Help for 'cf push' is misleading: app name is not required

[mhaas]

Please fill out the issue checklist below and provide ALL the requested information.

• I reviewed open and closed github issues that may be related to my problem.
• I tried updating to the latest version of the CF CLI to see if it fixed my problem.
• I attempted to run the command with CF_TRACE=1 to help debug the issue.
• I am reporting a bug that others will be able to reproduce.

Describe the bug and the command you saw an issue with

The output of cf push --help indicates that APP_NAME is a required argument:

$ cf --version
cf version 8.0.0+e8d41cf8e.2021-09-16
$ cf push --help
NAME:
   push - Push a new app or sync changes to an existing app

USAGE:
   cf push APP_NAME [-b BUILDPACK_NAME]
   [-c COMMAND] [-f MANIFEST_PATH | --no-manifest] [--no-start] [--no-wait] [-i NUM_INSTANCES]
   [-k DISK] [-m MEMORY] [-p PATH] [-s STACK] [-t HEALTH_TIMEOUT] [--task TASK]
   [-u (process | port | http)] [--no-route | --random-route]
   [--var KEY=VALUE] [--vars-file VARS_FILE_PATH]...
 
   cf push APP_NAME --docker-image [REGISTRY_HOST:PORT/]IMAGE[:TAG] [--docker-username USERNAME]
   [-c COMMAND] [-f MANIFEST_PATH | --no-manifest] [--no-start] [--no-wait] [-i NUM_INSTANCES]
   [-k DISK] [-m MEMORY] [-p PATH] [-s STACK] [-t HEALTH_TIMEOUT] [--task TASK]
   [-u (process | port | http)] [--no-route | --random-route ]
   [--var KEY=VALUE] [--vars-file VARS_FILE_PATH]...

This is confusing: I coded my automation around the fact that I have to give the APP_NAME instead of it being taken from the manifest.

I then tried to leave out the APP_NAME while pushing my manifest and it worked perfectly.

I would propose to update the help to indicate that APP_NAME is not mandatory.

Provide more context

cf version 8.0.0+e8d41cf8e.2021-09-16

$ cf target
API endpoint:   https://api.cf.sap.hana.ondemand.com
API version:    3.103.0

[gururajsh]

Thank you @mhaas for your submission. APP_NAME is mandatory when using default settings for cf push as mentioned here. Only while using manifest file, which is an optional flag, the app name is taken from manifest if one is not provided.