‘How to build pluggable libraries in Go’

What is go buildmode=plugin?

Because we want to implement a pluggable library called cache Cache， Therefore, we need to implement this interface. We can implement this interface anywhere, even in a separate repository. In this example, I created two implementations: one using memory caching and the other using Redis, both in separate repositories.

In-Memory Cache Plugin

package mainimport (
 "context"
 "log/slog"
 "sync"
 "time" "github.com/josestg/yt-go-plugin/cache"
)// Value represents a cache entry.
type Value struct {
 Data  string
 ExpAt time.Time
}// Memcache is a simple in-memory cache.
type Memcache struct {
 mu    sync.RWMutex
 log   *slog.Logger
 store map[string]Value
}// Factory is the symbol the plugin loader will try to load. It must implement the cache.Factory signature.
var Factory cache.Factory = New// New creates a new Memcache instance.
func New(log *slog.Logger) (cache.Cache, error) {
 log.Info("[plugin/memcache] loaded")
 c := &Memcache{
  mu:    sync.RWMutex{},
  log:   log,
  store: make(map[string]Value),
 }
 return c, nil
}func (m *Memcache) Set(ctx context.Context, key, val string, exp time.Duration) error {
 m.log.InfoContext(ctx, "[plugin/memcache] set", "key", key, "val", val, "exp", exp)
 m.mu.Lock()
 m.log.DebugContext(ctx, "[plugin/memcache] lock acquired")
 defer func() {
  m.mu.Unlock()
  m.log.DebugContext(ctx, "[plugin/memcache] lock released")
 }() m.store[key] = Value{
  Data:  val,
  ExpAt: time.Now().Add(exp),
 } return nil
}func (m…