usability: fleetctl / fleetd help output with double hyphens

[kayrus]

According to this issue fleetctl -%someinvalidcommand% should print commands list with the double hyphens.

$ fleetd -foo
flag provided but not defined: -foo
fleetd is the server component of fleet, a simple orchestration system for scheduling systemd units in a cluster.
Usage of fleetd:
  -config="": Path to config file. Fleet will look for a config at /etc/fleet/fleet.conf by default.
  -version=false: Print the version and exit
$ fleetctl --foo
flag provided but not defined: -foo
Usage of fleetctl:
  -ca-file="": Location of TLS CA file used to secure communication with the fleet API or etcd
  -cert-file="": Location of TLS cert file used to secure communication with the fleet API or etcd
  -debug=false: Print out more debug information to stderr
  -driver="API": Adapter used to execute fleetctl commands. Options include "API" and "etcd".
  -endpoint="unix:///var/run/fleet.sock": Location of the fleet API if --driver=API. Alternatively, if --driver=etcd, location of the etcd API.
  -etcd-cafile="": hidden
  -etcd-certfile="": hidden
  -etcd-key-prefix="/_coreos.com/fleet/": Keyspace for fleet data in etcd (development use only!)
  -etcd-keyfile="": hidden
  -experimental-api=true: hidden
  -h=false: Print usage information and exit
  -help=false: Print usage information and exit
  -key-file="": Location of TLS key file used to secure communication with the fleet API or etcd
  -known-hosts-file="~/.fleetctl/known_hosts": File used to store remote machine fingerprints. Ignored if strict host key checking is disabled.
  -request-timeout=3: Amount of time in seconds to allow a single request before considering it failed.
  -ssh-timeout=10: Amount of time in seconds to allow for SSH connection initialization before failing.
  -ssh-username="core": Username to use when connecting to CoreOS instance.
  -strict-host-key-checking=true: Verify host keys presented by remote machines before initiating SSH connections.
  -tunnel="": Establish an SSH tunnel through the provided address for communication with fleet and etcd.
  -version=false: Print the version and exit

relates to #1445 etcd-io/etcd#4595

[kayrus]

It is also better to unify fleetctl --help and fleetctl --foo commands output.

[kayrus]

@reneengelhard same issue with subhelp:

$ fleetctl list-unit-files --foo
flag provided but not defined: -foo
Usage:
  -fields="unit,hash,dstate,state,target": Columns to print for each Unit file. Valid fields are "desc,dstate,global,hash,state,target,tmachine,unit"
  -full=false: Do not ellipsize fields on output
  -no-legend=false: Do not print a legend (column headers)
flag provided but not defined: -foo

[reneengelhard]

See reneengelhard/cli and #1570

core@core-01 ~/fleet $ /usr/bin/fleetctl -foo
flag provided but not defined: -foo
Usage of fleetctl:
  -ca-file="": Location of TLS CA file used to secure communication with the fleet API or etcd
  -cert-file="": Location of TLS cert file used to secure communication with the fleet API or etcd
  -debug=false: Print out more debug information to stderr
  -driver="API": Adapter used to execute fleetctl commands. Options include "API" and "etcd".
  -endpoint="unix:///var/run/fleet.sock": Location of the fleet API if --driver=API. Alternatively, if --driver=etcd, location of the etcd API.
  -etcd-cafile="": hidden
  -etcd-certfile="": hidden
  -etcd-key-prefix="/_coreos.com/fleet/": Keyspace for fleet data in etcd (development use only!)
  -etcd-keyfile="": hidden
  -experimental-api=true: hidden
  -h=false: Print usage information and exit
  -help=false: Print usage information and exit
  -key-file="": Location of TLS key file used to secure communication with the fleet API or etcd
  -known-hosts-file="~/.fleetctl/known_hosts": File used to store remote machine fingerprints. Ignored if strict host key checking is disabled.
  -request-timeout=3: Amount of time in seconds to allow a single request before considering it failed.
  -ssh-timeout=10: Amount of time in seconds to allow for SSH connection initialization before failing.
  -ssh-username="core": Username to use when connecting to CoreOS instance.
  -strict-host-key-checking=true: Verify host keys presented by remote machines before initiating SSH connections.
  -tunnel="": Establish an SSH tunnel through the provided address for communication with fleet and etcd.
  -version=false: Print the version and exit
core@core-01 ~/fleet $ ./bin/fleetctl -foo
Incorrect Usage.

NAME:
   fleetctl - command-line interface to fleet.

USAGE:
   fleetctl [global options] command [command options] [arguments...]

VERSION:
   v0.12.0-40-g6f8cfda-dirty

COMMANDS:
   cat          Output the contents of a submitted unit
   destroy      Destroy one or more units in the cluster
   fd-forward       Proxy stdin and stdout to a unix domain socket
   journal      Print the journal of a unit in the cluster to stdout
   list-machines    Enumerate the current hosts in the cluster
   list-unit-files  List the units that exist in the cluster.
   list-units       List the current state of units in the cluster
   load         Schedule one or more units in the cluster, first submitting them if necessary.
   ssh          Open interactive shell on a machine in the cluster
   start        Instruct systemd to start one or more units in the cluster, first submitting and loading if necessary.
   status       Output the status of one or more units in the cluster
   stop         Instruct systemd to stop one or more units in the cluster.
   submit       Upload one or more units to the cluster without starting them
   unload       Unschedule one or more units in the cluster.
   verify       DEPRECATED - No longer works
   help, h      Shows a list of commands or help for one command

GLOBAL OPTIONS:
   --debug                  Print out more debug information to stderr
   --driver "API"               Adapter used to execute fleetctl commands. Options include "API" and "etcd".
   --endpoint "unix:///var/run/fleet.sock"  Location of the fleet API if --driver=API. Alternatively, if --driver=etcd, location of the etcd API.
   --etcd-key-prefix "/_coreos.com/fleet/"  Keyspace for fleet data in etcd (development use only!)
   --key-file                   Location of TLS key file used to secure communication with the fleet API or etcd
   --cert-file                  Location of TLS cert file used to secure communication with the fleet API or etcd
   --ca-file                    Location of TLS CA file used to secure communication with the fleet API or etcd
   --known-hosts-file "~/.fleetctl/known_hosts" File used to store remote machine fingerprints. Ignored if strict host key checking is disabled.
   --strict-host-key-checking           Verify host keys presented by remote machines before initiating SSH connections.
   --ssh-timeout "10s"              Amount of time in seconds to allow for SSH connection initialization before failing.
   --tunnel                     Establish an SSH tunnel through the provided address for communication with fleet and etcd.
   --request-timeout "3s"           Amount of time in seconds to allow a single request before considering it failed.
   --ssh-username "core"            Username to use when connecting to CoreOS instance.
   --experimental-api               DEPRECATED
   --etcd-keyfile               DEPRECATED
   --etcd-certfile              DEPRECATED
   --etcd-cafile                DEPRECATED
   --help, -h                   show help
   --version, -v                print the version

[kayrus]

@reneengelhard Awesome! Thanks!