Refactor join-server configuration. Add server option.

This renames the certificates config section to servers. When server is
set, DNS resolving is disabled and the JoinEUI matches, ChirpStack
Network Server will use the matching server for handling the
join-request.

cmd/chirpstack-network-server/cmd/configfile.go

@@ -694,15 +694,21 @@ resolve_join_eui={{ .JoinServer.ResolveJoinEUI }}
 resolve_domain_suffix="{{ .JoinServer.ResolveDomainSuffix }}"
 
 
-  # Join-server certificates.
+  # Per Join Server configuration.
   #
   # Example:
-  # [[join_server.certificates]]
+  # [[join_server.servers]]
   # # JoinEUI.
   # #
   # # The JoinEUI of the joinserver to to use the certificates for.
   # join_eui="0102030405060708"
 
+  # # Server (optional).
+  # #
+  # # The endpoint to the Join Server. If set, the DNS lookup will not be used
+  # # for the JoinEUI associated with this server.
+  # server="https://example.com:1234/join/endpoint"
+
   # # CA certificate (optional).
   # #
   # # Set this to validate the join-server server certificate (e.g. when the
@@ -718,8 +724,9 @@ resolve_domain_suffix="{{ .JoinServer.ResolveDomainSuffix }}"
   # #
   # # Set this to enable client-certificate authentication with the join-server.
   # tls_key="/path/to/tls_key.pem"
-  {{ range $index, $element := .JoinServer.Certificates }}
-  [[join_server.certificates]]
+  {{ range $index, $element := .JoinServer.Servers }}
+  [[join_server.servers]]
+  server="{{ $element.Server }}"
   join_eui="{{ $element.JoinEUI }}"
   ca_cert="{{ $element.CACert }}"
   tls_cert="{{ $element.TLSCert }}"
@@ -731,7 +738,7 @@ resolve_domain_suffix="{{ .JoinServer.ResolveDomainSuffix }}"
   # This join-server will be used when resolving the JoinEUI is set to false
   # or as a fallback when resolving the JoinEUI fails.
   [join_server.default]
-  # hostname:port of the default join-server
+  # Default server endpoint.
   #
   # This API is provided by ChirpStack Application Server.
   server="{{ .JoinServer.Default.Server }}"

docs/content/install/config.md

@@ -744,15 +744,21 @@ resolve_join_eui=false
 resolve_domain_suffix=".joineuis.lora-alliance.org"
 
 
-  # Join-server certificates.
+  # Per Join Server configuration.
   #
   # Example:
-  # [[join_server.certificates]]
+  # [[join_server.servers]]
   # # JoinEUI.
   # #
   # # The JoinEUI of the joinserver to to use the certificates for.
   # join_eui="0102030405060708"
 
+  # # Server (optional).
+  # #
+  # # The endpoint to the Join Server. If set, the DNS lookup will not be used
+  # # for the JoinEUI associated with this server.
+  # server="https://example.com:1234/join/endpoint"
+
   # # CA certificate (optional).
   # #
   # # Set this to validate the join-server server certificate (e.g. when the
@@ -775,7 +781,7 @@ resolve_domain_suffix=".joineuis.lora-alliance.org"
   # This join-server will be used when resolving the JoinEUI is set to false
   # or as a fallback when resolving the JoinEUI fails.
   [join_server.default]
-  # hostname:port of the default join-server
+  # Default server endpoint.
   #
   # This API is provided by ChirpStack Application Server.
   server="http://localhost:8003"

internal/backend/joinserver/joinserver.go

@@ -23,18 +23,19 @@ func Setup(c config.Config) error {
 		return errors.Wrap(err, "joinserver: create default client error")
 	}
 
-	var certificates []certificate
-	for _, cert := range conf.Certificates {
+	var servers []server
+	for _, s := range conf.Servers {
 		var eui lorawan.EUI64
-		if err := eui.UnmarshalText([]byte(cert.JoinEUI)); err != nil {
+		if err := eui.UnmarshalText([]byte(s.JoinEUI)); err != nil {
 			return errors.Wrap(err, "joinserver: unmarshal JoinEUI error")
 		}
 
-		certificates = append(certificates, certificate{
+		servers = append(servers, server{
+			server:  s.Server,
 			joinEUI: eui,
-			caCert:  cert.CACert,
-			tlsCert: cert.TLSCert,
-			tlsKey:  cert.TLSKey,
+			caCert:  s.CACert,
+			tlsCert: s.TLSCert,
+			tlsKey:  s.TLSKey,
 		})
 	}
 
@@ -43,7 +44,7 @@ func Setup(c config.Config) error {
 		resolveJoinEUI:      conf.ResolveJoinEUI,
 		resolveDomainSuffix: conf.ResolveDomainSuffix,
 		clients:             make(map[lorawan.EUI64]poolClient),
-		certificates:        certificates,
+		servers:             servers,
 	}
 
 	return nil

internal/backend/joinserver/pool.go

@@ -12,6 +12,9 @@ import (
 	"github.com/brocaar/lorawan"
 )
 
+// ErrServerNotFound indicates that no server is configured for the given JoinEUI.
+var ErrServerNotFound = errors.New("server not found")
+
 // Pool defines the join-server client pool.
 type Pool interface {
 	Get(joinEUI lorawan.EUI64) (Client, error)
@@ -26,11 +29,12 @@ type pool struct {
 	defaultClient       Client
 	resolveJoinEUI      bool
 	clients             map[lorawan.EUI64]poolClient
-	certificates        []certificate
+	servers             []server
 	resolveDomainSuffix string
 }
 
