package resolver import ( "fmt" "sync" "google.golang.org/grpc/resolver" ) // registry of ServerResolverBuilder. This type exists because grpc requires that // resolvers are registered globally before any requests are made. This is // incompatible with our resolver implementation and testing strategy, which // requires a different Resolver for each test. type registry struct { lock sync.RWMutex byAuthority map[string]*ServerResolverBuilder } func (r *registry) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) { r.lock.RLock() defer r.lock.RUnlock() //nolint:staticcheck res, ok := r.byAuthority[target.Authority] if !ok { //nolint:staticcheck return nil, fmt.Errorf("no resolver registered for %v", target.Authority) } return res.Build(target, cc, opts) } func (r *registry) Scheme() string { return "consul" } var _ resolver.Builder = (*registry)(nil) var reg = ®istry{byAuthority: make(map[string]*ServerResolverBuilder)} func init() { resolver.Register(reg) } // Register a ServerResolverBuilder with the global registry. func Register(res *ServerResolverBuilder) { reg.lock.Lock() defer reg.lock.Unlock() reg.byAuthority[res.Authority()] = res } // Deregister the ServerResolverBuilder associated with the authority. Only used // for testing. func Deregister(authority string) { reg.lock.Lock() defer reg.lock.Unlock() delete(reg.byAuthority, authority) }