notify: preparation for the API

Signed-off-by: Lukas Wagner <l.wagner@proxmox.com>

proxmox-notify/src/api/mod.rs

@@ -0,0 +1,94 @@
+use std::error::Error as StdError;
+use std::fmt::Display;
+
+use crate::Config;
+use serde::Serialize;
+
+#[derive(Debug, Serialize)]
+pub struct ApiError {
+    /// HTTP Error code
+    code: u16,
+    /// Error message
+    message: String,
+    #[serde(skip_serializing)]
+    /// The underlying cause of the error
+    source: Option<Box<dyn StdError + Send + Sync + 'static>>,
+}
+
+impl ApiError {
+    fn new<S: AsRef<str>>(
+        message: S,
+        code: u16,
+        source: Option<Box<dyn StdError + Send + Sync + 'static>>,
+    ) -> Self {
+        Self {
+            message: message.as_ref().into(),
+            code,
+            source,
+        }
+    }
+
+    pub fn bad_request<S: AsRef<str>>(
+        message: S,
+        source: Option<Box<dyn StdError + Send + Sync + 'static>>,
+    ) -> Self {
+        Self::new(message, 400, source)
+    }
+
+    pub fn not_found<S: AsRef<str>>(
+        message: S,
+        source: Option<Box<dyn StdError + Send + Sync + 'static>>,
+    ) -> Self {
+        Self::new(message, 404, source)
+    }
+
+    pub fn internal_server_error<S: AsRef<str>>(
+        message: S,
+        source: Option<Box<dyn StdError + Send + Sync + 'static>>,
+    ) -> Self {
+        Self::new(message, 500, source)
+    }
+}
+
+impl Display for ApiError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(&format!("{} {}", self.code, self.message))
+    }
+}
+
+impl StdError for ApiError {
+    fn source(&self) -> Option<&(dyn StdError + 'static)> {
+        match &self.source {
+            None => None,
+            Some(source) => Some(&**source),
+        }
+    }
+}
+
+fn verify_digest(config: &Config, digest: Option<&[u8]>) -> Result<(), ApiError> {
+    if let Some(digest) = digest {
+        if config.digest != *digest {
+            return Err(ApiError::bad_request(
+                "detected modified configuration - file changed by other user? Try again.",
+                None,
+            ));
+        }
+    }
+
+    Ok(())
+}
+
+fn endpoint_exists(config: &Config, name: &str) -> bool {
+    let mut exists = false;
+
+    exists
+}
+
+#[cfg(test)]
+mod test_helpers {
+    use crate::Config;
+
+    pub fn empty_config() -> Config {
+        Config::new("", "").unwrap()
+    }
+}

proxmox-notify/src/lib.rs

@@ -9,6 +9,7 @@ use serde_json::Value;
 
 use std::error::Error as StdError;
 
+pub mod api;
 mod config;
 pub mod endpoints;
 pub mod schema;