Introducing HTTPAdvertise config

docs/configuration-raft.md

@@ -51,7 +51,19 @@ as well as this:
   ],
 ```
 
-If your orchestrator/raft nodes need to communicate via NAT gateways, you can additionally set "RaftAdvertise" to IP or hostname which other nodes should contact. Otherwise other nodes would try to talk to the "RaftBind" address and fail.
+### NAT, firewalls, routing
+
+If your orchestrator/raft nodes need to communicate via NAT gateways, you can additionally set:
+
+- `"RaftAdvertise": "<ip.or.fqdn.visible.to.other.nodes>"`
+
+to IP or hostname which other nodes should contact. Otherwise other nodes would try to talk to the "RaftBind" address and fail.
+
+Raft nodes will reverse proxy HTTP requests to the leader. `orchestrator` will attempt to heuristically compute the leader's URL to which redirect requests. If behind NAT, rerouting ports etc., `orchestrator` may not be able to compute that URL. You may configure:
+
+- `"HTTPAdvertise": "scheme://hostname:port"`
+
+to explicitly specify where a node, assuming it were the leader, would be accessed through HTTP API. As example, you would: `"HTTPAdvertise": "http://my.public.hostname:3000"`
 
 ### Backend DB
 

go/config/config.go

@@ -19,6 +19,7 @@ package config
 import (
 	"encoding/json"
 	"fmt"
+	"net/url"
 	"os"
 	"regexp"
 	"strings"
@@ -86,6 +87,7 @@ type Configuration struct {
 	EnableSyslog                               bool   // Should logs be directed (in addition) to syslog daemon?
 	ListenAddress                              string // Where orchestrator HTTP should listen for TCP
 	ListenSocket                               string // Where orchestrator HTTP should listen for unix socket (default: empty; when given, TCP is disabled)
+	HTTPAdvertise                              string // optional, for raft setups, what is the HTTP address this node will advertise to its peers (potentially use where behind NAT or when rerouting ports; example: "http://11.22.33.44:3030")
 	AgentsServerPort                           string // port orchestrator agents talk back to
 	MySQLTopologyUser                          string
 	MySQLTopologyPassword                      string // my.cnf style configuration file from where to pick credentials. Expecting `user`, `password` under `[client]` section
@@ -266,6 +268,7 @@ func newConfiguration() *Configuration {
 		EnableSyslog:                               false,
 		ListenAddress:                              ":3000",
 		ListenSocket:                               "",
+		HTTPAdvertise:                              "",
 		AgentsServerPort:                           ":3001",
 		StatusEndpoint:                             "/api/status",
 		StatusOUVerify:                             false,
@@ -519,12 +522,15 @@ func (this *Configuration) postReadAdjustments() error {
 	if this.RemoteSSHForMasterFailover && this.RemoteSSHCommand == "" {
 		return fmt.Errorf("RemoteSSHCommand is required when RemoteSSHForMasterFailover is set")
 	}
-	if this.RaftAdvertise == "" {
-		this.RaftAdvertise = this.RaftBind
-	}
 	if this.RaftEnabled && this.RaftDataDir == "" {
 		return fmt.Errorf("RaftDataDir must be defined since raft is enabled (RaftEnabled)")
 	}
+	if this.RaftEnabled && this.RaftBind == "" {
+		return fmt.Errorf("RaftBind must be defined since raft is enabled (RaftEnabled)")
+	}
+	if this.RaftAdvertise == "" {
+		this.RaftAdvertise = this.RaftBind
+	}
