Merge pull request #158 from hairyhenderson/add-net-lookup-funcs

Adding net.Lookup* functions

7 files changed, 383 insertions, 0 deletions

diff --git a/docs/content/functions/net.md b/docs/content/functions/net.md
new file mode 100644
index 00000000..08e4c137
--- /dev/null
+++ b/docs/content/functions/net.md
@@ -0,0 +1,200 @@
+---
+title: net functions
+menu:
+  main:
+    parent: functions
+---
+
+## `net.LookupIP`
+
+Resolve an IPv4 address for a given host name. When multiple IP addresses
+are resolved, the first one is returned.
+
+**Note:** Unresolvable hostnames will result in an error, and `gomplate` will panic.
+
+### Usage
+
+```go
+net.LookupIP name
+```
+
+### Arguments
+
+| name   | description |
+|--------|-------|
+| `name` | The hostname to look up. This can be a simple hostname, or a fully-qualified domain name. |
+
+### Examples
+
+```console
+$ gomplate -i '{{ net.LookupIP "example.com" }}'
+93.184.216.34
+```
+
+## `net.LookupIPs`
+
+Resolve all IPv4 addresses for a given host name. Returns an array of strings.
+
+**Note:** Unresolvable hostnames will result in an error, and `gomplate` will panic.
+
+### Usage
+
+```go
+net.LookupIPs name
+```
+
+### Arguments
+
+| name   | description |
+|--------|-------|
+| `name` | The hostname to look up. This can be a simple hostname, or a fully-qualified domain name. |
+
+### Examples
+
+```console
+$ gomplate -i '{{ join (net.LookupIPs "twitter.com") "," }}'  
+104.244.42.65,104.244.42.193
+```
+
+## `net.LookupCNAME`
+
+Resolve the canonical name for a given host name. This does a DNS lookup for the
+`CNAME` record type. If no `CNAME` is present, a canonical form of the given name
+is returned -- e.g. `net.LookupCNAME "localhost"` will return `"localhost."`.
+
+**Note:** Unresolvable hostnames will result in an error, and `gomplate` will panic.
+
+### Usage
+
+```go
+net.LookupCNAME name
+```
+
+### Arguments
+
+| name   | description |
+|--------|-------|
+| `name` | The hostname to look up. This can be a simple hostname, or a fully-qualified domain name. |
+
+### Examples
+
+```console
+$ gomplate -i '{{ net.LookupCNAME "www.amazon.com" }}'  
+d3ag4hukkh62yn.cloudfront.net.
+```
+
+## `net.LookupSRV`
+
+Resolve a DNS [`SRV` service record](https://en.wikipedia.org/wiki/SRV_record).
+This implementation supports the canonical [RFC2782](https://tools.ietf.org/html/rfc2782)
+form (i.e. `_Service._Proto.Name`), but other forms are also supported, such as
+those served by [Consul's DNS interface](https://www.consul.io/docs/agent/dns.html#standard-lookup).
+
+When multiple records are returned, this function returns the first.
+
+A [`net.SRV`](https://golang.org/pkg/net/#SRV) data structure is returned. The
+following properties are available:
+- `Target` - _(string)_ the hostname where the service can be reached
+- `Port` - _(uint16)_ the service's port
+- `Priority`, `Weight` - see [RFC2782](https://tools.ietf.org/html/rfc2782) for details
+
+**Note:** Unresolvable hostnames will result in an error, and `gomplate` will panic.
+
+### Usage
+
+```go
+net.LookupSRV name
+```
+
+### Arguments
+
+| name   | description |
+|--------|-------|
+| `name` | The service name to look up |
+
+### Examples
+
+```console
+$ gomplate -i '{{ net.LookupSRV "_sip._udp.sip.voice.google.com" | toJSONPretty "  " }}
+'
+{
+  "Port": 5060,
+  "Priority": 10,
+  "Target": "sip-anycast-1.voice.google.com.",
+  "Weight": 1
+}
+```
+
+## `net.LookupSRVs`
+
+Resolve a DNS [`SRV` service record](https://en.wikipedia.org/wiki/SRV_record).