-type certificate struct {
+type server struct {
+	server  string
 	joinEUI lorawan.EUI64
 	caCert  string
 	tlsCert string
@@ -39,52 +43,55 @@ type certificate struct {
 
 // Get returns the join-server client for the given joinEUI.
 func (p *pool) Get(joinEUI lorawan.EUI64) (Client, error) {
-	if !p.resolveJoinEUI {
-		return p.defaultClient, nil
-	}
-
+	// return from cache
 	p.RLock()
 	pc, ok := p.clients[joinEUI]
 	p.RUnlock()
 	if ok {
 		return pc.client, nil
 	}
 
-	client, err := p.resolveJoinServer(joinEUI)
-	if err != nil {
-		log.WithField("join_eui", joinEUI).WithError(err).Warning("resolving JoinEUI failed, using default join-server")
-		return p.defaultClient, nil
+	client := p.getClient(joinEUI)
+	if client != p.defaultClient {
+		p.Lock()
+		p.clients[joinEUI] = poolClient{client: client}
+		p.Unlock()
 	}
 
-	p.Lock()
-	p.clients[joinEUI] = poolClient{client: client}
-	p.Unlock()
-
 	return client, nil
 }
 
-func (p *pool) resolveJoinServer(joinEUI lorawan.EUI64) (Client, error) {
-	// resolve the join-server EUI to an url (using DNS)
-	server, err := p.resolveJoinEUIToJoinServerURL(joinEUI)
-	if err != nil {
-		return nil, errors.Wrap(err, "resolve joineui to join-server url error")
+func (p *pool) getClient(joinEUI lorawan.EUI64) Client {
+	var err error
+	s := p.getServer(joinEUI)
+
+	// if the server endpoint is empty and resolve JoinEUI is enabled, try to get it from DNS
+	if s.server == "" && p.resolveJoinEUI {
+		s.server, err = p.resolveJoinEUIToJoinServerURL(joinEUI)
+		if err != nil {
+			log.WithFields(log.Fields{
+				"join_eui": joinEUI,
+			}).WithError(err).Warning("resolving JoinEUI failed, returning default join-server client")
+			return p.defaultClient
+		}
 	}
 
-	log.WithFields(log.Fields{
-		"join_eui": joinEUI,
-		"server":   server,
-	}).Debug("resolved joineui to join-server")
-
-	var caCert, tlsCert, tlsKey string
-	for _, cert := range p.certificates {
-		if cert.joinEUI == joinEUI {
-			caCert = cert.caCert
-			tlsCert = cert.tlsCert
-			tlsKey = cert.tlsKey
+	// if the server endpoint is set, return the client
+	if s.server != "" {
+		c, err := NewClient(s.server, s.caCert, s.tlsCert, s.tlsKey)
+		if err != nil {
+			log.WithFields(log.Fields{
+				"join_eui": joinEUI,
+				"server":   s.server,
+			}).WithError(err).Error("creating join-server client failed, returning default join-server client")
+			return p.defaultClient
 		}
+
+		return c
 	}
 
-	return NewClient(server, caCert, tlsCert, tlsKey)
+	// in any other case, return the default client
+	return p.defaultClient
 }
 
 func (p *pool) resolveJoinEUIToJoinServerURL(joinEUI lorawan.EUI64) (string, error) {
@@ -118,3 +125,13 @@ func (p *pool) joinEUIToServer(joinEUI lorawan.EUI64) string {
 
 	return strings.Join(nibbles, ".") + p.resolveDomainSuffix
 }
+
+func (p *pool) getServer(joinEUI lorawan.EUI64) server {
+	for _, s := range p.servers {
+		if s.joinEUI == joinEUI {
+			return s
+		}
+	}
+
+	return server{}
+}

internal/backend/joinserver/pool_test.go

@@ -65,6 +65,37 @@ func (ts *PoolTestSuite) TestAToServer() {
 	}
 }
 
+func (ts *PoolTestSuite) TestGetClient() {
+	pool := GetPool().(*pool)
+	pool.resolveJoinEUI = false
+	pool.defaultClient = &client{}
+
+	joinEUI := lorawan.EUI64{1, 2, 3, 4, 5, 6, 7, 8}
+
+	ts.T().Run("Return default client", func(t *testing.T) {
+		assert := require.New(t)
+
+		c := pool.getClient(joinEUI)
+		assert.Equal(pool.defaultClient, c)
+	})
+
+	ts.T().Run("Return pre-configured server", func(t *testing.T) {
+		assert := require.New(t)
+
+		pool.servers = []server{
+			{
+				server:  "http://localhost:12345/foo",
+				joinEUI: joinEUI,
+			},
+		}
+
+		c := pool.getClient(joinEUI)
+		assert.NotEqual(pool.defaultClient, c)
+
+		assert.Equal("http://localhost:12345/foo", c.(*client).server)
+	})
+}
+
 func TestPool(t *testing.T) {
 	suite.Run(t, new(PoolTestSuite))
 }

internal/config/config.go

@@ -157,12 +157,13 @@ type Config struct {
 		ResolveJoinEUI      bool   `mapstructure:"resolve_join_eui"`
 		ResolveDomainSuffix string `mapstructure:"resolve_domain_suffix"`
 
-		Certificates []struct {
+		Servers []struct {
+			Server  string `mapstructure:"server"`
 			JoinEUI string `mapstructure:"join_eui"`
 			CACert  string `mapstructure:"ca_cert"`
 			TLSCert string `mapstructure:"tls_cert"`
 			TLSKey  string `mapstructure:"tls_key"`
-		} `mapstructure:"certificates"`
+		} `mapstructure:"servers"`
 
 		Default struct {
 			Server  string `mapstructure:"server"`