Carry #102 : improvements for command help

[vdemeester]

Closes #101, Carrying #102 and makes help on commands (description, usage and such) more close to what docker-compose does 🐰. It is not mandatory but 😝.

It looks like that :

$ .libcompose-cli help up
WARN[0000] Note: This is an experimental alternate implementation of the Compose CLI (https://github.com/docker/compose) 
Builds, (re)creates, starts, and attaches to containers for a service.

Unless they are already running, this command also starts any linked services.

The `libcompose-cli up` command aggregates the output of each container. When
the command exits, all containers are stopped. Running `libcompose-cli up -d`
starts the containers in the background and leaves them running.

If there are existing containers for a service, and the service's configuration
or image was changed after the container's creation, `libcompose-cli up` picks
up the changes by stopping and recreating the containers (preserving mounted
volumes). To prevent Compose from picking up changes, use the `--no-recreate`
flag.

If you want to force Compose to stop and recreate all containers, use the
`--force-recreate` flag.

Usage: libcompose-cli_linux-amd64 up [options] [SERVICE...]

Options:
   -d                   Do not block and log
   --no-recreate        If containers already exist, don't recreate them. Incompatible with --force-recreate.
   --force-recreate     Recreate containers even if their configuration and image haven't changed. Incompatible with --no-recreate.

$ libcompose-cli help pull
WARN[0000] Note: This is an experimental alternate implementation of the Compose CLI (https://github.com/docker/compose) 
Pulls images for services.

Usage: libcompose-cli_linux-amd64 pull [SERVICE...]

• Find a better way for description
• Re-order commands (alphabetically, like docker-compose)

At some point we should remove the WARN and make it clear elsewhere (like on the main help/usage command), but that's another story/PR 😉.

/cc @dnephin @aanand @ibuildthecloud

🐸

[thaJeztah]

It's unfortunate we need the back-tics in the string; having to do all the concatenation and \n\n for new lines looks tedious

[vdemeester]

Yeah 😓 I'm looking around to see a better way to do that (and hopefully, I'll find one).

[thaJeztah]

Yup, also thinking what a solution would be. Perhaps a separate TOML file containing the strings/descriptions? idk

[vdemeester]

@thaJeztah I wonder, I could also use backticks to not have to escape the carriage-return but.. I had trouble with them for these (backticks inside backticks…).

[thaJeztah]

Thinking if GoDoc can be used somehow, I know @calavera did some experimenting in this area in this PR moby/moby#16125. However (obviously) that's used to generate external documentation, not for usage in the output of the software itself

[dnephin]

spf13/cobra has a good way of dealing with this I think: https://github.com/spf13/cobra#manually-create-rootcmd

[thaJeztah]

Looks like that also uses back-tics for quotes. Still might be worth looking into; something that's easy to maintain and reusable

[vdemeester]

I'm closing this for now, will handle this when migration to spf13/cobra 😉