Fix parsing values containing = from os environment

plugin.go

@@ -110,7 +110,7 @@ func installCaCert(cacert string) *exec.Cmd {
 func CopyTfEnv() {
 	tfVar := regexp.MustCompile(`^TF_VAR_.*$`)
 	for _, e := range os.Environ() {
-		pair := strings.Split(e, "=")
+		pair := strings.SplitN(e, "=", 2)
 		if tfVar.MatchString(pair[0]) {
 			name := strings.Split(pair[0], "TF_VAR_")
 			os.Setenv(fmt.Sprintf("TF_VAR_%s", strings.ToLower(name[1])), pair[1])

plugin_test.go

@@ -143,12 +143,14 @@ func TestPlugin(t *testing.T) {
 			// Set some initial TF_VAR_ that are uppercase
 			os.Setenv("TF_VAR_SOMETHING", "some value")
 			os.Setenv("TF_VAR_SOMETHING_ELSE", "some other value")
+			os.Setenv("TF_VAR_BASE64", "dGVzdA==")
 
 			CopyTfEnv()
 
 			// Make sure new env vars exist with proper values
 			g.Assert(os.Getenv("TF_VAR_something")).Equal("some value")
 			g.Assert(os.Getenv("TF_VAR_something_else")).Equal("some other value")
+			g.Assert(os.Getenv("TF_VAR_base64")).Equal("dGVzdA==")
 		})
 	})
 }