POC: Add sprig library

docs/templating-language.md

@@ -82,6 +82,7 @@ provides the following functions:
   - [toYAML](#toyaml)
   - [sockaddr](#sockaddr)
   - [writeToFile](#writeToFile)
+- [Sprig Functions](#sprig-functions)
 - [Math Functions](#math-functions)
   - [add](#add)
   - [subtract](#subtract)
@@ -1613,6 +1614,13 @@ For example:
 
 ---
 
+## Sprig Functions
+
+Consul-template provides access to the Sprig library
+in templates. To use a Sprig function in your template, prepend `sprig_` to the function name.  A full list of Sprig functions can be found in the [Sprig Function Documentation](http://masterminds.github.io/sprig/)
+
+---
+
 ## Math Functions
 
 The following functions are available on floats and integer values.

go.mod

@@ -4,11 +4,15 @@ go 1.16
 
 require (
 	github.com/BurntSushi/toml v0.3.1
+	github.com/Masterminds/goutils v1.1.0 // indirect
+	github.com/Masterminds/semver v1.5.0 // indirect
+	github.com/Masterminds/sprig v2.22.0+incompatible
 	github.com/armon/go-metrics v0.3.4 // indirect
 	github.com/davecgh/go-spew v1.1.1
 	github.com/frankban/quicktest v1.4.0 // indirect
 	github.com/golang/snappy v0.0.2 // indirect
 	github.com/google/btree v1.0.0 // indirect
+	github.com/google/uuid v1.1.1 // indirect
 	github.com/hashicorp/consul/api v1.4.0
 	github.com/hashicorp/consul/sdk v0.4.1-0.20200910203702-bb2b5dd871ca
 	github.com/hashicorp/errwrap v1.1.0 // indirect
@@ -26,6 +30,7 @@ require (
 	github.com/hashicorp/logutils v1.0.0
 	github.com/hashicorp/serf v0.9.4 // indirect
 	github.com/hashicorp/vault/api v1.0.5-0.20190730042357-746c0b111519
+	github.com/huandu/xstrings v1.2.0 // indirect
 	github.com/imdario/mergo v0.3.12
 	github.com/mattn/go-colorable v0.1.7 // indirect
 	github.com/mitchellh/go-homedir v1.1.0

