cleaned up and added install subcommand

Cargo.lock

@@ -2,6 +2,12 @@
 # It is not intended for manual editing.
 version = 4
 
+[[package]]
+name = "anyhow"
+version = "1.0.97"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dcfed56ad506cb2c684a14971b8861fdc3baaaae314b9e5f9bb532cbe3ba7a4f"
+
 [[package]]
 name = "autocfg"
 version = "1.1.0"
@@ -20,6 +26,21 @@ version = "2.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5c8214115b7bf84099f1309324e63141d4c5d7cc26862f97a0a857dbefe165bd"
 
+[[package]]
+name = "camino"
+version = "1.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b96ec4966b5813e2c0507c1f86115c8c5abaadc3980879c3424042a02fd1ad3"
+
+[[package]]
+name = "cc"
+version = "1.2.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1fcb57c740ae1daf453ae85f16e37396f672b039e00d9d866e07ddb24e328e3a"
+dependencies = [
+ "shlex",
+]
+
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
@@ -88,11 +109,14 @@ dependencies = [
 name = "lookaround"
 version = "0.1.6"
 dependencies = [
+ "anyhow",
+ "camino",
  "configparser",
  "directories",
  "mac_address",
  "nix",
  "rand",
+ "sys-info",
  "thiserror",
  "tokio",
 ]
@@ -249,6 +273,12 @@ dependencies = [
  "redox_syscall",
 ]
 
+[[package]]
+name = "shlex"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
+
 [[package]]
 name = "syn"
 version = "1.0.82"
@@ -260,6 +290,16 @@ dependencies = [
  "unicode-xid",
 ]
 
+[[package]]
+name = "sys-info"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b3a0d0aba8bf96a0e1ddfdc352fc53b3df7f39318c71854910c3c4b024ae52c"
+dependencies = [
+ "cc",
+ "libc",
+]
+
 [[package]]
 name = "thiserror"
 version = "1.0.30"

Cargo.toml

@@ -12,11 +12,14 @@ repository = "https://six-five-six-four.com/git/reactor/lookaround"
 version = "0.1.6"
 
 [dependencies]
+anyhow = "1.0.97"
+camino = "1.1.9"
 configparser = "3.0.0"
 directories = "5.0.0"
 mac_address = "1.1.8"
 nix = "0.29.0"
 rand = "0.8.4"
+sys-info = "0.9.1"
 thiserror = "1.0.30"
 tokio = { version = "1.14.0", features = ["fs", "net", "rt", "time"] }
 

README.md

@@ -28,51 +28,38 @@ Make sure Cargo is installed from [RustUp.](https://rustup.rs/)
 cargo install lookaround
 
 # Find your config directory
-# Prints something like `Using config dir "/home/user/.config/lookaround"`
+# e.g. `$HOME/.config/lookaround`
 lookaround config
 ```
 
-Create the files `client.ini` and/or `server.ini` in that directory
+Use `$HOME/.config/lookaround/client.ini` as a hosts file if it's more convenient
-(e.g. /home/user/.config/lookaround/server.ini)
+for your client to be the source of truth for nicknames.
 
 ```ini
-# Clients can store MAC-nickname pairs in client.ini, like a hosts file.
-# This is useful if your servers are short-lived and you want the clients
-# to be the source of truth for nicknames.
 [nicknames]
-11-11-11-11-11-11 = laptop
+11-11-11-11-11-11 = bob-laptop
-22-22-22-22-22-22 = desktop
+22-22-22-22-22-22 = alice-desktop
 ```
 
+LookAround will use the system's hostname as its server nickname.
+If you have a generic hostname like `ubuntu`, override this in `$HOME/.config/lookaround/server.ini`:
+
 ```ini
-# Long-lived servers can have their nickname configured in server.ini
 [server]
-nickname = my-computer
+nickname = alice-desktop
 ```
 
 ## Auto-Start (Linux)
 
-Put this systemd unit in `~/.config/systemd/user/lookaround.service`:
+Run `lookaround install` or `lookaround install $NICKNAME` if you want to set a nickname.
 
-```ini
+This will create `$HOME/.config/lookaround/server.ini` and `$HOME/.config/systemd/user/lookaround.service`, and start the systemd user service.
-[Unit]
-Description=LookAround
 
-[Service]
+To check that it's running
-ExecStart=/home/user/.cargo/bin/lookaround server
-Restart=always
-
-[Install]
-WantedBy=default.target
-```
-
-Then start the service, check that it's running okay, and enable it for
-auto-start:
 
