Files
memby/server/internal/api/update.go
T
ponzischeme89andClaude Opus 5 62f6345a40 Server-controlled app updates, optional or forced
The gateway decides whether a TV may keep running its current build.
Clients send X-Memby-Version on every request and ask GET /v1/update on
each launch; the verdict is none, optional or mandatory.

- internal/appupdate holds the decision as pure, tested logic: below
  minimumVersion is mandatory, below latestVersion is optional.
- Admin page gains an App updates section — latest version, APK URL,
  notes, and a "Require this update" toggle that sets the forced floor.
- Client shows a dismissable prompt for optional, and a full-screen
  panel that swallows Back for mandatory. Instructions say what the
  system installer will ask before it asks.

Two safeguards: a client that cannot report its version is never forced,
and the client ignores a verdict with no download URL, so a
half-configured policy cannot produce an unblockable screen with a dead
button. An unreachable gateway shows nothing.

The verdict is deliberately not part of /v1/home: that payload is cached
per user, while this answer depends on the requesting client's version.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-27 08:34:04 +12:00

75 lines
2.1 KiB
Go

package api
import (
"context"
"net/http"
"strings"
"sync"
"time"
"github.com/ponzischeme89/memby/server/internal/appupdate"
"github.com/ponzischeme89/memby/server/internal/store"
)
// updatePolicyCache keeps the policy in memory. It is read on every home request, and a
// database round trip per home load to answer "nothing to say" would be wasteful.
type updatePolicyCache struct {
mu sync.RWMutex
value appupdate.Policy
}
func (c *updatePolicyCache) get() appupdate.Policy {
c.mu.RLock()
defer c.mu.RUnlock()
return c.value
}
func (c *updatePolicyCache) set(value appupdate.Policy) {
c.mu.Lock()
defer c.mu.Unlock()
c.value = value
}
// LoadUpdatePolicy primes the cached policy. Called at boot and after every change.
func (s *Server) LoadUpdatePolicy(ctx context.Context) error {
policy, err := s.store.UpdatePolicy(ctx)
if err != nil {
return err
}
s.updatePolicy.set(policy)
return nil
}
// WatchUpdatePolicy re-reads the policy periodically, so a change made directly in the
// database is picked up without a restart.
func (s *Server) WatchUpdatePolicy(ctx context.Context, interval time.Duration) {
ticker := time.NewTicker(interval)
defer ticker.Stop()
for {
select {
case <-ctx.Done():
return
case <-ticker.C:
if err := s.LoadUpdatePolicy(ctx); err != nil {
s.log.Warn("update policy refresh failed", "error", err)
}
}
}
}
// clientVersion reads the version a TV reports. Absent means an older build that predates
// the header — [appupdate.Decide] treats that as "say nothing".
func clientVersion(r *http.Request) string {
return strings.TrimSpace(r.Header.Get("X-Memby-Version"))
}
// handleUpdate answers the client's version check.
//
// Its own endpoint rather than a field on /v1/home: the home payload is cached per user,
// while this answer depends on the requesting client's version, so the two cannot share a
// cache entry. It costs nothing — the policy is held in memory.
func (s *Server) handleUpdate(w http.ResponseWriter, r *http.Request, _ store.Session) {
decision := appupdate.Decide(s.updatePolicy.get(), clientVersion(r))
writeJSON(w, http.StatusOK, decision)
}