yadunut/clan-core
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

feat(clan-services): enable recursive services

Browse Source 
Using recursive services is potentially complex and requires carefully
designed services. Nested Services create nixos modules which must be
mergable as always.
This commit is contained in:
Johannes Kirschbauer
2025-06-14 20:03:25 +02:00
parent aa65e8e533
commit aa26d2ebf2
4 changed files with 205 additions and 49 deletions
Download Patch File Download Diff File Expand all files Collapse all files

102
lib/inventory/distributed-service/service-module.nix
View File

@@ -26,8 +26,6 @@ let
The caller is responsible to use .config or .extendModules
*/
# TODO: evaluate against the role.settings statically and use extendModules to get the machineSettings
# Doing this might improve performance
evalMachineSettings =
{
roleName,
@@ -91,15 +89,12 @@ let
instanceName: instance:
lib.mapAttrs (roleName: role: {
machines = lib.mapAttrs (machineName: v: {
# TODO: evaluate the settings against the interface
# settings = (evalMachineSettings { inherit roleName instanceName; inherit (v) settings; }).config;
settings =
(evalMachineSettings {
inherit roleName instanceName machineName;
inherit (v) settings;
}).config;
}) role.machines;
# TODO: evaluate the settings against the interface
settings =
(evalMachineSettings {
inherit roleName instanceName;
@@ -140,11 +135,6 @@ in
(
{ name, ... }:
{
# options.settings = mkOption {
# description = "settings of 'instance': ${name}";
# default = {};
# apply = v: lib.seq (checkInstanceSettings name v) v;
# };
options.roles = mkOption {
description = ''
Roles of the instance.
@@ -328,8 +318,6 @@ in
- *defaults* that depend on the *machine* or *instance* should be added to *settings* later in 'perInstance' or 'perMachine'
'';
type = types.deferredModule;
# TODO: Default to an empty module
# need to test that an the empty module can be evaluated to empty settings
default = { };
};
options.perInstance = mkOption {
@@ -424,7 +412,6 @@ in
```
'';
};
# TODO: Recursive services
options.services = mkOption {
visible = false;
type = attrsWith {
@@ -444,7 +431,6 @@ in
];
};
};
apply = _: throw "Not implemented yet";
default = { };
};
})
@@ -551,7 +537,6 @@ in
```
'';
};
# TODO: Recursive services
options.services = mkOption {
visible = false;
type = attrsWith {
@@ -569,7 +554,6 @@ in
];
};
};
apply = _: throw "Not implemented yet";
default = { };
};
})
@@ -603,7 +587,6 @@ in
in
uniqueStrings (collectRoles machineScope.instances);
};
# TODO: instances.<instanceName>.roles should contain all roles, even if nobody has the role
inherit (machineScope) instances;
# There are no machine settings.
@@ -641,7 +624,7 @@ in
allMachines :: {
<machineName> :: {
nixosModule :: NixOSModule;
services :: { }; # TODO: nested services
services :: { };
};
};
};
@@ -680,6 +663,7 @@ in
type = types.attrsOf types.raw;
};
# The result collected from 'perMachine'
result.allMachines = mkOption {
visible = false;
readOnly = true;
@@ -734,13 +718,40 @@ in
default = lib.mapAttrs (
machineName: machineResult:
let
instanceResults = lib.foldlAttrs (
acc: roleName: role:
acc
++ lib.foldlAttrs (
acc: instanceName: instance:
instanceResults =
lib.foldlAttrs
(
roleAcc: roleName: role:
roleAcc
// lib.foldlAttrs (
instanceAcc: instanceName: instance:
instanceAcc
// {
nixosModules =
(
(lib.mapAttrsToList (
nestedServiceName: serviceModule:
let
unmatchedMachines = lib.attrNames (
lib.removeAttrs serviceModule.result.final (lib.attrNames config.result.allMachines)
);
in
if unmatchedMachines != [ ] then
throw ''
The following machines are not part of the parent service: ${builtins.toJSON unmatchedMachines}
Either remove the machines, or include them into the parent via a role.
(Added via roles.${roleName}.perInstance.services.${nestedServiceName})
${errorContext}
''
else
serviceModule.result.final.${machineName}.nixosModule
) instance.allMachines.${machineName}.services)
)
++ (
if instance.allMachines.${machineName}.nixosModule or { } != { } then
acc
instanceAcc.nixosModules
++ [
(lib.setDefaultModuleLocation
"Via instances.${instanceName}.roles.${roleName}.machines.${machineName}"
@@ -748,14 +759,22 @@ in
)
]
else
acc
) [ ] role.allInstances
) [ ] config.result.allRoles;
instanceAcc.nixosModules
);
}
) roleAcc role.allInstances
)
{
nixosModules = [ ];
# ...
}
config.result.allRoles;
in
{
inherit instanceResults;
inherit instanceResults machineResult;
nixosModule = {
imports = [
imports =
[
# include service assertions:
(
let
@@ -765,12 +784,27 @@ in
assertions = lib.attrValues failedAssertions;
}
)
(lib.setDefaultModuleLocation "Via ${config.manifest.name}.perMachine - machine='${machineName}';" machineResult.nixosModule)
]
++ (lib.mapAttrsToList (
nestedServiceName: serviceModule:
let
unmatchedMachines = lib.attrNames (
lib.removeAttrs serviceModule.result.final (lib.attrNames config.result.allMachines)
);
in
if unmatchedMachines != [ ] then
throw ''
The following machines are not part of the parent service: ${builtins.toJSON unmatchedMachines}
Either remove the machines, or include them into the parent via a role.
(Added via perMachine.services.${nestedServiceName})
# For error backtracing. This module was produced by the 'perMachine' function
# TODO: check if we need this or if it leads to better errors if we pass the underlying module locations
# (lib.setDefaultModuleLocation "clan.service: ${config.manifest.name} - via perMachine" machineResult.nixosModule)
(machineResult.nixosModule)
] ++ instanceResults;
${errorContext}
''
else
serviceModule.result.final.${machineName}.nixosModule
) machineResult.services)
++ instanceResults.nixosModules;
};
}
) config.result.allMachines;

