packages/repostitories: add pacman support

Adds support for package and repository reporting on pacman-based
distributions.

As implemented--currently omits security update information, these
rolling distributions only support complete updates and do not support
security-only update options.

PatchMon/PatchMon#373

Author: ocelotsloth

go.mod

@@ -11,6 +11,7 @@ require (
 	github.com/spf13/cobra v1.10.1
 	github.com/spf13/viper v1.21.0
 	github.com/stretchr/testify v1.11.1
+	gopkg.in/ini.v1 v1.67.0
 	gopkg.in/natefinch/lumberjack.v2 v2.2.1
 )
 

go.sum

@@ -157,6 +157,8 @@ google.golang.org/protobuf v1.36.8/go.mod h1:fuxRtAxBytpl4zzqUh6/eyUujkJdNiuEkXn
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
+gopkg.in/ini.v1 v1.67.0 h1:Dgnx+6+nfE+IfzjUEISNeydPJh9AXNNsWbGP9KzCsOA=
+gopkg.in/ini.v1 v1.67.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
 gopkg.in/natefinch/lumberjack.v2 v2.2.1 h1:bBRl1b0OH9s/DuPhuXpNl+VtCaJXFZ5/uEFST95x9zc=
 gopkg.in/natefinch/lumberjack.v2 v2.2.1/go.mod h1:YD8tP3GAjkrDg1eZH7EGmyESg/lsYskCTPBJVb9jqSc=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/constants/constants.go

@@ -51,6 +51,7 @@ const (
 	RepoTypeDebSrc = "deb-src"
 	RepoTypeRPM    = "rpm"
 	RepoTypeAPK    = "apk"
+	RepoTypePacman = "pacman"
 )
 
 // Log level constants

internal/packages/packages.go

@@ -11,23 +11,26 @@ import (
 
 // Manager handles package information collection
 type Manager struct {
-	logger     *logrus.Logger
-	aptManager *APTManager
-	dnfManager *DNFManager
-	apkManager *APKManager
+	logger        *logrus.Logger
+	aptManager    *APTManager
+	dnfManager    *DNFManager
+	apkManager    *APKManager
+	pacmanManager *PacmanManager
 }
 
 // New creates a new package manager
 func New(logger *logrus.Logger) *Manager {
 	aptManager := NewAPTManager(logger)
 	dnfManager := NewDNFManager(logger)
 	apkManager := NewAPKManager(logger)
+	pacmanManager := NewPacmanManager(logger)
 
 	return &Manager{
-		logger:     logger,
-		aptManager: aptManager,
-		dnfManager: dnfManager,
-		apkManager: apkManager,
+		logger:        logger,
+		aptManager:    aptManager,
+		dnfManager:    dnfManager,
+		apkManager:    apkManager,
+		pacmanManager: pacmanManager,
 	}
 }
 
@@ -44,6 +47,8 @@ func (m *Manager) GetPackages() ([]models.Package, error) {
 		return m.dnfManager.GetPackages(), nil
 	case "apk":
 		return m.apkManager.GetPackages(), nil
+	case "pacman":
+		return m.pacmanManager.GetPackages()
 	default:
 		return nil, fmt.Errorf("unsupported package manager: %s", packageManager)
 	}
@@ -72,6 +77,11 @@ func (m *Manager) detectPackageManager() string {
 		return "yum"
 	}
 
+	// Check for Pacman
+	if _, err := exec.LookPath("pacman"); err == nil {
+		return "pacman"
+	}
+
 	return "unknown"
 }
 

internal/packages/pacman.go

@@ -0,0 +1,126 @@
+package packages
+
+import (
+	"bufio"
+	"errors"
+	"os/exec"
+	"regexp"
+	"strings"
+
+	"patchmon-agent/pkg/models"
+
+	"github.com/sirupsen/logrus"
+)
+
+var installedPackageRe = regexp.MustCompile(`^(\S+)\s+(\S+)$`)
+var checkUpdateRe = regexp.MustCompile(`^(\S+)\s+(\S+)\s+->\s+(\S+)$`)
+
+// PacmanManager handles pacman package information collection
+type PacmanManager struct {
+	logger *logrus.Logger
+}
+
+// NewPacmanManager creates a new Pacman package manager
+func NewPacmanManager(logger *logrus.Logger) *PacmanManager {
+	return &PacmanManager{
+		logger: logger,
+	}
+}
+
+// indirections for testability
+var (
+	lookPath   = exec.LookPath
+	runCommand = exec.Command
+)
+
+// GetPackages gets package information for pacman-based systems
+func (m *PacmanManager) GetPackages() ([]models.Package, error) {
+	// Get installed packages
+	installedCmd := runCommand("pacman", "-Q")
+	installedOutput, err := installedCmd.Output()
+	var installedPackages map[string]string
+	if err != nil {
+		m.logger.WithError(err).Error("Failed to get installed packages")
+		installedPackages = make(map[string]string)
+	} else {
+		installedPackages = m.parseInstalledPackages(string(installedOutput))
+	}
+
+	upgradablePackages, err := m.getUpgradablePackages()
+	if err != nil {
+		return nil, err
+	}
+
+	// Merge and deduplicate packages
+	packages := CombinePackageData(installedPackages, upgradablePackages)
+	return packages, nil
+}
+
+// getUpgradablePackages runs checkupdates and returns parsed packages.
+func (m *PacmanManager) getUpgradablePackages() ([]models.Package, error) {
+	if _, err := lookPath("checkupdates"); err != nil {
+		m.logger.WithError(err).Error("checkupdates not found (pacman-contrib not installed)")
+		return nil, err
+	}
+
+	upgradeCmd := runCommand("checkupdates")
+	upgradeOutput, err := upgradeCmd.Output()
+	if err != nil {
+		// 0 = success with output, 1 = unknown failure, 2 = no updates available.
+		var exitErr *exec.ExitError
+		if errors.As(err, &exitErr) {
+			if exitErr.ExitCode() == 2 {
+				return []models.Package{}, nil
+			}
+		}
+		m.logger.WithError(err).Error("checkupdates failed")
+		return nil, err
+	}
+
+	pkgs := m.parseCheckUpdate(string(upgradeOutput))
+	return pkgs, nil
+}
+
+// parseCheckUpdate parses checkupdates output
+func (m *PacmanManager) parseCheckUpdate(output string) []models.Package {
+	packages := make([]models.Package, 0)
+
+	scanner := bufio.NewScanner(strings.NewReader(output))
+	for scanner.Scan() {
+		line := scanner.Text()
+		matches := checkUpdateRe.FindStringSubmatch(line)
+		if matches == nil {
+			continue
+		}
+
+		pkg := models.Package{
+			Name:             matches[1],
+			CurrentVersion:   matches[2],
+			AvailableVersion: matches[3],
+			NeedsUpdate:      true,
+			IsSecurityUpdate: false, // Data not provided
+		}
+		packages = append(packages, pkg)
+	}
+
+	return packages
+}
+
+// parseInstalledPackages parses pacman -Q output and returns a map of package name to version
+func (m *PacmanManager) parseInstalledPackages(output string) map[string]string {
+	installedPackages := make(map[string]string)
+
+	scanner := bufio.NewScanner(strings.NewReader(output))
+	for scanner.Scan() {
+		matches := installedPackageRe.FindStringSubmatch(scanner.Text())
+		if matches == nil {
+			continue
+		}
+
+		packageName := matches[1]
+		version := matches[2]
+		installedPackages[packageName] = version
+	}
+
+	return installedPackages
+}