Commit Graph

9 Commits

Author SHA1 Message Date
Pim van Pelt
0049c2ae73 VPP reconciler: event-driven sync, pool failover, bug fixes
This commit wires the checker's state machine through to the VPP dataplane:
every backend state transition flows through a single code path that
recomputes the effective per-backend weight (with pool failover) and pushes
the result to VPP. Along the way several latent bugs in the state machine
and the sync path were fixed.

internal/vpp/reconciler.go (new)
- New Reconciler type subscribes to checker.Checker events and, on every
  transition, calls Client.SyncLBStateVIP for the affected frontend. This
  is the ONLY place in the codebase where backend state changes cause VPP
  calls — the "single path" discipline requested during design.
- Defines an EventSource interface (checker.Checker satisfies it) so the
  dependency direction stays vpp → checker; the checker never imports vpp.

internal/vpp/client.go
- Renamed ConfigSource → StateSource. The interface now has two methods:
  Config() and BackendState(name) — the reconciler and the desired-state
  builder both need live health state to compute effective weights.
- SetConfigSource → SetStateSource; internal cfgSrc field → stateSrc.
- New getStateSource() helper for internal locked access.
- lbSyncLoop still uses the state source for its periodic drift
  reconciliation; it's fully idempotent and runs the same code path as
  event-driven syncs.

internal/vpp/lbsync.go
- desiredAS grows a Flush bool so the mapping function can signal "on
  transition to weight 0, flush existing flow-table entries".
- asFromBackend is now the single source of truth for the state →
  (weight, flush) rule. Documented with a full truth table. Takes an
  activePool parameter so it can distinguish "up in active pool" from
  "up but standby".
- activePoolIndex(fe, states) implements priority failover: returns the
  index of the first pool containing any StateUp backend. pool[0] wins
  when at least one member is up; pool[1] takes over when pool[0] is
  empty; and so on. Defaults to 0 (unobservable, since all backends map
  to weight 0 when nothing is up).
- desiredFromFrontend snapshots backend states once, computes activePool,
  then walks every backend through asFromBackend. No more filtering on
  b.Enabled — disabled backends stay in the desired set so they keep
  their AS entry in VPP with weight=0. The previous filter caused delAS
  on disable, which destroyed the entry and broke enable afterwards.
- EffectiveWeights(fe, src) exported helper that returns the per-pool
  per-backend weight map for one frontend. Used by the gRPC GetFrontend
  handler and robot tests to observe failover without touching VPP.
- reconcileVIP computes flush at the weight-change call site:
    flush = desired.Flush && cur.Weight > 0 && desired.Weight == 0
  This ensures only the *transition* to disabled flushes sessions —
  steady-state syncs with already-zero weight skip the call entirely.
- setASWeight now plumbs IsFlush into lb_as_set_weight.

internal/vpp/lbsync_test.go (new)
- TestAsFromBackend: 15 cases locking down the truth table, including
  failover scenarios (up in standby pool, up promoted in pool[1]).
- TestActivePoolIndex: 8 cases covering pool[0]-has-up, pool[0]-all-down,
  all-disabled, all-paused, all-unknown, nothing-up-anywhere, and
  three-tier failover.
- TestDesiredFromFrontendFailover: 5 end-to-end scenarios wiring a fake
  StateSource through desiredFromFrontend and asserting the final
  per-IP weight map. Exercises the complete pipeline without VPP.

internal/checker/checker.go
- Added BackendState(name) (health.State, bool) — one-line method that
  satisfies vpp.StateSource. The checker is otherwise unchanged.
- EnableBackend rewritten to reuse the existing worker (parallel to
  ResumeBackend). The old code called startWorker which constructed a
  brand-new Backend via health.New, throwing away the transition
  history; the resulting 'backend-transition' log showed the bogus
  from=unknown,to=unknown. Now uses w.backend.Enable() to record a
  proper disabled→unknown transition and launches a fresh goroutine.
- Static (no-healthcheck) backends now fire their synthetic 'always up'
  pass on the first iteration of runProbe instead of sleeping 30s
  first. Previously static backends sat in StateUnknown for 30s after
  startup — useless for deterministic testing and surprising for
  operators. The fix is a simple first-iteration flag.

