wip: restore xtask run

.cargo/config.toml

@@ -0,0 +1,2 @@
+[alias]
+xtask = "run --package xtask --"

README.md

@@ -4,7 +4,10 @@
 
 1. Install bpf-linker: `cargo install bpf-linker`
 
-## Build, Run
+## Build & Run
 
-Use `cargo build`, `cargo run`, etc. as normal. Cargo build scripts are used to
-automatically build the eBPF correctly and include it in the program.
+Use `cargo build`, `cargo check`, etc. as normal. Run your program with `xtask run`.
+
+Cargo build scripts are used to automatically build the eBPF correctly and include it in the
+program. When not using `xtask run`, eBPF code generation is skipped for a faster developer
+experience; this compromise necessitates the use of `xtask` to actually build the eBPF.

xtask/Cargo.toml

@@ -2,3 +2,7 @@
 name = "xtask"
 version = "0.1.0"
 edition = "2021"
+
+[dependencies]
+anyhow = { workspace = true, default-features = true }
+clap = { workspace = true, default-features = true, features = ["derive"] }

xtask/src/main.rs

@@ -0,0 +1,23 @@
+mod run;
+
+use anyhow::Result;
+use clap::Parser;
+
+#[derive(Debug, Parser)]
+pub struct Options {
+    #[clap(subcommand)]
+    command: Command,
+}
+
+#[derive(Debug, Parser)]
+enum Command {
+    Run(run::Options),
+}
+
+fn main() -> Result<()> {
+    let Options { command } = Parser::parse();
+
+    match command {
+        Command::Run(opts) => run::run(opts),
+    }
+}

xtask/src/run.rs

@@ -0,0 +1,47 @@
+use std::{ffi::OsString, process::Command};
+
+use anyhow::{bail, Context as _, Result};
+use clap::Parser;
+use xtask::AYA_BUILD_EBPF;
+
+#[derive(Debug, Parser)]
+pub struct Options {
+    /// Build and run the release target.
+    #[clap(long)]
+    release: bool,
+    /// The command used to wrap your application.
+    #[clap(short, long, default_value = "sudo -E")]
+    runner: String,
+    /// Arguments to pass to your application.
+    #[clap(global = true, last = true)]
+    run_args: Vec<OsString>,
+}
+
+/// Build and run the project.
+pub fn run(opts: Options) -> Result<()> {
+    let Options {
+        release,
+        runner,
+        run_args,
+    } = opts;
+
+    let mut cmd = Command::new("cargo");
+    cmd.env(AYA_BUILD_EBPF, "true");
+    cmd.args(["run", "--package", "{{project-name}}-ebpf", "--config"]);
+    if release {
+        cmd.arg(format!("target.release.runner=\"{}\"", runner));
+        cmd.arg("--release");
+    } else {
+        cmd.arg(format!("target.dev.runner=\"{}\"", runner));
+    }
+    if !run_args.is_empty() {
+        cmd.arg("--").args(run_args);
+    }
+    let status = cmd
+        .status()
+        .with_context(|| format!("failed to run {cmd:?}"))?;
+    if status.code() != Some(0) {
+        bail!("{cmd:?} failed: {status:?}")
+    }
+    Ok(())
+}

{{project-name}}/build.rs

@@ -40,7 +40,7 @@ use xtask::AYA_BUILD_EBPF;
 fn main() {
     println!("cargo:rerun-if-env-changed={}", AYA_BUILD_EBPF);
 
-    let build_integration_bpf = env::var(AYA_BUILD_EBPF)
+    let build_ebpf = env::var(AYA_BUILD_EBPF)
         .as_deref()
         .map(str::parse)
         .map(Result::unwrap)
@@ -64,7 +64,7 @@ fn main() {
         panic!("unsupported endian={:?}", endian)
     };
 
-    if build_integration_bpf {
+    if build_ebpf {
         let arch = env::var_os("CARGO_CFG_TARGET_ARCH").unwrap();
 
         let target = format!("{target}-unknown-none");