Add puffin venv command to create virtual environments (#83)

Closes https://github.com/astral-sh/puffin/issues/58.

Cargo.lock

@@ -1773,6 +1773,7 @@ dependencies = [
  "colored",
  "directories",
  "futures",
+ "gourgeist",
  "indicatif",
  "install-wheel-rs",
  "itertools 0.11.0",
@@ -1791,6 +1792,7 @@ dependencies = [
  "tracing-subscriber",
  "tracing-tree",
  "url",
+ "which",
 ]
 
 [[package]]

crates/gourgeist/src/interpreter.rs

@@ -23,7 +23,12 @@ pub struct InterpreterInfo {
 }
 
 /// Gets the interpreter.rs info, either cached or by running it.
-pub fn get_interpreter_info(interpreter: &Utf8Path) -> Result<InterpreterInfo, Error> {
+pub fn get_interpreter_info(
+    interpreter: impl AsRef<std::path::Path>,
+) -> Result<InterpreterInfo, Error> {
+    let interpreter = Utf8Path::from_path(interpreter.as_ref())
+        .ok_or_else(|| Error::NonUTF8Path(interpreter.as_ref().to_path_buf()))?;
+
     let cache_dir = crate_cache_dir()?.join("interpreter_info");
 
     let index = seahash::hash(interpreter.as_str().as_bytes());

crates/gourgeist/src/lib.rs

@@ -50,6 +50,8 @@ pub enum Error {
         #[source]
         err: install_wheel_rs::Error,
     },
+    #[error("{0} is not a valid UTF-8 path")]
+    NonUTF8Path(std::path::PathBuf),
 }
 
 pub(crate) fn crate_cache_dir() -> io::Result<Utf8PathBuf> {
@@ -61,11 +63,16 @@ pub(crate) fn crate_cache_dir() -> io::Result<Utf8PathBuf> {
 
 /// Create a virtualenv and if not bare, install `wheel`, `pip` and `setuptools`.
 pub fn create_venv(
-    location: &Utf8Path,
-    base_python: &Utf8Path,
+    location: impl AsRef<std::path::Path>,
+    base_python: impl AsRef<std::path::Path>,
     info: &InterpreterInfo,
     bare: bool,
 ) -> Result<(), Error> {
+    let location = Utf8Path::from_path(location.as_ref())
+        .ok_or_else(|| Error::NonUTF8Path(location.as_ref().to_path_buf()))?;
+    let base_python = Utf8Path::from_path(base_python.as_ref())
+        .ok_or_else(|| Error::NonUTF8Path(base_python.as_ref().to_path_buf()))?;
+
     let paths = create_bare_venv(location, base_python, info)?;
 
     if !bare {

crates/gourgeist/src/main.rs

@@ -25,7 +25,7 @@ fn run() -> Result<(), gourgeist::Error> {
     let location = cli.path.unwrap_or(Utf8PathBuf::from(".venv"));
     let python = parse_python_cli(cli.python)?;
     let data = get_interpreter_info(&python)?;
-    create_venv(&location, &python, &data, cli.bare)?;
+    create_venv(location, &python, &data, cli.bare)?;
 
     Ok(())
 }

crates/puffin-cli/Cargo.toml

@@ -8,6 +8,7 @@ name = "puffin"
 path = "src/main.rs"
 
 [dependencies]
+gourgeist = { path = "../gourgeist" }
 install-wheel-rs = { path = "../install-wheel-rs", default-features = false }
 pep440_rs = { path = "../pep440-rs" }
 pep508_rs = { path = "../pep508-rs" }
@@ -34,3 +35,4 @@ tracing = { workspace = true }
 tracing-subscriber = { workspace = true }
 tracing-tree = { workspace = true }
 url = { workspace = true }
+which = { workspace = true}

crates/puffin-cli/src/commands/mod.rs

@@ -6,6 +6,7 @@ pub(crate) use compile::compile;
 pub(crate) use freeze::freeze;
 pub(crate) use sync::{sync, SyncFlags};
 pub(crate) use uninstall::uninstall;
+pub(crate) use venv::venv;
 
 mod clean;
 mod compile;
@@ -13,6 +14,7 @@ mod freeze;
 mod reporters;
 mod sync;
 mod uninstall;
+mod venv;
 
