## Summary
Closes#15
When `logging.json: true` (or `DLC_LOGGING_JSON=true`), the logger was unconditionally initialised to console/text format at the top of `LoadConfig()`, so early log lines — most visibly **"Config file loaded"** — were always written as human-readable text regardless of configuration.
## Root cause
Classic chicken-and-egg: the format flag lives inside the config that is being loaded. The format-switch block only ran *after* `v.Unmarshal()`, too late for the config-file log.
## Changes
### `pkg/config/config.go`
- Add `peekJSONLogging()`: resolves the JSON flag **before** any log is emitted by (1) checking `DLC_LOGGING_JSON` directly via `os.Getenv`, then (2) doing a minimal throwaway Viper pre-read of the config file for the `logging.json` key. This mirrors Viper's own priority order without parsing the full config twice.
- Apply the resolved format immediately and emit **"Logging configured"** as the very first log line.
- Remove the now-redundant format-switch block that ran after `Unmarshal()`.
### `scripts/start-server.sh`, `test-graceful-shutdown.sh`, `test-opentelemetry.sh`
- Replace hardcoded `PROJECT_DIR` path with a dynamic `SCRIPTS_DIR=$(dirname $(realpath ${BASH_SOURCE[0]}))` derivation so scripts work from any worktree or clone location.
## Test plan
- [x] `go test ./pkg/...` — all pass
- [x] `scripts/test-graceful-shutdown.sh` — all JSON valid, all startup logs present
- [x] Manual smoke test: first line is `{"level":"info",...,"message":"Logging configured"}`, every line is valid JSON
Reviewed-on: #16
Co-authored-by: Gabriel Radureau <arcodange@gmail.com>
Co-committed-by: Gabriel Radureau <arcodange@gmail.com>
Implement readiness endpoint (/api/ready) that returns:
- {"ready":true} (HTTP 200) during normal operation
- {"ready":false} (HTTP 503) during graceful shutdown
Key changes:
- Added readiness context to control readiness state
- Modified server.NewServer() to accept readiness context
- Implemented handleReadiness() with context-aware logic
- Updated cmd/server/main.go to manage readiness state
- Readiness set to false when shutdown signal received
- Updated test script to validate readiness behavior
- Added comprehensive documentation for readiness endpoint
This allows Kubernetes/service meshes to stop routing traffic
to the pod during graceful shutdown while allowing existing
requests to complete. Health endpoint continues to return
happy status during shutdown for proper orchestration.
- Added signal.NotifyContext for modern signal handling in cmd/server/main.go
- Implemented BaseContext for proper context propagation to HTTP handlers
- Added readiness drain delay before shutdown for graceful degradation
- Fixed PID detection in start-server.sh to target actual server process
- Added Logging.JSON configuration option with DLC_LOGGING_JSON environment variable
- Created comprehensive test script that validates entire server lifecycle
- Updated documentation with JSON logging configuration examples
- All shutdown logs now appear correctly in JSON format
- Server terminates gracefully on SIGTERM with proper log flushing
The graceful shutdown implementation follows VictoriaMetrics best practices:
1. Catches termination signals (SIGTERM, SIGINT)
2. Stops accepting new requests but allows ongoing requests to complete
3. Waits for active requests to finish within configured timeout
4. Releases resources and performs cleanup
5. Logs all shutdown steps for observability
Test script validates:
- Server startup and API functionality
- Graceful shutdown sequence
- JSON log format validation
- Complete log sequence verification
- Proper signal handling and context propagation
Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>