 	if this.KVClusterMasterPrefix != "/" {
 		// "/" remains "/"
 		// "prefix" turns to "prefix/"
@@ -542,6 +548,24 @@ func (this *Configuration) postReadAdjustments() error {
 		this.DetectPseudoGTIDQuery = SelectTrueQuery
 		this.PseudoGTIDPreferIndependentMultiMatch = true
 	}
+	if this.HTTPAdvertise != "" {
+		u, err := url.Parse(this.HTTPAdvertise)
+		if err != nil {
+			return fmt.Errorf("Failed parsing HTTPAdvertise %s: %s", this.HTTPAdvertise, err.Error)
+		}
+		if u.Scheme == "" {
+			return fmt.Errorf("If specified, HTTPAdvertise must include scheme (http:// or https://)")
+		}
+		if u.Hostname() == "" {
+			return fmt.Errorf("If specified, HTTPAdvertise must include host name")
+		}
+		if u.Port() == "" {
+			return fmt.Errorf("If specified, HTTPAdvertise must include port number")
+		}
+		if u.Path != "" {
+			return fmt.Errorf("If specified, HTTPAdvertise must not specify a path")
+		}
+	}
 	return nil
 }
 

go/config/config_test.go

@@ -150,3 +150,68 @@ func TestRecoveryPeriodBlock(t *testing.T) {
 		test.S(t).ExpectEquals(c.RecoveryPeriodBlockSeconds, 15)
 	}
 }
+
+func TestRaft(t *testing.T) {
+	{
+		c := newConfiguration()
+		c.RaftBind = "1.2.3.4:1008"
+		c.RaftDataDir = "/path/to/somewhere"
+		err := c.postReadAdjustments()
+		test.S(t).ExpectNil(err)
+		test.S(t).ExpectEquals(c.RaftAdvertise, c.RaftBind)
+	}
+	{
+		c := newConfiguration()
+		c.RaftEnabled = true
+		err := c.postReadAdjustments()
+		test.S(t).ExpectNotNil(err)
+	}
+	{
+		c := newConfiguration()
+		c.RaftEnabled = true
+		c.RaftDataDir = "/path/to/somewhere"
+		err := c.postReadAdjustments()
+		test.S(t).ExpectNil(err)
+	}
+	{
+		c := newConfiguration()
+		c.RaftEnabled = true
+		c.RaftDataDir = "/path/to/somewhere"
+		c.RaftBind = ""
+		err := c.postReadAdjustments()
+		test.S(t).ExpectNotNil(err)
+	}
+}
+
+func TestHttpAdvertise(t *testing.T) {
+	{
+		c := newConfiguration()
+		c.HTTPAdvertise = ""
+		err := c.postReadAdjustments()
+		test.S(t).ExpectNil(err)
+	}
+	{
+		c := newConfiguration()
+		c.HTTPAdvertise = "http://127.0.0.1:1234"
+		err := c.postReadAdjustments()
+		test.S(t).ExpectNil(err)
+	}
+	{
+		c := newConfiguration()
+		c.HTTPAdvertise = "http://127.0.0.1"
+		err := c.postReadAdjustments()
+		test.S(t).ExpectNotNil(err)
+	}
+	{
+		c := newConfiguration()
+		c.HTTPAdvertise = "127.0.0.1:1234"
+		err := c.postReadAdjustments()
+		test.S(t).ExpectNotNil(err)
+	}
+	{
+		c := newConfiguration()
+		c.HTTPAdvertise = "http://127.0.0.1:1234/mypath"
+		err := c.postReadAdjustments()
+		test.S(t).ExpectNotNil(err)
+	}
+}

go/raft/raft.go

@@ -82,17 +82,22 @@ func FatalRaftError(err error) error {
 }
 
 func computeLeaderURI() (uri string, err error) {
-	protocol := "http"
+	if config.Config.HTTPAdvertise != "" {
+		// Explicitly given
+		return config.Config.HTTPAdvertise, nil
+	}
+	// Not explicitly given. Let's heuristically compute using RaftAdvertise
+	scheme := "http"
 	if config.Config.UseSSL {
-		protocol = "https"
+		scheme = "https"
 	}
 	hostname := config.Config.RaftAdvertise
 	listenTokens := strings.Split(config.Config.ListenAddress, ":")
 	if len(listenTokens) < 2 {
 		return uri, fmt.Errorf("computeLeaderURI: cannot determine listen port out of config.Config.ListenAddress: %+v", config.Config.ListenAddress)
 	}
 	port := listenTokens[1]
-	uri = fmt.Sprintf("%s://%s:%s", protocol, hostname, port)
+	uri = fmt.Sprintf("%s://%s:%s", scheme, hostname, port)
 	return uri, nil
 }