add support for HELMFILE_FILE_PATH envvar to set -f (#1255)

* fix imports

Signed-off-by: Shane Starcher <shanestarcher@gmail.com>

* unset env var

Signed-off-by: Shane Starcher <shanestarcher@gmail.com>

---------

Signed-off-by: Shane Starcher <shanestarcher@gmail.com>

pkg/app/app.go

@@ -15,6 +15,7 @@ import (
 	"go.uber.org/zap"
 
 	"github.com/helmfile/helmfile/pkg/argparser"
+	"github.com/helmfile/helmfile/pkg/envvar"
 	"github.com/helmfile/helmfile/pkg/filesystem"
 	"github.com/helmfile/helmfile/pkg/helmexec"
 	"github.com/helmfile/helmfile/pkg/plugins"
@@ -1216,7 +1217,7 @@ func (a *App) findDesiredStateFiles(specifiedPath string, opts LoadOpts) ([]stri
 		case defaultFile != "":
 			return []string{defaultFile}, nil
 		default:
-			return []string{}, fmt.Errorf("no state file found. It must be named %s/*.{yaml,yml,yaml.gotmpl,yml.gotmpl}, %s, or %s, otherwise specified with the --file flag", DefaultHelmfileDirectory, DefaultHelmfile, DefaultGotmplHelmfile)
+			return []string{}, fmt.Errorf("no state file found. It must be named %s/*.{yaml,yml,yaml.gotmpl,yml.gotmpl}, %s, or %s, otherwise specified with the --file flag or %s environment variable", DefaultHelmfileDirectory, DefaultHelmfile, DefaultGotmplHelmfile, envvar.FilePath)
 		}
 	}
 

pkg/config/global.go

@@ -8,6 +8,7 @@ import (
 	"go.uber.org/zap"
 	"golang.org/x/term"
 
+	"github.com/helmfile/helmfile/pkg/envvar"
 	"github.com/helmfile/helmfile/pkg/maputil"
 	"github.com/helmfile/helmfile/pkg/state"
 )
@@ -120,7 +121,12 @@ func (g *GlobalImpl) Chart() string {
 
 // FileOrDir returns the path to the Helmfile.
 func (g *GlobalImpl) FileOrDir() string {
-	return g.GlobalOptions.File
+	file := g.GlobalOptions.File
+	if file == "" {
+		file = os.Getenv(envvar.FilePath)
+	}
+
+	return file
 }
 
 // Selectors returns the selectors to use.

pkg/config/global_test.go

@@ -0,0 +1,47 @@
+package config
+
+import (
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/helmfile/helmfile/pkg/envvar"
+)
+
+// TestFileOrDir tests if statement
+func TestFileOrDir(t *testing.T) {
+	tests := []struct {
+		opts     GlobalOptions
+		env      string
+		expected string
+	}{
+		{
+			opts:     GlobalOptions{},
+			env:      "",
+			expected: "",
+		},
+		{
+			opts:     GlobalOptions{},
+			env:      "envset",
+			expected: "envset",
+		},
+		{
+			opts:     GlobalOptions{File: "folderset"},
+			env:      "",
+			expected: "folderset",
+		},
+		{
+			opts:     GlobalOptions{File: "folderset"},
+			env:      "envset",
+			expected: "folderset",
+		},
+	}
+
+	for _, test := range tests {
+		os.Setenv(envvar.FilePath, test.env)
+		received := NewGlobalImpl(&test.opts).FileOrDir()
+		require.Equalf(t, test.expected, received, "FileOrDir expected %t, received %t", test.expected, received)
+	}
+	os.Unsetenv(envvar.FilePath)
+}

pkg/envvar/const.go

@@ -6,6 +6,7 @@ const (
 	SkipInsecureTemplateFunctions = "HELMFILE_SKIP_INSECURE_TEMPLATE_FUNCTIONS"
 	Experimental                  = "HELMFILE_EXPERIMENTAL" // environment variable for experimental features, expecting "true" lower case
 	Environment                   = "HELMFILE_ENVIRONMENT"
+	FilePath                      = "HELMFILE_FILE_PATH"
 	TempDir                       = "HELMFILE_TEMPDIR"
 	UpgradeNoticeDisabled         = "HELMFILE_UPGRADE_NOTICE_DISABLED"
 	V1Mode                        = "HELMFILE_V1MODE"