Merge pull request #817 from caos/nginx-file-descriptors

fix: enable more file descriptors for nginx

internal/operator/nodeagent/dep/nginx/dep.go

@@ -15,6 +15,9 @@ import (
 	"github.com/caos/orbos/mntr"
 )
 
+const LimitNoFileKey = "LimitNOFILE="
+const LimitNoFile8192Entry = LimitNoFileKey + "8192 # Line added by CAOS node agent"
+
 type Installer interface {
 	isNgninx()
 	nodeagent.Installer
@@ -68,6 +71,21 @@ func (s *nginxDep) Current() (pkg common.Package, err error) {
 		"nginx.conf": string(config),
 	}
 
+	unitPath, err := s.systemd.UnitPath("nginx")
+	if err != nil {
+		return pkg, err
+	}
+
+	svc, err := ioutil.ReadFile(unitPath)
+	if err != nil {
+		return pkg, err
+	}
+
+	// make pkg config different, so (*nginxDep).Ensure() is called
+	if !strings.Contains(string(svc), LimitNoFile8192Entry) {
+		pkg.Config["ensuresystemdconf"] = "yes"
+	}
+
 	return pkg, nil
 }
 
@@ -127,9 +145,26 @@ module_hotfixes=true`, repoURL)), 0600); err != nil {
 		return err
 	}
 
+	unitPath, err := s.systemd.UnitPath("nginx")
+	if err != nil {
+		return err
+	}
+
+	if err := dep.ManipulateFile(unitPath, []string{LimitNoFileKey}, nil, func(line string) *string {
+		serviceLine := "[Service]"
+		if strings.HasPrefix(line, serviceLine) {
+			return strPtr(serviceLine + "\n" + LimitNoFile8192Entry)
+		}
+		return strPtr(line)
+	}); err != nil {
+		return err
+	}
+
 	if err := s.systemd.Enable("nginx"); err != nil {
 		return err
 	}
 
 	return s.systemd.Start("nginx")
 }
+
+func strPtr(str string) *string { return &str }

internal/operator/nodeagent/dep/systemd.go

@@ -84,7 +84,7 @@ func (s *SystemD) Enable(binary string) error {
 	}
 
 	if err := cmd.Run(); err != nil {
-		return fmt.Errorf("enabling systemd unit %s failed with stderr %s", binary, errBuf.String(), err)
+		return fmt.Errorf("enabling systemd unit %s failed with stderr %s: %w", binary, errBuf.String(), err)
 	}
 
 	if !s.Active(binary) {
@@ -101,3 +101,33 @@ func (s *SystemD) Active(binary string) bool {
 	}
 	return cmd.Run() == nil
 }
+
+func (s *SystemD) UnitPath(unit string) (string, error) {
+
+	const showProperty = "FragmentPath"
+	const expectOutputPrefix = showProperty + "="
+
+	errBuf := new(bytes.Buffer)
+	defer errBuf.Reset()
+	outBuf := new(bytes.Buffer)
+	defer outBuf.Reset()
+	cmd := exec.Command("systemctl", "show", "-p", showProperty, unit)
+	cmd.Stderr = errBuf
+	cmd.Stdout = outBuf
+	err := cmd.Run()
+	errStr := errBuf.String()
+	outStr := outBuf.String()
+	s.monitor.WithFields(map[string]interface{}{
+		"stdout": outStr,
+		"stderr": errStr,
+	}).Debug("Executed " + strings.Join(cmd.Args, " "))
+	if err != nil {
+		return "", fmt.Errorf("getting systemd unit path for %s failed with stderr %s: %w", unit, errStr, err)
+	}
+
+	if !strings.HasPrefix(outStr, expectOutputPrefix) {
+		return "", fmt.Errorf("expected prefix %s but got %s", expectOutputPrefix, outStr)
+	}
+
+	return strings.Trim(strings.TrimPrefix(outStr, expectOutputPrefix), "\n"), nil
+}