add optional versioning of charts

Author: JeanMertz

README.md

@@ -64,7 +64,7 @@ Here's an example of a project's configuration file:
 ```yaml
 apiVersion: v1
 charts:
-  stable/factorio:
+  stable/factorio:0.2.0:
     resources:
       requests:
         memory: 1024Mi
@@ -86,6 +86,9 @@ For the above example, see here for the default configurations:
   * stable/factorio: https://git.io/v9Tyr
   * stable/minecraft: https://git.io/v9Tya
 
+You can optionally pin your chart to a specific version, by appending `:x.y.z`
+to the chart name.
+
 The Chart Configuration file can also contain templated language which is
 processed by [epp](https://github.com/blendle/epp).
 

parser/chart.go

@@ -53,18 +53,18 @@ func (c *Chart) ToResources(name, namespace string) ([]byte, error) {
 		return nil, err
 	}
 
-	resources, err := chartToResources(c.Location, name, namespace, tmpfile.Name())
+	resources, err := chartToResources(c.Location, c.Version, name, namespace, tmpfile.Name())
 	if err != nil {
 		return nil, err
 	}
 
 	return resources, nil
 }
 
-func chartToResources(location, releaseName, namespace, values string) ([]byte, error) {
+func chartToResources(location, version, releaseName, namespace, values string) ([]byte, error) {
 	var output string
 
-	location, err := locateChartPath(location, "")
+	location, err := locateChartPath(location, version)
 	if err != nil {
 		return nil, err
 	}

parser/config.go

@@ -2,7 +2,9 @@ package parser
 
 import (
 	"errors"
+	"strings"
 
+	"github.com/Masterminds/semver"
 	"github.com/blendle/epp/epp"
 	"github.com/blendle/kubecrt/config"
 	yaml "gopkg.in/yaml.v2"
@@ -19,6 +21,7 @@ type ChartsConfiguration struct {
 // Chart ...
 type Chart struct {
 	Location string
+	Version  string
 	Config   interface{}
 }
 
@@ -71,10 +74,19 @@ func NewChartsConfiguration(m map[string]interface{}, opts *config.ChartsConfigO
 
 	charts, _ = m["charts"].(map[interface{}]interface{})
 	for key, config := range charts {
-		location, _ := key.(string)
+		var version, location string
+
+		s, _ := key.(string)
+		p := strings.Split(s, ":")
+		location = p[0]
+		if len(p) > 1 {
+			version, p = p[len(p)-1], p[:len(p)-1]
+			location = strings.Join(p, ":")
+		}
 
 		c := &Chart{
 			Location: location,
+			Version:  version,
 			Config:   config,
 		}
 
@@ -118,6 +130,12 @@ func validateConfig(cc *ChartsConfiguration) error {
 		if c.Location == "" {
 			return errors.New("Invalid or missing chart name")
 		}
+
+		if c.Version != "" {
+			if _, err := semver.NewVersion(c.Version); err != nil {
+				return errors.New(c.Version + ": " + err.Error())
+			}
+		}
 	}
 
 	return nil