internal/health/state.go
- New Enable(maxHistory) method parallel to Disable. Transitions the
  backend from whatever state it's in (typically StateDisabled) to
  StateUnknown, resets the health counter to rise-1 so the expedited
  resolution kicks in on the first probe result, and emits a transition
  with code 'enabled'.

proto/maglev.proto
- PoolBackendInfo gains effective_weight: the state-aware weight that
  would be programmed into VPP (distinct from the configured weight in
  the YAML). Exposed via GetFrontend.

internal/grpcapi/server.go
- frontendToProto takes a vpp.StateSource, computes effective weights
  via vpp.EffectiveWeights, and populates PoolBackendInfo.EffectiveWeight.
- GetFrontend and SetFrontendPoolBackendWeight updated to pass the
  checker in.

cmd/maglevc/commands.go
- 'show frontends <name>' now renders every pool backend row as
    <name>  weight <cfg>  effective <eff>  [disabled]?
  so both values are always visible. The VPP-style key/value format
  avoids the ANSI-alignment pitfall we hit earlier and makes the output
  regex-parseable for robot tests.

cmd/maglevd/main.go
- Construct and start the Reconciler alongside the VPP client. Two
  extra lines, no other changes to startup.

tests/01-maglevd/maglevd-lab/maglev.yaml
- Two new static backends (static-primary, static-fallback) and a new
  failover-vip frontend with one backend per pool. No healthcheck, so
  the state machine resolves them to 'up' immediately via the synthetic
  pass. Used by the failover robot tests.

tests/01-maglevd/01-healthcheck.robot
- Three new test cases exercising pool failover end-to-end:
  1. primary up, secondary standby (initial state)
  2. disable primary → fallback takes over (effective weight flips)
  3. enable primary → fallback steps back
  All run without VPP: they scrape 'maglevc show frontends <name>' and
  regex-match the effective weight in the output. Deterministic and
  fast (~2s total) because the static backends don't probe.
- Two helper keywords: Static Backend Should Be Up and
  Effective Weight Should Be.

Net result: 16/16 robot tests pass. Backend state transitions now
flow through a single documented path (checker event → reconciler →
SyncLBStateVIP → desiredFromFrontend → asFromBackend → reconcileVIP →
setASWeight), and the pool failover / enable-after-disable / static-
backend-startup bugs are all fixed.
2026-04-12 12:40:09 +02:00
Pim van Pelt
d3c5c86037 VPP load-balancer dataplane integration: state, sync, and global conf
This commit wires maglevd through to VPP's LB plugin end-to-end, using
locally-generated GoVPP bindings for the newer v2 API messages.

VPP binapi (vendored)
- New package internal/vpp/binapi/ containing lb, lb_types, ip_types, and
  interface_types, generated from a local VPP build (~/src/vpp) via a new
  'make vpp-binapi' target. GoVPP v0.12.0 upstream lacks the v2 messages we
  need (lb_conf_get, lb_add_del_vip_v2, lb_add_del_as_v2, lb_as_v2_dump,
  lb_as_set_weight), so we commit the generated output in-tree.
- All generated files go through our loggedChannel wrapper; every VPP API
  send/receive is recorded at DEBUG via slog (vpp-api-send / vpp-api-recv /
  vpp-api-send-multi / vpp-api-recv-multi) so the full wire-level trail is
  auditable. NewAPIChannel is unexported — callers must use c.apiChannel().

Read path: GetLBState{All,VIP}
- GetLBStateAll returns a full snapshot (global conf + every VIP with its
  attached application servers).
- GetLBStateVIP looks up a single VIP by (prefix, protocol, port) and
  returns (nil, nil) when the VIP doesn't exist in VPP. This is the
  efficient path for targeted updates on a busy LB.
- Helpers factored out: getLBConf, dumpAllVIPs, dumpASesForVIP, lookupVIP,
  vipFromDetails.

