When trying to use an invalid flag, the CLI currently prints the a short
error message, instructions to use the `--help` flag to learn about the
correct usage, followed by the command's usage output.
While this is a common convention, and may have been a nice gesture when
docker was still young and only had a few commands and options ("you did
something wrong, but here's an overview of what you can use"), that's no
longer the case, and many commands have a _very_ long output.
The result of this is that the error message, which is the relevant
information in this case - "You mis-typed something" - is lost in the
output, and hard to find (sometimes even requiring scrolling back).
The output is also confusing, because it _looks_ like something ran
successfully (most of the output is not about the error!).
Even further; the suggested resolution (try `--help` to see the correct
options) is rather redundant, because running teh command with `--help`
produces _exactly_ the same output as was just showh, baring the error
message. As a fun fact, due to the usage output being printed, the
output even contains not one, but _two_ "call to actions";
- `See 'docker volume --help'.` (under the erro message)
- `Run 'docker volume COMMAND --help' for more information on a command.`
(under the usage output)
In short; the output is too verbose, confusing, and doesn't provide
a good UX. Let's reduce the output produced so that the focus is on the
important information.
This patch:
- Changes the usage to the short-usage.
- Prefixes the error message with the binary / root-command name
(usually `docker:`) to be consistent with `unknon command`, and helps
to distinguish where the message originated from (the `docker` CLI in
this case).
- Adds an empty line between the error-message and the "call to action"
(`Run 'docker volume --help' ...` in the example below). This helps
separating the error message ("unkown flag") from the call-to-action.
Before this patch:
docker volume --no-such-flag
unknown flag: --no-such-flag
See 'docker volume --help'.
Usage: docker volume COMMAND
Manage volumes
Commands:
create Create a volume
inspect Display detailed information on one or more volumes
ls List volumes
prune Remove unused local volumes
rm Remove one or more volumes
update Update a volume (cluster volumes only)
Run 'docker volume COMMAND --help' for more information on a command.
With this patch:
docker volume --no-such-flag
docker: unknown flag: --no-such-flag
Usage: docker volume COMMAND
Run 'docker volume --help' for more information
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
This confused me fore a bit, because I thought the test was checking for
an actual `context.Canceled` error (which is spelled "context canceled"
with a single "l". But then I found that this was a string that's printed
as part of a test-utility, just looking very similar but with the British
spelling ("cancelled").
Let's change this to a message that's unique for the test, also to make it
more grep'able.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Improve the output for these validation errors:
- Removes the short command description from the output. This information
does not provide much useful help, and distracts from the error message.
- Reduces punctuation, and
- Prefixes the error message with the binary / root-command name
(usually `docker:`) to be consistent with other similar errors.
- Adds an empty line between the error-message and the "call to action"
(`Run 'docker volume --help'...` in the example below). This helps
separating the error message and "usage" from the call-to-action.
Before this patch:
$ docker volume ls one two three
"docker volume ls" accepts no arguments.
See 'docker volume ls --help'.
Usage: docker volume ls [OPTIONS]
List volumes
$ docker volume create one two three
"docker volume create" requires at most 1 argument.
See 'docker volume create --help'.
Usage: docker volume create [OPTIONS] [VOLUME]
Create a volume
With this patch:
$ docker volume ls one two three
docker: 'docker volume ls' accepts no arguments
Usage: docker volume ls [OPTIONS]
Run 'docker volume ls --help' for more information
$ docker voludocker volume create one two three
docker: 'docker volume create' requires at most 1 argument
Usage: docker volume create [OPTIONS] [VOLUME]
SRun 'docker volume create --help' for more information
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Before this patch, output for invalid top-level and sub-commands differed.
For top-level commands, the CLI would print an error-message and a suggestion
to use `--help`. For missing *subcommands*, we would hit a different code-path,
and different output, which includes full "usage" / "help" output.
While it is a common convention to show usage output, and may have been
a nice gesture when docker was still young and only had a few commands
and options ("you did something wrong; here's an overview of what you
can use"), that's no longer the case, and many commands have a _very_
long output.
