wip: replace dyn Error with concrete

src/bin/init.rs

@@ -6,7 +6,7 @@ use wingmate_rs::init;
 async fn main() -> Result<(), Box<dyn error::Error>> {
     if let Err(e) = init::start().await {
         eprintln!("{}", e);
-        return Err(e);
+        return Err(e.into());
     }
 
     Ok(())

src/init.rs

@@ -3,12 +3,14 @@ mod config;
 pub(crate) mod error;
 
 use std::env;
-use std::error as std_err;
+use anyhow::Context;
 
-pub async fn start() -> Result<(), Box<dyn std_err::Error>> {
+const WINGMATE_CONFIG_PATH: &'static str = "WINGMATE_CONFIG_PATH";
+
+pub async fn start() -> Result<(), error::WingmateInitError> {
     let mut vec_search: Vec<String> = Vec::new();
 
-    match env::var("WINGMATE_CONFIG_PATH") {
+    match env::var(WINGMATE_CONFIG_PATH) {
         Ok(paths) => {
             for p in paths.split(':') {
                 vec_search.push(String::from(p));
@@ -16,7 +18,8 @@ pub async fn start() -> Result<(), Box<dyn std_err::Error>> {
         },
         Err(e) => {
             if let env::VarError::NotUnicode(_) = e {
-                return Err(e.into());
+                return Err(e).context(format!("reading {} env var", WINGMATE_CONFIG_PATH))
+                    .map_err(|e| {error::WingmateInitError::Other { source: e }} );
             } else {
                 vec_search.push(String::from("/etc/wingmate"));
             }

src/init/config.rs

@@ -2,11 +2,23 @@ use std::fs;
 use std::env;
 use std::path::PathBuf;
 use std::io::{BufReader, BufRead};
-use std::error as std_error;
 use crate::init::error as wingmate_error;
 use nix::unistd::{access, AccessFlags};
 use lazy_static::lazy_static;
 use regex::Regex;
+use anyhow::Context;
+
+const CRON_REGEX_STR: &'static str = r"^\s*(?P<minute>\S+)\s+(?P<hour>\S+)\s+(?P<dom>\S+)\s+(?P<month>\S+)\s+(?P<dow>\S+)\s+(?P<command>\S.*\S)\s*$";
+const MINUTE: &'static str = "minute";
+const HOUR: &'static str = "hour";
+const DAY_OF_MONTH_ABBRV: &'static str = "dom";
+const DAY_OF_MONTH: &'static str = "day of month";
+const MONTH: &'static str = "month";
+const DAY_OF_WEEK_ABBRV: &'static str = "dow";
+const DAY_OF_WEEK: &'static str = "day of week";
+const COMMAND: &'static str = "command";
+const WINGMATE_SHELL_ENV: &'static str = "WINGMATE_SHELL";
+
 
 #[derive(Debug)]
 pub enum Command {
@@ -40,7 +52,7 @@ pub struct Config {
 }
 
 impl Config {
-    pub fn find(search_path: Vec<String>) -> Result<Config, Box<dyn std_error::Error>> {
+    pub fn find(search_path: Vec<String>) -> Result<Config, wingmate_error::WingmateInitError> {
         if search_path.is_empty() {
             return Err(wingmate_error::WingmateInitError::InvalidConfigSearchPath.into());
         }
@@ -68,7 +80,7 @@ impl Config {
                         }
                     }
 
-                    cron = Self::read_crontab(&mut buf)?;
+                    cron = Self::read_crontab(&mut buf).map_err(|e| { wingmate_error::WingmateInitError::Cron { source: e }})?;
 
                     //TODO: need to include cron in the condition
                     if !svc_commands.is_empty() || !cron.is_empty() {
@@ -89,16 +101,14 @@ impl Config {
             cron,
             shell_path: None,
         };
-        config.find_shell()?;
+        config.find_shell().map_err(|e| { wingmate_error::WingmateInitError::FindShell { source: e } })?;
 
