feat: add yaml to/from functions

Author: blakepettersson

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/Masterminds/sprig/v3 v3.2.3
 	github.com/fsouza/go-dockerclient v1.10.2
 	github.com/stretchr/testify v1.8.4
+	gopkg.in/yaml.v3 v3.0.1
 )
 
 require (
@@ -47,5 +48,4 @@ require (
 	golang.org/x/sys v0.16.0 // indirect
 	golang.org/x/tools v0.6.0 // indirect
 	gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f // indirect
-	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

internal/template/template.go

@@ -75,6 +75,10 @@ func newTemplate(name string) *template.Template {
 		"replace":                strings.Replace,
 		"parseBool":              strconv.ParseBool,
 		"parseJson":              unmarshalJson,
+		"fromYaml":               fromYaml,
+		"toYaml":                 toYaml,
+		"mustFromYaml":           mustFromYaml,
+		"mustToYaml":             mustToYaml,
 		"queryEscape":            url.QueryEscape,
 		"sha1":                   hashSha1,
 		"split":                  strings.Split,

internal/template/yaml.go

@@ -0,0 +1,31 @@
+package template
+
+import "gopkg.in/yaml.v3"
+
+// fromYaml decodes YAML into a structured value, ignoring errors.
+func fromYaml(v string) interface{} {
+	output, _ := mustFromYaml(v)
+	return output
+}
+
+// mustFromYaml decodes YAML into a structured value, returning errors.
+func mustFromYaml(v string) (interface{}, error) {
+	var output interface{}
+	err := yaml.Unmarshal([]byte(v), &output)
+	return output, err
+}
+
+// toYaml encodes an item into a YAML string
+func toYaml(v interface{}) string {
+	output, _ := mustToYaml(v)
+	return string(output)
+}
+
+// toYaml encodes an item into a YAML string, returning errors
+func mustToYaml(v interface{}) (string, error) {
+	output, err := yaml.Marshal(v)
+	if err != nil {
+		return "", err
+	}
+	return string(output), nil
+}