The result of this is that the error message, which is the relevant
information in this case - "You mis-typed something" - is lost in the
output, and hard to find (sometimes even requiring scrolling back).
The output is also confusing, because it _looks_ like something ran
successfully (most of the output is not about the error!).
Even further; the suggested resolution (try `--help` to see the correct
options) is rather redundant, because running teh command with `--help`
produces _exactly_ the same output as was just showh, baring the error
message. As a fun fact, due to the usage output being printed, the
output even contains not one, but _two_ "call to actions";
- `See 'docker volume --help'.` (under the erro message)
- `Run 'docker volume COMMAND --help' for more information on a command.`
(under the usage output)
In short; the output is too verbose, confusing, and doesn't provide
a good UX. Let's reduce the output produced so that the focus is on the
important information.
This patch:
- Changes the usage to the short-usage.
- Changes the error-message to mention the _full_ command instead of only
the command after `docker` (so `docker no-such-command` instead of
`no-such-command`).
- Prefixes the error message with the binary / root-command name
(usually `docker:`); this is something we can still decide on, but
it's a pattern we already use in some places. The motivation for this
is that `docker` commands can often produce output that's a combination
of output from the CLI itself, output from the daemon, and even output
from the container. The `docker:` prefix helps to distinguish where
the message originated from (the `docker` CLI in this case).
- Adds an empty line between the error-message and the "call to action"
(`Run 'docker volume --help'...` in the example below). This helps
separating the error message ("unkown flag") from the call-to-action.
Before this patch:
Unknown top-level command:
docker nosuchcommand foo
docker: 'nosuchcommand' is not a docker command.
See 'docker --help'
Unknown sub-command:
docker volume nosuchcommand foo
Usage: docker volume COMMAND
Manage volumes
Commands:
create Create a volume
inspect Display detailed information on one or more volumes
ls List volumes
prune Remove unused local volumes
rm Remove one or more volumes
update Update a volume (cluster volumes only)
Run 'docker volume COMMAND --help' for more information on a command.
After this patch:
Unknown top-level command:
docker nosuchcommand foo
docker: unknown command: docker nosuchcommand
Run 'docker --help' for more information
Unknown sub-command:
docker volume nosuchcommand foo
docker: unknown command: 'docker volume nosuchcommand'
Usage: docker volume COMMAND
Run 'docker volume --help' for more information
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Explicitly create the context and set it on the CLI, instead of depending on
NewDockerCli() to instance a default context.
Co-authored-by: Sebastiaan van Stijn <github@gone.nl>
Co-authored-by: Alano Terblanche <18033717+Benehiko@users.noreply.github.com>
Signed-off-by: Alano Terblanche <18033717+Benehiko@users.noreply.github.com>
Adds a new plugin to the e2e plugins that simulates an older
plugin binary and a test suite to ensure older plugin binaries
keep behaving the same with newer CLI versions.
Signed-off-by: Laura Brehm <laurabrehm@hey.com>
We are currently loading plugin command stubs for every
invocation which still has a significant performance hit.
With this change we are doing this operation only if cobra
completion arg request is found.
- 20.10.23: `docker --version` takes ~15ms
- 23.0.1: `docker --version` takes ~93ms
With this change `docker --version` takes ~9ms
Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>
- remove check for "A self-sufficient runtime for containers"; really
not important to check for.
- don't make the checks positional (just match that we find them, and
that we don't find them multiple times)
- account for leading whitespace to change instead of hard-coding the
number of spaces before output.
- change the badopt check; I think it should be sufficient to check
that the bad option was printed and that "run --help" output is
printed.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
All output of the usage / --help output uses spaces, and having a tab
in the output can be somewhat cumbersome (e.g. our YAML docs generator
doesn't like them, and copy/pasing the output in iTerm produces a warning).
This patch changes the output to use two spaces instead.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Comments should have a leading space unless the comment is
for special purposes (go:generate, nolint:)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
```
e2e/cli-plugins/flags_test.go:135:27: Using the variable on range scope `args` in function literal (scopelint)
res := icmd.RunCmd(run(args...))
