Add discard logger

Signed-off-by: Philip Laine <philip.laine@gmail.com>

pkg/log/nop.go

@@ -0,0 +1,31 @@
+/*
+Copyright 2022 The Flux authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package log
+
+type NopLogger struct{}
+
+func (NopLogger) Actionf(format string, a ...interface{}) {}
+
+func (NopLogger) Generatef(format string, a ...interface{}) {}
+
+func (NopLogger) Waitingf(format string, a ...interface{}) {}
+
+func (NopLogger) Successf(format string, a ...interface{}) {}
+
+func (NopLogger) Warningf(format string, a ...interface{}) {}
+
+func (NopLogger) Failuref(format string, a ...interface{}) {}