agent: refactor loadChecks/loadServices, fixes a few minor bugs

command/agent/agent.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"log"
 	"net"
 	"os"
@@ -955,54 +956,61 @@ func (a *Agent) loadServices(conf *Config) error {
 
 	// Load any persisted services
 	svcDir := filepath.Join(a.config.DataDir, servicesDir)
-	if _, err := os.Stat(svcDir); os.IsNotExist(err) {
-		return nil
-	}
-
-	err := filepath.Walk(svcDir, func(path string, fi os.FileInfo, err error) error {
-		if err != nil {
-			return err
-		}
-		if fi.Name() == servicesDir {
+	files, err := ioutil.ReadDir(svcDir)
+	if err != nil {
+		if os.IsNotExist(err) {
 			return nil
 		}
-		filePath := filepath.Join(svcDir, fi.Name())
-		fh, err := os.Open(filePath)
+		return fmt.Errorf("Failed reading services dir %q: %s", svcDir, err)
+	}
+	for _, fi := range files {
+		// Skip all dirs
+		if fi.IsDir() {
+			continue
+		}
+
+		// Open the file for reading
+		file := filepath.Join(svcDir, fi.Name())
+		fh, err := os.Open(file)
 		if err != nil {
-			return err
-		}
-		content := make([]byte, fi.Size())
-		if _, err := fh.Read(content); err != nil {
-			return err
+			return fmt.Errorf("failed opening service file %q: %s", file, err)
 		}
 
-		var wrapped *persistedService
-		var token string
-		var svc *structs.NodeService
-		if err := json.Unmarshal(content, &wrapped); err != nil {
+		// Read the contents into a buffer
+		buf, err := ioutil.ReadAll(fh)
+		fh.Close()
+		if err != nil {
+			return fmt.Errorf("failed reading service file %q: %s", file, err)
+		}
+
+		// Try decoding the service definition
+		var p persistedService
+		if err := json.Unmarshal(buf, &p); err != nil {
 			// Backwards-compatibility for pre-0.5.1 persisted services
-			if err := json.Unmarshal(content, &svc); err != nil {
-				return fmt.Errorf("failed decoding service from %s: %s", filePath, err)
+			if err := json.Unmarshal(buf, &p.Service); err != nil {
+				return fmt.Errorf("failed decoding service file %q: %s", file, err)
 			}
-		} else {
-			svc = wrapped.Service
-			token = wrapped.Token
 		}
+		serviceID := p.Service.ID
 
-		if _, ok := a.state.services[svc.ID]; ok {
+		if _, ok := a.state.services[serviceID]; ok {
 			// Purge previously persisted service. This allows config to be
 			// preferred over services persisted from the API.
 			a.logger.Printf("[DEBUG] agent: service %q exists, not restoring from %q",
-				svc.ID, filePath)
-			return a.purgeService(svc.ID)
+				serviceID, file)
+			if err := a.purgeService(serviceID); err != nil {
+				return fmt.Errorf("failed purging service %q: %s", serviceID, err)
+			}
 		} else {
 			a.logger.Printf("[DEBUG] agent: restored service definition %q from %q",
-				svc.ID, filePath)
-			return a.AddService(svc, nil, false, token)
+				serviceID, file)
+			if err := a.AddService(p.Service, nil, false, p.Token); err != nil {
+				return fmt.Errorf("failed adding service %q: %s", serviceID, err)
+			}
 		}
-	})
+	}
 
-	return err
+	return nil
 }
 
 // unloadServices will deregister all services other than the 'consul' service
@@ -1034,38 +1042,48 @@ func (a *Agent) loadChecks(conf *Config) error {
 
 	// Load any persisted checks
 	checkDir := filepath.Join(a.config.DataDir, checksDir)
-	if _, err := os.Stat(checkDir); os.IsNotExist(err) {
-		return nil
-	}
-
-	err := filepath.Walk(checkDir, func(path string, fi os.FileInfo, err error) error {
-		if err != nil {
-			return err
-		}
-		if fi.Name() == checksDir {
+	files, err := ioutil.ReadDir(checkDir)
+	if err != nil {
+		if os.IsNotExist(err) {
 			return nil
 		}
-		filePath := filepath.Join(checkDir, fi.Name())
-		fh, err := os.Open(filePath)
+		return fmt.Errorf("Failed reading checks dir %q: %s", checkDir, err)
+	}
+	for _, fi := range files {
+		// Ignore dirs - we only care about the check definition files
+		if fi.IsDir() {
+			continue
+		}
+
+		// Open the file for reading
+		file := filepath.Join(checkDir, fi.Name())
+		fh, err := os.Open(file)
 		if err != nil {
-			return err
-		}
-		content := make([]byte, fi.Size())
-		if _, err := fh.Read(content); err != nil {
-			return err
+			return fmt.Errorf("Failed opening check file %q: %s", file, err)
 		}
 
+		// Read the contents into a buffer
+		buf, err := ioutil.ReadAll(fh)
+		fh.Close()
+		if err != nil {
+			return fmt.Errorf("failed reading check file %q: %s", file, err)
+		}
+
+		// Decode the check
 		var p persistedCheck
-		if err := json.Unmarshal(content, &p); err != nil {
-			return err
+		if err := json.Unmarshal(buf, &p); err != nil {
+			return fmt.Errorf("Failed decoding check file %q: %s", file, err)
 		}
+		checkID := p.Check.CheckID
 
-		if _, ok := a.state.checks[p.Check.CheckID]; ok {
+		if _, ok := a.state.checks[checkID]; ok {
 			// Purge previously persisted check. This allows config to be
 			// preferred over persisted checks from the API.
 			a.logger.Printf("[DEBUG] agent: check %q exists, not restoring from %q",
-				p.Check.CheckID, filePath)
-			return a.purgeCheck(p.Check.CheckID)
+				checkID, file)
+			if err := a.purgeCheck(checkID); err != nil {
+				return fmt.Errorf("Failed purging check %q: %s", checkID, err)
+			}
 		} else {
 			// Default check to critical to avoid placing potentially unhealthy
 			// services into the active pool
@@ -1074,17 +1092,17 @@ func (a *Agent) loadChecks(conf *Config) error {
 			if err := a.AddCheck(p.Check, p.ChkType, false, p.Token); err != nil {
 				// Purge the check if it is unable to be restored.
 				a.logger.Printf("[WARN] agent: Failed to restore check %q: %s",
-					p.Check.CheckID, err)
-				return a.purgeCheck(p.Check.CheckID)
+					checkID, err)
+				if err := a.purgeCheck(checkID); err != nil {
+					return fmt.Errorf("Failed purging check %q: %s", checkID, err)
+				}
 			}
-
 			a.logger.Printf("[DEBUG] agent: restored health check %q from %q",
-				p.Check.CheckID, filePath)
-			return nil
+				p.Check.CheckID, file)
 		}
-	})
+	}
 
-	return err
+	return nil
 }
 
 // unloadChecks will deregister all checks known to the local agent.