^
```
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
This regressed in 3af168c7df ("Ensure plugins can use `PersistentPreRunE`
again.") but this wasn't noticed because the helloworld test plugin has it's
own `PersistentPreRunE` which has the effect of deferring the resolution of the
global variable. In the case where the hook isn't used the variable is resolved
during `newPluginCommand` which is before the global variable was set.
Initialize the plugin command with a stub function wrapping the call to the
(global) hook, this defers resolving the variable until after it has been set,
otherwise the initial value (`nil`) is used in the struct.
Signed-off-by: Ian Campbell <ijc@docker.com>
This was omitted when these tests were added.
Adding this means that the tests now see the `$DOCKER_HOST` configured (via
`$TEST_DOCKER_HOST`) where they didn't before. In some cases (specifically the
`test-e2e-connhelper-ssh` case) this results in additional output on stderr
when `-D` (debug) is used:
time="2019-04-03T11:10:27Z" level=debug msg="commandconn: starting ssh with [-l penguin 172.20.0.2 -- docker system dial-stdio]"
Address this by switching the affected test cases to use `-l info` instead of
`-D`, they all just require some option not specifically `-D`. Note that `info`
is the default log level so this is effectively a nop (which is good).
Signed-off-by: Ian Campbell <ijc@docker.com>
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>
In some cases this means switching to `icmd.Expected` rather than
`icmd.Success`, but this improves readability overall.
Signed-off-by: Ian Campbell <ijc@docker.com>
Since #1654 so far we've had problems with it not working on Windows (npipe
lacked the `CloseRead` method) and problems with using tcp with tls (the tls
connection also lacks `CloseRead`). Both of these were workedaround in #1718
which added a nop `CloseRead` method.
However I am now seeing hangs (on Windows) where the `system dial-stdio`
subprocess is not exiting (I'm unsure why so far).
I think the 3rd problem found with this is an indication that `dial-stdio` is
not quite ready for wider use outside of its initial usecase (support for
`ssh://` URLs to connect to remote daemons).
This change simply disables the `dial-stdio` path for all plugins. However
rather than completely reverting 891b3d953e ("cli-plugins: use `docker system
dial-stdio` to call the daemon") I've just disabled the functionality at the
point of use and left in a trap door environment variable so that those who
want to experiment with this mode (and perhaps fully debug it) have an easier
path do doing so.
The e2e test for this case is disabled unless the trap door envvar is set. I
also renamed the test to clarify that it is about cli plugins.
Signed-off-by: Ian Campbell <ijc@docker.com>
I regressed this in d4ced2ef77 ("allow plugins to have argument which match a
top-level flag.") by unconditionally overwriting any `PersistentRunE` that the
user may have supplied.
We need to ensure two things:
1. That the user can use `PersistentRunE` (or `PersistentRun`) for their own
purposes.
2. That our initialisation always runs, even if the user has used
`PersistentRun*`, since that will shadow the root.
To do this add a `PersistentRunE` to the helloworld plugin which logs (covers 1
above) and then use it when calling the `apiversion` subcommand (which covers 2
since that uses the client)
Signed-off-by: Ian Campbell <ijc@docker.com>
Previous commits fixed the first issue on #1661, this simply adds a test for
it. Note that this is testing the current behaviour, without regard for the
second issue in #1661 which proposes a different behaviour.
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>
These won't pass right now due to https://github.com/docker/cli/issues/1699
("Plugins can't re-use the same flags as cli global flags") and the change in
935d47bbe9 ("Ignore unknown arguments on the top-level command."), but the
intention is to fix them now.
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>
Sebastiaan van Stijn
Sebastiaan van Stijn
Grace Choi
Alano Terblanche
Laura Brehm
Brian Goff
Kevin Alvarez
Nicolas De Loof
Ian Campbell
Silvin Lubecki
Jean-Christophe Sirot
Akihiro Suda
Corey Quon
Ulysses Souza