Fix #4: Try to reconnect when there is network problem

build

@@ -3,7 +3,7 @@
 set -e
 
 base='docker.io/tpimenta/nginx-ldap-auth'
-version='v1.0.2'
+version='v1.0.3'
 image="$base:$version"
 
 atexit() {

ldap/connect.go

@@ -19,7 +19,7 @@ func (p *Pool) Connect() error {
 	}
 
 	if p.conn != nil {
-		return nil
+		p.conn.Close()
 	}
 
 	address := fmt.Sprintf("%s:%d", p.url, p.port)
@@ -37,6 +37,11 @@ func (p *Pool) Connect() error {
 		err = conn.StartTLS(&tls.Config{InsecureSkipVerify: true})
 		if err != nil {
 			log.Printf("It was not possble to start TLS, falling back to plain: %v.\n", err)
+			conn.Close()
+			conn, err = ldap.Dial("tcp", address)
+			if err != nil {
+				return err
+			}
 		}
 		p.conn = conn
 	}

ldap/jail.go

@@ -0,0 +1,20 @@
+package ldap
+
+import (
+	"log"
+
+	ldap "gopkg.in/ldap.v2"
+)
+
+func (p *Pool) networkJail(f func() error) error {
+	err := f()
+	if err != nil && ldap.IsErrorWithCode(err, ldap.ErrorNetwork) {
+		log.Printf("Network problem, trying to reconnect once: %v.\n", err)
+		err = p.Connect()
+		if err != nil {
+			return err
+		}
+		err = f()
+	}
+	return err
+}

ldap/login.go

@@ -10,7 +10,9 @@ func (p *Pool) Validate(username, password string) (bool, error) {
 	}
 
 	p.admin = false
-	err = p.conn.Bind(username, password)
+	err = p.networkJail(func() error {
+		return p.conn.Bind(username, password)
+	})
 	if err != nil {
 		return true, err
 	}
@@ -28,7 +30,9 @@ func (p *Pool) auth() error {
 		return nil
 	}
 
-	err := p.conn.Bind(p.username, p.password)
+	err := p.networkJail(func() error {
+		return p.conn.Bind(p.username, p.password)
+	})
 	if err == nil {
 		p.admin = true
 	}

ldap/search.go

@@ -21,22 +21,27 @@ func (p *Pool) Search(base, filter string, attr string) (bool, string, []string,
 		list = []string{attr}
 	}
 
-	res, err := p.conn.Search(ldap.NewSearchRequest(
-		base,
-		ldap.ScopeWholeSubtree,
-		ldap.NeverDerefAliases,
-		0,
-		0,
-		false,
-		filter,
-		list,
-		nil,
-	))
+	var res *ldap.SearchResult
+	err = p.networkJail(func() error {
+		res, err = p.conn.Search(ldap.NewSearchRequest(
+			base,
+			ldap.ScopeWholeSubtree,
+			ldap.NeverDerefAliases,
+			0,
+			0,
+			false,
+			filter,
+			list,
+			nil,
+		))
+		return err
+	})
+
 	if err != nil {
 		return false, "", nil, err
 	}
 
-	if len(res.Entries) == 0 {
+	if res == nil || len(res.Entries) == 0 {
 		return true, "", nil, fmt.Errorf("No results for %s filter %s", base, filter)
 	}
 

rule/service.go

@@ -33,7 +33,7 @@ func (p *Service) Validate(username, password string) bool {
 
 	ok, err := p.validate(username, password)
 	if err != nil {
-		log.Printf("Could not validade user %s: %v\n", username, err)
+		log.Printf("Could not validate user %s: %v\n", username, err)
 		return false
 	}
 

test-server

@@ -0,0 +1,44 @@
+#!/bin/sh
+
+set -e
+
+for name in ldap-test-server ldap-test-client; do
+	if docker ps -a --format '{{.Names}}' | egrep -q "^${name}\$"; then
+		docker rm -f "$name" || :
+	fi
+done
+
+docker run \
+	-p 389:389 \
+	-p 636:636 \
+	--name ldap-test-server \
+	-d \
+	osixia/openldap:1.2.2
+
+# docker exec ldap-test-server ldapsearch -x -H ldap://localhost -b dc=example,dc=org -D "cn=admin,dc=example,dc=org" -w admin
+
+cat > /tmp/config.yaml <<EOF
+web: 0.0.0.0:5555
+path: /
+servers:
+- ldap://$(hostname -I | cut -d\  -f1)
+auth:
+  bindDN: cn=admin,dc=example,dc=org
+  bindPW: admin
+user:
+  baseDN: dc=example,dc=org
+  filter: "(cn={0})"
+EOF
+
+while ! nc -z -w5 127.0.0.1 389; do
+	sleep 1
+done
+
+sleep 2
+
+docker run \
+	-p 5555:5555 \
+	-v '/tmp/config.yaml:/etc/nginx-ldap-auth/config.yaml:ro' \
+	--name ldap-test-client \
+	-d \
+	docker.io/tpimenta/nginx-ldap-auth:v1.0.3