Merge pull request #5 from numtide/readme

README: refactor the text a bit
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Jörg Thalheim 2 years ago committed by GitHub
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@ -1,13 +1,16 @@
# systemd-vaultd
# systemd-vaultd - load vault credentials with systemd units
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>`.
> Mostly written in a train
- Jörg Thalheim
## Systemd's `LoadCredential` option
This project's goal is to simplify the loading of [HashiCorp
Vault](https://www.vaultproject.io/) secrets from
[systemd](https://systemd.io/) units.
Systemd has an option called `LoadCredentials` that allows to provide credentials to a service:
## Problem statement
Systemd has an option called `LoadCredentials` that allows to provide
credentials to a service:
```conf
# myservice.service
@ -16,15 +19,28 @@ 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 `$CREDENTIAL_PATH/foobar`.
In this case systemd will load credential the file
`/etc/myfoobarcredential.txt` and provide it to the service at
`$CREDENTIAL_PATH/foobar`.
It's handy because it bypasses file permission issues.
/etc/myfoobarcredential.txt can be owned by root, and the unit run as a
different or dynamic user.
While vault agent also supports writing these secrets, a major issue is that
the consumer service may be started before vault agent was able to retrieve
secrets from vault. In that case, systemd would fail to start the service.
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.
## The solution
Here is where `systemd-vaultd` is put to use: In additional to normal paths,
systemd also supports loading credentials from unix sockets.
In order to do so, I wrote a `systemd-vaultd` service which acts as a proxy
between systemd and vault agent that is running on the machine. 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>`.
We take advantage that in addition to normal paths, systemd also supports
loading credentials from unix sockets.
With `systemd-vaultd` the service `myservice.service` would look like this:
@ -43,17 +59,34 @@ template {
}
```
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.
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`:
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
```
## License
Copyright (c) 2022 [Jörg Thalheim](https://github.com/mic92) and contributors.
This project is free software, and may be redistributed under the terms
specified in the [LICENSE](LICENSE) file.
## About
This project is maintained by Numtide.
Need help or support? [Contact us](https://numtide.com/contact)

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