         Ok(config)
     }
 
-    fn read_crontab(path: &mut PathBuf) -> Result<Vec<Crontab>, Box<dyn std_error::Error>> {
+    fn read_crontab(path: &mut PathBuf) -> Result<Vec<Crontab>, wingmate_error::CronParseError> {
         lazy_static! {
-            static ref CRON_REGEX: Regex = Regex::new(
-                r"^\s*(?P<minute>\S+)\s+(?P<hour>\S+)\s+(?P<dom>\S+)\s+(?P<month>\S+)\s+(?P<dow>\S+)\s+(?P<command>\S.*\S)\s*$"
-            ).unwrap();
+            static ref CRON_REGEX: Regex = Regex::new(CRON_REGEX_STR).unwrap();
         }
 
         let cron_path = path.join("crontab");
@@ -107,45 +117,72 @@ impl Config {
         if let Ok(f) = fs::File::open(cron_path.as_path()) {
             for line in BufReader::new(f).lines() {
                 if let Ok(l) = line {
-                    let cap = CRON_REGEX.captures(&l).ok_or::<Box<dyn std_error::Error>>(wingmate_error::CronSyntaxError(String::from(&l)).into())?;
+                    let cap = CRON_REGEX.captures(&l).ok_or::<wingmate_error::CronParseError>(
+                        wingmate_error::CronParseError::InvalidSyntax(String::from(&l))
+                    )?;
                     
-                    let mut match_str = cap.name("minute").ok_or::<Box<dyn std_error::Error>>(
-                        wingmate_error::CronSyntaxError(format!("cannot capture minute in \"{}\"", &l)).into()
+                    let mut match_str = cap.name(MINUTE).ok_or::<wingmate_error::CronParseError>(
+                        wingmate_error::CronParseError::FieldMatch { cron_line: String::from(&l), field_name: String::from(MINUTE) }
                     )?;
                     let minute = Self::to_cron_time_field_spec(&match_str).map_err(|e| { 
-                        Box::new(wingmate_error::CronSyntaxError(format!("failed to parse minute \"{}\" in \"{}\": {}", &match_str.as_str(), &l, e)))
+                        wingmate_error::CronParseError::Parse {
+                            source: e,
+                            cron_line: String::from(&l),
+                            matched: String::from(match_str.as_str()),
+                            field_name: String::from(MINUTE)
+                        }
                     })?;
     
-                    match_str = cap.name("hour").ok_or::<Box<dyn std_error::Error>>(
-                        wingmate_error::CronSyntaxError(format!("cannot capture hour in \"{}\"", &l)).into()
+                    match_str = cap.name(HOUR).ok_or::<wingmate_error::CronParseError>(
+                        wingmate_error::CronParseError::FieldMatch { cron_line: String::from(&l), field_name: String::from(HOUR) }
                     )?;
                     let hour = Self::to_cron_time_field_spec(&match_str).map_err(|e| { 
-                        Box::new(wingmate_error::CronSyntaxError(format!("failed to parse hour \"{}\" in \"{}\": {}", &match_str.as_str(), &l, e)))
+                        wingmate_error::CronParseError::Parse {
+                            source: e,
+                            cron_line: String::from(&l),
+                            matched: String::from(match_str.as_str()),
+                            field_name: String::from(HOUR)
+                        }
                     })?;
     
-                    match_str = cap.name("dom").ok_or::<Box<dyn std_error::Error>>(
-                        wingmate_error::CronSyntaxError(format!("cannot capture day of month in \"{}\"", &l)).into()
+                    match_str = cap.name(DAY_OF_MONTH_ABBRV).ok_or::<wingmate_error::CronParseError>(
+                        wingmate_error::CronParseError::FieldMatch { cron_line: String::from(&l), field_name: String::from(DAY_OF_MONTH) }
                     )?;
                     let dom = Self::to_cron_time_field_spec(&match_str).map_err(|e| {
-                        Box::new(wingmate_error::CronSyntaxError(format!("failed to parse day of month \"{}\" in \"{}\": {}", &match_str.as_str(), &l, e)))
+                        wingmate_error::CronParseError::Parse {
+                            source: e,
+                            cron_line: String::from(&l),
+                            matched: String::from(match_str.as_str()),
+                            field_name: String::from(DAY_OF_MONTH)
+                        }
                     })?;
     
