| ## Structured logging with Elastic Stack 8 | |
| ### Overview | |
| * application logging | |
| * produces log events with newline-delimited JSON (ndjson) according to the Elastic Common Schema | |
| * ElasticSearch ingress (ElasticSearch, Kibana, Fleet) | |
| * the Fleet server, Kibana and ElasticSearch all run on a single machine. | |
| * each application server node has Elastic Agent installed, deployed and managed by the Fleet Server. | |
| * the Fleet **agent policy** specifies the following centrally manged integrations: | |
| * "Docker Metrics & Logs" | |
| * "Elastic Agent" | |
| * "System" | |
| ### Application Logging | |
| * JSON structured logging (newline delimited JSON) - one entry per newline | |
| * Log4J2 with JsonTemplateLayout and a modified version of EcsLayout.json (Elastic Common Schema) | |
| * fields are defined in vcell-util/src/main/resources/VCellEcsLayout.json). | |
| * TODO (short term): use logging context to populate metadata (e.g. user, simid) during transactions | |
| * TODO (longer term): introduce tracing context (e.g. OpenTelemetry) with trace/span ids added to logging context. | |
| ### Fleet configuration (for elastic agents) | |
| 1. **Elastic Agent installation** (start new elastic-agent with ```--insecure``` switch if the Fleet server uses an untrusted root cert.) | |
| 3. **"Docker Metrics & Logs" integration** (under "Collect Docker container logs" -> "Additional parsers configuration") | |
| ```yaml | |
| - ndjson: | |
| target: "" | |
| overwrite_keys: true | |
| add_error_key: true | |
| ``` | |