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https://github.com/coredns/coredns.git
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d1f17fa7e0
Move all (almost all) Go files in middleware into their own packages. This makes for better naming and discoverability. Lot of changes elsewhere to make this change. The middleware.State was renamed to request.Request which is better, but still does not cover all use-cases. It was also moved out middleware because it is used by `dnsserver` as well. A pkg/dnsutil packages was added for shared, handy, dns util functions. All normalize functions are now put in normalize.go
112 lines
2.8 KiB
Go
112 lines
2.8 KiB
Go
package proxy
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// functions OTHER middleware might want to use to do lookup in the same
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// style as the proxy.
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import (
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"sync/atomic"
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"time"
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"github.com/miekg/coredns/request"
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"github.com/miekg/dns"
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)
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// New create a new proxy with the hosts in host and a Random policy.
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func New(hosts []string) Proxy {
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p := Proxy{Next: nil, Client: Clients()}
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upstream := &staticUpstream{
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from: "",
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Hosts: make([]*UpstreamHost, len(hosts)),
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Policy: &Random{},
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Spray: nil,
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FailTimeout: 10 * time.Second,
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MaxFails: 1,
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}
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for i, host := range hosts {
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uh := &UpstreamHost{
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Name: host,
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Conns: 0,
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Fails: 0,
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FailTimeout: upstream.FailTimeout,
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Unhealthy: false,
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CheckDown: func(upstream *staticUpstream) UpstreamHostDownFunc {
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return func(uh *UpstreamHost) bool {
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if uh.Unhealthy {
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return true
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}
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fails := atomic.LoadInt32(&uh.Fails)
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if fails >= upstream.MaxFails && upstream.MaxFails != 0 {
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return true
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}
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return false
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}
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}(upstream),
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WithoutPathPrefix: upstream.WithoutPathPrefix,
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}
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upstream.Hosts[i] = uh
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}
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p.Upstreams = []Upstream{upstream}
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return p
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}
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// Lookup will use name and type to forge a new message and will send that upstream. It will
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// set any EDNS0 options correctly so that downstream will be able to process the reply.
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// Lookup is not suitable for forwarding request. Ssee for that.
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func (p Proxy) Lookup(state request.Request, name string, tpe uint16) (*dns.Msg, error) {
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req := new(dns.Msg)
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req.SetQuestion(name, tpe)
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state.SizeAndDo(req)
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return p.lookup(state, req)
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}
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func (p Proxy) Forward(state request.Request) (*dns.Msg, error) {
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return p.lookup(state, state.Req)
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}
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func (p Proxy) lookup(state request.Request, r *dns.Msg) (*dns.Msg, error) {
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var (
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reply *dns.Msg
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err error
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)
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for _, upstream := range p.Upstreams {
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// allowed bla bla bla TODO(miek): fix full proxy spec from caddy?
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start := time.Now()
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// Since Select() should give us "up" hosts, keep retrying
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// hosts until timeout (or until we get a nil host).
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for time.Now().Sub(start) < tryDuration {
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host := upstream.Select()
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if host == nil {
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return nil, errUnreachable
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}
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atomic.AddInt64(&host.Conns, 1)
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if state.Proto() == "tcp" {
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reply, _, err = p.Client.TCP.Exchange(r, host.Name)
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} else {
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reply, _, err = p.Client.UDP.Exchange(r, host.Name)
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}
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atomic.AddInt64(&host.Conns, -1)
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if err == nil {
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return reply, nil
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}
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timeout := host.FailTimeout
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if timeout == 0 {
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timeout = 10 * time.Second
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}
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atomic.AddInt32(&host.Fails, 1)
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go func(host *UpstreamHost, timeout time.Duration) {
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time.Sleep(timeout)
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atomic.AddInt32(&host.Fails, -1)
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}(host, timeout)
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}
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return nil, errUnreachable
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}
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return nil, errUnreachable
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}
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