+This implementation supports the canonical [RFC2782](https://tools.ietf.org/html/rfc2782)
+form (i.e. `_Service._Proto.Name`), but other forms are also supported, such as
+those served by [Consul's DNS interface](https://www.consul.io/docs/agent/dns.html#standard-lookup).
+
+This function returns all available SRV records.
+
+An array of [`net.SRV`](https://golang.org/pkg/net/#SRV) data structures is
+returned. For each element, the following properties are available:
+- `Target` - _(string)_ the hostname where the service can be reached
+- `Port` - _(uint16)_ the service's port
+- `Priority`, `Weight` - see [RFC2782](https://tools.ietf.org/html/rfc2782) for details
+
+**Note:** Unresolvable hostnames will result in an error, and `gomplate` will panic.
+
+### Usage
+
+```go
+net.LookupSRVs name
+```
+
+### Arguments
+
+| name   | description |
+|--------|-------|
+| `name` | The service name to look up |
+
+### Examples
+
+_input.tmpl:_
+```
+{{ range (net.LookupSRVs "_sip._udp.sip.voice.google.com") -}}
+priority={{.Priority}}/port={{.Port}}
+{{- end }}
+```
+
+```console
+$ gomplate -f input.tmpl
+priority=10/port=5060
+priority=20/port=5060
+```
+
+## `net.LookupTXT`
+
+Resolve a DNS [`TXT` record](https://en.wikipedia.org/wiki/SRV_record).
+
+This function returns all available TXT records as an array of strings.
+
+**Note:** Unresolvable hostnames will result in an error, and `gomplate` will panic.
+
+### Usage
+
+```go
+net.LookupTXT name
+```
+
+### Arguments
+
+| name   | description |
+|--------|-------|
+| `name` | The host name to look up |
+
+### Examples
+
+```console
+$ gomplate -i '{{net.LookupTXT "example.com" | toJSONPretty "\t" }}'
+[
+	"$Id: example.com 4415 2015-08-24 20:12:23Z davids $",
+	"v=spf1 -all"
+]
+```
diff --git a/funcs.go b/funcs.go
index bd1367f4..6a1504de 100644
--- a/funcs.go
+++ b/funcs.go
@@ -53,5 +53,6 @@ func initFuncs(data *Data) template.FuncMap {
 	}
 	funcs.AWSFuncs(f)
 	funcs.AddBase64Funcs(f)
+	funcs.AddNetFuncs(f)
 	return f
 }
diff --git a/funcs/net.go b/funcs/net.go
new file mode 100644
index 00000000..75a47498
--- /dev/null
+++ b/funcs/net.go
@@ -0,0 +1,57 @@
+package funcs
+
+import (
+	stdnet "net"
+	"sync"
+
+	"github.com/hairyhenderson/gomplate/net"
+)
+
+var (
+	netNS     *NetFuncs
+	netNSInit sync.Once
+)
+
+// NetNS - the net namespace
+func NetNS() *NetFuncs {
+	netNSInit.Do(func() { netNS = &NetFuncs{} })
+	return netNS
+}
+
+// AddNetFuncs -
+func AddNetFuncs(f map[string]interface{}) {
+	f["net"] = NetNS
+}
+
+// NetFuncs -
+type NetFuncs struct{}
+
+// LookupIP -
+func (f *NetFuncs) LookupIP(name string) string {
+	return net.LookupIP(name)
+}
+
+// LookupIPs -
+func (f *NetFuncs) LookupIPs(name string) []string {
+	return net.LookupIPs(name)
+}
+
+// LookupCNAME -
+func (f *NetFuncs) LookupCNAME(name string) string {
+	return net.LookupCNAME(name)
+}
+
+// LookupSRV -
+func (f *NetFuncs) LookupSRV(name string) *stdnet.SRV {
+	return net.LookupSRV(name)
+}
+
+// LookupSRVs -
+func (f *NetFuncs) LookupSRVs(name string) []*stdnet.SRV {
