switch argument handling from clap to pico-args

Signed-off-by: Filip Schauer <f.schauer@proxmox.com>

Cargo.toml

@@ -7,7 +7,7 @@ edition = "2021"
 [dependencies]
 anyhow = "1.0"
 bincode = "1.3"
-clap = { version = "4.0.32", features = ["cargo", "env"] }
+pico-args = "0.4"
 md5 = "0.7.0"
 scopeguard = "1.1.0"
 serde = "1.0"

src/main.rs

@@ -1,91 +1,106 @@
-use anyhow::{Context, Error};
+use std::ffi::OsString;
-use clap::{command, Arg, ArgAction};
+
+use anyhow::{bail, Context, Error};
 use proxmox_sys::linux::tty;
 
 mod vma;
 mod vma2pbs;
 use vma2pbs::{backup_vma_to_pbs, BackupVmaToPbsArgs};
 
-fn main() -> Result<(), Error> {
+const CMD_HELP: &str = "\
-    let matches = command!()
+Usage: vma-to-pbs [OPTIONS] --repository <auth_id@host:port:datastore> --vmid <VMID> [vma_file]
-        .arg(
-            Arg::new("repository")
-                .long("repository")
-                .value_name("auth_id@host:port:datastore")
-                .help("Repository URL")
-                .required(true),
-        )
-        .arg(
-            Arg::new("vmid")
-                .long("vmid")
-                .value_name("VMID")
-                .help("Backup ID")
-                .required(true),
-        )
-        .arg(
-            Arg::new("fingerprint")
-                .long("fingerprint")
-                .value_name("FINGERPRINT")
-                .help("Proxmox Backup Server Fingerprint")
-                .env("PBS_FINGERPRINT"),
-        )
-        .arg(
-            Arg::new("keyfile")
-                .long("keyfile")
-                .value_name("KEYFILE")
-                .help("Key file"),
-        )
-        .arg(
-            Arg::new("master_keyfile")
-                .long("master_keyfile")
-                .value_name("MASTER_KEYFILE")
-                .help("Master key file"),
-        )
-        .arg(
-            Arg::new("compress")
-                .long("compress")
-                .short('c')
-                .help("Compress the Backup")
-                .action(ArgAction::SetTrue),
-        )
-        .arg(
-            Arg::new("encrypt")
-                .long("encrypt")
-                .short('e')
-                .help("Encrypt the Backup")
-                .action(ArgAction::SetTrue),
-        )
-        .arg(
-            Arg::new("password-file")
-                .long("password-file")
-                .value_name("PASSWORD_FILE")
-                .help("Password file"),
-        )
-        .arg(
-            Arg::new("key-password-file")
-                .long("key-password-file")
-                .value_name("KEY_PASSWORD_FILE")
-                .help("Key password file"),
-        )
-        .arg(Arg::new("vma_file"))
-        .get_matches();
 
-    let pbs_repository = matches.get_one::<String>("repository").unwrap().to_string();
+Arguments:
-    let vmid = matches.get_one::<String>("vmid").unwrap().to_string();
+  [vma_file]
 
-    let fingerprint = matches
+Options:
-        .get_one::<String>("fingerprint")
+      --repository <auth_id@host:port:datastore>
-        .context("Fingerprint not set. Use $PBS_FINGERPRINT or --fingerprint")?
+          Repository URL
-        .to_string();
+      --vmid <VMID>
+          Backup ID
+      --fingerprint <FINGERPRINT>
+          Proxmox Backup Server Fingerprint [env: PBS_FINGERPRINT=]
+      --keyfile <KEYFILE>
+          Key file
+      --master_keyfile <MASTER_KEYFILE>
+          Master key file
+  -c, --compress
+          Compress the Backup
+  -e, --encrypt
+          Encrypt the Backup
+      --password_file <PASSWORD_FILE>
+          Password file
+      --key_password_file <KEY_PASSWORD_FILE>
+          Key password file
+  -h, --help
+          Print help
+  -V, --version
+          Print version
+";
 
-    let keyfile = matches.get_one::<String>("keyfile");
+fn parse_args() -> Result<BackupVmaToPbsArgs, Error> {
-    let master_keyfile = matches.get_one::<String>("master_keyfile");
+    let mut args: Vec<_> = std::env::args_os().collect();
-    let compress = matches.get_flag("compress");
+    args.remove(0); // remove the executable path.
-    let encrypt = matches.get_flag("encrypt");
 
-    let vma_file_path = matches.get_one::<String>("vma_file");
+    let mut first_later_args_index = 0;
+    let options = ["-h", "--help", "-c", "--compress", "-e", "--encrypt"];
 
