Standardize on tokio::fs

.editorconfig

@@ -8,3 +8,6 @@ end_of_line = lf
 charset = utf-8
 trim_trailing_whitespace = true
 insert_final_newline = true
+
+[*.rs]
+indent_size = 4

magic-nix-cache/src/api.rs

@@ -6,6 +6,7 @@ use attic::nix_store::StorePath;
 use axum::{extract::Extension, routing::post, Json, Router};
 use axum_macros::debug_handler;
 use serde::{Deserialize, Serialize};
+use tokio::fs::read_to_string;
 
 use super::State;
 use crate::error::{Error, Result};
@@ -114,7 +115,7 @@ async fn workflow_finish(
 
     // NOTE(cole-h): see `init_logging`
     if let Some(logfile) = &state.logfile {
-        let logfile_contents = std::fs::read_to_string(logfile)?;
+        let logfile_contents = read_to_string(logfile).await?;
         println!("Every log line throughout the lifetime of the program:");
         println!("\n{logfile_contents}\n");
     }

magic-nix-cache/src/main.rs

@@ -23,7 +23,7 @@ mod util;
 
 use std::borrow::BorrowMut;
 use std::collections::HashSet;
-use std::fs::{self, create_dir_all};
+use std::fs::Permissions;
 use std::io::Write;
 use std::net::SocketAddr;
 use std::os::unix::fs::PermissionsExt;
@@ -35,7 +35,7 @@ use anyhow::{anyhow, Context, Result};
 use axum::{extract::Extension, routing::get, Router};
 use clap::Parser;
 use tempfile::NamedTempFile;
-use tokio::fs::File;
+use tokio::fs::{self, create_dir_all, File, OpenOptions};
 use tokio::io::AsyncWriteExt;
 use tokio::process::Command;
 use tokio::sync::{oneshot, Mutex, RwLock};
@@ -176,7 +176,7 @@ struct StateInner {
 }
 
 async fn main_cli() -> Result<()> {
-    let guard = init_logging()?;
+    let guard = init_logging().await?;
     let _tracing_guard = guard.appender_guard;
 
     let args = Args::parse();
@@ -186,21 +186,24 @@ async fn main_cli() -> Result<()> {
 
     let metrics = Arc::new(telemetry::TelemetryReport::new());
 
-    let mut nix_conf_file: Option<std::fs::File> = None;
-
-    if let Some(nix_conf_path) = &args.nix_conf {
+    let mut nix_conf_file: Option<File> = if let Some(nix_conf_path) = &args.nix_conf {
         if let Some(parent) = Path::new(&nix_conf_path).parent() {
-            create_dir_all(parent).with_context(|| "Creating parent directories of nix.conf")?;
+            create_dir_all(parent)
+                .await
+                .with_context(|| "Creating parent directories of nix.conf")?;
         }
 
-        nix_conf_file = Some(
-            std::fs::OpenOptions::new()
+        Some(
+            OpenOptions::new()
                 .create(true)
                 .append(true)
                 .open(nix_conf_path)
+                .await
                 .with_context(|| "Creating nix.conf")?,
-        );
-    }
+        )
+    } else {
+        None
+    };
 
     let store = Arc::new(NixStore::connect()?);
 
@@ -238,6 +241,7 @@ async fn main_cli() -> Result<()> {
                             )
                             .as_bytes(),
                         )
+                        .await
                         .with_context(|| "Writing to nix.conf")?;
                 }
 
@@ -257,7 +261,7 @@ async fn main_cli() -> Result<()> {
     let gha_cache = if args.use_gha_cache {
         let credentials = if let Some(credentials_file) = &args.credentials_file {
             tracing::info!("Loading credentials from {:?}", credentials_file);
-            let bytes = fs::read(credentials_file).with_context(|| {
+            let bytes = fs::read(credentials_file).await.with_context(|| {
                 format!(
                     "Failed to read credentials file '{}'",
                     credentials_file.display()
@@ -288,6 +292,7 @@ async fn main_cli() -> Result<()> {
         if let Some(ref mut nix_conf_file) = nix_conf_file {
             nix_conf_file
           .write_all(format!("extra-substituters = http://{}?trusted=1&compression=zstd&parallel-compression=true&priority=1\n", args.listen).as_bytes())
+          .await
           .with_context(|| "Writing to nix.conf")?;
         }
 
@@ -324,7 +329,8 @@ async fn main_cli() -> Result<()> {
             .with_context(|| "Keeping the post-build hook")?
             .1;
 
-        fs::set_permissions(&path, fs::Permissions::from_mode(0o755))
+        fs::set_permissions(&path, Permissions::from_mode(0o755))
+            .await
             .with_context(|| "Setting permissions on the post-build hook")?;
 
         /* Copy the script to the Nix store so we know for sure that
@@ -358,6 +364,7 @@ async fn main_cli() -> Result<()> {
                 )
                 .as_bytes(),
             )
+            .await
             .with_context(|| "Writing to nix.conf")?;
     }
 
@@ -524,7 +531,7 @@ pub struct LogGuard {
     logfile: Option<PathBuf>,
 }
 
-fn init_logging() -> Result<LogGuard> {
+async fn init_logging() -> Result<LogGuard> {
     let filter = EnvFilter::try_from_default_env().unwrap_or_else(|_| {
         #[cfg(debug_assertions)]
         return EnvFilter::new("info")
@@ -542,12 +549,13 @@ fn init_logging() -> Result<LogGuard> {
     let (guard, file_layer) = match std::env::var("RUNNER_DEBUG") {
         Ok(val) if val == "1" => {
             let logfile = debug_logfile();
-            let file = std::fs::OpenOptions::new()
+            let file = OpenOptions::new()
                 .create(true)
                 .write(true)
                 .truncate(true)
-                .open(&logfile)?;
-            let (nonblocking, guard) = tracing_appender::non_blocking(file);
+                .open(&logfile)
+                .await?;
+            let (nonblocking, guard) = tracing_appender::non_blocking(file.into_std().await);
             let file_layer = tracing_subscriber::fmt::layer()
                 .with_writer(nonblocking)
                 .pretty();