[nginx-ingress-controller] Add ssl certificate checksum to template

ingress/controllers/nginx/controller.go

@@ -733,20 +733,21 @@ func (lbc *loadBalancerController) createServers(data []interface{}) map[string]
 				servers[host] = &nginx.Server{Name: host, Locations: locs}
 			}
 
-			if pemFile, ok := pems[host]; ok {
+			if ngxCert, ok := pems[host]; ok {
 				server := servers[host]
 				server.SSL = true
-				server.SSLCertificate = pemFile
-				server.SSLCertificateKey = pemFile
+				server.SSLCertificate = ngxCert.PemFileName
+				server.SSLCertificateKey = ngxCert.PemFileName
+				server.SSLPemChecksum = ngxCert.PemSHA
 			}
 		}
 	}
 
 	return servers
 }
 
-func (lbc *loadBalancerController) getPemsFromIngress(data []interface{}) map[string]string {
-	pems := make(map[string]string)
+func (lbc *loadBalancerController) getPemsFromIngress(data []interface{}) map[string]nginx.SSLCert {
+	pems := make(map[string]nginx.SSLCert)
 
 	for _, ingIf := range data {
 		ing := ingIf.(*extensions.Ingress)
@@ -769,12 +770,7 @@ func (lbc *loadBalancerController) getPemsFromIngress(data []interface{}) map[st
 				continue
 			}
 
-			pemFileName, err := lbc.nginx.AddOrUpdateCertAndKey(fmt.Sprintf("%v-%v", ing.Namespace, secretName), string(cert), string(key))
-			if err != nil {
-				glog.Errorf("No valid SSL certificate found in secret %v: %v", secretName, err)
-				continue
-			}
-			cn, err := lbc.nginx.CheckSSLCertificate(pemFileName)
+			ngxCert, err := lbc.nginx.AddOrUpdateCertAndKey(fmt.Sprintf("%v-%v", ing.Namespace, secretName), string(cert), string(key))
 			if err != nil {
 				glog.Errorf("No valid SSL certificate found in secret %v: %v", secretName, err)
 				continue
@@ -786,14 +782,14 @@ func (lbc *loadBalancerController) getPemsFromIngress(data []interface{}) map[st
 					continue
 				}
 
-				pems["_"] = pemFileName
+				pems["_"] = ngxCert
 				glog.Infof("Using the secret %v as source for the default SSL certificate", secretName)
 				continue
 			}
 
 			for _, host := range tls.Hosts {
-				if isHostValid(host, cn) {
-					pems[host] = pemFileName
+				if isHostValid(host, ngxCert.CN) {
+					pems[host] = ngxCert
 				} else {
 					glog.Warningf("SSL Certificate stored in secret %v is not valid for the host %v defined in the Ingress rule %v", secretName, host, ing.Name)
 				}

ingress/controllers/nginx/nginx.tmpl

@@ -155,6 +155,8 @@ http {
     server {
         listen 80{{ if $cfg.useProxyProtocol }} proxy_protocol{{ end }};
         {{ if $server.SSL }}listen 443{{ if $cfg.useProxyProtocol }} proxy_protocol{{ end }} ssl http2;
+        {{/* comment PEM sha is required to detect changes in the generated configuration and force a reload */}}
+        # PEM sha: {{ $server.SSLPemChecksum }}        
         ssl_certificate {{ $server.SSLCertificate }};
         ssl_certificate_key {{ $server.SSLCertificateKey }};{{ end }}
 

ingress/controllers/nginx/nginx/nginx.go

@@ -69,6 +69,7 @@ type Server struct {
 	SSL               bool
 	SSLCertificate    string
 	SSLCertificateKey string
+	SSLPemChecksum    string
 }
 
 // ServerByName sorts server by name

ingress/controllers/nginx/nginx/ssl.go

@@ -17,7 +17,9 @@ limitations under the License.
 package nginx
 
 import (
+	"crypto/sha1"
 	"crypto/x509"
+	"encoding/hex"
 	"encoding/pem"
 	"fmt"
 	"io/ioutil"
@@ -26,28 +28,52 @@ import (
 	"github.com/golang/glog"
 )
 
