Add JSON parsing from executables

Cargo.lock

@@ -431,6 +431,7 @@ dependencies = [
  "log 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "percent-encoding 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.116 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_json 1.0.57 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_yaml 0.8.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "simple_logger 1.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",

Cargo.toml

@@ -15,6 +15,7 @@ actix-rt = "1.1"
 dirs = "3.0"
 serde = "1.0"
 serde_yaml = "0.8"
+serde_json = "1.0"
 handlebars = "3.5"
 hotwatch = "0.4"
 percent-encoding = "2.1"

bunbun.default.yaml

@@ -17,11 +17,15 @@ default_route: "g"
 # defined route is used.
 #
 # You may provide an (absolute, recommended) path to an executable file to out-
-# source route resolution to a program. The program will receive one argument
-# only, which is the entire string provided from the user after matching the
-# route. It is up to the out-sourced program to parse the arguments and to
-# interpret those arguments. These programs should print one line to standard
-# out, which should be a fully resolved URL to lead the user to.
+# source route resolution to a program. The program will receive the arguments
+# as space-separated words, without any shell parsing.
+#
+# These programs must return a JSON object with either one of the following
+# key-value pairs:
+#  - "redirect": "some-path-to-redirect-to.com"
+#  - "body": The actual body to return.
+# For example, to return a page that only prints out `3`, the function should
+# return `{"redirect": "3"}`.
 #
 # These programs must be developed defensively, as they accept arbitrary user
 # input. Improper handling of user input can easily lead to anywhere from simple

src/error.rs

@@ -12,6 +12,7 @@ pub enum BunBunError {
   InvalidConfigPath(std::path::PathBuf, std::io::Error),
   ConfigTooLarge(u64),
   ZeroByteConfig,
+  JsonParse(serde_json::Error),
 }
 
 impl Error for BunBunError {}
@@ -29,7 +30,8 @@ impl fmt::Display for BunBunError {
         write!(f, "Failed to access {:?}: {}", path, reason)
       }
       Self::ConfigTooLarge(size) => write!(f, "The config file was too large ({} bytes)! Pass in --large-config to bypass this check.", size),
-      Self::ZeroByteConfig => write!(f, "The config provided reported a size of 0 bytes. Please check your config path!")
+      Self::ZeroByteConfig => write!(f, "The config provided reported a size of 0 bytes. Please check your config path!"),
+      Self::JsonParse(e) => e.fmt(f),
     }
   }
 }
@@ -50,3 +52,4 @@ from_error!(std::io::Error, Io);
 from_error!(serde_yaml::Error, Parse);
 from_error!(hotwatch::Error, Watch);
 from_error!(log::SetLoggerError, LoggerInit);
+from_error!(serde_json::Error, JsonParse);

src/routes.rs

@@ -101,18 +101,18 @@ pub async fn hop(
           route_type: RouteType::External,
           path,
           ..
-        } => Ok(path.to_owned().into_bytes()),
+        } => Ok(HopAction::Redirect(path.clone())),
       };
 
       match resolved_template {
-        Ok(path) => HttpResponse::Found()
+        Ok(HopAction::Redirect(path)) => HttpResponse::Found()
           .header(
             header::LOCATION,
             req
               .app_data::<Handlebars>()
               .unwrap()
               .render_template(
-                std::str::from_utf8(&path).unwrap(),
+                std::str::from_utf8(path.as_bytes()).unwrap(),
                 &template_args::query(
                   utf8_percent_encode(&args, FRAGMENT_ENCODE_SET).to_string(),
                 ),
@@ -120,6 +120,7 @@ pub async fn hop(
               .unwrap(),
           )
           .finish(),
+        Ok(HopAction::Body(body)) => HttpResponse::Ok().body(body),
         Err(e) => {
           error!("Failed to redirect user for {}: {}", path, e);
           HttpResponse::InternalServerError().body("Something went wrong :(\n")
@@ -203,15 +204,24 @@ fn check_route(route: &Route, arg_count: usize) -> bool {
   true
 }
 
+#[derive(Deserialize, Debug, PartialEq, Eq)]
+#[serde(rename_all = "snake_case")]
+enum HopAction {
+  Redirect(String),
+  Body(String),
+}
+
 /// Runs the executable with the user's input as a single argument. Returns Ok
 /// so long as the executable was successfully executed. Returns an Error if the
 /// file doesn't exist or bunbun did not have permission to read and execute the
 /// file.
-fn resolve_path(path: PathBuf, args: &str) -> Result<Vec<u8>, BunBunError> {
-  let output = Command::new(path.canonicalize()?).arg(args).output()?;
+fn resolve_path(path: PathBuf, args: &str) -> Result<HopAction, BunBunError> {
+  let output = Command::new(path.canonicalize()?)
+    .args(args.split(" "))
+    .output()?;
 
   if output.status.success() {
-    Ok(output.stdout)
+    Ok(serde_json::from_slice(&output.stdout[..])?)
   } else {
     error!(
       "Program exit code for {} was not 0! Dumping standard error!",
@@ -359,7 +369,7 @@ mod check_route {
 
 #[cfg(test)]
 mod resolve_path {
-  use super::resolve_path;
+  use super::{resolve_path, HopAction};
   use std::env::current_dir;
   use std::path::PathBuf;
 
@@ -370,7 +380,9 @@ mod resolve_path {
 
   #[test]
   fn valid_path_returns_ok() {
-    assert!(resolve_path(PathBuf::from("/bin/echo"), "hello").is_ok());
+    assert!(
+      resolve_path(PathBuf::from("/bin/echo"), r#"{"body": "a"}"#).is_ok()
+    );
   }
 
   #[test]
@@ -379,7 +391,7 @@ mod resolve_path {
     let nest_level = current_dir().unwrap().ancestors().count() - 1;
     let mut rel_path = PathBuf::from("../".repeat(nest_level));
     rel_path.push("./bin/echo");
-    assert!(resolve_path(rel_path, "hello").is_ok());
+    assert!(resolve_path(rel_path, r#"{"body": "a"}"#).is_ok());
   }
 
   #[test]
@@ -399,4 +411,20 @@ mod resolve_path {
     // cat-ing a folder always returns exit code 1
     assert!(resolve_path(PathBuf::from("/bin/cat"), "/").is_err());
   }
+
+  #[test]
+  fn return_body() {
+    assert_eq!(
+      resolve_path(PathBuf::from("/bin/echo"), r#"{"body": "a"}"#).unwrap(),
+      HopAction::Body("a".to_string())
+    );
+  }
+
+  #[test]
+  fn return_redirect() {
+    assert_eq!(
+      resolve_path(PathBuf::from("/bin/echo"), r#"{"redirect": "a"}"#).unwrap(),
+      HopAction::Redirect("a".to_string())
+    );
+  }
 }