http: Add version and help flag

radicle-httpd/src/main.rs

@@ -2,15 +2,39 @@ use std::num::NonZeroUsize;
 use std::{collections::HashMap, process};
 
 use radicle::prelude::RepoId;
+use radicle::version::Version;
 use radicle_httpd as httpd;
 
+pub const VERSION: Version = Version {
+    name: "radicle-httpd",
+    commit: env!("GIT_HEAD"),
+    version: env!("RADICLE_VERSION"),
+    timestamp: env!("SOURCE_DATE_EPOCH"),
+};
+
+pub const HELP_MSG: &str = r#"
+Usage
+
+   radicle-httpd [<option>...]
+   
+Options
+
+    --listen       <address>         Address to listen on (default: 0.0.0.0:8080)
+    --alias, -a    <alias> <rid>     Provide alias and RID pairs to shorten git clone commands for repositories,
+                                     e.g. heartwood and rad:z3gqcJUoA1n9HaHKufZs5FCSGazv5 to produce https://seed.radicle.xyz/heartwood.git
+    --cache        <number>          Max amount of items in cache for /tree endpoints (default: 100)
+    --version, -v                    Print program version
+    --help, -h                       Print help
+"#;
+
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
     let options = parse_options()?;
 
     // SAFETY: The logger is only initialized once.
     httpd::logger::init().unwrap();
-    tracing::info!("version {}-{}", env!("RADICLE_VERSION"), env!("GIT_HEAD"));
+    tracing::info!("starting http daemon..");
+    tracing::info!("version {} ({})", env!("RADICLE_VERSION"), env!("GIT_HEAD"));
 
     match httpd::run(options).await {
         Ok(()) => {}
@@ -43,12 +67,19 @@ fn parse_options() -> Result<httpd::Options, lexopt::Error> {
 
                 aliases.insert(alias, id);
             }
+            Long("version") | Short('v') => {
+                if let Err(e) = VERSION.write(std::io::stdout()) {
+                    eprintln!("error: {e}");
+                    process::exit(1);
+                };
+                process::exit(0);
+            }
             Long("cache") => {
                 let size = parser.value()?.parse()?;
                 cache = NonZeroUsize::new(size);
             }
             Long("help") | Short('h') => {
-                println!("usage: radicle-httpd [--listen <addr>] [--alias <name> <rid>] [--cache <size>]..");
+                println!("{HELP_MSG}");
                 process::exit(0);
             }
             _ => return Err(arg.unexpected()),