README
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net.Resolver instances with caching, opportunistic encryption, and DNS over TLS/HTTPS
Documentation
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Overview ¶
Package dns provides net.Resolver instances implementing caching, opportunistic encryption, and DNS over TLS/HTTPS.
To replace the net.DefaultResolver with a caching DNS over HTTPS instance using the Google Public DNS resolver:
net.DefaultResolver = dns.NewDoHResolver( "https://dns.google/dns-query", dns.DoHCache())
Index ¶
- Constants
- Variables
- func NewCachingResolver(parent *net.Resolver, options ...CacheOption) *net.Resolver
- func NewDoHResolver(uri string, options ...DoHOption) (*net.Resolver, error)
- func NewDoTResolver(server string, options ...DoTOption) (*net.Resolver, error)
- type CacheOption
- type DialFunc
- type DoHOption
- type DoTOption
Examples ¶
Constants ¶
const DefaultMaxCacheEntries = 150
Variables ¶
var OpportunisticResolver = &net.Resolver{ Dial: opportunisticDial, PreferGo: true, }
OpportunisticResolver opportunistically tries encrypted DNS over TLS using the local resolver.
Functions ¶
func NewCachingResolver ¶
func NewCachingResolver(parent *net.Resolver, options ...CacheOption) *net.Resolver
NewCachingResolver creates a caching net.Resolver that uses parent to resolve names.
Example ¶
resolver := dns.NewCachingResolver(nil)
ips, _ := resolver.LookupIPAddr(context.TODO(), "one.one.one.one")
for _, ip := range ips {
fmt.Println(ip.String())
}
Output: 1.1.1.1 1.0.0.1 2606:4700:4700::1111 2606:4700:4700::1001
func NewDoHResolver ¶
NewDoHResolver creates a DNS over HTTPS resolver. The uri may be an URI Template.
Example ¶
resolver, err := dns.NewDoHResolver("https://dns.google/dns-query{?dns}")
if err != nil {
log.Fatal(err)
}
ips, _ := resolver.LookupIPAddr(context.TODO(), "dns.google")
for _, ip := range ips {
fmt.Println(ip.String())
}
Output: 8.8.8.8 8.8.4.4 2001:4860:4860::8888 2001:4860:4860::8844
func NewDoTResolver ¶
NewDoTResolver creates a DNS over TLS resolver. The server can be an IP address, a host name, or a network address of the form "host:port".
Example ¶
resolver, err := dns.NewDoTResolver("dns.google")
if err != nil {
log.Fatal(err)
}
ips, _ := resolver.LookupIPAddr(context.TODO(), "dns.google")
for _, ip := range ips {
fmt.Println(ip.String())
}
Output: 8.8.8.8 8.8.4.4 2001:4860:4860::8888 2001:4860:4860::8844
Types ¶
type CacheOption ¶
type CacheOption interface {
// contains filtered or unexported methods
}
A CacheOption customizes the resolver cache.
func MaxCacheEntries ¶
func MaxCacheEntries(n int) CacheOption
MaxCacheEntries sets the maximum number of entries to cache. If zero, DefaultMaxCacheEntries is used; negative means no limit.
func MaxCacheTTL ¶
func MaxCacheTTL(d time.Duration) CacheOption
MaxCacheTTL sets the maximum time-to-live for entries in the cache.
func MinCacheTTL ¶
func MinCacheTTL(d time.Duration) CacheOption
MinCacheTTL sets the minimum time-to-live for entries in the cache.
func NegativeCache ¶ added in v1.2.2
func NegativeCache(b bool) CacheOption
NegativeCache sets whether to cache negative responses.
type DialFunc ¶
DialFunc is a net.Resolver.Dial function.
func NewCachingDialer ¶
func NewCachingDialer(parent DialFunc, options ...CacheOption) DialFunc
NewCachingDialer adds caching to a net.Resolver.Dial function.
type DoHOption ¶
type DoHOption interface {
// contains filtered or unexported methods
}
A DoHOption customizes the DNS over HTTPS resolver.
func DoHAddresses ¶
DoHAddresses sets the network addresses of the resolver. These should be IP addresses, or network addresses of the form "IP:port". This avoids having to resolve the resolver's addresses, improving performance and privacy.
Example ¶
dns.NewDoHResolver("https://dns.google/dns-query{?dns}",
dns.DoHAddresses("8.8.8.8", "8.8.4.4", "2001:4860:4860::8888", "2001:4860:4860::8844"),
dns.DoHCache())
Output:
func DoHCache ¶
func DoHCache(options ...CacheOption) DoHOption
DoHCache adds caching to the resolver, with the given options.
func DoHTransport ¶
DoHTransport sets the http.Transport used by the resolver.
type DoTOption ¶
type DoTOption interface {
// contains filtered or unexported methods
}
A DoTOption customizes the DNS over TLS resolver.
func DoTAddresses ¶
DoTAddresses sets the network addresses of the resolver. These should be IP addresses, or network addresses of the form "IP:port". This avoids having to resolve the resolver's addresses, improving performance and privacy.
Example ¶
dns.NewDoTResolver("dns.google",
dns.DoTAddresses("8.8.8.8", "8.8.4.4", "2001:4860:4860::8888", "2001:4860:4860::8844"),
dns.DoTCache())
Output:
func DoTCache ¶
func DoTCache(options ...CacheOption) DoTOption
DoTCache adds caching to the resolver, with the given options.
func DoTDialFunc ¶ added in v1.1.0
DoTDialFunc sets the DialFunc used by the resolver. By default net.Dialer.DialContext is used.
Source Files