hostctl: init module

[shyim]

Fixes #227

Config looks like

hosts = {
  "foo" = "127.0.0.1";
};

It will be setup by entering the shell. I did add a proper "caching" so it's calling only hostctl when required because we need to run sudo.

To deactivate, the user has to run deactivate-hosts in the shell and leave the shell. Next opening of the shell readds them

[shyim]

I guess I would add this to devenv up and call the hostctl remove when the command gets canceled using a trap

[domenkozar]

I'm thinking that hostctl is the implementation detail and the interface should be more like:

hosts = [ "127.0.0.1 foobar" ];

This aligns with how processes work, I don't see any specific reason to have explicit enable. What do you think?

[domenkozar]

What happens if you have two devenvs setting different hosts?

[shyim]

The last one wins. That's why I added the profileName option 😅

[domenkozar]

What if we use "devenv-${hostHash" for the profile name?

[shyim]

It needs to be something unique to this devenv to update also the area in the hosts

[domenkozar]

"devenv-${builtins.hashString "sha256" env.DEVENV_ROOT}"

[shyim]

@domenkozar are you okay with the Idea to add pre and post scripts to devenv up. So we are able to start hostctl and stop it after running the processes. I guess without processes there is not usecase for custom hosts 🤔

[domenkozar]

@domenkozar are you okay with the Idea to add pre and post scripts to devenv up. So we are able to start hostctl and stop it after running the processes. I guess without processes there is not usecase for custom hosts thinking

It's still better to always set the hosts, as someone might rely on that as part of the scripts, etc.

[shyim]

The problem is when do we remove the hosts. Currently, I am adding a new command. Feels wrong and can be easily forgotten and then the hosts entries says there 😅.

I would also assume the host entries points to processes running 🤔

[roberth]

Not sure what you'd like me to cover. Do you have a nix issue for it?

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[domenkozar]

Not sure what you'd like me to cover. Do you have a nix issue for it?
…
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On Monday, December 26th, 2022 at 12:16, Domen Kožar @.> wrote: @.(https://github.com/roberth) could you cover this one for the next Nix team meeting? — Reply to this email directly, [view it on GitHub](#249 (comment)), or unsubscribe. You are receiving this because you were mentioned.Message ID: @.***>

Sorry, I wrote this to the wrong browser tab :)

[domenkozar]

I'm still unsure how to handle the unloading correctly.

Ideally we'd set a trap function in bash and expose that via exitShell for cleanup.

We'd need to fix the whole env loading business, so probably after #191 and #237

[shyim]

Even that would not work. When you have two shells inside it and one leaves the hosts are gone for all 🙈

I still somehow like the Idea to couple it with devenv up

[domenkozar]

👍 let's couple it with devenv up

[domenkozar]

@shyim would be great if you plan to finish 🥳

[shyim]

Had no time to look currently in 🙈 . maybe weekend

[bobvanderlinden]

Nice! Looks good 👍 I was wondering whether an attrset has been considered for configuration?

{
  hosts = {
    "myhost" = "127.0.0.1";
  };
}

So that it is easier to override/remove. Or are there features of /etc/hosts that I'm overlooking?

[shyim]

The only problem is that you want to merge all entries by ip to one line as multiple domains with same IP for some reason slow down DNS resolving on Mac

[domenkozar]

It should still be possible to convert this into the required format with a bit of transformations.

[bobvanderlinden]

This should be able to convert the structure to a hosts file content.

let
  hosts = {
    "myhost" = "127.0.0.1";
    "otherhost" = "127.0.0.1";
    "anotherhost" = "192.168.0.1";
  };
  entries = lib.mapAttrsToList (hostname: ip: { inherit hostname ip; }) hosts;
  entriesByIp = builtins.groupBy ({ ip, ... }: ip) entries;
  hostnamesByIp = builtins.mapAttrs (hostname: entries: builtins.map ({ hostname, ...}: hostname) entries) entriesByIp;
  lines = lib.mapAttrsToList (ip: hostnames: "${ip} ${lib.concatStringsSep " " hostnames}") hostnamesByIp;
in
  lib.concatStringsSep "\n" lines

[shyim]

Sooo I have updated it. First of all @bobvanderlinden thanks <3 it works flawlessly

hosts = {
    "foo" = "127.0.0.1";
  };

processes.test.exec = "ping foo";

That was my example nix file.

[shyim]

We can use the same base to support mkcert to add like SSL to caddy

[bobvanderlinden]

Awesome 👍 thanks!