cmd/upspin-ui: document the generated files and their locations

Also rename the log file from browser.log to upspin-ui.log.

Fix upspin/upspin#535

Change-Id: Id3a8e0009bfd80b8094e71e29c35366883231293
Reviewed-on: https://upspin-review.googlesource.com/17520
Reviewed-by: Rob Pike <r@golang.org>
diff --git a/cmd/upspin-ui/doc.go b/cmd/upspin-ui/doc.go
index e0cc5af..e045268 100644
--- a/cmd/upspin-ui/doc.go
+++ b/cmd/upspin-ui/doc.go
@@ -44,5 +44,23 @@
 
 The info buttons (a little "i" in a circle, to the right of each file) display
 extended information for a given directory entry.
+
+Files created by upspin-ui
+
+The signup process creates a config file at the location provided by the
+-config flag. The flag's default value is $HOME/upspin/config.
+Signup also generates key files and puts them in the directory
+$HOME/.ssh/$USER, where $USER is the Upspin user name.
+
+The upspinserver deployment process records its state in a file with the same
+name as the config file with the additional suffix ".gcpState".
+This state file is used to resume the deployment process should the upspin-ui
+program crash or be terminated by the user.
+Once deployment is complete this file may be removed.
+Deployment also generates key files which it puts in $HOME/.ssh/$USER,
+where $USER is the Upspin user name of the server being deployed.
+
+During the signup and deployment processes, upspin-ui logs debugging
+information to $HOME/upspin/log/upspin-ui.log.
 */
 package main
diff --git a/cmd/upspin-ui/log.go b/cmd/upspin-ui/log.go
index 1c932ad..d78c107 100644
--- a/cmd/upspin-ui/log.go
+++ b/cmd/upspin-ui/log.go
@@ -33,14 +33,14 @@
 	l, err := newLogger()
 	if err != nil {
 		// Fall back to standard error if we can't log to a file.
-		l = log.New(os.Stderr, "browser: ", log.LstdFlags)
+		l = log.New(os.Stderr, "upspin-ui: ", log.LstdFlags)
 		l.Print(err)
 	}
 	logger.Logger = l
 }
 
 // newLogger initializes a log.Logger that writes to
-// $HOME/upspin/log/browser.log and redirects the Upspin logger and the
+// $HOME/upspin/log/upspin-ui.log and redirects the Upspin logger and the
 // standard logger to that file.
 func newLogger() (*log.Logger, error) {
 	home, err := config.Homedir()
@@ -51,7 +51,7 @@
 	if err := os.MkdirAll(dir, 0755); err != nil {
 		return nil, err
 	}
-	file := filepath.Join(dir, "browser.log")
+	file := filepath.Join(dir, "upspin-ui.log")
 	const flags = os.O_WRONLY | os.O_CREATE | os.O_APPEND
 	f, err := os.OpenFile(file, flags, 0600)
 	if err != nil {