github.com/searKing/golang/go@v1.2.117/net/url/resolver.go (about)

     1  // Copyright 2021 The searKing Author. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package url
     6  
     7  import (
     8  	"context"
     9  	"net/url"
    10  
    11  	"github.com/searKing/golang/go/net/resolver"
    12  )
    13  
    14  // ResolveWithTarget reset Host in url.Url by resolver.Target
    15  // ResolveWithTarget always returns a new URL instance,
    16  // even if the returned URL is identical to either the
    17  // base or reference.
    18  func ResolveWithTarget(ctx context.Context, u *url.URL, target string) (*url.URL, error) {
    19  	if u == nil {
    20  		return nil, nil
    21  	}
    22  	u2 := *u
    23  	if target == "" {
    24  		return &u2, nil
    25  	}
    26  	address, err := resolver.ResolveOneAddr(ctx, target)
    27  	if err != nil {
    28  		return nil, err
    29  	}
    30  	u2.Host = address.Addr
    31  	return &u2, nil
    32  }