[Nix-dev] Fwd: NixOps: How do I bind services to internal IP addresses on GCE?

[roconnor at theorem.ca]

On Wed, 24 Jun 2015, roconnor at theorem.ca wrote:

> On Wed, 24 Jun 2015, Rob Vermaas wrote:
>
>> Hi,
>>
>>> My question is, is there some way to access the internal IP address of a
>>> deployed machine so I can add it to my cassandra.yaml file during
>>> deployment?  Alternatively is there some way to have the /etc/hosts
>>> resolve the machines name, "db", to the internal IP address instead of the
>>> external IP address?  Or is there some other solution to this problem I am
>>> having?
>>
>>
>> NixOps provides two options that will allow accessing public and
>> private IP addresses. In your case you can use networking.privateIPv4.
>>
>>> From the manual:
>>
>> ===========
>>
>> networking.privateIPv4
>>
>> IPv4 address of this machine within in the logical network. This
>> address can be used by other machines in the logical network to reach
>> this machine. However, it need not be visible to the outside (i.e.,
>> publicly routable).
>>
>> Example: "10.1.2.3"
>>
>> Declared by:
>>
>> <nixops/options.nix>
>>
>>
>> networking.publicIPv4
>>
>> Publicly routable IPv4 address of this machine.
>>
>> Example: "198.51.100.123"
>>
>> Declared by:
>>
>> <nixops/options.nix>
>
> That seems like the way to go.  Unfortunately when I try to use
> config.networking.privateIPv4 I get the rror
>
> error: The option `networking.privateIPv4' is used but not defined.
>
> To double check that I've got my expression correct, I tried
> config.networking.publicIPv4, and that expression succeeds (though isn't
> the value I want).
>
> On the off chance I'm supposed to manage my private IP addresses myself, I
> tried setting networking.privateIPv4 address myself, but setting that
> parameter doesn't influence the private IP address that is assigned.
> Anyhow, I think NixOps is supposed to be setting the
> config.networking.privateIPv4 value.
>
> I've tried NixOps 1.3pre1484_a932a9e and NixOps 1.3pre1486_7489764.

After reviewing the NixOps source code, I'm pretty sure that GCE doesn't 
support the privateIPv4 value.  I've opened issue #309 
<https://github.com/NixOS/nixops/issue/309> for this.

I'm happy to try to cargo cult some code to add support for privateIPv4 on 
GCE, but I'm not sure I'm the best person to do this.

-- 
Russell O'Connor                                      <http://r6.ca/>
``All talk about `theft,''' the general counsel of the American Graphophone
Company wrote, ``is the merest claptrap, for there exists no property in
ideas musical, literary or artistic, except as defined by statute.''