-    let password_file = matches.get_one::<String>("password-file");
+    for (i, arg) in args.iter().enumerate() {
+        if let Some(arg) = arg.to_str() {
+            if arg.starts_with('-') {
+                if arg == "--" {
+                    args.remove(i);
+                    first_later_args_index = i;
+                    break;
+                }
+
+                first_later_args_index = i + 1;
+
+                if !options.contains(&arg) {
+                    first_later_args_index += 1;
+                }
+            }
+        }
+    }
+
+    let forwarded_args = if first_later_args_index > args.len() {
+        Vec::new()
+    } else {
+        args.split_off(first_later_args_index)
+    };
+
+    let mut args = pico_args::Arguments::from_vec(args);
+
+    if args.contains(["-h", "--help"]) {
+        print!("{CMD_HELP}");
+        std::process::exit(0);
+    }
+
+    let pbs_repository = args.value_from_str("--repository")?;
+    let vmid = args.value_from_str("--vmid")?;
+    let fingerprint = args.opt_value_from_str("--fingerprint")?;
+    let keyfile = args.opt_value_from_str("--keyfile")?;
+    let master_keyfile = args.opt_value_from_str("--master_keyfile")?;
+    let compress = args.contains(["-c", "--compress"]);
+    let encrypt = args.contains(["-e", "--encrypt"]);
+    let password_file: Option<OsString> = args.opt_value_from_str("--password-file")?;
+    let key_password_file: Option<OsString> = args.opt_value_from_str("--key-password-file")?;
+
+    if !args.finish().is_empty() {
+        bail!("unexpected extra arguments, use '-h' for usage");
+    }
+
+    let fingerprint = match fingerprint {
+        Some(v) => v,
+        None => std::env::var("PBS_FINGERPRINT")
+            .context("Fingerprint not set. Use $PBS_FINGERPRINT or --fingerprint")?,
+    };
+
+    if forwarded_args.len() > 1 {
+        bail!("too many arguments");
+    }
+
+    let vma_file_path = forwarded_args.first();
 
     let pbs_password = match password_file {
         Some(password_file) => {
@@ -101,14 +116,20 @@ fn main() -> Result<(), Error> {
 
             password
         }
-        None => String::from_utf8(tty::read_password("Password: ")?)?,
+        None => {
+            if vma_file_path.is_none() {
+                bail!(
+                    "Please use --password-file to provide the password \
+                    when passing the VMA file to stdin"
+                );
+            }
+
+            String::from_utf8(tty::read_password("Password: ")?)?
+        }
     };
 
     let key_password = match keyfile {
-        Some(_) => {
+        Some(_) => Some(match key_password_file {
-            let key_password_file = matches.get_one::<String>("key_password_file");
-
-            Some(match key_password_file {
             Some(key_password_file) => {
                 let mut key_password = std::fs::read_to_string(key_password_file)
                     .context("Could not read key password file")?;
@@ -122,25 +143,38 @@ fn main() -> Result<(), Error> {
 
                 key_password
             }
-                None => String::from_utf8(tty::read_password("Key Password: ")?)?,
+            None => {
-            })
+                if vma_file_path.is_none() {
+                    bail!(
+                        "Please use --key-password-file to provide the password \
+                        when passing the VMA file to stdin"
+                    );
                 }
+
+                String::from_utf8(tty::read_password("Key Password: ")?)?
+            }
+        }),
         None => None,
     };
 
-    let args = BackupVmaToPbsArgs {
+    let options = BackupVmaToPbsArgs {
         vma_file_path: vma_file_path.cloned(),
         pbs_repository,
         backup_id: vmid,
         pbs_password,
-        keyfile: keyfile.cloned(),
+        keyfile,
         key_password,
-        master_keyfile: master_keyfile.cloned(),
+        master_keyfile,
         fingerprint,
         compress,
         encrypt,
     };
 
+    Ok(options)
+}
+
+fn main() -> Result<(), Error> {
+    let args = parse_args()?;
     backup_vma_to_pbs(args)?;
 
     Ok(())

src/vma2pbs.rs

@@ -1,7 +1,7 @@
 use std::cell::RefCell;
 use std::collections::hash_map::Entry;
 use std::collections::HashMap;
-use std::ffi::{c_char, CStr, CString};
+use std::ffi::{c_char, CStr, CString, OsString};
 use std::fs::File;
 use std::io::{stdin, BufRead, BufReader, Read};
 use std::ptr;
@@ -22,7 +22,7 @@ use crate::vma::VmaReader;
 const VMA_CLUSTER_SIZE: usize = 65536;
 
 pub struct BackupVmaToPbsArgs {
-    pub vma_file_path: Option<String>,
+    pub vma_file_path: Option<OsString>,
     pub pbs_repository: String,
     pub backup_id: String,
     pub pbs_password: String,