Files
clan-core/lib/exports.nix
Johannes Kirschbauer f9fc47093b Exports POC
2025-10-30 16:13:31 +01:00

89 lines
2.0 KiB
Nix

{ lib }:
let
/**
Creates a scope string for global exports
At least one of serviceName or machineName must be set.
The scope string has the format:
"/SERVICE/INSTANCE/ROLE/MACHINE"
If the parameter is not set, the corresponding part is left empty.
Semantically this means "all".
Examples:
mkScope { serviceName = "A"; }
-> "/A///"
mkScope { machineName = "jon"; }
-> "///jon"
mkScope { serviceName = "A"; instanceName = "i1"; roleName = "peer"; machineName = "jon"; }
-> "/A/i1/peer/jon"
*/
mkScope =
{
serviceName ? "",
instanceName ? "",
roleName ? "",
machineName ? "",
}:
let
parts = [
serviceName
instanceName
roleName
machineName
];
checkedParts = lib.map (
part:
lib.throwIf (builtins.match ".?/.?" part != null) ''
clanLib.exports.mkScope: ${part} cannot contain the "/" character
''
) parts;
in
lib.throwIf ((serviceName == "" && machineName == "")) ''
clanLib.exports.mkScope requires at least 'serviceName' or 'machineName' to be set
In case your use case requires neither
'' (lib.join "/" checkedParts);
/**
Parses a scope string into its components
Returns an attribute set with the keys:
- serviceName
- instanceName
- roleName
- machineName
Example:
parseScope "A/i1/peer/jon"
->
{
serviceName = "A";
instanceName = "i1";
roleName = "peer";
machineName = "jon";
}
*/
parseScope =
scopeStr:
let
parts = lib.splitString "/" scopeStr;
checkedParts = lib.throwIf (lib.length parts != 4) ''
clanLib.exports.parseScope: invalid scope string format, expected 4 parts separated by 3 "/"
'' (parts);
in
{
serviceName = lib.elemAt 0 checkedParts;
instanceName = lib.elemAt 1 checkedParts;
roleName = lib.elemAt 2 checkedParts;
machineName = lib.elemAt 3 checkedParts;
};
in
{
inherit mkScope parseScope;
}