Confusing error message when deploying to incorrectly formatted hostname

[Matt Brown]

If the hostname passed to helios deploy looks like a URL (or simply contains a slash) when the --json switch is present, a confusing error message Conversion = 'F' is printed with no other output.

# creating the job
$ bin/helios -z http://localhost:5801 create testjob:1 some-image
Creating job: {"command":[],"created":null,"creatingUser":null,"env":{},"expires":null,"gracePeriod":null,"healthCheck":null,"hostname":null,"id":"testjob:1","image":"some-image","metadata":{},"networkMode":null,"ports":{},"registration":{},"registrationDomain":"","resources":null,"securityOpt":[],"token":"","volumes":{}}
Done.
testjob:1:2178b49ac982e92b87442b179b869b4414f770db

# regular deploy to a non-existent host
$ bin/helios --json -z http://localhost:5801 deploy testjob:1 some-host
{"host":"some-host","job":"testjob:1:2178b49ac982e92b87442b179b869b4414f770db","status":"HOST_NOT_FOUND"}

# deploy to host "foo/bar"
$ bin/helios --json -z http://localhost:5801 deploy testjob:1 foo/bar
Conversion = 'F'

To reduce any possible user confusion it would be nice if the HOST_NOT_FOUND was still output.

The cause is that the slash is encoded as %2F in the JSON response from the server and then this string is passed through printf / java.util.Formatter:

$ bin/helios -vvv --json -z http://localhost:5801 deploy testjob:1 foo/bar
...
10:11:25.987 TRACE DefaultRequestDispatcher: rep: PUT http://127.0.0.1:5801/hosts/foo%252Fbar/jobs/testjob:1:2178b49ac982e92b87442b179b869b4414f770db?token=&user=mattbrown 400 105 {
  "host" : "foo%2Fbar",
  "job" : "testjob:1:2178b49ac982e92b87442b179b869b4414f770db",
  "status" : "HOST_NOT_FOUND"
} gzip:false
java.util.UnknownFormatConversionException: Conversion = 'F'
    at java.util.Formatter$FormatSpecifier.conversion(Formatter.java:2691)
    at java.util.Formatter$FormatSpecifier.<init>(Formatter.java:2720)
    at java.util.Formatter.parse(Formatter.java:2560)
    at java.util.Formatter.format(Formatter.java:2501)
    at java.io.PrintStream.format(PrintStream.java:970)
    at java.io.PrintStream.printf(PrintStream.java:871)
    at com.spotify.helios.cli.command.JobDeployCommand.runWithJobId(JobDeployCommand.java:112)
    at com.spotify.helios.cli.command.WildcardJobCommand.run(WildcardJobCommand.java:82)
    at com.spotify.helios.cli.command.ControlCommand.run(ControlCommand.java:127)
    at com.spotify.helios.cli.command.ControlCommand.run(ControlCommand.java:90)
    at com.spotify.helios.cli.CliMain.run(CliMain.java:75)
    at com.spotify.helios.cli.CliMain.main(CliMain.java:53)

[Matt Brown]

For what it is worth this would probably also happen with any % character in the response or anything else that might end up URL encoded

[David Xia]

Fixed by #801