feat: override state(former "enviroment") values via command-line args (#644)

The addition of `--set k1=v1,k2=v2` and `--values file1 --values file2` was originally planned in #361.

But it turned out we already had `--values` for existing helmfile commands like `sync`. Duplicated flags doesn't work, obviously.

So this actually add `--state-values-set k1=v1,k2=v2` and `--set-values-file file1 --set-values-file file2`.

They are called "state" values according to the discussion we had at #640

Resolves #361

main.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"github.com/roboll/helmfile/pkg/app"
 	"github.com/roboll/helmfile/pkg/helmexec"
+	"github.com/roboll/helmfile/pkg/maputil"
 	"github.com/roboll/helmfile/pkg/state"
 	"github.com/urfave/cli"
 	"go.uber.org/zap"
@@ -57,6 +58,14 @@ func main() {
 			Name:  "environment, e",
 			Usage: "specify the environment name. defaults to `default`",
 		},
+		cli.StringSliceFlag{
+			Name:  "state-values-set",
+			Usage: "set state values on the command line (can specify multiple or separate values with commas: key1=val1,key2=val2)",
+		},
+		cli.StringSliceFlag{
+			Name:  "state-values-file",
+			Usage: "specify state values in a YAML file",
+		},
 		cli.BoolFlag{
 			Name:  "quiet, q",
 			Usage: "Silence output. Equivalent to log-level warn",
@@ -380,6 +389,8 @@ func main() {
 
 type configImpl struct {
 	c *cli.Context
+
+	set map[string]interface{}
 }
 
 func NewUrfaveCliConfigImpl(c *cli.Context) (configImpl, error) {
@@ -388,9 +399,27 @@ func NewUrfaveCliConfigImpl(c *cli.Context) (configImpl, error) {
 		return configImpl{}, fmt.Errorf("err: extraneous arguments: %s", strings.Join(c.Args(), ", "))
 	}
 
-	return configImpl{
+	conf := configImpl{
 		c: c,
-	}, nil
+	}
+
+	optsSet := c.GlobalStringSlice("state-values-set")
+	if len(optsSet) > 0 {
+		set := map[string]interface{}{}
+		for i := range optsSet {
+			ops := strings.Split(optsSet[i], ",")
+			for j := range ops {
+				op := strings.Split(ops[j], "=")
+				k := strings.Split(op[0], ".")
+				v := op[1]
+
+				set = maputil.Set(set, k, v)
+			}
+		}
+		conf.set = set
+	}
+
+	return conf, nil
 }
 
 func (c configImpl) Values() []string {
@@ -461,6 +490,14 @@ func (c configImpl) Selectors() []string {
 	return c.c.GlobalStringSlice("selector")
 }
 
+func (c configImpl) Set() map[string]interface{} {
+	return c.set
+}
+
+func (c configImpl) ValuesFiles() []string {
+	return c.c.GlobalStringSlice("state-values-file")
+}
+
 func (c configImpl) Interactive() bool {
 	return c.c.GlobalBool("interactive")
 }