Files
restic-manager/internal/server/http/host_bandwidth_push.go
T
steve cdf88c6dc3 agent+server: apply host bandwidth caps to restic invocations
P2R-13a. restic.Env gains LimitUploadKBps/LimitDownloadKBps which are
emitted as global --limit-upload/--limit-download flags before the
subcommand on every invocation. Agent dispatcher tracks host-wide
caps received via config.update; server pushes them on hello and
after PUT /api/hosts/{id}/bandwidth.

Also extends api.CommandRunPayload with optional per-job overrides
(BandwidthUpKBps/Down + PreHook/PostHook); the override consumers
land in T2/T6.
2026-05-04 10:38:34 +01:00

79 lines
2.8 KiB
Go

// host_bandwidth_push.go — server → agent fan-out of host-wide
// bandwidth caps via config.update.
//
// Two entry points: pushBandwidthOnHello (called from onAgentHello,
// always pushes the current state so the agent picks up edits made
// while it was offline) and pushBandwidthToAgent (called after the
// PUT bandwidth handler succeeds, so an online agent re-arms within
// seconds).
//
// We always send pointer fields (zero-valued when uncapped) so the
// agent can distinguish "no change" (nil → field absent on the wire)
// from "explicitly cleared" (non-nil zero pointer). See
// api.ConfigUpdatePayload doc for the wire semantics.
package http
import (
"context"
"log/slog"
"time"
"gitea.dcglab.co.uk/steve/restic-manager/internal/api"
"gitea.dcglab.co.uk/steve/restic-manager/internal/server/ws"
)
// pushBandwidthOnHello ships the host's current bandwidth caps as a
// config.update on the supplied conn. Silent no-op on lookup error.
func (s *Server) pushBandwidthOnHello(ctx context.Context, hostID string, conn *ws.Conn) {
host, err := s.deps.Store.GetHost(ctx, hostID)
if err != nil {
slog.Warn("on-hello: load host for bandwidth", "host_id", hostID, "err", err)
return
}
payload := bandwidthPayload(host.BandwidthUpKBps, host.BandwidthDownKBps)
env, err := api.Marshal(api.MsgConfigUpdate, "", payload)
if err != nil {
slog.Error("on-hello: marshal bandwidth config.update", "host_id", hostID, "err", err)
return
}
sendCtx, cancel := context.WithTimeout(ctx, 5*time.Second)
defer cancel()
if err := conn.Send(sendCtx, env); err != nil {
slog.Warn("on-hello: send bandwidth config.update", "host_id", hostID, "err", err)
}
}
// pushBandwidthToAgent ships the supplied caps via the hub. Caller is
// expected to check Hub.Connected first when it matters.
func (s *Server) pushBandwidthToAgent(ctx context.Context, hostID string, up, down *int) error {
env, err := api.Marshal(api.MsgConfigUpdate, "", bandwidthPayload(up, down))
if err != nil {
return err
}
sendCtx, cancel := context.WithTimeout(ctx, 5*time.Second)
defer cancel()
return s.deps.Hub.Send(sendCtx, hostID, env)
}
// bandwidthPayload builds a ConfigUpdatePayload with only the
// bandwidth fields populated. Pointers are passed through verbatim;
// callers wanting to clear a cap should pass a non-nil pointer to 0.
// On the on-hello path we materialize zero-valued pointers when the
// host record has no cap set, so the agent's stored state is always
// in sync (rather than retaining whatever value it last received).
func bandwidthPayload(up, down *int) api.ConfigUpdatePayload {
zero := 0
upPtr := up
if upPtr == nil {
upPtr = &zero
}
downPtr := down
if downPtr == nil {
downPtr = &zero
}
return api.ConfigUpdatePayload{
BandwidthUpKBps: upPtr,
BandwidthDownKBps: downPtr,
}
}