feat(192): added env expansion to the log_dir field of config::Config and .pem files used for SASL

CHANGELOG.md

@@ -18,6 +18,8 @@
   tiny does not update permissions of existing log files.
 - Add new server configuration option `autoconnect` to disable automatically
   connecting to a server on startup. (#443)
+- Expand tildes and shell variables in `pem` (SASL authentication) and
+  `log_dir` config fields. (#192, #463)
 
 # 2025/01/01: 0.13.0
 

crates/tiny/Cargo.toml

@@ -27,6 +27,7 @@ log = "0.4"
 serde = { version = "1.0.196", features = ["derive"] }
 serde_yaml = "0.8"
 shell-words = "1.1.0"
+shellexpand = "3.1.2"
 time = "0.1"
 tokio = { version = "1.36", default-features = false, features = [] }
 tokio-stream = { version = "0.1", features = [] }

crates/tiny/config.yml

@@ -49,7 +49,9 @@ servers:
       # sasl:
       #   username: tiny_user
       #   password: hunter2
-      #   pem: "/home/user/.config/tiny/oftc.pem"
+
+      # sasl:
+      #   pem: "$HOME/.config/tiny/oftc.pem"
 
       # nickserv_ident: hunter2
 

crates/tiny/src/config.rs

@@ -1,6 +1,8 @@
 use libtiny_client::SASLAuth as ClientSASLAuth;
 use serde::{Deserialize, Deserializer};
 
+use shellexpand::LookupError;
+use std::env::VarError;
 use std::fs;
 use std::fs::File;
 use std::io::{Read, Write};
@@ -314,6 +316,29 @@ impl Config<PassOrCmd> {
         errors
     }
 
+    pub(crate) fn expand_fields(
+        &mut self,
+        home_dir: impl Fn() -> Option<String>,
+        env_var: impl Fn(&str) -> Result<Option<String>, VarError>,
+    ) -> Result<(), LookupError<VarError>> {
+        for server in &mut self.servers {
+            server.sasl_auth = match &mut server.sasl_auth {
+                None => None,
+                Some(other @ SASLAuth::Plain { .. }) => Some(other.clone()),
+                Some(SASLAuth::External { pem }) => Some(SASLAuth::External {
+                    pem: expand_path(pem.to_path_buf(), &home_dir, &env_var)?,
+                }),
+            };
+        }
+
+        self.log_dir = match &self.log_dir {
+            None => None,
+            Some(dir) => Some(expand_path(dir.to_path_buf(), &home_dir, &env_var)?),
+        };
+
+        Ok(())
+    }
+
     /// Runs password commands and updates the config with plain passwords obtained from the
     /// commands.
     pub(crate) fn read_passwords(self) -> Option<Config<String>> {
@@ -396,6 +421,16 @@ impl Config<PassOrCmd> {
     }
 }
 
+fn expand_path(
+    path: PathBuf,
+    home_dir: &impl Fn() -> Option<String>,
+    env_var: &impl Fn(&str) -> Result<Option<String>, VarError>,
+) -> Result<PathBuf, LookupError<VarError>> {
+    let path_str = path.to_string_lossy();
+    let expanded = shellexpand::full_with_context(&path_str, home_dir, env_var)?;
+    Ok(PathBuf::from(expanded.as_ref()))
+}
+
 /// Returns tiny config file path. File may or may not exist.
 ///
 /// Places to look: (in priority order)
@@ -559,4 +594,76 @@ mod tests {
             ])
         );
     }
+
+    #[test]
+    fn config_shell_expansion() {
+        let mut config: Config<PassOrCmd> = Config {
+            servers: vec![Server {
+                addr: "my_server".to_owned(),
+                alias: None,
+                port: 123,
+                tls: false,
+                pass: None,
+                autoconnect: true,
+                user: None,
+                realname: "".to_owned(),
+                nicks: vec!["".to_owned()],
+                join: vec![],
+                nickserv_ident: None,
+                sasl_auth: Some(SASLAuth::External {
+                    pem: "~/a/$SASL/b".into(),
+                }),
+            }],
+            defaults: Defaults {
+                nicks: vec!["".to_owned()],
+                realname: "".to_owned(),
+                join: vec![],
+                tls: false,
+            },
+            log_dir: Some("~/b/$LOG/c".into()),
+        };
+        config
+            .expand_fields(
+                || Some("/home/test".to_string()),
+                |s| match s {
+                    "SASL" => Ok(Some("sasl_val".to_string())),
+                    "LOG" => Ok(Some("log_val".to_string())),
+                    _ => Err(VarError::NotPresent),
+                },
+            )
+            .unwrap();
+
+        assert_eq!(
+            config.servers[0].sasl_auth,
+            Some(SASLAuth::External {
+                pem: PathBuf::from("/home/test/a/sasl_val/b"),
+            })
+        );
+        assert_eq!(
+            config.log_dir,
+            Some(PathBuf::from("/home/test/b/log_val/c"))
+        );
+    }
+
+    #[test]
+    fn config_shell_expansion_var_fail() {
+        let mut config: Config<PassOrCmd> = Config {
+            servers: vec![],
+            defaults: Defaults {
+                nicks: vec!["nick".to_owned()],
+                realname: "real".to_owned(),
+                join: vec![],
+                tls: false,
+            },
+            log_dir: Some("~/logs/$MISSING/data".into()),
+        };
+        let err = config
+            .expand_fields(
+                || Some("/home/test".to_string()),
+                |_| Err(VarError::NotPresent),
+            )
+            .unwrap_err();
+        assert_eq!(err.var_name, "MISSING");
+        assert_eq!(err.cause, VarError::NotPresent);
+    }
 }

crates/tiny/src/main.rs

@@ -41,7 +41,7 @@ fn main() {
                 println!("{yaml_err}");
                 exit(1);
             }
-            Ok(config) => {
+            Ok(mut config) => {
                 let config_errors = config.validate();
                 if !config_errors.is_empty() {
                     println!(
@@ -54,6 +54,15 @@ fn main() {
                     exit(1);
                 }
 
+                if let Err(var_error) = config.expand_fields(
+                    || dirs::home_dir().and_then(|p| p.into_os_string().into_string().ok()),
+                    |s| std::env::var(s).map(Some),
+                ) {
+                    println!("Config file error:");
+                    println!("- Cannot expand variable: {var_error}");
+                    exit(1);
+                };
+
                 let config = match config.read_passwords() {
                     None => exit(1),
                     Some(config) => config,