Add system-manager support for deploying non-NixOS Linux machines

cmd/run.go

@@ -62,6 +62,8 @@ var runCmd = &cobra.Command{
 			}
 		case "nix":
 			executor, err = executorPkg.NewNixOSNix()
+		case "system-manager":
+			executor, err = executorPkg.NewSystemManagerFlake()
 		}
 		if err != nil {
 			logrus.Errorf("Failed to create the executor: %s", err)

flake.nix

@@ -60,6 +60,7 @@
       });
       nixosModules.comin = nixpkgs.lib.modules.importApply ./nix/module.nix { inherit self; };
       darwinModules.comin = nixpkgs.lib.modules.importApply ./nix/darwin-module.nix { inherit self; };
+      systemManagerModules.comin = nixpkgs.lib.modules.importApply ./nix/system-manager-module.nix { inherit self; };
       devShells = forAllSystems (
         system:
         let

internal/config/config.go

@@ -65,7 +65,7 @@ func Read(path string) (config types.Configuration, err error) {
 	if config.RepositorySubdir == "" {
 		config.RepositorySubdir = "."
 	}
-	supportedRepositoryTypes := []string{"flake", "nix"}
+	supportedRepositoryTypes := []string{"flake", "nix", "system-manager"}
 	if !slices.Contains(supportedRepositoryTypes, config.RepositoryType) {
 		return config, fmt.Errorf("config: repository type is '%s' while it be one of '%s'", config.RepositoryType, supportedRepositoryTypes)
 	}

internal/executor/executor.go

@@ -41,3 +41,9 @@ func NewNixOSNix() (e Executor, err error) {
 	e, err = NewNixExecutor()
 	return
 }
+
+func NewSystemManagerFlake() (e Executor, err error) {
+	logrus.Info("executor: creating a system-manager flake executor")
+	e, err = NewSystemManagerFlakeExecutor()
+	return
+}

internal/executor/system_manager_flake.go

@@ -0,0 +1,130 @@
+package executor
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+
+	"github.com/nlewo/comin/internal/utils"
+	"github.com/sirupsen/logrus"
+)
+
+const (
+	systemManagerProfileDir  = "/nix/var/nix/profiles/system-manager-profiles"
+	systemManagerProfileName = "system-manager"
+)
+
+type SystemManagerFlake struct{}
+
+func NewSystemManagerFlakeExecutor() (*SystemManagerFlake, error) {
+	return &SystemManagerFlake{}, nil
+}
+
+func (s *SystemManagerFlake) ReadMachineId() (string, error) {
+	return utils.ReadMachineIdLinux()
+}
+
+func (s *SystemManagerFlake) NeedToReboot(outPath, operation string) bool {
+	return false
+}
+
+func (s *SystemManagerFlake) IsStorePathExist(storePath string) bool {
+	return isStorePathExist(storePath)
+}
+
+func (s *SystemManagerFlake) Eval(ctx context.Context, repositoryPath, repositorySubdir, commitId, systemAttr, hostname string, submodules bool) (drvPath string, outPath string, machineId string, err error) {
+	flakeUrl := fmt.Sprintf("git+file://%s?dir=%s&rev=%s", repositoryPath, repositorySubdir, commitId)
+	if submodules {
+		flakeUrl += "&submodules=1"
+	}
+	drvPath, outPath, err = showDerivationSystemManager(ctx, flakeUrl, hostname)
+	if err != nil {
+		return
+	}
+	// system-manager does not have a services.comin module, so machineId is not available
+	machineId = ""
+	return
+}
+
+func (s *SystemManagerFlake) Build(ctx context.Context, drvPath string) (err error) {
+	return buildWithFlake(ctx, drvPath)
+}
+
+func (s *SystemManagerFlake) Deploy(ctx context.Context, outPath, operation string, profilePaths []string) (needToRestartComin bool, profilePath string, err error) {
+	return deploySystemManager(ctx, outPath, operation)
+}
+
+func showDerivationSystemManager(ctx context.Context, flakeUrl, hostname string) (drvPath string, outPath string, err error) {
+	// system-manager's makeSystemConfig returns the toplevel derivation directly,
+	// so we evaluate systemConfigs."<hostname>" without any .config.system.build.toplevel suffix
+	installable := fmt.Sprintf("%s#systemConfigs.\"%s\"", flakeUrl, hostname)
+	args := []string{
+		"derivation",
+		"show",
+		installable,
+		"-L",
+		"--show-trace",
+	}
+	var stdout bytes.Buffer
+	err = runNixFlakeCommand(ctx, args, &stdout, os.Stderr)
+	if err != nil {
+		return
+	}
+	return parseDerivationWithFlake(stdout)
+}
+
+func deploySystemManager(ctx context.Context, outPath, operation string) (needToRestartComin bool, profilePath string, err error) {
+	beforeCominUnitFileHash := cominUnitFileHashLinux()
+
+	enginePath := filepath.Join(outPath, "bin", "system-manager-engine")
+
+	dryRun := operation == "dry-run"
+	if dryRun {
+		logrus.Infof("system-manager: dry-run enabled: register and activate have not been executed")
+		return
+	}
+
+	// Register: creates nix profile generation (skip for "test" operation)
+	if operation != "test" {
+		logrus.Infof("system-manager: running '%s register --store-path %s'", enginePath, outPath)
+		cmd := exec.CommandContext(ctx, enginePath, "register", "--store-path", outPath)
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		if err = cmd.Run(); err != nil {
+			err = fmt.Errorf("system-manager register failed: %w", err)
+			return
+		}
+		logrus.Infof("system-manager: register succeeded")
+	}
+
+	// Activate: apply etc files and start services
+	logrus.Infof("system-manager: running '%s activate --store-path %s'", enginePath, outPath)
+	cmd := exec.CommandContext(ctx, enginePath, "activate", "--store-path", outPath)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	if err = cmd.Run(); err != nil {
+		err = fmt.Errorf("system-manager activate failed: %w", err)
+		return
+	}
+	logrus.Infof("system-manager: activate succeeded")
+
+	// Read the profile path for GC root tracking
+	profileLink := filepath.Join(systemManagerProfileDir, systemManagerProfileName)
+	if dst, readErr := os.Readlink(profileLink); readErr == nil {
+		profilePath = filepath.Join(systemManagerProfileDir, dst)
+		logrus.Infof("system-manager: current profile path is %s", profilePath)
+	} else {
+		logrus.Warnf("system-manager: could not read profile symlink %s: %s", profileLink, readErr)
+	}
+
+	afterCominUnitFileHash := cominUnitFileHashLinux()
+	if beforeCominUnitFileHash != afterCominUnitFileHash {
+		needToRestartComin = true
+	}
+
+	logrus.Infof("system-manager: deployment ended")
+	return
+}