Add env var which points to ko app

pkg/build/gobuild.go

@@ -908,13 +908,15 @@ func (g *gobuild) buildOne(ctx context.Context, refStr string, base v1.Image, pl
 
 		updatePath(cfg, `C:\ko-app`)
 		cfg.Config.Env = append(cfg.Config.Env, `KO_DATA_PATH=C:\var\run\ko`)
+		cfg.Config.Env = append(cfg.Config.Env, `KO_APP_PATH=C:\ko-app\`+appFileName)
 	} else {
 		if !g.disableEntrypointOverwrite {
 			cfg.Config.Entrypoint = []string{appPath}
 		}
 
 		updatePath(cfg, appDir)
 		cfg.Config.Env = append(cfg.Config.Env, "KO_DATA_PATH="+kodataRoot)
+		cfg.Config.Env = append(cfg.Config.Env, "KO_APP_PATH="+appPath)
 	}
 	cfg.Author = "github.com/ko-build/ko"
 

pkg/build/gobuild_test.go

@@ -669,6 +669,23 @@ func validateImage(t *testing.T, img oci.SignedImage, baseLayers int64, creation
 		}
 	})
 
+	// Check that the environment contains the KO_APP_PATH environment variable.
+	t.Run("check KO_APP_PATH env var", func(t *testing.T) {
+		cfg, err := img.ConfigFile()
+		if err != nil {
+			t.Errorf("ConfigFile() = %v", err)
+		}
+		found := false
+		for _, entry := range cfg.Config.Env {
+			if entry == "KO_APP_PATH=/ko-app/ko" {
+				found = true
+			}
+		}
+		if !found {
+			t.Error("Didn't find KO_APP_PATH.")
+		}
+	})
+
 	// Check that PATH contains the directory of the produced binary.
 	t.Run("check PATH env var", func(t *testing.T) {
 		cfg, err := img.ConfigFile()