+// SSLCert describes a SSL certificate to be used in NGINX
+type SSLCert struct {
+	CertFileName string
+	KeyFileName  string
+	// PemFileName contains the path to the file with the certificate and key concatenated
+	PemFileName string
+	// PemSHA contains the sha1 of the pem file.
+	// This is used to detect changes in the secret that contains the certificates
+	PemSHA string
+	// CN contains all the common names defined in the SSL certificate
+	CN []string
+}
+
 // AddOrUpdateCertAndKey creates a .pem file wth the cert and the key with the specified name
-func (nginx *Manager) AddOrUpdateCertAndKey(name string, cert string, key string) (string, error) {
+func (nginx *Manager) AddOrUpdateCertAndKey(name string, cert string, key string) (SSLCert, error) {
 	pemFileName := sslDirectory + "/" + name + ".pem"
 
 	pem, err := os.Create(pemFileName)
 	if err != nil {
-		return "", fmt.Errorf("Couldn't create pem file %v: %v", pemFileName, err)
+		return SSLCert{}, fmt.Errorf("Couldn't create pem file %v: %v", pemFileName, err)
 	}
 	defer pem.Close()
 
 	_, err = pem.WriteString(fmt.Sprintf("%v\n%v", cert, key))
 	if err != nil {
-		return "", fmt.Errorf("Couldn't write to pem file %v: %v", pemFileName, err)
+		return SSLCert{}, fmt.Errorf("Couldn't write to pem file %v: %v", pemFileName, err)
+	}
+
+	cn, err := nginx.commonNames(pemFileName)
+	if err != nil {
+		return SSLCert{}, err
 	}
 
-	return pemFileName, nil
+	return SSLCert{
+		CertFileName: cert,
+		KeyFileName:  key,
+		PemFileName:  pemFileName,
+		PemSHA:       nginx.pemSHA1(pemFileName),
+		CN:           cn,
+	}, nil
 }
 
-// CheckSSLCertificate checks if the certificate and key file are valid
+// commonNames checks if the certificate and key file are valid
 // returning the result of the validation and the list of hostnames
 // contained in the common name/s
-func (nginx *Manager) CheckSSLCertificate(pemFileName string) ([]string, error) {
+func (nginx *Manager) commonNames(pemFileName string) ([]string, error) {
 	pemCerts, err := ioutil.ReadFile(pemFileName)
 	if err != nil {
 		return []string{}, err
@@ -92,3 +118,14 @@ func (nginx *Manager) SearchDHParamFile(baseDir string) string {
 	glog.Warning("no file dhparam.pem found in secrets")
 	return ""
 }
+
+func (nginx *Manager) pemSHA1(filename string) string {
+	hasher := sha1.New()
+	s, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return ""
+	}
+
+	hasher.Write(s)
+	return hex.EncodeToString(hasher.Sum(nil))
+}

ingress/controllers/nginx/nginx/ssl_test.go

@@ -44,25 +44,20 @@ func TestAddOrUpdateCertAndKey(t *testing.T) {
 	ngx := &Manager{}
 
 	name := fmt.Sprintf("test-%v", time.Now().UnixNano())
-	pemPath, err := ngx.AddOrUpdateCertAndKey(name, string(dCrt), string(dKey))
+	ngxCert, err := ngx.AddOrUpdateCertAndKey(name, string(dCrt), string(dKey))
 	if err != nil {
 		t.Fatalf("unexpected error checking SSL certificate: %v", err)
 	}
 
-	if pemPath == "" {
+	if ngxCert.PemFileName == "" {
 		t.Fatalf("expected path to pem file but returned empty")
 	}
 
-	cnames, err := ngx.CheckSSLCertificate(pemPath)
-	if err != nil {
-		t.Fatalf("unexpected error checking SSL certificate: %v", err)
-	}
-
-	if len(cnames) == 0 {
+	if len(ngxCert.CN) == 0 {
 		t.Fatalf("expected at least one cname but none returned")
 	}
 
-	if cnames[0] != "echoheaders" {
-		t.Fatalf("expected cname echoheaders but %v returned", cnames[0])
+	if ngxCert.CN[0] != "echoheaders" {
+		t.Fatalf("expected cname echoheaders but %v returned", ngxCert.CN[0])
 	}
 }