 ```bash
-systemctl --user start lookaround
 systemctl --user status lookaround
-systemctl --user enable lookaround
+lookaround client
 ```
 
 ## Auto-Start (Windows)

src/app_common.rs

@@ -9,6 +9,10 @@ pub fn try_config_dir() -> Option<PathBuf> {
     Some(try_project_dir()?.config_local_dir().into())
 }
 
+pub fn try_server_config_path() -> Option<PathBuf> {
+    Some(try_config_dir()?.join("server.ini"))
+}
+
 #[derive(Debug, thiserror::Error)]
 pub enum AppError {
     #[error(transparent)]

src/install.rs

@@ -1,7 +1,83 @@
 use crate::prelude::*;
+use anyhow::{Context as _, Result, anyhow, ensure};
+use std::{io::Write as _, process::Command};
 
-pub(crate) fn main() -> Result<(), AppError> {
+pub(crate) fn main(nickname: Option<&str>) -> Result<()> {
-    let path = app_common::try_config_dir().unwrap().join("server.ini");
+    if let Some(nickname) = nickname {
+        let path = app_common::try_server_config_path().context("can't find config dir")?;
+        let text = format!(
+            "[server]
+nickname = {nickname}
+"
+        );
+
+        write_new(&path, &text).context("Didn't install LookAround server.ini")?;
+    }
+
+    setup_autostart()?;
 
     Ok(())
 }
+
+#[cfg(not(target_os = "linux"))]
+fn setup_autostart() -> Result<()> {
+    anyhow::bail!("LookAround autostart is only implemented for systemd + GNU/Linux");
+}
+
+#[cfg(target_os = "linux")]
+fn setup_autostart() -> Result<()> {
+    let dirs = directories::BaseDirs::new().context("Could not find home dir")?;
+    let home = dirs.config_local_dir();
+    let path = home.join("systemd").join("user").join("lookaround.service");
+
+    let exe_path =
+        Utf8PathBuf::from_path_buf(std::env::current_exe().context("Can't get current_exe")?)
+            .map_err(|_| anyhow!("current_exe isn't valid UTF-8"))?;
+    let text = format!(
+        "[Unit]
+Description=LookAround
+
+[Service]
+ExecStart={exe_path} server
+Restart=always
+
+[Install]
+WantedBy=default.target
+"
+    );
+
+    write_new(&path, &text).context("Didn't install systemd service unit")?;
+
+    ensure!(
+        Command::new("systemctl")
+            .args(["--user", "start", "lookaround"])
+            .status()?
+            .success(),
+        "starting service failed"
+    );
+    ensure!(
+        Command::new("systemctl")
+            .args(["--user", "enable", "lookaround"])
+            .status()?
+            .success(),
+        "enabling service failed"
+    );
+
+    Ok(())
+}
+
+fn write_new(path: &Path, content: &str) -> Result<()> {
+    use std::fs;
+    fs::create_dir_all(
+        path.parent()
+            .context("Impossible, path should always have a parent")?,
+    )?;
+    match fs::File::create_new(path) {
+        Err(err) if err.kind() == std::io::ErrorKind::AlreadyExists => {
+            eprintln!("File already exists, won't overwrite: `{path:?}`")
+        }
+        Err(err) => Err(err)?,
+        Ok(mut f) => f.write_all(content.as_bytes())?,
+    }
+    Ok(())
+}

src/main.rs

@@ -1,3 +1,4 @@
+use anyhow::{Result, bail};
 use prelude::*;
 
 pub mod app_common;
@@ -9,7 +10,7 @@ mod prelude;
 mod server;
 pub mod tlv;
 
-fn main() -> Result<(), AppError> {
+fn main() -> Result<()> {
     let rt = tokio::runtime::Builder::new_current_thread()
         .enable_io()
         .enable_time()
@@ -20,7 +21,7 @@ fn main() -> Result<(), AppError> {
     Ok(())
 }
 
-async fn async_main() -> Result<(), AppError> {
+async fn async_main() -> Result<()> {
     let mut args = env::args();
 
     let _exe_name = args.next();
@@ -32,19 +33,21 @@ async fn async_main() -> Result<(), AppError> {
     match subcommand.as_ref() {
         "--version" => {
             println!("lookaround v{}", env!("CARGO_PKG_VERSION"));
-            Ok(())
         }
-        "client" => client::client(args).await,
+        "client" => client::client(args).await?,
         "config" => {
             config();
-            Ok(())
         }
-        "find-nick" => client::find_nick(args).await,
+        "find-nick" => client::find_nick(args).await?,
-        "install" => install::main(),
+        "install" => {
-        "my-ips" => my_ips(),
+            let nickname = args.next();
-        "server" => server::server(args).await,
+            install::main(nickname.as_deref())?
-        x => Err(CliArgError::UnknownSubcommand(x.to_string()).into()),
+        }
+        "my-ips" => my_ips()?,
+        "server" => server::server(args).await?,
+        x => bail!("Unknown subcommand `{x}`"),
     }
+    Ok(())
 }
 
 fn config() {

src/prelude.rs

@@ -3,12 +3,13 @@ pub use std::{
     env,
     io::{Cursor, Write},
     net::{Ipv4Addr, SocketAddr, SocketAddrV4},
-    path::PathBuf,
+    path::{Path, PathBuf},
     str::FromStr,
     sync::Arc,
     time::Duration,
 };
 
+pub use camino::Utf8PathBuf;
 pub use configparser::ini::Ini;
 pub use mac_address::{MacAddress, get_mac_address};
 pub use rand::RngCore;

src/server.rs

@@ -42,10 +42,9 @@ pub async fn server<I: Iterator<Item = String>>(args: I) -> Result<(), AppError>
 fn configure<I: Iterator<Item = String>>(mut args: I) -> Result<Params, AppError> {
     let common = app_common::Params::default();
     let mut bind_addrs = vec![];
-    let mut nickname = String::new();
+    let mut nickname = sys_info::hostname().unwrap_or_default();
 
-    if let Some(dir) = app_common::try_config_dir() {
+    if let Some(path) = app_common::try_server_config_path() {
-        let path = dir.join("server.ini");
         let mut ini = Ini::new_cs();
         if ini.load(&path).is_ok() {
             if let Some(x) = ini.get("server", "nickname") {