-                    match_str = cap.name("month").ok_or::<Box<dyn std_error::Error>>(
-                        wingmate_error::CronSyntaxError(format!("cannot capture month in \"{}\"", &l)).into()
+                    match_str = cap.name(MONTH).ok_or::<wingmate_error::CronParseError>(
+                        wingmate_error::CronParseError::FieldMatch { cron_line: String::from(&l), field_name: String::from(MONTH) }
                     )?;
                     let month = Self::to_cron_time_field_spec(&match_str).map_err(|e| {
-                        Box::new(wingmate_error::CronSyntaxError(format!("failed to parse month \"{}\" in \"{}\": {}", &match_str.as_str(), &l, e)))
+                        wingmate_error::CronParseError::Parse {
+                            source: e,
+                            cron_line: String::from(&l),
+                            matched: String::from(match_str.as_str()),
+                            field_name: String::from(MONTH)
+                        }
                     })?;
     
-                    match_str = cap.name("dow").ok_or::<Box<dyn std_error::Error>>(
-                        wingmate_error::CronSyntaxError(format!("cannot capture day of week in \"{}\"", &l)).into()
+                    match_str = cap.name(DAY_OF_WEEK_ABBRV).ok_or::<wingmate_error::CronParseError>(
+                        wingmate_error::CronParseError::FieldMatch { cron_line: String::from(&l), field_name: String::from(DAY_OF_WEEK) }
                     )?;
                     let dow = Self::to_cron_time_field_spec(&match_str).map_err(|e| {
-                        Box::new(wingmate_error::CronSyntaxError(format!("failed to parse day of week \"{}\" in \"{}\": {}", &match_str.as_str(), &l, e)))
+                        wingmate_error::CronParseError::Parse {
+                            source: e,
+                            cron_line: String::from(&l),
+                            matched: String::from(match_str.as_str()),
+                            field_name: String::from(DAY_OF_WEEK)
+                        }
                     })?;
     
-                    match_str = cap.name("command").ok_or::<Box<dyn std_error::Error>>(
-                        wingmate_error::CronSyntaxError(format!("cannot capture command in \"{}\"", &l)).into()
+                    match_str = cap.name(COMMAND).ok_or::<wingmate_error::CronParseError>(
+                        wingmate_error::CronParseError::FieldMatch { cron_line: String::from(&l), field_name: String::from(COMMAND) }
                     )?;
     
                     ret_vec.push(Crontab {
@@ -163,34 +200,34 @@ impl Config {
         Ok(ret_vec)
     }
 
-    fn to_cron_time_field_spec(match_str: &regex::Match) -> Result<CronTimeFieldSpec, Box<dyn std_error::Error>> {
+    fn to_cron_time_field_spec(match_str: &regex::Match) -> Result<CronTimeFieldSpec, anyhow::Error> {
         let field = match_str.as_str();
 
         if field == "*" {
             return Ok(CronTimeFieldSpec::Any);
         } else if field.starts_with("*/") {
-            let every = field[2..].parse::<u8>()?;
+            let every = field[2..].parse::<u8>().context("parsing on field matching \"every\" pattern")?;
             return Ok(CronTimeFieldSpec::Every(every));
         } else if field.contains(",") {
             let multi: Vec<&str> = field.split(",").collect();
             let mut multi_occurrence: Vec<u8> = Vec::new();
 
             for m in multi {
-                let ur = m.parse::<u8>()?;
+                let ur = m.parse::<u8>().context("parsing on field matching \"multi occurrence\" pattern")?;
                 multi_occurrence.push(ur);
             }
 
             return Ok(CronTimeFieldSpec::MultiOccurrence(multi_occurrence));
         } else {
-            let n = field.parse::<u8>()?;
+            let n = field.parse::<u8>().context("parsing on field matching \"exact\" pattern")?;
             return Ok(CronTimeFieldSpec::Exact(n));
         }
     }
 
