[cipd] "selfupdate" command logs at Warning.

cipd/client/cli/main.go

 // Copyright 2014 The LUCI 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,
@@ skipping 91 matching lines @@
         if c.verbose {
                 ctx = logging.SetLevel(ctx, logging.Debug)
         } else {
                 ctx = c.logConfig.Set(ctx)
         }
         return ctx
 }
 
 // registerBaseFlags registers common flags used by all subcommands.
 func (c *cipdSubcommand) registerBaseFlags() {
-        // Set the default log level.
-        c.logConfig.Level = logging.Info
+        // Minimum default logging level is Info. This accommodates subcommands that
+        // don't explicitly set the log level, resulting in the zero value (Debug).
+        if c.logConfig.Level < logging.Info {
+                c.logConfig.Level = logging.Info
+        }
 
         c.Flags.StringVar(&c.jsonOutput, "json-output", "", "Path to write operation results to.")
         c.Flags.BoolVar(&c.verbose, "verbose", false, "Enable more logging (deprecated, use -log-level=debug).")
         c.logConfig.AddFlags(&c.Flags)
 }
 
 // checkArgs checks command line args.
 //
 // It ensures all required positional and flag-like parameters are set.
 // Returns true if they are, or false (and prints to stderr) if not.
@@ skipping 1903 matching lines @@
 ////////////////////////////////////////////////////////////////////////////////
 // 'selfupdate' subcommand.
 
 func cmdSelfUpdate(params Parameters) *subcommands.Command {
         return &subcommands.Command{
                 UsageLine: "selfupdate -version <version>",
                 ShortDesc: "updates the current cipd client binary",
                 LongDesc:  "does an in-place upgrade to the current cipd binary",
                 CommandRun: func() subcommands.CommandRun {
                         s := &selfupdateRun{}
+
+                        // By default, show a reduced number of logs unless something goes wrong.
+                        s.logConfig.Level = logging.Warning
+
                         s.registerBaseFlags()
                         s.clientOptions.registerFlags(&s.Flags, params)
                         s.Flags.StringVar(&s.version, "version", "", "Version of the client to update to.")
                         return s
                 },
         }
 }
 
 type selfupdateRun struct {
         cipdSubcommand
@@ skipping 187 matching lines @@
 // subcommand invocations look more natural.
 //
 // Compare:
 //   * Default: cipd set-ref -ref=abc -version=def package/name
 //   * Improved: cipd set-ref package/name -ref=abc -version=def
 //
 // Much better.
 func Main(params Parameters, args []string) int {
         return subcommands.Run(GetApplication(params), fixFlagsPosition(args))
 }