|
|
|
|
|
|
|
The installation requires a `go` compiler and `make` to be installed.
|
|
|
|
|
|
|
|
This command will install the `systemd-vaultd` binary to `/usr/bin/systemd-vaultd` as well
|
|
|
|
as installing a following systemd unit files: `systemd-vaultd.service`, `systemd-vaultd.socket`:
|
|
|
|
|
|
|
|
```shell
|
|
|
|
make install
|
|
|
|
```
|