From 28783a4146361381e57419aa4bcf623f7ab7b80d Mon Sep 17 00:00:00 2001
From: Wim <wim@42.be>
Date: Mon, 9 Sep 2019 23:48:00 +0200
Subject: [PATCH] Do configuration validation on start-up. Fixes #888 (#889)

Fail if:
* we don't have any gateways configured
* we have gateways configured but with non-existing bridge configuration
* we have gateways configured without any configuration
---
 bridge/config/config.go |  5 +++++
 gateway/gateway.go      | 14 ++++++++++++++
 gateway/gateway_test.go | 14 +++++++++++++-
 gateway/router.go       |  6 ++++++
 4 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/bridge/config/config.go b/bridge/config/config.go
index cf6872a0..5da535dc 100644
--- a/bridge/config/config.go
+++ b/bridge/config/config.go
@@ -206,6 +206,7 @@ type BridgeValues struct {
 }
 
 type Config interface {
+	Viper() *viper.Viper
 	BridgeValues() *BridgeValues
 	GetBool(key string) (bool, bool)
 	GetInt(key string) (int, bool)
@@ -274,6 +275,10 @@ func (c *config) BridgeValues() *BridgeValues {
 	return c.cv
 }
 
+func (c *config) Viper() *viper.Viper {
+	return c.v
+}
+
 func (c *config) GetBool(key string) (bool, bool) {
 	c.RLock()
 	defer c.RUnlock()
diff --git a/gateway/gateway.go b/gateway/gateway.go
index b875ccae..af8aecd8 100644
--- a/gateway/gateway.go
+++ b/gateway/gateway.go
@@ -85,6 +85,7 @@ func (gw *Gateway) FindCanonicalMsgID(protocol string, mID string) string {
 func (gw *Gateway) AddBridge(cfg *config.Bridge) error {
 	br := gw.Router.getBridge(cfg.Account)
 	if br == nil {
+		gw.checkConfig(cfg)
 		br = bridge.New(cfg)
 		br.Config = gw.Router.Config
 		br.General = &gw.BridgeValues().General
@@ -104,6 +105,19 @@ func (gw *Gateway) AddBridge(cfg *config.Bridge) error {
 	return nil
 }
 
+func (gw *Gateway) checkConfig(cfg *config.Bridge) {
+	match := false
+	for _, key := range gw.Router.Config.Viper().AllKeys() {
+		if strings.HasPrefix(key, cfg.Account) {
+			match = true
+			break
+		}
+	}
+	if !match {
+		gw.logger.Fatalf("Account %s defined in gateway %s but no configuration found, exiting.", cfg.Account, gw.Name)
+	}
+}
+
 // AddConfig associates a new configuration with the gateway object.
 func (gw *Gateway) AddConfig(cfg *config.Gateway) error {
 	gw.Name = cfg.Name
diff --git a/gateway/gateway_test.go b/gateway/gateway_test.go
index b9bb5b93..2d1a1065 100644
--- a/gateway/gateway_test.go
+++ b/gateway/gateway_test.go
@@ -15,10 +15,15 @@ import (
 
 var testconfig = []byte(`
 [irc.freenode]
+server=""
 [mattermost.test]
+server=""
 [gitter.42wim]
+server=""
 [discord.test]
+server=""
 [slack.test]
+server=""
 
 [[gateway]]
     name = "bridge1"
@@ -44,10 +49,15 @@ var testconfig = []byte(`
 
 var testconfig2 = []byte(`
 [irc.freenode]
+server=""
 [mattermost.test]
+server=""
 [gitter.42wim]
+server=""
 [discord.test]
+server=""
 [slack.test]
+server=""
 
 [[gateway]]
     name = "bridge1"
@@ -87,8 +97,11 @@ var testconfig2 = []byte(`
 
 var testconfig3 = []byte(`
 [irc.zzz]
+server=""
 [telegram.zzz]
+server=""
 [slack.zzz]
+server=""
 [[gateway]]
 name="bridge"
 enable=true
@@ -176,7 +189,6 @@ func TestNewRouter(t *testing.T) {
 	assert.Equal(t, 1, len(r.Gateways))
 	assert.Equal(t, 4, len(r.Gateways["bridge1"].Bridges))
 	assert.Equal(t, 4, len(r.Gateways["bridge1"].Channels))
-
 	r = maketestRouter(testconfig2)
 	assert.Equal(t, 2, len(r.Gateways))
 	assert.Equal(t, 4, len(r.Gateways["bridge1"].Bridges))
diff --git a/gateway/router.go b/gateway/router.go
index 3d531676..56573f74 100644
--- a/gateway/router.go
+++ b/gateway/router.go
@@ -59,8 +59,14 @@ func NewRouter(rootLogger *logrus.Logger, cfg config.Config, bridgeMap map[strin
 // between them.
 func (r *Router) Start() error {
 	m := make(map[string]*bridge.Bridge)
+	if len(r.Gateways) == 0 {
+		return fmt.Errorf("no [[gateway]] configured. See https://github.com/42wim/matterbridge/wiki/How-to-create-your-config for more info")
+	}
 	for _, gw := range r.Gateways {
 		r.logger.Infof("Parsing gateway %s", gw.Name)
+		if len(gw.Bridges) == 0 {
+			return fmt.Errorf("no bridges configured for gateway %s. See https://github.com/42wim/matterbridge/wiki/How-to-create-your-config for more info", gw.Name)
+		}
 		for _, br := range gw.Bridges {
 			m[br.Account] = br
 		}