Refactor: changed some names, the router was the server all along

serverinfo/service.go

@@ -0,0 +1,87 @@
+package serverinfo
+
+import (
+	"log"
+	"os"
+	"os/exec"
+	"path"
+	"strings"
+	"time"
+)
+
+type Config struct {
+	ScriptsDir   string
+	CacheTimeout time.Duration
+}
+
+type cacheEntry struct {
+	creationTime time.Time
+
+	output string
+}
+
+type Service struct {
+	Config *Config
+
+	scriptPaths       map[string]string
+	scriptOutputCache map[string]cacheEntry
+}
+
+func NewService(config *Config) *Service {
+	return &Service{
+		Config: config,
+
+		scriptPaths:       map[string]string{},
+		scriptOutputCache: map[string]cacheEntry{},
+	}
+}
+
+func (s *Service) LoadScripts() error {
+	entries, err := os.ReadDir(s.Config.ScriptsDir)
+	if err != nil {
+		return err
+	}
+
+	s.scriptPaths = map[string]string{}
+
+	for _, entry := range entries {
+		newScriptPath := path.Join(s.Config.ScriptsDir, entry.Name())
+		s.scriptPaths[entry.Name()] = newScriptPath
+	}
+
+	return nil
+}
+
+func (s *Service) InvalidateCache() {
+	log.Printf("Invalidating monitor cache")
+	s.scriptOutputCache = map[string]cacheEntry{}
+}
+
+func (s *Service) GetOutput(command string) (string, error) {
+	// check if output is present in cache
+	if entry, found := s.scriptOutputCache[command]; found {
+		// check if cached value is expired
+		if time.Now().Before(entry.creationTime.Add(s.Config.CacheTimeout)) {
+			log.Printf("Retrieving output of %q from cache", command)
+			return entry.output, nil
+		}
+	}
+
+	args := strings.Fields(command)
+
+	log.Printf("Running script %q with args %v", args[0], args[1:])
+
+	scriptPath := s.scriptPaths[args[0]]
+
+	bytes, err := exec.Command(scriptPath, args[1:]...).Output()
+	if err != nil {
+		return "", err
+	}
+
+	output := string(bytes)
+
+	log.Printf("Caching output of %q", command)
+	s.scriptOutputCache[command] = cacheEntry{time.Now(), output}
+
+	return output, nil
+}