cuprated: add startup delay if config is missing (#393)

* add startup delay if config is missing

* clean up

* fix typos

* fix imports + add small comment

* fmt

Cargo.lock

@@ -1094,6 +1094,7 @@ dependencies = [
  "hex-literal",
  "indexmap",
  "monero-serai",
+ "nu-ansi-term",
  "paste",
  "pin-project",
  "rand",

Cargo.toml

@@ -122,6 +122,7 @@ hex                   = { version = "0.4", default-features = false }
 hex-literal           = { version = "0.4", default-features = false }
 indexmap              = { version = "2", default-features = false }
 monero-serai          = { git = "https://github.com/Cuprate/serai.git", rev = "e6fdef6", default-features = false }
+nu-ansi-term          = { version = "0.46", default-features = false }
 paste                 = { version = "1", default-features = false }
 pin-project           = { version = "1", default-features = false }
 randomx-rs            = { git = "https://github.com/Cuprate/randomx-rs.git", rev = "e09955c", default-features = false }

binaries/cuprated/Cargo.toml

@@ -57,6 +57,7 @@ hex                   = { workspace = true }
 hex-literal           = { workspace = true }
 indexmap              = { workspace = true }
 monero-serai          = { workspace = true }
+nu-ansi-term          = { workspace = true }
 paste                 = { workspace = true }
 pin-project           = { workspace = true }
 randomx-rs            = { workspace = true }

binaries/cuprated/src/config.rs

@@ -17,6 +17,11 @@ use cuprate_helper::{
 use cuprate_p2p::block_downloader::BlockDownloaderConfig;
 use cuprate_p2p_core::{ClearNet, ClearNetServerCfg};
 
+use crate::{
+    constants::{DEFAULT_CONFIG_STARTUP_DELAY, DEFAULT_CONFIG_WARNING},
+    logging::eprintln_red,
+};
+
 mod args;
 mod fs;
 mod p2p;
@@ -42,7 +47,7 @@ pub fn read_config_and_args() -> Config {
         match Config::read_from_path(config_file) {
             Ok(config) => config,
             Err(e) => {
-                eprintln!("Failed to read config from file: {e}");
+                eprintln_red(&format!("Failed to read config from file: {e}"));
                 std::process::exit(1);
             }
         }
@@ -60,7 +65,10 @@ pub fn read_config_and_args() -> Config {
             })
             .inspect_err(|e| {
                 tracing::debug!("Failed to read config from config dir: {e}");
-                eprintln!("Failed to find/read config file, using default config.");
+                if !args.skip_config_warning {
+                    eprintln_red(DEFAULT_CONFIG_WARNING);
+                    std::thread::sleep(DEFAULT_CONFIG_STARTUP_DELAY);
+                }
             })
             .unwrap_or_default()
     };
@@ -101,13 +109,14 @@ impl Config {
         let file_text = read_to_string(file.as_ref())?;
 
         Ok(toml::from_str(&file_text)
-            .inspect(|_| eprintln!("Using config at: {}", file.as_ref().to_string_lossy()))
+            .inspect(|_| println!("Using config at: {}", file.as_ref().to_string_lossy()))
             .inspect_err(|e| {
-                eprintln!("{e}");
-                eprintln!(
+                eprintln_red(&format!(
                     "Failed to parse config file at: {}",
                     file.as_ref().to_string_lossy()
-                );
+                ));
+                eprintln_red(&format!("{e}"));
+                std::process::exit(1);
             })?)
     }
 

binaries/cuprated/src/config/args.rs

@@ -32,6 +32,10 @@ pub struct Args {
     #[arg(long)]
     pub generate_config: bool,
 
+    /// Stops the missing config warning and startup delay if a config file is missing.
+    #[arg(long)]
+    pub skip_config_warning: bool,
+
     /// Print misc version information in JSON.
     #[arg(short, long)]
     pub version: bool,

binaries/cuprated/src/constants.rs

@@ -1,4 +1,5 @@
 //! General constants used throughout `cuprated`.
+use std::time::Duration;
 
 use const_format::formatcp;
 
@@ -23,6 +24,16 @@ pub const VERSION_BUILD: &str = formatcp!("{VERSION}-{}", cuprate_constants::bui
 pub const PANIC_CRITICAL_SERVICE_ERROR: &str =
     "A service critical to Cuprate's function returned an unexpected error.";
 
+pub const DEFAULT_CONFIG_WARNING: &str = formatcp!(
+    "WARNING: no config file found, using default config.\
+    \nThe default config may not be optimal for your setup, see the user book here: https://user.cuprate.org/.\
+    \nPausing startup for {} seconds. \
+    \nUse the `--skip-config-warning` arg to skip this delay if you really want to use the default.",
+    DEFAULT_CONFIG_STARTUP_DELAY.as_secs()
+);
+
+pub const DEFAULT_CONFIG_STARTUP_DELAY: Duration = Duration::from_secs(15);
+
 pub const EXAMPLE_CONFIG: &str = include_str!("../config/Cuprated.toml");
 
 #[cfg(test)]

binaries/cuprated/src/logging.rs

@@ -140,3 +140,8 @@ pub fn modify_stdout_output(f: impl FnOnce(&mut CupratedTracingFilter)) {
 pub fn modify_file_output(f: impl FnOnce(&mut CupratedTracingFilter)) {
     FILE_WRITER_FILTER_HANDLE.get().unwrap().modify(f).unwrap();
 }
+
+/// Prints some text using [`eprintln`], with [`nu_ansi_term::Color::Red`] applied.
+pub fn eprintln_red(s: &str) {
+    eprintln!("{}", nu_ansi_term::Color::Red.bold().paint(s));
+}