github.com/tickoalcantara12/micro/v3@v3.0.0-20221007104245-9d75b9bcbab9/service/api/resolver/subdomain/subdomain.go (about)

     1  // Copyright 2020 Asim Aslam
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     https://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  //
    15  // Original source: github.com/micro/go-micro/v3/api/resolver/subdomain/subdomain.go
    16  
    17  // Package subdomain is a resolver which uses the subdomain to determine the domain to route to. It
    18  // offloads the endpoint resolution to a child resolver which is provided in New.
    19  package subdomain
    20  
    21  import (
    22  	"net"
    23  	"net/http"
    24  	"strings"
    25  
    26  	"github.com/tickoalcantara12/micro/v3/service/api/resolver"
    27  	"github.com/tickoalcantara12/micro/v3/service/logger"
    28  	"golang.org/x/net/publicsuffix"
    29  )
    30  
    31  func NewResolver(parent resolver.Resolver, opts ...resolver.Option) resolver.Resolver {
    32  	options := resolver.NewOptions(opts...)
    33  	return &Resolver{options, parent}
    34  }
    35  
    36  type Resolver struct {
    37  	opts resolver.Options
    38  	resolver.Resolver
    39  }
    40  
    41  func (r *Resolver) Resolve(req *http.Request, opts ...resolver.ResolveOption) (*resolver.Endpoint, error) {
    42  	if dom := r.Domain(req); len(dom) > 0 {
    43  		opts = append(opts, resolver.Domain(dom))
    44  	}
    45  
    46  	return r.Resolver.Resolve(req, opts...)
    47  }
    48  
    49  func (r *Resolver) Domain(req *http.Request) string {
    50  	// determine the host, e.g. foobar.m3o.app
    51  	host := req.URL.Hostname()
    52  	if len(host) == 0 {
    53  		if h, _, err := net.SplitHostPort(req.Host); err == nil {
    54  			host = h // host does contain a port
    55  		} else if strings.Contains(err.Error(), "missing port in address") {
    56  			host = req.Host // host does not contain a port
    57  		}
    58  	}
    59  
    60  	// check for an ip address
    61  	if net.ParseIP(host) != nil {
    62  		return ""
    63  	}
    64  
    65  	// check for dev enviroment
    66  	if host == "localhost" || host == "127.0.0.1" {
    67  		return ""
    68  	}
    69  
    70  	// extract the top level domain plus one (e.g. 'myapp.com')
    71  	domain, err := publicsuffix.EffectiveTLDPlusOne(host)
    72  	if err != nil {
    73  		logger.Debugf("Unable to extract domain from %v", host)
    74  		return ""
    75  	}
    76  
    77  	// there was no subdomain
    78  	if host == domain {
    79  		return ""
    80  	}
    81  
    82  	// remove the domain from the host, leaving the subdomain, e.g. "staging.foo.myapp.com" => "staging.foo"
    83  	subdomain := strings.TrimSuffix(host, "."+domain)
    84  
    85  	// ignore the API subdomain
    86  	if subdomain == "api" {
    87  		return ""
    88  	}
    89  
    90  	// return the reversed subdomain as the namespace, e.g. "staging.foo" => "foo-staging"
    91  	comps := strings.Split(subdomain, ".")
    92  	for i := len(comps)/2 - 1; i >= 0; i-- {
    93  		opp := len(comps) - 1 - i
    94  		comps[i], comps[opp] = comps[opp], comps[i]
    95  	}
    96  	return strings.Join(comps, "-")
    97  }
    98  
    99  func (r *Resolver) String() string {
   100  	return "subdomain"
   101  }