Write path: SyncLBState{All,VIP}
- SyncLBStateAll reconciles every configured frontend with VPP: creates
  missing VIPs, removes stale ones (with AS flush), and reconciles AS
  membership and weights within VIPs that exist on both sides.
- SyncLBStateVIP targets a single frontend by name. Never removes VIPs.
  Returns ErrFrontendNotFound (wrapped with the name) when the frontend
  isn't in config, so callers can use errors.Is.
- Shared reconcileVIP helper does the per-VIP AS diff; removeVIP is used
  only by the full-sync pass.
- LbAddDelVipV2 requests always set NewFlowsTableLength=1024. The .api
  default=1024 annotation is only applied by VAT/CLI parsers, not wire-
  level marshalling — sending 0 caused VPP to vec_validate with mask
  0xFFFFFFFF and OOM-panic.
- Pool semantics: backends in the primary (first) pool of a frontend get
  their configured weight; backends in secondary pools get weight 0. All
  backends are installed so higher layers can flip weights on failover
  without add/remove churn.
- Every individual change emits a DEBUG slog (vpp-lbsync-vip-add/del,
  vpp-lbsync-as-add/del, vpp-lbsync-as-weight). Start/done INFO logs
  carry a scope=all|vip label plus aggregate counts.

Global conf push: SetLBConf
- New SetLBConf(cfg) sends lb_conf with ipv4-src, ipv6-src, sticky-buckets,
  and flow-timeout. Called automatically on VPP (re)connect and after
  every config reload (via doReloadConfig). Results are cached on the
  Client so redundant pushes are silently skipped — only actual changes
  produce a vpp-lb-conf-set INFO log line.

Periodic drift reconciliation
- vpp.Client.lbSyncLoop runs in a goroutine tied to each VPP connection's
  lifetime. Its first tick is immediate (startup and post-reconnect
  sync quickly); subsequent ticks fire every vpp.lb.sync-interval from
  config (default 30s). Purpose: catch drift if something/someone
  modifies VPP state by hand. The loop uses a ConfigSource interface
  (satisfied by checker.Checker via its new Config() accessor) to avoid
  an import cycle with the checker package.

Config schema additions (maglev.vpp.lb)
- sync-interval: positive Go duration, default 30s.
- ipv4-src-address: REQUIRED. Used as the outer source for GRE4 encap
  to application servers. Missing this is a hard semantic error —
  maglevd --check exits 2 and the daemon refuses to start. VPP GRE
  needs a source address and every VIP we program uses GRE, so there
  is no meaningful config without it.
- ipv6-src-address: REQUIRED. Same treatment as ipv4-src-address.
- sticky-buckets-per-core: default 65536, must be a power of 2.
- flow-timeout: default 40s, must be a whole number of seconds in [1s, 120s].
- VPP validation runs at the end of convert() so structural errors in
  healthchecks/backends/frontends surface first — operators fix those,
  then get the VPP-specific requirements.

gRPC API
- New GetVPPLBState RPC returning VPPLBState: global conf + VIPs with
  ASes. Mirrors the read-path but strips fields irrelevant to our
  GRE-only deployment (srv_type, dscp, target_port).
- New SyncVPPLBState RPC with optional frontend_name. Unset → full sync
  (may remove stale VIPs). Set → single-VIP sync (never removes).
  Returns codes.NotFound for unknown frontends, codes.Unavailable when
  VPP integration is disabled or disconnected.

maglevc (CLI)
- New 'show vpp lbstate' command displaying the LB plugin state. VPP-only
  fields the dataplane irrelevant to GRE are suppressed. Per-AS lines use
  a key-value format ("address X  weight Y  flow-table-buckets Z")
  instead of a tabwriter column, which avoids the ANSI-color alignment
  issue we hit with mixed label/data rows.
- New 'sync vpp lbstate [<name>]' command. Without a name, triggers a
  full reconciliation; with a name, targets one frontend.
- Previous 'show vpp lb' renamed to 'show vpp lbstate' for consistency
  with the new sync command.

Test fixtures
- validConfig and all ad-hoc config_test.go fixtures that reach the end
  of convert() now include the two required vpp.lb src addresses.
- tests/01-maglevd/maglevd-lab/maglev.yaml gains a vpp.lb section so the
  robot integration tests can still load the config.
- cmd/maglevc/tree_test.go gains expected paths for the new commands.

