# Description
This adds three engine calls: `GetEnvVar`, `GetEnvVars`, for getting
environment variables from the plugin command context, and
`GetCurrentDir` for getting the current working directory.
Plugins are now launched in the directory of their executable to try to
make improper use of the current directory without first setting it more
obvious. Plugins previously launched in whatever the current directory
of the engine was at the time the plugin command was run, but switching
to persistent plugins broke this, because they stay in whatever
directory they launched in initially.
This also fixes the `gstat` plugin to use `get_current_dir()` to
determine its repo location, which was directly affected by this
problem.
# User-Facing Changes
- Adds new engine calls (`GetEnvVar`, `GetEnvVars`, `GetCurrentDir`)
- Runs plugins in a different directory from before, in order to catch
bugs
- Plugins will have to use the new engine calls if they do filesystem
stuff to work properly
# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
# After Submitting
- [ ] Document the working directory behavior on plugin launch
- [ ] Document the new engine calls + response type (`ValueMap`)
# Description
This PR uses the new plugin protocol to intelligently keep plugin
processes running in the background for further plugin calls.
Running plugins can be seen by running the new `plugin list` command,
and stopped by running the new `plugin stop` command.
This is an enhancement for the performance of plugins, as starting new
plugin processes has overhead, especially for plugins in languages that
take a significant amount of time on startup. It also enables plugins
that have persistent state between commands, making the migration of
features like dataframes and `stor` to plugins possible.
Plugins are automatically stopped by the new plugin garbage collector,
configurable with `$env.config.plugin_gc`:
```nushell
$env.config.plugin_gc = {
# Configuration for plugin garbage collection
default: {
enabled: true # true to enable stopping of inactive plugins
stop_after: 10sec # how long to wait after a plugin is inactive to stop it
}
plugins: {
# alternate configuration for specific plugins, by name, for example:
#
# gstat: {
# enabled: false
# }
}
}
```
If garbage collection is enabled, plugins will be stopped after
`stop_after` passes after they were last active. Plugins are counted as
inactive if they have no running plugin calls. Reading the stream from
the response of a plugin call is still considered to be activity, but if
a plugin holds on to a stream but the call ends without an active
streaming response, it is not counted as active even if it is reading
it. Plugins can explicitly disable the GC as appropriate with
`engine.set_gc_disabled(true)`.
The `version` command now lists plugin names rather than plugin
commands. The list of plugin commands is accessible via `plugin list`.
Recommend doing this together with #12029, because it will likely force
plugin developers to do the right thing with mutability and lead to less
unexpected behavior when running plugins nested / in parallel.
# User-Facing Changes
- new command: `plugin list`
- new command: `plugin stop`
- changed command: `version` (now lists plugin names, rather than
commands)
- new config: `$env.config.plugin_gc`
- Plugins will keep running and be reused, at least for the configured
GC period
- Plugins that used mutable state in weird ways like `inc` did might
misbehave until fixed
- Plugins can disable GC if they need to
- Had to change plugin signature to accept `&EngineInterface` so that
the GC disable feature works. #12029 does this anyway, and I'm expecting
(resolvable) conflicts with that
# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
Because there is some specific OS behavior required for plugins to not
respond to Ctrl-C directly, I've developed against and tested on both
Linux and Windows to ensure that works properly.
# After Submitting
I think this probably needs to be in the book somewhere
# Description
This allows plugins to make calls back to the engine to get config,
evaluate closures, and do other things that must be done within the
engine process.
Engine calls can both produce and consume streams as necessary. Closures
passed to plugins can both accept stream input and produce stream output
sent back to the plugin.
Engine calls referring to a plugin call's context can be processed as
long either the response hasn't been received, or the response created
streams that haven't ended yet.
This is a breaking API change for plugins. There are some pretty major
changes to the interface that plugins must implement, including:
1. Plugins now run with `&self` and must be `Sync`. Executing multiple
plugin calls in parallel is supported, and there's a chance that a
closure passed to a plugin could invoke the same plugin. Supporting
state across plugin invocations is left up to the plugin author to do in
whichever way they feel best, but the plugin object itself is still
shared. Even though the engine doesn't run multiple plugin calls through
the same process yet, I still considered it important to break the API
in this way at this stage. We might want to consider an optional
threadpool feature for performance.
2. Plugins take a reference to `EngineInterface`, which can be cloned.
This interface allows plugins to make calls back to the engine,
including for getting config and running closures.
3. Plugins no longer take the `config` parameter. This can be accessed
from the interface via the `.get_plugin_config()` engine call.
# User-Facing Changes
<!-- List of all changes that impact the user experience here. This
helps us keep track of breaking changes. -->
Not only does this have plugin protocol changes, it will require plugins
to make some code changes before they will work again. But on the plus
side, the engine call feature is extensible, and we can add more things
to it as needed.
Plugin maintainers will have to change the trait signature at the very
least. If they were using `config`, they will have to call
`engine.get_plugin_config()` instead.
If they were using the mutable reference to the plugin, they will have
to come up with some strategy to work around it (for example, for `Inc`
I just cloned it). This shouldn't be such a big deal at the moment as
it's not like plugins have ever run as daemons with persistent state in
the past, and they don't in this PR either. But I thought it was
important to make the change before we support plugins as daemons, as an
exclusive mutable reference is not compatible with parallel plugin
calls.
