Improve tracing (#1318)

* Add opentelemetry OTLP export support
* Rewrite top-level HTTP request handler - fix instrumentation
* Flush spans before shutdown
* Use OT "semantic conventions" for common fields

commit-id:4f45746e

Author: vlad-ivanov-name

Cargo.lock

@@ -229,7 +229,7 @@ pub fn get_change_id(commit: &git2::Commit, sha: git2::Oid) -> Change {
     change
 }
 
-#[tracing::instrument(skip(transaction))]
+#[tracing::instrument(level = tracing::Level::TRACE, skip(transaction))]
 pub fn filter_commit(
     transaction: &cache::Transaction,
     filterobj: filter::Filter,

josh-core/src/lib.rs

@@ -44,3 +44,5 @@ tempdir = "0.3.7"
 gix = { workspace = true }
 juniper = { workspace = true }
 git2 = { workspace = true }
+opentelemetry-semantic-conventions = "0.14.0"
+opentelemetry-otlp = "0.13.0"