Added sha256Hex function

this will compute the sha256 hash function and output the hex verion
of it.

tests and doc updated.

README.md

@@ -87,6 +87,7 @@ this functionality might prove useful.
       - [regexMatch](#regexmatch)
       - [regexReplaceAll](#regexreplaceall)
       - [replaceAll](#replaceall)
+      - [sha256Hex](#sha256hex)
       - [split](#split)
       - [timestamp](#timestamp)
       - [toJSON](#tojson)
@@ -1838,6 +1839,14 @@ This function can be chained with other functions as well:
 {{ service "web" }}{{ .Name | replaceAll ":" "_" }}{{ end }}
 ```
 
+##### `sha256Hex`
+
+Takes the argument as a string and compute the sha256_hex value
+
+```liquid
+{{ "bladibla" | sha256Hex }}
+```
+
 ##### `split`
 
 Splits the given string on the provided separator:

template/funcs.go

@@ -2,7 +2,9 @@ package template
 
 import (
 	"bytes"
+	"crypto/sha256"
 	"encoding/base64"
+	"encoding/hex"
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
@@ -1379,3 +1381,11 @@ func sockaddr(args ...string) (string, error) {
 	}
 	return k, nil
 }
+
+// sha256Hex return the sha256 hex of a string
+func sha256Hex(item string) (string, error) {
+	h := sha256.New()
+	h.Write([]byte(item))
+	output := hex.EncodeToString(h.Sum(nil))
+	return output, nil
+}

template/funcs_test.go

@@ -234,3 +234,36 @@ func Test_byMeta(t *testing.T) {
 		})
 	}
 }
+
+func Test_sha256Hex(t *testing.T) {
+	type args struct {
+		item string
+	}
+	tests := []struct {
+		name    string
+		args    args
+		want    string
+		wantErr bool
+	}{
+		{
+			name:    "Should return the proper string",
+			args:    args{
+				item: "bladibla",
+			},
+			want:    "54cf4c66bcabb5c20e25331c01dd600b73369e97a947861bd8d3a0e0b8b3d70b",
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := sha256Hex(tt.args.item)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("sha256Hex() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if got != tt.want {
+				t.Errorf("sha256Hex() got = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

template/template.go

@@ -277,6 +277,7 @@ func funcMap(i *funcMapInput) template.FuncMap {
 		"regexReplaceAll": regexReplaceAll,
 		"regexMatch":      regexMatch,
 		"replaceAll":      replaceAll,
+		"sha256Hex":       sha256Hex,
 		"timestamp":       timestamp,
 		"toLower":         toLower,
 		"toJSON":          toJSON,