In the initial implementation I thought it would be good to not pass on the
deprecation to plugins (since they are new). However it turns out this causes
`docker helloworld -h` to print a spurious "pflag: help requested" line:
$ docker helloworld -h
pflag: help requested
See 'docker helloworld --help'.
Usage: docker helloworld [OPTIONS] COMMAND
A basic Hello World plugin for tests
...
Compared with:
$ docker ps -h
Flag shorthand -h has been deprecated, please use --help
Usage: docker ps [OPTIONS]
This is in essence because having the flag undefined hits a different path
within cobra, causing `c.execute()` to return early due to getting an error
(`flag.ErrHelp`) from `c.ParseFlags`, which launders the error through our
`FlagErrorFunc` which wraps it in a `StatusError` which in turn defeats an `if
err == flag.ErrHelp` check further up the call chain. If the flag is defined we
instead hit a path which returns a bare `flag.ErrHelp` without wrapping it.
I considered updating our `FlagErrorFunc` to not wrap `flag.ErrHelp` (and then
following the chain to the next thing) however while doing that I realised that
the code for `-h` (and `--help`) is deeply embedded into cobra (and its flags
library) such that actually using `-h` as a plugin argument meaning something
other than `help` is basically impossible/impractical. Therefore we may as well
have plugins behave identically to the monolithic CLI and support (deprecated)
the `-h` argument.
With this changed the help related blocks of `SetupRootCommand` and
`SetupPluginRootCommand` are now identical, so consolidate into
`setupCommonRootCommand`.
Tests are updated to check `-h` in a variety of scenarios, including the happy
case here.
Signed-off-by: Ian Campbell <ijc@docker.com>
This makes things more idempotent, rather than relying on undoing the
interspersed settings.
Note that the underlying `Flag`s remain shared, it's just the `FlagSet` which
is duplicated.
Signed-off-by: Ian Campbell <ijc@docker.com>
The issue with plugin options clashing with globals is that when cobra is
parsing the command line and it comes across an argument which doesn't start
with a `-` it (in the absence of plugins) distinguishes between "argument to
current command" and "new subcommand" based on the list of registered sub
commands.
Plugins breaks that model. When presented with `docker -D plugin -c foo` cobra
parses up to the `plugin`, sees it isn't a registered sub-command of the
top-level docker (because it isn't, it's a plugin) so it accumulates it as an
argument to the top-level `docker` command. Then it sees the `-c`, and thinks
it is the global `-c` (for AKA `--context`) option and tries to treat it as
that, which fails.
In the specific case of the top-level `docker` subcommand we know that it has
no arguments which aren't `--flags` (or `-f` short flags) and so anything which
doesn't start with a `-` must either be a (known) subcommand or an attempt to
execute a plugin.
We could simply scan for and register all installed plugins at start of day, so
that cobra can do the right thing, but we want to avoid that since it would
involve executing each plugin to fetch the metadata, even if the command wasn't
going to end up hitting a plugin.
Instead we can parse the initial set of global arguments separately before
hitting the main cobra `Execute` path, which works here exactly because we know
that the top-level has no non-flag arguments.
One slight wrinkle is that the top-level `PersistentPreRunE` is no longer
called on the plugins path (since it no longer goes via `Execute`), so we
arrange for the initialisation done there (which has to be done after global
flags are parsed to handle e.g. `--config`) to happen explictly after the
global flags are parsed. Rather than make `newDockerCommand` return the
complicated set of results needed to make this happen, instead return a closure
which achieves this.
The new functionality is introduced via a common `TopLevelCommand` abstraction
which lets us adjust the plugin entrypoint to use the same strategy for parsing
the global arguments. This isn't strictly required (in this case the stuff in
cobra's `Execute` works fine) but doing it this way avoids the possibility of
subtle differences in behaviour.
Fixes#1699, and also, as a side-effect, the first item in #1661.
Signed-off-by: Ian Campbell <ijc@docker.com>
Plugins are expected to be management commands ("docker <object> <verb>").
This patch modified the usage output to shown plugins in the "Management commands"
section.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
- The placement of the vendor is now in the end of the line.
- A '*' is now added as suffix of plugins' top level commands.
Signed-off-by: Ulysses Souza <ulysses.souza@docker.com>
To do this we add a stub `cobra.Command` for each installed plugin (only when
invoking `help`, not for normal running).
This requires a function to list all available plugins so that is added here.
Signed-off-by: Ian Campbell <ijc@docker.com>
That is, the helper to be used from the plugin's `main`.
Also add a `helloworld` plugin example and build integration.
Signed-off-by: Ian Campbell <ijc@docker.com>
... and expose. I would like to use this from another site.
This implies also moving (and exposing) the `visitAll` helper.
Unit test them while I'm here.
Signed-off-by: Ian Campbell <ijc@docker.com>
This fixes the help template so that if a command
includes a Long form help message that is displayed instead
of ignoring it and always showing the Short message.
Signed-off-by: Daniel Hiltgen <daniel.hiltgen@docker.com>
This patch hides the [flags] in the usage output of commands, using the
new `.DisableFlagsInUseLine` option, instead of the temporary workaround
added in 8e600e10f7
Before this change:
docker run
"docker run" requires at least 1 argument.
See 'docker run --help'.
Usage: docker run [OPTIONS] IMAGE [COMMAND] [ARG...] [flags]
Run a command in a new container
After this change:
docker run
"docker run" requires at least 1 argument.
See 'docker run --help'.
Usage: docker run [OPTIONS] IMAGE [COMMAND] [ARG...]
Run a command in a new container
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
> HasAvailableFlags checks if the command contains any flags (local
> plus persistent from the entire structure) which are not hidden or
> deprecated.
This fix the `--help` display when the `Options` is empty (but
showing), like on `docker trust key`
Signed-off-by: Vincent Demeester <vincent@sbr.pm>
Ian Campbell
Sebastiaan van Stijn
Ulysses Souza
Silvin Lubecki
Daniel Hiltgen
Vincent Demeester
Daniel Nephin
Adrien Duermael
Daniel Nephin