actions/recipe.go: Add custom function map for generating v5 UUID

actions/image_partition_action.go

@@ -102,6 +102,10 @@ checks in boot time. By default is set to `true` allowing checks on boot.
 ext2, ext3, ext4 and xfs.
 
 - partuuid -- GPT partition UUID string.
+A version 5 UUID can be easily generated using the uuid5 template function
+{{ uuid5 $namespace $data }} $namespace should be a valid UUID and $data can be
+any string, to generate reproducible UUID value pass a fixed value of namespace
+and data.
 
 - extendedoptions -- list of additional filesystem extended options which need
 to be enabled for the partition.

actions/recipe.go

@@ -34,6 +34,7 @@ The following custom template functions are available:
 
 - sector: Returns the argument * 512 (convential sector size) e.g. `{{ sector 64 }}`
 - escape: Shell escape the  argument `{{ escape $var }}`
+- uuid5: Generates fixed UUID value `{{ uuid5 $random-uuid $text }}`
 - functions from [slim-sprig](https://go-task.github.io/slim-sprig/)
 
 Mandatory properties for recipe:
@@ -88,6 +89,7 @@ import (
 	"log"
 	"strings"
 	"reflect"
+	"github.com/google/uuid"
 )
 
 /* the YamlAction just embed the Action interface and implements the
@@ -158,6 +160,11 @@ func escape(s string) string {
 	return shellescape.Quote(s)
 }
 
+func uuid5(namespace string, data string) string {
+	id := uuid.NewSHA1(uuid.MustParse(namespace), []byte(data))
+	return id.String()
+}
+
 func DumpActionStruct(iface interface{}) string {
 	var a []string
 
@@ -245,6 +252,7 @@ func (r *Recipe) Parse(file string, printRecipe bool, dump bool, templateVars ..
 	funcs := template.FuncMap{
 		"sector": sector,
 		"escape": escape,
+		"uuid5": uuid5,
 	}
 	t.Funcs(funcs)
 

tests/templating/test.yaml

@@ -35,3 +35,18 @@ actions:
    description: sprig conversion function
    chroot: false
    command: test 42 -eq {{ 0x2a | int }}
+
+# expected.uuid5 contains value generated with $namespace and $text1
+{{ $namespace := or .namespace "6c9d1418-8fa9-11ee-b4ca-325096b39f47" }}
+{{ $text1 := or .text1 "ver1.0" }}
+{{ $text2 := or .text2 "ver2.0" }}
+{{ $expected := or .expected "3deb2a0e-692c-5a37-93c0-1123948bf5ae" }}
+
+ - action: run
+   description: test uuid5 generate same value when input is same
+   chroot: false
+   command: test {{ uuid5 $namespace $text1 }} = {{ $expected }}
+ - action: run
+   description: test uuid5 generate different value when input is different
+   chroot: false
+   command: test {{ uuid5 $namespace $text2 }} != {{ $expected }}