Docs
- config-guide.md: new 'vpp' section in the basic structure, detailed
  vpp.lb field reference, noting ipv4/ipv6 src addresses as REQUIRED
  (hard error) with no defaults; example config updated.
- user-guide.md: documented 'show vpp info', 'show vpp lbstate',
  'sync vpp lbstate [<name>]', new --vpp-api-addr and --vpp-stats-addr
  flags, the vpp-lb-conf-set log line, and corrected the pause/resume
  description to reflect that pause cancels the probe goroutine.
- debian/maglev.yaml: example config gains a vpp.lb block with src
  addresses and commented optional overrides.
2026-04-12 10:58:44 +02:00
Pim van Pelt
3227263d68 Add GoVPP integration and GetVPPInfo gRPC call
VPP client (internal/vpp/)
- New package managing connections to both VPP API and stats sockets,
  treated as a unit: if either drops, both are torn down and
  re-established together.
- Run() loop: connect, fetch version via vpe.ShowVersion, read
  /sys/boottime from the stats segment, log vpp-connect, then monitor
  with control_ping every 10s. On failure, disconnect both, retry
  after 5s.
- Registers as client name "vpp-maglev" (visible in VPP's
  "show api clients").
- Flags: --vpp-api-addr (default /run/vpp/api.sock) and
  --vpp-stats-addr (default /run/vpp/stats.sock). Empty api addr
  disables VPP integration entirely.

gRPC / proto
- Add GetVPPInfo RPC returning VPPInfo: version, build_date,
  build_directory, pid, boottime_ns, connecttime_ns. Both times are
  unix timestamps in nanoseconds — the client computes durations
  locally for display.
- Returns codes.Unavailable if VPP is disabled or not connected.

maglevc
- Add 'show vpp info' command displaying version, build-date,
  build-dir, vpp-pid, vpp-boottime (with duration), and connected
  time (with duration).
2026-04-11 22:03:28 +02:00
Pim van Pelt
3bd30b69f4 Refactor CLI: birdc-style help, collapsed nouns, ReloadConfig, bug fixes
maglevc
- Rewrite '?' handler (birdc-style): show full command paths from current
  position to every leaf, right-aligned help column, dynamic slot values
  displayed as an indented block when cursor is at a slot position.
- Collapse show frontends/frontend, backends/backend, healthchecks/healthcheck
  into single plural-noun nodes with an optional <name> slot. Allows
  'sh ba' (list all) and 'sh ba nginx0' (show one) without ambiguity.
- Add 'config reload' command.
- Fix tabwriter ANSI alignment: continuation lines in transition output
  now carry the same label() byte overhead as the header line.
- Fix broken Walk for 'set frontend' command: setFrontendPoolName and
  setWeightValue were fixed-word nodes that couldn't capture user input;
  mark them as slot nodes with dynNone.
- Add tree_test.go covering expandPaths, cycle detection, prefix matching,
  and the full weight-command walk.

gRPC / proto
- Add ReloadConfig RPC: checks config then applies it to the running
  checker, returning ok/parse_error/semantic_error/reload_error.
- Add logging to CheckConfig (config-check-start/config-check-done at
  INFO level).

maglevd
- SIGHUP handler now calls maglevServer.TriggerReload(), sharing the
  same code path as the gRPC ReloadConfig RPC.

docs
- Collapse show command documentation to use [<name>] optional syntax.
- Remove developer-facing 'Command tree and parser' section.
- Document 'config reload'.
2026-04-11 18:20:43 +02:00
Pim van Pelt
58391f5463 Add WatchEvents, enable/disable/weight RPCs, and config check
gRPC / proto
- Rename WatchBackendEvents → WatchEvents; return a stream of Event
  oneof (LogEvent, BackendEvent, FrontendEvent) with optional filter
  flags (log, log_level, backend, frontend)
- Add EnableBackend, DisableBackend, SetFrontendPoolBackendWeight RPCs
- Rename PauseResumeRequest → BackendRequest
- Add CheckConfig RPC returning ok/parse_error/semantic_error

maglevd
- Route slog through a LogBroadcaster (slog.Handler) so WatchEvents
  subscribers can receive structured log records independently of the
  daemon's own --log-level
- Add --reflection flag (default true) to toggle gRPC server reflection
- Add --check flag: validates config file and exits 0/1/2
- SIGHUP: use config.Check before applying reload; log parse vs semantic
  error separately; refuse reload on any error
- Rename default config path /etc/maglev → /etc/vpp-maglev

maglevc
- Add 'watch events [num <n>] [log [level <level>]] [backend] [frontend]'
  command; prints compact protojson, stops on any keypress or Ctrl-C;
  uses cbreak mode (not raw) so output post-processing is preserved
- Add 'set backend <name> enable|disable'
- Add 'set frontend <name> pool <pool> backend <name> weight <0-100>'
- Add 'config check' command