-    fn find_shell(&mut self) -> Result<(), Box<dyn std_error::Error>> {
+    fn find_shell(&mut self) -> Result<(), wingmate_error::FindShellError> {
 
         let  shell: String;
-        match env::var("WINGMATE_SHELL") {
+        match env::var(WINGMATE_SHELL_ENV) {
             Ok(sh) => {
                 shell = sh;
             },
@@ -200,13 +237,15 @@ impl Config {
                         shell = String::from("sh");
                     },
                     env::VarError::NotUnicode(_) => {
-                        return Err(e.into());
+                        return Err(e).context(format!("reading {} env var", WINGMATE_SHELL_ENV))
+                            .map_err(|e| { wingmate_error::FindShellError::Other { source: e } })
                     }
                 }
             }
         }
 
-        let env_path  = env::var("PATH")?;
+        let env_path  = env::var("PATH").context("getting PATH env variable")
+            .map_err(|e| { wingmate_error::FindShellError::Other { source: e } })?;
         let vec_path: Vec<&str> = env_path.split(':').collect();
 
         for p in vec_path {
@@ -220,7 +259,7 @@ impl Config {
             }
         }
 
-        Err(wingmate_error::ShellNotFoundError(shell).into())
+        Err(wingmate_error::FindShellError::ShellNotFound)
     }
 
     pub fn get_service_iter(&self) -> std::slice::Iter<Command> {

src/init/daemon.rs

@@ -3,13 +3,14 @@ mod waiter;
 mod starter;
 mod constants;
 
-use std::error;
 use tokio::task::JoinSet;
 use tokio_util::sync::CancellationToken;
 use std::sync::{Arc, Mutex};
 use crate::init::config;
+use crate::init::error as wmerr;
+use crate::init::error::WingmateInitError;
 
-pub async fn start(cfg: config::Config) -> Result<(), Box<dyn error::Error>> {
+pub async fn start(cfg: config::Config) -> Result<(), WingmateInitError> {
     let sync_flag = Arc::new(Mutex::new(false));
     let sig_sync_flag = sync_flag.clone();
 
@@ -19,7 +20,7 @@ pub async fn start(cfg: config::Config) -> Result<(), Box<dyn error::Error>> {
     let cancel = CancellationToken::new();
     let starter_cancel = cancel.clone();
 
-    let mut set: JoinSet<Result<(), Box<dyn error::Error + Send + Sync>>> = JoinSet::new();
+    let mut set: JoinSet<Result<(), wmerr::WingmateInitError>> = JoinSet::new();
     set.spawn(async move {
         sighandler::sighandler(sig_sync_flag, cancel, sighandler_cancel).await
     });
@@ -38,12 +39,20 @@ pub async fn start(cfg: config::Config) -> Result<(), Box<dyn error::Error>> {
             Ok(v) => {
                 if let Err(ev) = v {
                     dbg!(&ev);
-                    return Err(ev as Box<dyn error::Error>);
+                    match ev {
+                        WingmateInitError::SpawnError { source, message } => {
+                            eprintln!("{}", WingmateInitError::SpawnError { source, message });
+                        },
+                        _ => {
+                            return Err(ev);
+                        }
+                    }
+                    // return Err(ev as Box<dyn error::Error>);
                 }
             },
             Err(e) => {
                 dbg!(&e);
-                return Err(e.into());
+                return Err(WingmateInitError::Join { source: e });
             },
         }
     }

src/init/daemon/sighandler.rs

@@ -1,13 +1,13 @@
-use std::error;
 use tokio::signal::unix::{signal, SignalKind};
 use tokio::select;
 use std::sync::{Arc, Mutex};
 use tokio_util::sync::CancellationToken;
+use crate::init::error::WingmateInitError;
 
