dockerfile fix

docker/Dockerfile.linux.amd64

@@ -1,7 +1,9 @@
-FROM --platform=linux/amd64 alpine:latest
+FROM alpine:latest
 
 RUN apk --no-cache add ca-certificates
 
 ADD ./drone-helm /bin/
 
+RUN chmod +x /bin/drone-helm
+
 ENTRYPOINT ["/bin/drone-helm"]

docker/Dockerfile.linux.arm64

@@ -1,4 +1,4 @@
-FROM --platform=linux/arm64 alpine:latest as base
+FROM alpine:latest as base
 
 WORKDIR /app
 

docker/Dockerfile.windows.amd64

@@ -1,4 +1,4 @@
-FROM --platform=windows/amd64 plugins/base:windows-ltsc2022-amd64
+FROM plugins/base:windows-ltsc2022-amd64
 
 USER ContainerAdministrator
 

main_test.go

@@ -0,0 +1,16 @@
+package main
+
+import (
+	"os"
+	"testing"
+)
+
+func TestEnvironmentVariables(t *testing.T) {
+	os.Setenv("PLUGIN_REGISTRY_URL", "")
+	// Set other required env variables to non-empty values
+
+	if os.Getenv("PLUGIN_REGISTRY_URL") == "" {
+		t.Error("Expected an error due to missing PLUGIN_REGISTRY_URL")
+	}
+	// Repeat for other variables
+}