func (l *labelWrapper) Call(ctx context.Context, req client.Request, rsp interface{}, opts ...client.CallOption) error {
md, _ := metadata.FromContext(ctx)
labels := make(map[string]string)
for k, v := range md {
if strings.HasPrefix(k, LabelPrefix) {
key := strings.TrimPrefix(k, LabelPrefix)
key = strings.ToLower(key)
labels[key] = strings.ToLower(v)
}
}
filter := func(services []*registry.Service) []*registry.Service {
var filtered []*registry.Service
SERVICE:
for _, service := range services {
// check labels for the service
for lk, lv := range labels {
// if we match then append the service and return
if v := service.Metadata[lk]; v == lv {
filtered = append(filtered, service)
continue SERVICE
}
}
var nodes []*registry.Node
NODE:
for _, node := range service.Nodes {
// check labels against the node
for lk, lv := range labels {
// if it matches then append node
if v := node.Metadata[lk]; v == lv {
nodes = append(nodes, node)
continue NODE
}
}
}
if len(nodes) > 0 {
service.Nodes = nodes
filtered = append(filtered, service)
}
}
return filtered
}
callOptions := append(opts, client.WithSelectOption(
selector.Filter(filter),
))
return l.Client.Call(ctx, req, rsp, callOptions...)
}
func (dc *dcWrapper) Call(ctx context.Context, req client.Request, rsp interface{}, opts ...client.CallOption) error {
md, _ := c.GetMetadata(ctx)
filter := func(services []*registry.Service) []*registry.Service {
for _, service := range services {
var nodes []*registry.Node
for _, node := range service.Nodes {
if node.Metadata["datacenter"] == md["datacenter"] {
nodes = append(nodes, node)
}
}
service.Nodes = nodes
}
return services
}
callOptions := append(opts, client.WithSelectOption(
selector.Filter(filter),
))
fmt.Printf("[DC Wrapper] filtering for datacenter %s\n", md["datacenter"])
return dc.Client.Call(ctx, req, rsp, callOptions...)
}