-pub async fn sighandler(flag: Arc<Mutex<bool>>, cancel: CancellationToken, exit: CancellationToken) -> Result<(), Box<dyn error::Error + Send + Sync>> {
-    let mut sigint = signal(SignalKind::interrupt())?; 
-    let mut sigterm = signal(SignalKind::terminate())?;
-    let mut sigchld = signal(SignalKind::child())?;
+pub async fn sighandler(flag: Arc<Mutex<bool>>, cancel: CancellationToken, exit: CancellationToken) -> Result<(), WingmateInitError> {
+    let mut sigint = signal(SignalKind::interrupt()).map_err(|e| { WingmateInitError::Signal { source: e } })?; 
+    let mut sigterm = signal(SignalKind::terminate()).map_err(|e| { WingmateInitError::Signal { source: e } })?;
+    let mut sigchld = signal(SignalKind::child()).map_err(|e| { WingmateInitError::Signal { source: e } })?;
 
     'signal: loop {
         select! {

src/init/daemon/starter.rs

@@ -6,21 +6,21 @@ use tokio::io::Result as tokio_result;
 use tokio::time::sleep;
 use std::time::Duration;
 use std::process::ExitStatus;
-use std::error;
 use nix::sys::signal::{kill, Signal};
 use nix::errno::Errno;
 use nix::unistd::Pid;
+use anyhow::Context;
 use crate::init::config;
-use crate::init::error::{NoShellAvailableError, WingmateInitError};
+use crate::init::error::WingmateInitError;
 
 
-pub fn start_services(ts: &mut JoinSet<Result<(), Box<dyn error::Error + Send + Sync>>>, cfg: &config::Config, cancel: CancellationToken)
-    -> Result<(), Box<dyn error::Error>> {
+pub fn start_services(ts: &mut JoinSet<Result<(), WingmateInitError>>, cfg: &config::Config, cancel: CancellationToken)
+    -> Result<(), WingmateInitError> {
 
     for svc_ in cfg.get_service_iter() {
         let mut shell: String = String::new();
         if let config::Command::ShellPrefixed(_) = svc_ {
-            shell = cfg.get_shell().ok_or::<Box<dyn error::Error>>(NoShellAvailableError.into())?;
+            shell = cfg.get_shell().ok_or::<WingmateInitError>(WingmateInitError::NoShellAvailable)?;
         }
         let svc = svc_.clone();
         let cancel = cancel.clone();
@@ -32,7 +32,7 @@ pub fn start_services(ts: &mut JoinSet<Result<(), Box<dyn error::Error + Send +
                     config::Command::Direct(c) => {
                         let exp_str = c.clone();
                         child = Command::new(c).spawn().map_err(|e| {
-                            Box::new(WingmateInitError::SpawnError { source: e, message: exp_str })
+                            WingmateInitError::SpawnError { source: e, message: exp_str }
                         })?;
                     },
                     config::Command::ShellPrefixed(s) => {
@@ -40,7 +40,7 @@ pub fn start_services(ts: &mut JoinSet<Result<(), Box<dyn error::Error + Send +
                         let exp_str = s.clone();
                         let exp_shell = shell.clone();
                         child = Command::new(shell).arg(s).spawn().map_err(|e| {
-                            Box::new(WingmateInitError::SpawnError { source: e, message: format!("{} {}", exp_shell, exp_str) })
+                            WingmateInitError::SpawnError { source: e, message: format!("{} {}", exp_shell, exp_str) }
                         })?;
                     } 
                 }
@@ -56,7 +56,7 @@ pub fn start_services(ts: &mut JoinSet<Result<(), Box<dyn error::Error + Send +
                                         },
                                         result = child.wait() => {
                                             if let Err(e) = result_match(result) {
-                                                return Err(e);
+                                                return Err(WingmateInitError::ChildExit { source: e });
                                             }
                                             break 'autorestart;
                                         }
@@ -64,7 +64,7 @@ pub fn start_services(ts: &mut JoinSet<Result<(), Box<dyn error::Error + Send +
                                 },
                                 Err(e) => {
                                     if e != Errno::ESRCH {
-                                        return Err(e.into());
+                                        return Err(WingmateInitError::ChildNotFound);
                                     } else {
                                         break 'autorestart;
                                     }
@@ -76,7 +76,7 @@ pub fn start_services(ts: &mut JoinSet<Result<(), Box<dyn error::Error + Send +
                     },
                     result = child.wait() => {
                         if let Err(e) = result_match(result) {
-                            return Err(e);
+                            return Err(WingmateInitError::ChildExit { source: e });
                         }
                     },
                 }
@@ -91,14 +91,14 @@ pub fn start_services(ts: &mut JoinSet<Result<(), Box<dyn error::Error + Send +
     Ok(())
 }
 
