15954: Add comment about stdout.

[arvados.git] / lib / boot / cmd.go

diff --git a/lib/boot/cmd.go b/lib/boot/cmd.go
index 95f96a7aecdb53709364c45d9c07da9001bcf511..1abc93722d8b872cce0d524bf55f5277e6487a5c 100644 (file)
--- a/lib/boot/cmd.go
+++ b/lib/boot/cmd.go
@@ -81,6 +81,9 @@ func (bootCommand) RunCommand(prog string, args []string, stdin io.Reader, stdou
        if !ok {
                return 1
        }
+       // Write controller URL to stdout. Nothing else goes to
+       // stdout, so this provides an easy way for a calling script
+       // to discover the controller URL when everything is ready.
        fmt.Fprintln(stdout, url)
        // Wait for signal/crash + orderly shutdown
        <-super.done