I suggest this gets merged sometime *after* the current pending release,
so that we have some time to adjust to the previous plugin protocol
changes that don't require code changes before making ones that do.
# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
# After Submitting
I will document the additional protocol features (`EngineCall`,
`EngineCallResponse`), and constraints on plugin call processing if
engine calls are used - basically, to be aware that an engine call could
result in a nested plugin call, so the plugin should be able to handle
that.
# Description
When nushell calls a plugin it now sends a configuration `Value` from
the nushell config under `$env.config.plugins.PLUGIN_SHORT_NAME`. This
allows plugin authors to read configuration provided by plugin users.
The `PLUGIN_SHORT_NAME` must match the registered filename after
`nu_plugin_`. If you register `target/debug/nu_plugin_config` the
`PLUGIN_NAME` will be `config` and the nushell config will loook like:
$env.config = {
# ...
plugins: {
config: [
some
values
]
}
}
Configuration may also use a closure which allows passing values from
`$env` to a plugin:
$env.config = {
# ...
plugins: {
config: {||
$env.some_value
}
}
}
This is a breaking change for the plugin API as the `Plugin::run()`
function now accepts a new configuration argument which is an
`&Option<Value>`. If no configuration was supplied the value is `None`.
Plugins compiled after this change should work with older nushell, and
will behave as if the configuration was not set.
Initially discussed in #10867
# User-Facing Changes
* Plugins can read configuration data stored in `$env.config.plugins`
* The plugin `CallInfo` now includes a `config` entry, existing plugins
will require updates
# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
# After Submitting
- [ ] Update [Creating a plugin (in
Rust)](https://www.nushell.sh/contributor-book/plugins.html#creating-a-plugin-in-rust)
[source](https://github.com/nushell/nushell.github.io/blob/main/contributor-book/plugins.md)
- [ ] Add "Configuration" section to [Plugins
documentation](https://www.nushell.sh/contributor-book/plugins.html)
# Description
The `PluginSignature` type supports extra usage but this was not
available in `plugin_name --help`. It also supports search terms but
these did not appear in `help commands`
New behavior show below is the "Extra usage for nu-example-1" line and
the "Search terms:" line
```
❯ nu-example-1 --help
PluginSignature test 1 for plugin. Returns Value::Nothing
Extra usage for nu-example-1
Search terms: example
Usage:
> nu-example-1 {flags} <a> <b> (opt) ...(rest)
Flags:
-h, --help - Display the help message for this command
-f, --flag - a flag for the signature
-n, --named <String> - named string
Parameters:
a <int>: required integer value
b <string>: required string value
opt <int>: Optional number (optional)
...rest <string>: rest value string
Examples:
running example with an int value and string value
> nu-example-1 3 bb
```
Search terms are also available in `help commands`:
```
❯ help commands | where name == "nu-example-1" | select name search_terms
╭──────────────┬──────────────╮
│ name │ search_terms │
├──────────────┼──────────────┤
│ nu-example-1 │ example │
╰──────────────┴──────────────╯
```
# User-Facing Changes
Users can now see plugin extra usage and search terms
# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
# After Submitting
N/A
# Description
As title, we can't provide examples for plugin commands, this pr would
make it possible
# User-Facing Changes
Take plugin `nu-example-1` as example:
```
❯ nu-example-1 -h
PluginSignature test 1 for plugin. Returns Value::Nothing
Usage:
> nu-example-1 {flags} <a> <b> (opt) ...(rest)
Flags:
-h, --help - Display the help message for this command
-f, --flag - a flag for the signature
-n, --named <String> - named string
Parameters:
a <int>: required integer value
b <string>: required string value
(optional) opt <int>: Optional number
...rest <string>: rest value string
Examples:
running example with an int value and string value
> nu-example-1 3 bb
```
The examples session is newly added.
## Basic idea behind these changes
when nushell query plugin signatures, plugin just returns it's signature
without any examples, so nushell have no idea about the examples of
plugin commands.
To adding the feature, we just making plugin returns it's signature with
examples.
Before:
```
1. get signature
---------------->
Nushell ------------------ Plugin
<-----------------
2. returns Vec<Signature>
```
After:
```
1. get signature
---------------->
Nushell ------------------ Plugin
<-----------------
2. returns Vec<PluginSignature>
```
When writing plugin signature to $nu.plugin-path:
Serialize `<PluginSignature>` rather than `<Signature>`, which would
enable us to serialize examples to `$nu.plugin-path`
## Shortcoming
It's a breaking changes because `Plugin::signature` is changed, and it
requires plugin authors to change their code for new signatures.
Fortunally it should be easy to change, for rust based plugin, we just
need to make a global replace from word `Signature` to word
`PluginSignature` in their plugin project.
Our content of plugin-path is really large, if one plugin have many
examples, it'd results to larger body of $nu.plugin-path, which is not
really scale. A solution would be save register information in other
binary formats rather than `json`. But I think it'd be another story.
# Tests + Formatting
Don't forget to add tests that cover your changes.
Make sure you've run and fixed any issues with these commands:
- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass
# After Submitting
If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
* Add search terms to command
* Rename Signature desc to usage
To be named uniformly with extra_usage
* Throw in foldl search term for reduce
* Add missing usage to post
* Add search terms to signature
* Try to add capnp Signature serialization
