Support file functions in templates

cmd/template.go

@@ -13,8 +13,10 @@ import (
 )
 
 type context struct {
-	Vars interface{}
-	Args map[string]string
+	Vars        interface{}
+	Args        map[string]string
+	PlanPath    string
+	ProjectPath string
 }
 
 var templateOutput string
@@ -51,8 +53,10 @@ var templateCmd = &cobra.Command{
 		}
 
 		context := context{
-			Args: namedArgs,
-			Vars: projectContext.Config.Variables,
+			Args:        namedArgs,
+			Vars:        projectContext.Config.Variables,
+			PlanPath:    projectContext.LocalPlanPath,
+			ProjectPath: projectContext.ProjectPath,
 		}
 
 		if templateOutput == "" {

pkg/templates/funcs.go

@@ -2,6 +2,9 @@ package templates
 
 import (
 	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
 	"strings"
 	"text/template"
 
@@ -19,14 +22,19 @@ func GetFuncMap() template.FuncMap {
 	f := sprig.TxtFuncMap()
 
 	extra := template.FuncMap{
-		"get":         TmplGet,
-		"string":      TmplString,
-		"array":       TmplArray,
-		"objectArray": TmplObjectArray,
-		"strConst":    TmplStrConst,
-		"int":         TmplInt,
-		"is":          TmplIs,
-		"isnt":        TmplIsnt,
+		"get":            TmplGet,
+		"string":         TmplString,
+		"array":          TmplArray,
+		"objectArray":    TmplObjectArray,
+		"strConst":       TmplStrConst,
+		"int":            TmplInt,
+		"is":             TmplIs,
+		"isnt":           TmplIsnt,
+		"toYaml":         TmplToYaml,
+		"fromYaml":       TmplFromYaml,
+		"getFiles":       TmplGetFiles,
+		"getFileContent": TmplGetFileContent,
+		"fileExists":     TmplFileExists,
 	}
 
 	for k, v := range extra {
@@ -130,13 +138,13 @@ func TmplIsnt(a interface{}, b interface{}) bool {
 	return a != b
 }
 
-// ToYaml takes an interface, marshals it to yaml, and returns a string. It will
+// TmplToYaml takes an interface, marshals it to yaml, and returns a string. It will
 // always return a string, even on marshal error (empty string).
 //
 // This is designed to be called from a template.
 //
 // Borrowed from github.com/helm/helm/pkg/chartutil
-func ToYaml(v interface{}) string {
+func TmplToYaml(v interface{}) string {
 	data, err := yaml.Marshal(v)
 	if err != nil {
 		// Swallow errors inside of a template.
@@ -145,15 +153,15 @@ func ToYaml(v interface{}) string {
 	return string(data)
 }
 
-// FromYaml converts a YAML document into a map[string]interface{}.
+// TmplFromYaml converts a YAML document into a map[string]interface{}.
 //
 // This is not a general-purpose YAML parser, and will not parse all valid
 // YAML documents. Additionally, because its intended use is within templates
 // it tolerates errors. It will insert the returned error message string into
 // m["Error"] in the returned map.
 //
 // Borrowed from github.com/helm/helm/pkg/chartutil
-func FromYaml(str string) map[string]interface{} {
+func TmplFromYaml(str string) map[string]interface{} {
 	m := map[string]interface{}{}
 
 	if err := yaml.Unmarshal([]byte(str), &m); err != nil {
@@ -162,6 +170,29 @@ func FromYaml(str string) map[string]interface{} {
 	return m
 }
 
+func TmplGetFileContent(filePath string) string {
+	byteContent, err := ioutil.ReadFile(filePath)
+	if err != nil {
+		return "" // TODO: Print error to shuttle output
+	}
+	return string(byteContent)
+}
+
+func TmplFileExists(filePath string) bool {
+	if _, err := os.Stat(filePath); !os.IsNotExist(err) {
+		return true
+	}
+	return false
+}
+
+func TmplGetFiles(directoryPath string) []os.FileInfo {
+	files, err := ioutil.ReadDir(directoryPath)
+	if err != nil {
+		log.Fatal(err)
+	}
+	return files
+}
+
 // TODO: Add description
 func getInner(property string, input interface{}) interface{} {
 	switch t := input.(type) {