Add completions sub-command to generate shell completion scripts

cli/Cargo.toml

@@ -23,6 +23,7 @@ async-trait = { workspace = true }
 base64 = { workspace = true }
 chrono = { workspace = true }
 clap = { workspace = true }
+clap_complete = "4.5.1"
 dialoguer = { workspace = true }
 dirs = { workspace = true }
 env_logger = { workspace = true }

cli/src/cmd_completion.rs

@@ -0,0 +1,83 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+// Copyright 2024 Oxide Computer Company
+
+use crate::RunnableCmd;
+use anyhow::Result;
+use async_trait::async_trait;
+use clap::Parser;
+use clap_complete::{generate, Shell};
+use std::io;
+
+/// Generate shell completion scripts for Oxide CLI commands.
+///
+/// This command generates scripts for various shells that can be used to
+/// enable completion.
+///
+/// >>> bash
+///
+/// Add this to your `~/.bash_profile`:
+///
+///     eval "$(oxide completion -s bash)"
+///
+/// >>> zsh
+///
+/// Generate an `_oxide` completion script and put it somewhere in your
+/// `$fpath`, for example:
+///
+///    oxide completion -s zsh > ~/.zfunc/_oxide
+///
+/// and check that you have the following lines in your `~/.zshrc`:
+///
+///    autoload -U compinit
+///    compinit -i
+///
+/// >>> fish
+///
+/// Generate an `oxide.fish` completion script:
+///
+///    oxide completion -s fish > ~/.config/fish/completions/oxide.fish
+///
+/// >>> PowerShell
+///
+/// Open your profile script with:
+///
+///    mkdir -Path (Split-Path -Parent $profile)
+///    notepad $profile
+///
+/// Add the following line and save the file:
+///
+///    Invoke-Expression -Command $(oxide completion -s powershell | Out-String)
+///
+/// >>> Elvish
+///
+/// Generate an `oxide.elv` completion script and put it in a module search
+/// directory, for example:
+///
+///    oxide completion -s elvish > ~/.local/share/elvish/lib/oxide.elv
+///
+/// and import this by adding the following to `~/.config/elvish/rc.elv`
+///
+///    use oxide
+#[derive(Parser, Debug, Clone)]
+#[command(verbatim_doc_comment)]
+#[command(name = "generate-completions")]
+pub struct CmdCompletion {
+    /// Type of the shell
+    #[clap(short, long)]
+    shell: Shell,
+}
+
+#[async_trait]
+impl RunnableCmd for CmdCompletion {
+    async fn run(&self, _ctx: &oxide::context::Context) -> Result<()> {
+        let cli = crate::make_cli();
+        let mut cmd = cli.command_take();
+        let name = cmd.get_name().to_string();
+        generate(self.shell, &mut cmd, name, &mut io::stdout());
+
+        Ok(())
+    }
+}

cli/src/main.rs

@@ -19,6 +19,7 @@ use oxide::types::{IdpMetadataSource, IpRange, Ipv4Range, Ipv6Range};
 mod cli_builder;
 mod cmd_api;
 mod cmd_auth;
+mod cmd_completion;
 mod cmd_disk;
 mod cmd_docs;
 mod cmd_instance;
@@ -47,6 +48,7 @@ pub fn make_cli() -> NewCli<'static> {
         .add_custom::<cmd_disk::CmdDiskImport>("disk import")
         .add_custom::<cmd_instance::CmdInstanceSerial>("instance serial")
         .add_custom::<cmd_instance::CmdInstanceFromImage>("instance from-image")
+        .add_custom::<cmd_completion::CmdCompletion>("completion")
 }
 
 #[tokio::main]