 #[derive(Copy, Clone)]
 pub(crate) enum ExitStatus {

crates/puffin-cli/src/commands/venv.rs

@@ -0,0 +1,36 @@
+use std::fmt::Write;
+use std::path::Path;
+
+use anyhow::Result;
+use colored::Colorize;
+
+use crate::commands::ExitStatus;
+use crate::printer::Printer;
+
+/// Create a virtual environment.
+pub(crate) async fn venv(path: &Path, mut printer: Printer) -> Result<ExitStatus> {
+    // Locate the Python interpreter.
+    // TODO(charlie): Look at how Maturin discovers and ranks all the available Python interpreters.
+    let executable = which::which("python3").or_else(|_| which::which("python"))?;
+    let interpreter_info = gourgeist::get_interpreter_info(&executable)?;
+    writeln!(
+        printer,
+        "Using Python interpreter: {}",
+        format!("{}", executable.display()).cyan()
+    )?;
+
+    // If the path already exists, remove it.
+    tokio::fs::remove_file(path).await.ok();
+    tokio::fs::remove_dir_all(path).await.ok();
+
+    writeln!(
+        printer,
+        "Creating virtual environment at: {}",
+        format!("{}", path.display()).cyan()
+    )?;
+
+    // Create the virtual environment.
+    gourgeist::create_venv(path, &executable, &interpreter_info, true)?;
+
+    Ok(ExitStatus::Success)
+}

crates/puffin-cli/src/main.rs

@@ -25,6 +25,10 @@ struct Cli {
     /// Use verbose output.
     #[arg(global = true, long, short, conflicts_with = "quiet")]
     verbose: bool,
+
+    /// Avoid reading from or writing to the cache.
+    #[arg(long)]
+    no_cache: bool,
 }
 
 #[derive(Subcommand)]
@@ -36,19 +40,17 @@ enum Commands {
     /// Clear the cache.
     Clean,
     /// Enumerate the installed packages in the current environment.
-    Freeze(FreezeArgs),
+    Freeze,
     /// Uninstall a package.
     Uninstall(UninstallArgs),
+    /// Create a virtual environment.
+    Venv(VenvArgs),
 }
 
 #[derive(Args)]
 struct CompileArgs {
     /// Path to the `requirements.txt` file to compile.
     src: PathBuf,
-
-    /// Avoid reading from or writing to the cache.
-    #[arg(long)]
-    no_cache: bool,
 }
 
 #[derive(Args)]
@@ -56,30 +58,21 @@ struct SyncArgs {
     /// Path to the `requirements.txt` file to install.
     src: PathBuf,
 
-    /// Avoid reading from or writing to the cache.
-    #[arg(long)]
-    no_cache: bool,
-
     /// Ignore any installed packages, forcing a re-installation.
     #[arg(long)]
     ignore_installed: bool,
 }
 
-#[derive(Args)]
-struct FreezeArgs {
-    /// Avoid reading from or writing to the cache.
-    #[arg(long)]
-    no_cache: bool,
-}
-
 #[derive(Args)]
 struct UninstallArgs {
     /// The name of the package to uninstall.
     name: String,
+}
 
-    /// Avoid reading from or writing to the cache.
-    #[arg(long)]
-    no_cache: bool,
+#[derive(Args)]
+struct VenvArgs {
+    /// The path to the virtual environment to create.
+    name: PathBuf,
 }
 
 #[tokio::main]
@@ -108,7 +101,7 @@ async fn main() -> ExitCode {
                 &args.src,
                 dirs.as_ref()
                     .map(ProjectDirs::cache_dir)
-                    .filter(|_| !args.no_cache),
+                    .filter(|_| !cli.no_cache),
                 printer,
             )
             .await
@@ -118,7 +111,7 @@ async fn main() -> ExitCode {
                 &args.src,
                 dirs.as_ref()
                     .map(ProjectDirs::cache_dir)
-                    .filter(|_| !args.no_cache),
+                    .filter(|_| !cli.no_cache),
                 if args.ignore_installed {
                     commands::SyncFlags::IGNORE_INSTALLED
                 } else {
@@ -131,11 +124,11 @@ async fn main() -> ExitCode {
         Commands::Clean => {
             commands::clean(dirs.as_ref().map(ProjectDirs::cache_dir), printer).await
         }
-        Commands::Freeze(args) => {
+        Commands::Freeze => {
             commands::freeze(
                 dirs.as_ref()
                     .map(ProjectDirs::cache_dir)
-                    .filter(|_| !args.no_cache),
+                    .filter(|_| !cli.no_cache),
                 printer,
             )
             .await
@@ -145,11 +138,12 @@ async fn main() -> ExitCode {
                 &args.name,
                 dirs.as_ref()
                     .map(ProjectDirs::cache_dir)
-                    .filter(|_| !args.no_cache),
+                    .filter(|_| !cli.no_cache),
                 printer,
             )
             .await
         }
+        Commands::Venv(args) => commands::venv(&args.name, printer).await,
     };
 
     match result {