[FEATURE]: Support for "GetPrivateIP" in Vault Config.

[tristanmorgan]

Is your feature request related to a problem? Please describe.
I would like to use the GetPrivateIP function from go-sockaddr in config files to simplify config.

Describe the solution you'd like
Similar to Consul I would like support for GetPrivateIP in the Vault config

Describe alternatives you've considered
in some situation an external script can be used but in others this is not possible.

Explain any additional use-cases
Primarily for setting the service address in from scratch containers but also packer builds with SystemD that doesn't use init.d style scripts for service startup.

Additional context
please see Consul v0.1.0

[tristanmorgan]

This would solve the issue in #1528 and make scripted installation easier for OSS and Enterprise deployments.

[the-maldridge]

I just got bit by this trying to stand up a cluster running 1.4 using immutable images. Is there a recommended workaround until Vault supports this natively?

[tristanmorgan]

Hi @the-maldridge , I hit this regularly for my enterprise customers all the time and the best I can do is to use things like Systemd environment variable files, wrapper scripts or HashiCorp Nomad variables. Its frustrating when using from-scratch containers that don't have bash by their nature and especially the method to fix exists in HashiCorp Consul already.

[the-maldridge]

Hmm, I'm deploying directly on top of an immutable VM and adjacent to Nomad for this, so those options are out. Would consul-template be an appropriate workaround here?

Clarification: the init in the VM is not systemd, so those vars are out. I can drop arbitrary files into the machine, but getting those to Vault I'd have to use a wrapper not using the official container image, which I was hopeful to avoid.

[tristanmorgan]

for consul-template you'd need to use an interpolation like "{{ with node }}{{ .Node.Address }}{{ end }}" to get the IP address.

but then you need this infor before the service start so it might not work for you anyway.

[sebastianreloaded]

This is still not available?
It would be such a quality of of life improvement for setting up the server from an image.