Added basic hook functionality

utils/hooks.go

@@ -0,0 +1,149 @@
+package utils
+
+import (
+	"errors"
+	"fmt"
+	"gopkg.in/yaml.v3"
+	"os"
+	"os/exec"
+	"slices"
+	"strings"
+	"syscall"
+)
+
+type BPMHook struct {
+	SourcePath        string
+	SourceContent     string
+	TriggerOperations []string `yaml:"trigger_operations"`
+	TargetType        string   `yaml:"target_type"`
+	Targets           []string `yaml:"targets"`
+	Depends           []string `yaml:"depends"`
+	Run               string   `yaml:"run"`
+}
+
+// CreateHook returns a BPMHook instance based on the content of the given string
+func CreateHook(sourcePath string) (*BPMHook, error) {
+	// Read hook from source path
+	bytes, err := os.ReadFile(sourcePath)
+	if err != nil {
+		return nil, err
+	}
+
+	// Create base hook structure
+	hook := &BPMHook{
+		SourcePath:        sourcePath,
+		SourceContent:     string(bytes),
+		TriggerOperations: nil,
+		TargetType:        "",
+		Targets:           nil,
+		Depends:           nil,
+		Run:               "",
+	}
+
+	// Unmarshal yaml string
+	err = yaml.Unmarshal(bytes, hook)
+	if err != nil {
+		return nil, err
+	}
+
+	// Ensure hook is valid
+	if err := hook.IsValid(); err != nil {
+		return nil, err
+	}
+
+	return hook, nil
+}
+
+// IsValid ensures hook is valid
+func (hook *BPMHook) IsValid() error {
+	ValidOperations := []string{"install", "upgrade", "remove"}
+
+	// Return error if any trigger operation is not valid or none are given
+	if len(hook.TriggerOperations) == 0 {
+		return errors.New("no trigger operations specified")
+	}
+	for _, operation := range hook.TriggerOperations {
+		if !slices.Contains(ValidOperations, operation) {
+			return errors.New("trigger operation '" + operation + "' is not valid")
+		}
+	}
+
+	if hook.TargetType != "package" && hook.TargetType != "path" {
+		return errors.New("target type '" + hook.TargetType + "' is not valid")
+	}
+
+	if len(hook.Run) == 0 {
+		return errors.New("command to run is empty")
+	}
+
+	// Return nil as hook is valid
+	return nil
+}
+
+// Execute hook if all conditions are met
+func (hook *BPMHook) Execute(packageChanges map[string]string, verbose bool, rootDir string) error {
+	// Check if package dependencies are met
+	installedPackages, err := GetInstalledPackages(rootDir)
+	if err != nil {
+		return err
+	}
+
+	for _, depend := range hook.Depends {
+		if !slices.Contains(installedPackages, depend) {
+			return nil
+		}
+	}
+
+	// Get modified files slice
+	modifiedFiles := make([]*PackageFileEntry, 0)
+	for pkg, _ := range packageChanges {
+		modifiedFiles = append(modifiedFiles, GetPackageFiles(pkg, rootDir)...)
+	}
+
+	// Check if any targets are met
+	targetMet := false
+	for _, t1 := range hook.Targets {
+		if targetMet {
+			break
+		}
+		if hook.TargetType == "package" {
+			for t2, operation := range packageChanges {
+				if t1 == t2 && slices.Contains(hook.TriggerOperations, operation) {
+					targetMet = true
+					break
+				}
+			}
+		} else {
+			for _, t2 := range modifiedFiles {
+				if strings.HasPrefix(t2.Path, t1) {
+					targetMet = true
+					break
+				}
+			}
+		}
+	}
+	if !targetMet {
+		return nil
+	}
+
+	// Execute the command
+	splitCommand := strings.Split(hook.Run, " ")
+	cmd := exec.Command(splitCommand[0], splitCommand[1:]...)
+	// Setup subprocess environment
+	cmd.Dir = "/"
+	// Run hook in chroot if using the -R flag
+	if rootDir != "/" {
+		cmd.SysProcAttr = &syscall.SysProcAttr{Chroot: rootDir}
+	}
+
+	if verbose {
+		fmt.Printf("Running hook (%s) with run command: %s\n", hook.SourcePath, strings.Join(splitCommand, " "))
+	}
+
+	err = cmd.Run()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}