-fn result_match(result: tokio_result<ExitStatus>) -> Result<(), Box<dyn error::Error + Send + Sync>> {
+fn result_match(result: tokio_result<ExitStatus>) -> Result<(), anyhow::Error> {
     if let Err(e) = result {
         if let Some(eos) = e.raw_os_error() {
             if eos != nix::Error::ECHILD as i32 {
-                return Err(e.into());
+                return Err(e).context("unexpected child exit status");
             }
         } else {
-            return Err(e.into());
+            return Err(e).context("unexpected child error");
         }
     }
 

src/init/daemon/waiter.rs

@@ -37,7 +37,6 @@ pub fn wait_all(flag: Arc<Mutex<bool>>, stop_sighandler: CancellationToken) {
                 }
             },
         }
-        // dbg!("sanity");
     }
 
 }

src/init/error.rs

@@ -1,9 +1,5 @@
 use thiserror::Error;
 
-use std::fmt;
-use std::error;
-
-
 #[derive(Error,Debug)]
 pub enum WingmateInitError {
     #[error("invalid config search path")]
@@ -17,38 +13,80 @@ pub enum WingmateInitError {
         #[source]
         source: std::io::Error,
         message: String,
+    },
+
+    #[error("parsing cron")]
+    Cron {
+        #[source]
+        source: CronParseError,        
+    },
+
+    #[error("looking for shell")]
+    FindShell {
+        #[source]
+        source: FindShellError,
+    },
+
+    #[error("child exited")]
+    ChildExit {
+        #[source]
+        source: anyhow::Error,
+    },
+
+    #[error("cannot find the child process")]
+    ChildNotFound,
+
+    #[error("failed to setup signal handler")]
+    Signal {
+        #[source]
+        source: std::io::Error,
+    },
+
+    #[error("no shell available")]
+    NoShellAvailable,
+
+    #[error("problem when join task")]
+    Join {
+        #[source]
+        source: tokio::task::JoinError,
+    },
+
+    #[error("tripped over")]
+    Other {
+        #[source]
+        source: anyhow::Error,
     }
 }
 
-#[derive(Debug,Clone)]
-pub struct CronSyntaxError(pub String);
+#[derive(Error,Debug)]
+pub enum CronParseError {
+    #[error("invalid cron syntax: {}", .0)]
+    InvalidSyntax(String),
     
-impl fmt::Display for CronSyntaxError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "cron syntax error at: {}", self.0)
+    #[error("cannot capture {} in \"{}\"", field_name, cron_line)]
+    FieldMatch {
+        cron_line: String,
+        field_name: String,
+    },
+
+    #[error("failed to parse {} \"{}\" in \"{}\"", field_name, matched, cron_line)]
+    Parse {
+        #[source]
+        source: anyhow::Error,
+        cron_line: String,
+        matched: String,
+        field_name: String,
     }
 }
 
-impl error::Error for CronSyntaxError {}
+#[derive(Error,Debug)]
+pub enum FindShellError {
+    #[error("shell not found")]
+    ShellNotFound,
 
-#[derive(Debug,Clone)]
-pub struct ShellNotFoundError(pub String);
-
-impl fmt::Display for ShellNotFoundError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "shell not found: {}", self.0)
+    #[error("when finding shell")]
+    Other {
+        #[source]
+        source: anyhow::Error
     }
 }
-
-impl error::Error for ShellNotFoundError {}
-
-#[derive(Debug,Clone)]
-pub struct NoShellAvailableError;
-
-impl fmt::Display for NoShellAvailableError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "no shell available")
-    }
-}
-
-impl error::Error for NoShellAvailableError {}