Debian packaging
- Rename service unit to vpp-maglevd.service
- Rename conffiles to /etc/default/vpp-maglev and /etc/vpp-maglev/
- Create maglevd system user/group in postinst; add to vpp group if present
- Add postrm; add adduser to Depends
2026-04-11 16:42:11 +02:00
Pim van Pelt
d612086a5f Pools, CLI, versioning, Debian packaging, HTTPS fix
- Replaced flat `backends: [...]` list on frontends with an ordered `pools:`
  list; each pool has a name and a map of backends with per-pool weights (0–100,
  default 100). Pools express priority: first pool with a healthy backend wins.
- Removed global backend weight (was on the backend, now lives in the pool).
- Config validation enforces non-empty pools, non-empty pool names, weight
  range, and consistent address families across all pools of a frontend.

- Added `PoolBackendInfo { name, weight }` and changed `PoolInfo.backends` from
  `repeated string` to `repeated PoolBackendInfo` so weights are visible over
  the API.

- Full interactive shell with readline, tab completion, and `?` inline help.
- Command tree parser (Walk) handles fixed keywords and dynamic slot nodes;
  prefix matching with exact-match priority.
- Commands: `show version/frontends/frontend/backends/backend/healthchecks/
  healthcheck`, `set backend <name> pause|resume`, `quit`/`exit`.
- `show frontend` output is hierarchical (pools → backends) with per-backend
  weights and `[disabled]` notation; pool section uses fixed-width formatting
  so ANSI color codes don't corrupt tabwriter alignment.
- `-color` flag (default true) wraps static field labels in dark-blue ANSI;
  works correctly with tabwriter because all labels carry identical-length
  escape sequences.

- `cmd/version.go` package holds `version`, `commit`, `date` vars set at build
  time via `-ldflags -X`.
- `make build` / `make build-amd64` / `make build-arm64` all inject
  `VERSION=0.1.1`, `COMMIT_HASH` (from `git rev-parse --short HEAD`), and
  `DATE` (UTC ISO-8601).
- `maglevc` prints version on interactive startup and exposes `show version`.
- `maglevd` logs version/commit/date at startup; `-version` flag prints and exits.

- `doHTTPProbe` was building a `https://` target URL even though TLS was already
  applied to the connection inside `inNetns`. `http.Transport` then wrapped the
  connection in a second TLS layer, producing "http: server gave HTTP response
  to HTTPS client". Fixed by always using `http://` in the target URL.
- Added `TestHTTPSProbe` using `httptest.NewTLSServer` to cover the full path.

- New `docs/user-guide.md`: maglevd flags/signals, maglevc commands, shell
  completion, and command-tree parser walkthrough.
- New `docs/healthchecks.md`: state machine, rise/fall model, probe intervals,
  all transition events with log examples.
- Updated `docs/config-guide.md`: pools design, removed global weight from
  backends, updated all examples.
- Updated `README.md`: packaging table, build paths, corrected binary locations
  (`/usr/sbin/maglevd`), config filename (`.yaml`).

- `debian/` directory contains `control.in`, `maglevd.service`, `default.maglev`,
  `maglev.yaml` (example config), `conffiles`, `postinst`, `prerm`.
- `debian/build-deb.sh` stages a package tree and calls `dpkg-deb`; emits
  `build/vpp-maglev_<version>~<commit>_<arch>.deb`.
- Cross-compiles for amd64 and arm64 in one `make pkg-deb` invocation.
- `maglevd` installed to `/usr/sbin/`, `maglevc` to `/usr/bin/`.
- Service reads `MAGLEV_CONFIG` from `/etc/default/maglev`
  (default: `/etc/maglev/maglev.yaml`).
- Man pages `maglevd(8)` and `maglevc(1)` live in `docs/` and are gzip'd into
  the package.
- All build output goes to `build/<arch>/`; `build/` is gitignored.
2026-04-11 12:18:17 +02:00
Pim van Pelt
ad7d7e20fc go fmt 2026-04-11 03:05:07 +02:00
Pim van Pelt
56a4a6ba25 Some output tweaks; and some additional transition events upon resume (paused->unknown->{up|down}) 2026-04-11 03:04:47 +02:00
Pim van Pelt
46e78ec36f First stab at maglevc 2026-04-11 02:48:00 +02:00