From c7880b9891999805f6b74e0066eda44db6d2c35d Mon Sep 17 00:00:00 2001
From: Sander Mol <sandermol95@hotmail.com>
Date: Thu, 17 Feb 2022 20:41:44 +0100
Subject: [PATCH]  feature: add go-sockaddr/template support for nomad consul
 address

---
 nomad/structs/config/consul.go                |  8 ++++-
 nomad/structs/config/consul_test.go           | 31 +++++++++++++++++++
 website/content/docs/configuration/consul.mdx |  2 ++
 3 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/nomad/structs/config/consul.go b/nomad/structs/config/consul.go
index f228c6321d42..f9224ae233c4 100644
--- a/nomad/structs/config/consul.go
+++ b/nomad/structs/config/consul.go
@@ -1,11 +1,13 @@
 package config
 
 import (
+	"fmt"
 	"net/http"
 	"strings"
 	"time"
 
 	consul "github.com/hashicorp/consul/api"
+	"github.com/hashicorp/go-sockaddr/template"
 	"github.com/hashicorp/nomad/helper"
 )
 
@@ -251,7 +253,11 @@ func (c *ConsulConfig) ApiConfig() (*consul.Config, error) {
 	// http.Transport.
 	config := consul.DefaultConfig()
 	if c.Addr != "" {
-		config.Address = c.Addr
+		out, err := template.Parse(c.Addr)
+		if err != nil {
+			panic(fmt.Errorf("unable to parse address template %q: %v", c.Addr, err))
+		}
+		config.Address = out
 	}
 	if c.Token != "" {
 		config.Token = c.Token
diff --git a/nomad/structs/config/consul_test.go b/nomad/structs/config/consul_test.go
index eb228814fd1c..79a501132968 100644
--- a/nomad/structs/config/consul_test.go
+++ b/nomad/structs/config/consul_test.go
@@ -5,10 +5,12 @@ import (
 	"fmt"
 	"os"
 	"os/exec"
+	"strings"
 	"testing"
 	"time"
 
 	consulapi "github.com/hashicorp/consul/api"
+	sockaddr "github.com/hashicorp/go-sockaddr"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -167,3 +169,32 @@ func TestConsulConfig_Exec(t *testing.T) {
 	require.NotNil(t, conf.VerifySSL)
 	assert.True(t, *conf.VerifySSL)
 }
+
+func TestConsulConfig_SockAddr(t *testing.T) {
+	t.Parallel()
+
+	privateIps, err := sockaddr.GetPrivateIPs()
+	if err != nil {
+		t.Fatalf("failed to get private IPs: %v", err)
+	}
+	privateIp := strings.Split(privateIps, " ")[0]
+	conf := ConsulConfig{
+		Addr: "{{ GetPrivateInterfaces | limit 1 | attr \"address\" }}:8500",
+	}
+
+	apiConf, err := conf.ApiConfig()
+	assert.Nil(t, err)
+	assert.Equal(t, apiConf.Address, privateIp+":8500")
+}
+
+func TestConsulConfig_StringAddr(t *testing.T) {
+	t.Parallel()
+
+	conf := ConsulConfig{
+		Addr: "10.0.1.0:8500",
+	}
+
+	apiConf, err := conf.ApiConfig()
+	assert.Nil(t, err)
+	assert.Equal(t, apiConf.Address, "10.0.1.0:8500")
+}
diff --git a/website/content/docs/configuration/consul.mdx b/website/content/docs/configuration/consul.mdx
index a53cf6d89bb5..37b18509fc3c 100644
--- a/website/content/docs/configuration/consul.mdx
+++ b/website/content/docs/configuration/consul.mdx
@@ -44,6 +44,7 @@ configuring Nomad to talk to Consul via DNS such as consul.service.consul
   Consul agent, given in the format `host:port`. Supports Unix sockets with the
   format: `unix:///tmp/consul/consul.sock`. Will default to the
   `CONSUL_HTTP_ADDR` environment variable if set.
+  The value supports [go-sockaddr/template format][go-sockaddr/template].
 
 - `allow_unauthenticated` `(bool: true)` - Specifies if users submitting jobs to
   the Nomad server should be required to provide their own Consul token, proving
@@ -225,3 +226,4 @@ namespace "nomad-ns" {
 
 [consul]: https://www.consul.io/ 'Consul by HashiCorp'
 [bootstrap]: https://learn.hashicorp.com/tutorials/nomad/clustering 'Automatic Bootstrapping'
+[go-sockaddr/template]: https://godoc.org/github.com/hashicorp/go-sockaddr/template