Wait for a hook to end before starting the next one

Not doing so may result in race conditions, hence breaking the promise
that hooks are called in sequential order.
Also, debug output has been added to the hooks.

acmed/src/hooks.rs

@@ -1,6 +1,7 @@
 use crate::config::Hook;
 use crate::errors::Error;
 use handlebars::Handlebars;
+use log::debug;
 use serde::Serialize;
 use std::fs::File;
 use std::io::prelude::*;
@@ -27,6 +28,7 @@ pub fn call_multiple<T: Serialize>(data: &T, hooks: &Vec<Hook>) -> Result<(), Er
 }
 
 pub fn call<T: Serialize>(data: &T, hook: &Hook) -> Result<(), Error> {
+    debug!("Calling hook: {}", hook.name);
     let reg = Handlebars::new();
     let mut v = vec![];
     let args = match &hook.args {
@@ -39,6 +41,8 @@ pub fn call<T: Serialize>(data: &T, hook: &Hook) -> Result<(), Error> {
         }
         None => &[],
     };
+    debug!("Hook {}: cmd: {}", hook.name, hook.cmd);
+    debug!("Hook {}: args: {:?}", hook.name, args);
     let mut cmd = Command::new(&hook.cmd)
         .args(args)
         .stdout(get_hook_output!(&hook.stdout, reg, data))
@@ -50,8 +54,15 @@ pub fn call<T: Serialize>(data: &T, hook: &Hook) -> Result<(), Error> {
         .spawn()?;
     if hook.stdin.is_some() {
         let data_in = reg.render_template(&hook.stdin.to_owned().unwrap(), data)?;
+        debug!("Hook {}: stdin: {}", hook.name, data_in);
         let stdin = cmd.stdin.as_mut().ok_or("stdin not found")?;
         stdin.write_all(data_in.as_bytes())?;
     }
+    // TODO: add a timeout
+    let status = cmd.wait()?;
+    match status.code() {
+        Some(code) => debug!("Hook {}: exited with code {}", hook.name, code),
+        None => debug!("Hook {}: exited", hook.name),
+    };
     Ok(())
 }