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>
With this patch:
docker run --volumes-from amazing_nobel
amazing_cannon boring_wozniak determined_banzai
elegant_solomon reverent_booth amazing_nobel
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
registerCompletionFuncForGlobalFlags was called from newDockerCommand,
at which time no context-store is initialized yet, so it would return
a nil value, probably resulting in `store.Names` to panic, but these
errors are not shown when running the completion. As a result, the flag
completion would fall back to completing from filenames.
This patch changes the function to dynamically get the context-store;
this fixes the problem mentioned above, because at the time the completion
function is _invoked_, the CLI is fully initialized, and does have a
context-store available.
A (non-exported) interface is defined to allow the function to accept
alternative implementations (not requiring a full command.DockerCLI).
Before this patch:
docker context create one
docker context create two
docker --context <TAB>
.DS_Store .idea/ Makefile
.dockerignore .mailmap build/
...
With this patch:
docker context create one
docker context create two
docker --context <TAB>
default one two
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
"docker run" and "docker create" are mostly identical, so we can copy
the same completion functions,
We could possibly create a utility for this (similar to `addFlags()` which
configures both commands with the flags they share). I considered combining
his with `addFlags()`, but that utility is also used in various tests, in
which we don't need this feature, so keeping that for a future exercise.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
It's an alias for cobra.FixedCompletions but takes a variadic list
of strings, so that it's not needed to construct an array for this.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
EnvVarNames offers completion for environment-variable names. This
completion can be used for "--env" and "--build-arg" flags, which
allow obtaining the value of the given environment-variable if present
in the local environment, so we only should complete the names of the
environment variables, and not their value. This also prevents the
completion script from printing values of environment variables
containing sensitive values.
For example;
export MY_VAR=hello
docker run --rm --env MY_VAR alpine printenv MY_VAR
hello
Before this patch:
docker run --env GO
GO111MODULE=auto GOLANG_VERSION=1.21.12 GOPATH=/go GOTOOLCHAIN=local
With this patch:
docker run --env GO<tab>
GO111MODULE GOLANG_VERSION GOPATH GOTOOLCHAIN
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
This is just a convenience function to allow defining completion to
use the default (complete with filenames and directories).
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
No changes in vendored files. This one got out of sync with the other modules
from the same repository.
full diff: d307bd883b...49dd2c1f3d
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Add a "completion" target to install the generated completion
scripts inside the dev-container. As generating this script
depends on the docker binary, it calls "make binary" first.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
It's not initialized, because there's no `docker` command installed
by default, but at least this makes sure that the basics are present
for testing.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
This allows dockerMain() to return an error "as usual", and puts the
responsibility for turning that into an appropriate exit-code in
main() (which also sets the exit-code when terminating).
We could consider putting this utility in the cli package and exporting
it if would be useful for doing a similar handling in plugins.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
The logic in this function is confusing; let's start make it obvious where
the error that is returned is produced,
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>
This error didn't do a great job at formatting. If a StatusError was
produced without a Status message, it would print a very non-informative
error, with information missing.
Let's update the output:
- If a status-message is provided; print just that (after all the
status code is something that can be found from the shell, e.g.
through `echo $?` in Bash).
- If no status-message is provided: print a message more similar to
Go's `exec.ExecError`, which uses `os.rocessState.String()` (see [1]).
Before this patch, an error without custom status would print:
Status: , Code: 2
After this patch:
exit status 2
In situations where a custom error-message is provided, the error-message
is print as-is, whereas before this patch, the message got combined with
the `Status:` and `Code:`, which resulted in some odd output.
Before this patch:
docker volume --no-such-flag
Status: 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.
, Code: 125
With this patch, the error is shown as-is;
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.
While the exit-code is no longer printed, it's still properly handled;
echo $?
125
[1]: 82c14346d8/src/os/exec_posix.go (L107-L135)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Trying to make the logic slightly clearer, and adding a custom
message for the skip,
Before this:
=== RUN TestSplitCpArg/absolute_path_with_drive
cp_test.go:184: tc.os == "windows" && runtime.GOOS != "windows" || tc.os == "linux" && runtime.GOOS == "windows"
After this:
=== RUN TestSplitCpArg/absolute_path_with_drive
cp_test.go:184: skipping windows test on non-windows platform
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Sebastiaan van Stijn
Sebastiaan van Stijn
Paweł Gronowski
Alano Terblanche
David Karlsson