Reject command-line if it contains invalid unlock method

src/bin/stratis-min/stratis-min.rs

@@ -9,11 +9,10 @@ use serde_json::{json, Map, Value};
 
 use stratisd::{
     engine::{
-        EncryptionInfo, KeyDescription, Name, PoolIdentifier, PoolUuid, UnlockMethod,
-        CLEVIS_TANG_TRUST_URL,
+        EncryptionInfo, KeyDescription, Name, PoolIdentifier, PoolUuid, CLEVIS_TANG_TRUST_URL,
     },
     jsonrpc::client::{filesystem, key, pool, report},
-    stratis::{StratisError, VERSION},
+    stratis::{UnlockMethod, VERSION},
 };
 
 fn parse_args() -> Command {
@@ -41,7 +40,12 @@ fn parse_args() -> Command {
                 Command::new("start")
                     .arg(Arg::new("id").required(true))
                     .arg(Arg::new("name").long("name").num_args(0))
-                    .arg(Arg::new("unlock_method").long("unlock-method").num_args(1))
+                    .arg(
+                        Arg::new("unlock_method")
+                            .long("unlock-method")
+                            .num_args(1)
+                            .value_parser(clap::value_parser!(UnlockMethod)),
+                    )
                     .arg(
                         Arg::new("prompt")
                             .long("prompt")
@@ -235,13 +239,7 @@ fn main() -> Result<(), String> {
                             .expect("required"),
                     )?)
                 };
-                let unlock_method =
-                    match args.get_one::<String>("unlock_method").map(|s| s.as_str()) {
-                        Some(um) => Some(UnlockMethod::try_from(um).map_err(|_| {
-                            StratisError::Msg(format!("{um} is an invalid unlock method"))
-                        })?),
-                        None => None,
-                    };
+                let unlock_method = args.get_one::<UnlockMethod>("unlock_method").copied();
                 let prompt = args.get_flag("prompt");
                 pool::pool_start(id, unlock_method, prompt)?;
                 Ok(())

src/engine/types/mod.rs

@@ -16,7 +16,7 @@ use std::{
 use libudev::EventType;
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
-use strum_macros::{self, EnumString, FromRepr};
+use strum_macros::{self, EnumString, FromRepr, IntoStaticStr, VariantArray};
 use uuid::Uuid;
 
 pub use crate::engine::{
@@ -131,7 +131,18 @@ impl Display for StratisUuid {
 }
 
 /// Use Clevis or keyring to unlock LUKS volume.
-#[derive(Serialize, Deserialize, Clone, Copy, Eq, PartialEq, Debug, EnumString)]
+#[derive(
+    Serialize,
+    Deserialize,
+    Clone,
+    Copy,
+    Eq,
+    PartialEq,
+    Debug,
+    EnumString,
+    VariantArray,
+    IntoStaticStr,
+)]
 #[strum(serialize_all = "snake_case")]
 pub enum UnlockMethod {
     Clevis,

src/stratis/command_line.rs

@@ -0,0 +1,20 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+use clap::{builder::PossibleValue, ValueEnum};
+
+use strum::VariantArray;
+
+pub use crate::engine::UnlockMethod;
+
+impl ValueEnum for UnlockMethod {
+    fn value_variants<'a>() -> &'a [UnlockMethod] {
+        UnlockMethod::VARIANTS
+    }
+
+    fn to_possible_value(&self) -> Option<PossibleValue> {
+        let value: &'static str = self.into();
+        Some(PossibleValue::new(value))
+    }
+}

src/stratis/mod.rs

@@ -3,11 +3,13 @@
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 pub use self::{
+    command_line::UnlockMethod,
     errors::{StratisError, StratisResult},
     run::run,
     stratis::VERSION,
 };
 
+mod command_line;
 mod dm;
 mod errors;
 mod ipc_support;

tests/stratis_min.rs

@@ -254,12 +254,7 @@ fn test_stratis_min_pool_start_invalid_unlock_method() {
         .arg("--name")
         .arg("pn")
         .arg("--unlock-method=bogus");
-    cmd.assert()
-        .failure()
-        .code(1)
-        .stderr(predicate::str::contains(
-            "bogus is an invalid unlock method",
-        ));
+    cmd.assert().failure().code(2);
 }
 
 #[test]