handle precondition failed for POST

Author: ghubertpalo

docs/runbook/README.md

@@ -10,6 +10,7 @@ This page gathers the available guides to operate a Mithril network.
 |------------|------------|------------
 | **Genesis manually** | [manual-genesis](./genesis-manually/README.md) | Proceed to manual (re)genesis of the aggregator certificate chain.
 | **Era markers** | [era-markers](./era-markers/README.md) | Create and update era markers on the Cardano chain.
+| **Downloads statistics** | [downloads statistics](./statistics/README.md) | Display the number of downloads per day and per snapshot.
 | **Signer registrations monitoring** | [registrations-monitoring](./registrations-monitoring/README.md) | Gather aggregated data about signer registrations (versions, stake, ...).
 | **Update protocol parameters** | [protocol-parameters](./protocol-parameters/README.md) | Update the protocol parameters of a Mithril network.
 | **Recompute certificates hash** | [recompute-certificates-hash](./recompute-certificates-hash/README.md) | Recompute the certificates has of an aggregator.

docs/runbook/statistics/README.md

@@ -0,0 +1,14 @@
+# Statistics
+
+## Snapshot downloads per snapshot per day
+
+```sh
+$> sqlite3 -table -batch \
+       $DATA_STORES_DIRECTORY/monitoring.sqlite3 \
+       <  snapshot_downloads.sql
+```
+
+The variable `$DATA_STORES_DIRECTORY` should point to the directory where the
+databases files are stored (see files in `mithril-aggregator/config` using the
+key `data_stores_directory` to know where they are).
+

mithril-aggregator/src/http_server/routes/statistics_routes.rs

@@ -1,4 +1,3 @@
-use mithril_common::MITHRIL_SIGNER_VERSION_HEADER;
 use std::sync::Arc;
 use warp::Filter;
 
@@ -17,9 +16,6 @@ fn post_statistics(
 ) -> impl Filter<Extract = (impl warp::Reply,), Error = warp::Rejection> + Clone {
     warp::path!("statistics" / "snapshot")
         .and(warp::post())
-        .and(warp::header::optional::<String>(
-            MITHRIL_SIGNER_VERSION_HEADER,
-        ))
         .and(warp::body::json())
         .and(middlewares::with_event_transmitter(
             dependency_manager.clone(),
@@ -37,23 +33,20 @@ mod handlers {
     use crate::http_server::routes::reply;
 
     pub async fn post_snapshot_statistics(
-        signer_node_version: Option<String>,
         snapshot_message: SnapshotMessage,
         event_transmitter: Arc<TransmitterService<EventMessage>>,
     ) -> Result<impl warp::Reply, Infallible> {
-        let headers: Vec<(&str, &str)> = signer_node_version
-            .as_ref()
-            .map(|v| ("signer-node-version", v.as_str()))
-            .into_iter()
-            .collect();
-        let _ = event_transmitter.send_event_message(
+        let headers: Vec<(&str, &str)> = Vec::new();
+
+        match event_transmitter.send_event_message(
             "HTTP::statistics",
             "snapshot_downloaded",
             &snapshot_message,
             headers,
-        );
-
-        Ok(reply::empty(StatusCode::CREATED))
+        ) {
+            Err(e) => Ok(reply::internal_server_error(e)),
+            Ok(_) => Ok(reply::empty(StatusCode::CREATED)),
+        }
     }
 }
 

mithril-client/src/aggregator_client/http_client.rs

@@ -157,6 +157,7 @@ impl AggregatorHTTPClient {
     }
 
     /// Issue a POST HTTP request.
+    #[async_recursion]
     async fn post(&self, url: &str, json: &str) -> Result<Response, AggregatorHTTPClientError> {
         let request_builder = Client::new().post(url.to_owned()).json(json);
         let current_api_version = self
@@ -168,13 +169,31 @@ impl AggregatorHTTPClient {
         let request_builder =
             request_builder.header(MITHRIL_API_VERSION_HEADER, current_api_version);
 
-        request_builder
-            .send()
-            .await
-            .map_err(|e| AggregatorHTTPClientError::SubsystemError {
-                message: format!("Error while posting data '{json}' to URL '{url}'."),
+        let response = request_builder.send().await.map_err(|e| {
+            AggregatorHTTPClientError::SubsystemError {
+                message: format!("Error while POSTing data '{json}' to URL='{url}'."),
                 error: e.into(),
-            })
+            }
+        })?;
+
+        match response.status() {
+            StatusCode::OK => Ok(response),
+            StatusCode::PRECONDITION_FAILED => {
+                if self.discard_current_api_version().await.is_some()
+                    && !self.api_versions.read().await.is_empty()
+                {
+                    return self.post(url, json).await;
+                }
+
+                Err(self.handle_api_error(&response).await)
+            }
+            StatusCode::NOT_FOUND => Err(AggregatorHTTPClientError::RemoteServerLogical(format!(
+                "Url='{url} not found"
+            ))),
+            status_code => Err(AggregatorHTTPClientError::RemoteServerTechnical(format!(
+                "Unhandled error {status_code}"
+            ))),
+        }
     }
 
     /// API version error handling

mithril-client/src/lib.rs

@@ -16,3 +16,5 @@ pub mod utils;
 
 pub use entities::*;
 pub use message_adapters::{FromCertificateMessageAdapter, FromSnapshotMessageAdapter};
+
+pub const MITHRIL_CLIENT_VERSION_HEADER: &str = "client-node-version";

openapi.yaml

@@ -362,8 +362,8 @@ paths:
                 $ref: "#/components/schemas/Error"
   /statistics/snapshot:
     post:
-      summary: Increments download statistics
-      description: Increments snapshot download statistics
+      summary: Records snapshot download event
+      description: Records snapshot download event
       requestBody:
         description: Downloaded snapshot
         required: true
@@ -373,17 +373,17 @@ paths:
               $ref: "#/components/schemas/SnapshotMessage"
       responses:
         "201":
-          description: Statistic succesfully posted
+          description: Event successfully recorded
         "400":
-          description: Increments download statistics bad request
+          description: Record event bad request
           content:
             application/json:
               schema:
                 $ref: "#/components/schemas/Error"
         "412":
           description: API version mismatch
         default:
-          description: Snapshot download statistics error
+          description: Record event error
           content:
             application/json:
               schema: