// Package subdomain is a resolver which uses the subdomain to determine the domain to route to. It // offloads the endpoint resolution to a child resolver which is provided in New. package subdomain import ( "net" "net/http" "strings" "github.com/micro/go-micro/v2/api/resolver" "github.com/micro/go-micro/v2/logger" "golang.org/x/net/publicsuffix" ) func NewResolver(parent resolver.Resolver, opts ...resolver.Option) resolver.Resolver { options := resolver.NewOptions(opts...) return &Resolver{options, parent} } type Resolver struct { opts resolver.Options resolver.Resolver } func (r *Resolver) Resolve(req *http.Request, opts ...resolver.ResolveOption) (*resolver.Endpoint, error) { if dom := r.Domain(req); len(dom) > 0 { opts = append(opts, resolver.Domain(dom)) } return r.Resolver.Resolve(req, opts...) } func (r *Resolver) Domain(req *http.Request) string { // determine the host, e.g. foobar.m3o.app host := req.URL.Hostname() if len(host) == 0 { if h, _, err := net.SplitHostPort(req.Host); err == nil { host = h // host does contain a port } else if strings.Contains(err.Error(), "missing port in address") { host = req.Host // host does not contain a port } } // check for an ip address if net.ParseIP(host) != nil { return "" } // check for dev enviroment if host == "localhost" || host == "127.0.0.1" { return "" } // extract the top level domain plus one (e.g. 'myapp.com') domain, err := publicsuffix.EffectiveTLDPlusOne(host) if err != nil { logger.Debugf("Unable to extract domain from %v", host) return "" } // there was no subdomain if host == domain { return "" } // remove the domain from the host, leaving the subdomain, e.g. "staging.foo.myapp.com" => "staging.foo" subdomain := strings.TrimSuffix(host, "."+domain) // return the reversed subdomain as the namespace, e.g. "staging.foo" => "foo-staging" comps := strings.Split(subdomain, ".") for i := len(comps)/2 - 1; i >= 0; i-- { opp := len(comps) - 1 - i comps[i], comps[opp] = comps[opp], comps[i] } return strings.Join(comps, "-") } func (r *Resolver) String() string { return "subdomain" }