Add allowed signers option to CLI and Config (#11)

* Add allowed signers CLI option

* Add allowed signers field to configuration

* Add dummy `git_allowed_signers_path` fn

* Shorten arg descriptions

* Fix typo "ALLLOWED"

Author: SRv6d

src/cli/main.rs

@@ -8,16 +8,25 @@ use std::{env, path::PathBuf};
 #[derive(Parser)]
 #[command(version, about, long_about = None)]
 pub struct Cli {
-    /// The path to the configuration file.
+    /// The configuration file.
     #[arg(
         short,
         long,
-        value_name = "FILE",
+        value_name = "PATH",
         env = "HANKO_CONFIG",
         default_value = default_config_path()
     )]
     pub config: PathBuf,
 
+    /// The allowed signers file used by Git.
+    #[arg(
+        long,
+        value_name = "PATH",
+        env = "HANKO_ALLOWED_SIGNERS",
+        default_value = git_allowed_signers_path()
+    )]
+    pub allowed_signers: PathBuf,
+
     #[command(flatten)]
     logging: Logging,
 
@@ -66,6 +75,12 @@ fn default_config_path() -> Resettable<OsStr> {
     }
 }
 
+/// The path to the allowed signers file as configured within Git.
+fn git_allowed_signers_path() -> Resettable<OsStr> {
+    // TODO: Get value from Git config.
+    Resettable::Value("~/.config/git/allowed_signers".into())
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/config.rs

@@ -4,11 +4,12 @@ use figment::{
     Figment,
 };
 use serde::{Deserialize, Serialize};
-use std::path::Path;
+use std::path::{Path, PathBuf};
 
 /// The main configuration.
 #[derive(Debug, Deserialize, Serialize, PartialEq)]
 pub struct Config {
+    allowed_signers: Option<PathBuf>,
     users: Option<Vec<User>>,
     organizations: Option<Vec<Organization>>,
     local: Option<Vec<String>>,
@@ -19,6 +20,7 @@ impl Default for Config {
     /// The default configuration containing common sources.
     fn default() -> Self {
         Config {
+            allowed_signers: None,
             users: None,
             organizations: None,
             local: None,
@@ -107,6 +109,7 @@ mod tests {
         url = "https://git.acme.corp"
         "#};
         let expected = Config {
+            allowed_signers: None,
             users: Some(vec![
                 User {
                     name: "torvalds".to_string(),