hubble

Hubble is a fully distributed networking and security observability platform for cloud native workloads, built on top of Cilium and eBPF. It provides deep visibility into service communication and behavior as well as the networking infrastructure, without requiring application changes. Key capabilities described in the README: - Service dependency and communication mapping: shows which services communicate, how frequently, and the resulting service dependency graph. It can surface HTTP calls and Kafka topic consumption/production. - Operational monitoring and alerting: helps determine whether network communication is failing and why, including DNS issues, application versus network problems, and whether failures occur at layer 4 (TCP) or layer 7 (HTTP). It can report DNS resolution problems, interrupted or timed-out TCP connections, and rates of unanswered TCP SYN requests. - Application monitoring: tracks HTTP 4xx/5xx response rates for a service or across clusters, and reports latency percentiles (95th and 99th) between requests and responses, including latency between two services. - Security observability: identifies connections blocked by network policy, services accessed from outside the cluster, and which services resolved a particular DNS name. The project leverages eBPF for programmable, dynamic visibility that aims to minimize overhead while providing detailed insight where needed. The README notes that the Hubble CLI is backward compatible with all supported Cilium releases, and that only the latest CLI version is maintained. Component stability is documented as follows: Hubble CLI, Hubble Server, and Hubble Metrics are marked Stable; Hubble Relay is Stable; Hubble UI is Beta. Features highlighted include a zero-effort automatic service dependency graph at L3/L4 and L7 with a Service Map visualization, metrics and monitoring for networking behavior, network policy observation, HTTP request/response rate and latency, and DNS request/response monitoring. Flow visibility covers individual TCP connections, DNS queries, HTTP requests, Kafka communication and more. The README also documents raw flow filters using allowlist and denylist semantics, JSON-encoded FlowFilters, environment variables HUBBLE_ALLOWLIST and HUBBLE_DENYLIST, and the --print-raw-filters and --config flags for saving and reusing filter configurations. Hubble is an Apache 2.0 licensed open source project following the governance rules of the Cilium project, with community support via the Cilium Slack #hubble channel.