tcptop/.planning/milestones/v1.0-phases/01-data-pipeline/01-01-SUMMARY.md

phase, plan, subsystem, tags, requires, provides, affects, tech-stack, key-files, key-decisions, patterns-established, requirements-completed, duration, completed

phase	plan	subsystem	tags	requires	provides	affects	tech-stack	key-files	key-decisions	patterns-established	requirements-completed	duration	completed
01-data-pipeline	01	infra	rust aya ebpf workspace repr-c ringbuf		Aya eBPF workspace with three crates (tcptop, tcptop-common, tcptop-ebpf) Shared types (TcptopEvent, DataEvent, StateEvent) with repr(C) union layout NetworkCollector platform abstraction trait with mpsc channel pattern Privilege check (root or CAP_BPF+CAP_PERFMON, exit code 77) ConnectionRecord and ConnectionKey model types eBPF build pipeline via aya-build in build.rs	01-02 01-03 02-tui 04-macos	added patterns aya aya-build aya-ebpf tokio clap anyhow thiserror nix async-trait signal-hook aya-build in build.rs (not xtask) platform-conditional deps repr(C) union for kernel-userspace shared types	created modified Cargo.toml rust-toolchain.toml .cargo/config.toml tcptop/Cargo.toml tcptop/build.rs tcptop/src/main.rs tcptop/src/privilege.rs tcptop/src/collector/mod.rs tcptop/src/collector/linux.rs tcptop/src/model.rs tcptop-common/Cargo.toml tcptop-common/src/lib.rs tcptop-ebpf/Cargo.toml tcptop-ebpf/src/main.rs	aya-build API takes Package structs and Toolchain enum, not string slices -- adapted build.rs accordingly procfs, aya, aya-log are Linux-only target deps to allow macOS development build.rs ignores eBPF compilation failure (let _ =) to allow development without bpf-linker	Platform-conditional dependencies: cfg(target_os = linux) for kernel-specific crates Shared types use #[repr(C)] with only primitive fields, union for tagged event data NetworkCollector trait uses async-trait + mpsc::Sender<CollectorEvent> pattern	PLAT-01 PLAT-03 OPS-01 OPS-02	3min	2026-03-21

Phase 01 Plan 01: Workspace Scaffold Summary

Aya eBPF three-crate workspace with repr(C) union shared types, privilege check (exit 77), and NetworkCollector platform trait

Performance

• Duration: 3 min
• Started: 2026-03-21T23:08:54Z
• Completed: 2026-03-21T23:12:13Z
• Tasks: 2
• Files modified: 14

Accomplishments

• Three-crate Aya workspace compiles (userspace + common crates verified, eBPF crate skeleton ready)
• All shared types defined with #[repr(C)] union layout and IPv6-ready [u8; 16] address fields
• Privilege check exits with code 77 and exact error message per D-09/D-10/D-11
• NetworkCollector trait defined with async start/stop and mpsc channel pattern per PLAT-03
• ConnectionRecord model has all required fields for DATA-01 through DATA-07

Task Commits

Each task was committed atomically:

1. Task 1: Create Aya workspace with shared types and eBPF build pipeline - 554aadb (feat)
2. Task 2: Implement privilege check and platform abstraction trait - 006abca (feat)

Files Created/Modified

• Cargo.toml - Workspace root with three members and shared dependencies
• rust-toolchain.toml - Pinned nightly-2026-01-15 with bpfel-unknown-none target
• .cargo/config.toml - Minimal build config (aya-build handles eBPF target)
• tcptop/Cargo.toml - Userspace crate with platform-conditional Linux deps
• tcptop/build.rs - aya-build integration for eBPF compilation
• tcptop/src/main.rs - Entry point with privilege check
• tcptop/src/privilege.rs - Root/CAP_BPF+CAP_PERFMON check, exit code 77
• tcptop/src/collector/mod.rs - NetworkCollector trait and CollectorEvent enum
• tcptop/src/collector/linux.rs - Placeholder for Linux eBPF collector (Plan 02)
• tcptop/src/model.rs - ConnectionRecord, ConnectionKey, Protocol, TcpState types
• tcptop-common/Cargo.toml - no_std compatible shared types crate
• tcptop-common/src/lib.rs - TcptopEvent, DataEvent, StateEvent, TcptopEventData union
• tcptop-ebpf/Cargo.toml - eBPF kernel program crate
• tcptop-ebpf/src/main.rs - eBPF skeleton with RingBuf map declaration

Decisions Made

• aya-build 0.1.3 API takes Package structs and Toolchain enum, not string slices as the plan assumed -- adapted build.rs to match actual API
• Made procfs, aya, and aya-log Linux-only target dependencies (cfg(target_os = "linux")) since procfs fails to compile on macOS
• build.rs uses let _ = to ignore eBPF build failures, allowing development without bpf-linker installed

Deviations from Plan

Auto-fixed Issues

1. [Rule 3 - Blocking] Fixed aya-build API mismatch

• Found during: Task 1 (workspace creation)
• Issue: Plan specified aya_build::build_ebpf(&["tcptop-ebpf"]) but actual API requires Package structs and a Toolchain argument
• Fix: Updated build.rs to use Package { name, root_dir, ..Default::default() } and Toolchain::default()
• Files modified: tcptop/build.rs
• Verification: cargo check -p tcptop succeeds
• Committed in: 554aadb (Task 1 commit)

2. [Rule 3 - Blocking] Made procfs/aya Linux-only dependencies

• Found during: Task 1 (workspace creation)
• Issue: procfs crate fails to compile on macOS with "unsupported platform" build script error
• Fix: Moved procfs, aya, and aya-log to [target.'cfg(target_os = "linux")'.dependencies]
• Files modified: tcptop/Cargo.toml
• Verification: cargo check -p tcptop succeeds on macOS
• Committed in: 554aadb (Task 1 commit)

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Total deviations: 2 auto-fixed (2 blocking issues) Impact on plan: Both fixes necessary for compilation. No scope creep.

Issues Encountered

None beyond the auto-fixed deviations above.

User Setup Required

None - no external service configuration required.

Next Phase Readiness

• Workspace structure ready for Plan 02 (Linux eBPF collector implementation)
• NetworkCollector trait defined and ready for implementation
• Shared types locked and ready for use in eBPF kprobe programs
• bpf-linker will be needed on Linux for eBPF crate compilation in Plan 02

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Phase: 01-data-pipeline Completed: 2026-03-21