+	return net.LookupSRVs(name)
+}
+
+// LookupTXT -
+func (f *NetFuncs) LookupTXT(name string) []string {
+	return net.LookupTXT(name)
+}
diff --git a/funcs/net_test.go b/funcs/net_test.go
new file mode 100644
index 00000000..18412954
--- /dev/null
+++ b/funcs/net_test.go
@@ -0,0 +1,12 @@
+package funcs
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNetLookupIP(t *testing.T) {
+	n := &NetFuncs{}
+	assert.Equal(t, "127.0.0.1", n.LookupIP("localhost"))
+}
diff --git a/net/net.go b/net/net.go
new file mode 100644
index 00000000..c0bfe594
--- /dev/null
+++ b/net/net.go
@@ -0,0 +1,62 @@
+package net
+
+import (
+	"log"
+	"net"
+)
+
+// LookupIP -
+func LookupIP(name string) string {
+	i := LookupIPs(name)
+	if len(i) == 0 {
+		return ""
+	}
+	return i[0]
+}
+
+// LookupIPs -
+func LookupIPs(name string) []string {
+	srcIPs, err := net.LookupIP(name)
+	if err != nil {
+		log.Fatal(err)
+	}
+	var ips []string
+	for _, v := range srcIPs {
+		if v.To4() != nil {
+			ips = append(ips, v.String())
+		}
+	}
+	return ips
+}
+
+// LookupCNAME -
+func LookupCNAME(name string) string {
+	cname, err := net.LookupCNAME(name)
+	if err != nil {
+		log.Fatal(err)
+	}
+	return cname
+}
+
+// LookupTXT -
+func LookupTXT(name string) []string {
+	records, err := net.LookupTXT(name)
+	if err != nil {
+		log.Fatal(err)
+	}
+	return records
+}
+
+// LookupSRV -
+func LookupSRV(name string) *net.SRV {
+	return LookupSRVs(name)[0]
+}
+
+// LookupSRVs -
+func LookupSRVs(name string) []*net.SRV {
+	_, addrs, err := net.LookupSRV("", "", name)
+	if err != nil {
+		log.Fatal(err)
+	}
+	return addrs
+}
diff --git a/net/net_test.go b/net/net_test.go
new file mode 100644
index 00000000..ff4ffd37
--- /dev/null
+++ b/net/net_test.go
@@ -0,0 +1,32 @@
+package net
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestLookupIP(t *testing.T) {
+	assert.Equal(t, "127.0.0.1", LookupIP("localhost"))
+	assert.Equal(t, "169.254.255.254", LookupIP("hostlocal.io"))
+	assert.Equal(t, "93.184.216.34", LookupIP("example.com"))
+
+}
+
+func TestLookupIPs(t *testing.T) {
+	assert.Equal(t, []string{"127.0.0.1"}, LookupIPs("localhost"))
+	assert.Equal(t, []string{"169.254.255.254"}, LookupIPs("hostlocal.io"))
+	assert.Equal(t, []string{"93.184.216.34"}, LookupIPs("example.com"))
+}
+
+func TestLookupTXT(t *testing.T) {
+	assert.NotEmpty(t, LookupTXT("example.com"))
+}
+
+func TestLookupCNAME(t *testing.T) {
+	assert.Equal(t, "hairyhenderson.ca.", LookupCNAME("www.hairyhenderson.ca."))
+}
+
+func TestLookupSRV(t *testing.T) {
+	assert.Equal(t, uint16(5060), LookupSRV("_sip._udp.sip.voice.google.com").Port)
+}
diff --git a/test/integration/net.bats b/test/integration/net.bats
new file mode 100644
index 00000000..d63eaf1b
--- /dev/null
+++ b/test/integration/net.bats
@@ -0,0 +1,19 @@
+#!/usr/bin/env bats
+
+load helper
+
+tmpdir=$(mktemp -u)
+
+function setup () {
+  mkdir -p $tmpdir
+}
+
+function teardown () {
+  rm -rf $tmpdir || true
+}
+
+@test "'net.LookupIP'" {
+  gomplate -i '{{ net.LookupIP "localhost" }}'
+  [ "$status" -eq 0 ]
+  [[ "${output}" == "127.0.0.1" ]]
+}