go.sum

@@ -2,6 +2,12 @@ cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMT
 github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/DataDog/datadog-go v3.2.0+incompatible/go.mod h1:LButxg5PwREeZtORoXG3tL4fMGNddJ+vMq1mwgfaqoQ=
+github.com/Masterminds/goutils v1.1.0 h1:zukEsf/1JZwCMgHiK3GZftabmxiCw4apj3a28RPBiVg=
+github.com/Masterminds/goutils v1.1.0/go.mod h1:8cTjp+g8YejhMuvIA5y2vz3BpJxksy863GQaJW2MFNU=
+github.com/Masterminds/semver v1.5.0 h1:H65muMkzWKEuNDnfl9d70GUjFniHKHRbFPGBuZ3QEww=
+github.com/Masterminds/semver v1.5.0/go.mod h1:MB6lktGJrhw8PrUyiEoblNEGEQ+RzHPF078ddwwvV3Y=
+github.com/Masterminds/sprig v2.22.0+incompatible h1:z4yfnGrZ7netVz+0EDJ0Wi+5VZCSYp4Z0m2dk6cEM60=
+github.com/Masterminds/sprig v2.22.0+incompatible/go.mod h1:y6hNFY5UBTIWBxnzTeuNhlNS5hqE0NB0E6fgfo2Br3o=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
@@ -54,6 +60,8 @@ github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMyw
 github.com/google/go-cmp v0.4.0 h1:xsAVV57WRhGj6kEIi8ReJzQlHHqcBYCElAvkovg3B/4=
 github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
+github.com/google/uuid v1.1.1 h1:Gkbcsh/GbpXz7lPftLA3P6TYMwjCLYm83jiFQZF/3gY=
+github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/hashicorp/consul/api v1.4.0 h1:jfESivXnO5uLdH650JU/6AnjRoHrLhULq0FnC3Kp9EY=
 github.com/hashicorp/consul/api v1.4.0/go.mod h1:xc8u05kyMa3Wjr9eEAsIAo3dg8+LywT5E/Cl7cNS5nU=
 github.com/hashicorp/consul/sdk v0.4.0/go.mod h1:fY08Y9z5SvJqevyZNy6WWPXiG3KwBPAvlcdx16zZ0fM=
@@ -122,6 +130,8 @@ github.com/hashicorp/vault/sdk v0.1.14-0.20190730042320-0dc007d98cc8 h1:fLUoZ8cI
 github.com/hashicorp/vault/sdk v0.1.14-0.20190730042320-0dc007d98cc8/go.mod h1:B+hVj7TpuQY1Y/GPbCpffmgd+tSEwvhkWnjtSYCaS2M=
 github.com/hashicorp/yamux v0.0.0-20180604194846-3520598351bb/go.mod h1:+NfK9FKeTrX5uv1uIXGdwYDTeHna2qgaIlx54MXqjAM=
 github.com/hashicorp/yamux v0.0.0-20181012175058-2f1d1f20f75d/go.mod h1:+NfK9FKeTrX5uv1uIXGdwYDTeHna2qgaIlx54MXqjAM=
+github.com/huandu/xstrings v1.2.0 h1:yPeWdRnmynF7p+lLYz0H2tthW9lqhMJrQV/U7yy4wX0=
+github.com/huandu/xstrings v1.2.0/go.mod h1:DvyZB1rfVYsBIigL8HwpZgxHwXozlTgGqn63UyNX5k4=
 github.com/imdario/mergo v0.3.12 h1:b6R2BslTbIEToALKP7LxUvijTsNI9TAe80pLWN2g/HU=
 github.com/imdario/mergo v0.3.12/go.mod h1:jmQim1M+e3UYxmgPu/WyfjB3N3VflVyUjjjwH0dnCYA=
 github.com/json-iterator/go v1.1.6/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCVDaaPEHmU=
@@ -152,6 +162,7 @@ github.com/miekg/dns v1.1.26 h1:gPxPSwALAeHJSjarOs00QjVdV9QoBvc1D2ujQUr5BzU=
 github.com/miekg/dns v1.1.26/go.mod h1:bPDLeHnStXmXAq1m/Ch/hvfNHr14JKNPMBo3VZKjuso=
 github.com/mitchellh/cli v1.0.0/go.mod h1:hNIlj7HEI86fIcpObd7a0FcrxTWetlwJDGcceTlRvqc=
 github.com/mitchellh/cli v1.1.0/go.mod h1:xcISNoH86gajksDmfB23e/pu+B+GeFRMYmoHXxx3xhI=
+github.com/mitchellh/copystructure v1.0.0 h1:Laisrj+bAB6b/yJwB5Bt3ITZhGJdqmxquMKeZ+mmkFQ=
 github.com/mitchellh/copystructure v1.0.0/go.mod h1:SNtv71yrdKgLRyLFxmLdkAbkKEFWgYaq1OVrnRcwhnw=
 github.com/mitchellh/go-homedir v1.1.0 h1:lukF9ziXFxDFPkA1vsr5zpc1XuPDn/wFntq5mG+4E0Y=
 github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
@@ -167,6 +178,7 @@ github.com/mitchellh/mapstructure v0.0.0-20160808181253-ca63d7c062ee/go.mod h1:F
 github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
 github.com/mitchellh/mapstructure v1.3.3 h1:SzB1nHZ2Xi+17FP0zVQBHIZqvwRN9408fJO8h+eeNA8=
 github.com/mitchellh/mapstructure v1.3.3/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo=
+github.com/mitchellh/reflectwalk v1.0.0 h1:9D+8oIskB4VJBN5SFlmc27fSlIBZaov1Wpk/IfikLNY=
 github.com/mitchellh/reflectwalk v1.0.0/go.mod h1:mSTlrgnPZtwu0c4WaC2kGObEpuNDbx0jmZXqmk4esnw=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=

template/template.go

@@ -7,9 +7,9 @@ import (
 	"io/ioutil"
 	"text/template"
 
-	"github.com/pkg/errors"
-
+	"github.com/Masterminds/sprig"
 	dep "github.com/hashicorp/consul-template/dependency"
+	"github.com/pkg/errors"
 )
 
 var (
@@ -313,6 +313,12 @@ func funcMap(i *funcMapInput) template.FuncMap {
 		"spew_sprintf": spewSprintf,
 	}
 
+	// Add the Sprig functions to the funcmap
+	for k, v := range sprig.FuncMap() {
+		target := "sprig_" + k
+		r[target] = v
+	}
+
 	for _, bf := range i.functionDenylist {
 		if _, ok := r[bf]; ok {
 			r[bf] = denied