1
lib/inventory/distributed-service/tests/default.nix
View File

@@ -278,4 +278,5 @@ in
per_machine_args = import ./per_machine_args.nix { inherit lib callInventoryAdapter; };
per_instance_args = import ./per_instance_args.nix { inherit lib callInventoryAdapter; };
nested = import ./nested_services { inherit lib clanLib; };
}

4
lib/inventory/distributed-service/tests/nested_services/default.nix Normal file
View File

@@ -0,0 +1,4 @@
{ clanLib, lib, ... }:
{
test_simple = import ./simple.nix { inherit clanLib lib; };
}

117
lib/inventory/distributed-service/tests/nested_services/simple.nix Normal file
View File

@@ -0,0 +1,117 @@
/*
service-B :: Service
exports a nixosModule which set "address" and "hostname"
Note: How we use null together with mkIf to create optional values.
This is a method, to create mergable modules
service-A :: Service
service-A.roles.server.perInstance.services."B"
imports service-B
configures a client with hostname = "johnny"
service-A.perMachine.services."B"
imports service-B
configures a client with address = "root"
*/
{ clanLib, lib, ... }:
let
service-B = (
{ lib, ... }:
{
manifest.name = "service-B";
roles.client.interface = {
options.hostname = lib.mkOption { default = null; };
options.address = lib.mkOption { default = null; };
};
roles.client.perInstance =
{ settings, ... }:
{
nixosModule = {
imports = [
# Only export the value that is actually set.
(lib.mkIf (settings.hostname != null) {
hostname = settings.hostname;
})
(lib.mkIf (settings.address != null) {
address = settings.address;
})
];
};
};
}
);
service-A =
{ ... }:
{
manifest.name = "service-A";
instances.foo = {
roles.server.machines."jon" = { };
};
instances.bar = {
roles.server.machines."jon" = { };
};
roles.server = {
perInstance =
{ machine, instanceName, ... }:
{
services."B" = {
imports = [
service-B
];
instances."B-for-A" = {
roles.client.machines.${machine.name} = {
settings.hostname = instanceName + "+johnny";
};
};
};
};
};
perMachine =
{ machine, ... }:
{
services."B" = {
imports = [
service-B
];
instances."B-for-A" = {
roles.client.machines.${machine.name} = {
settings.address = "root";
};
};
};
};
};
eval = clanLib.inventory.evalClanService {
modules = [
(service-A)
];
prefix = [ ];
};
evalNixos = lib.evalModules {
modules = [
{
options.assertions = lib.mkOption { };
options.hostname = lib.mkOption { type = lib.types.separatedString " "; };
options.address = lib.mkOption { type = lib.types.str; };
}
eval.config.result.final."jon".nixosModule
];
};
in
{
# Check that the nixos system has the settings from the nested module, as well as those from the "perMachine" and "perInstance"
inherit eval;
expr = evalNixos.config;
expected = {
address = "root";
assertions = [ ];
# Concatenates hostnames from both instances
hostname = "bar+johnny foo+johnny";
};
}