diff options
Diffstat (limited to 'plugin/proxy/lookup.go')
-rw-r--r-- | plugin/proxy/lookup.go | 127 |
1 files changed, 0 insertions, 127 deletions
diff --git a/plugin/proxy/lookup.go b/plugin/proxy/lookup.go deleted file mode 100644 index 0437e8eb7..000000000 --- a/plugin/proxy/lookup.go +++ /dev/null @@ -1,127 +0,0 @@ -package proxy - -// functions other plugin might want to use to do lookup in the same style as the proxy. - -import ( - "context" - "fmt" - "net" - "sync/atomic" - "time" - - "github.com/coredns/coredns/plugin/pkg/healthcheck" - "github.com/coredns/coredns/request" - - "github.com/miekg/dns" -) - -// NewLookup create a new proxy with the hosts in host and a Random policy. -func NewLookup(hosts []string) Proxy { return NewLookupWithOption(hosts, Options{}) } - -// NewLookupWithOption process creates a simple round robin forward with potentially forced proto for upstream. -func NewLookupWithOption(hosts []string, opts Options) Proxy { - p := Proxy{Next: nil} - - // TODO(miek): this needs to be unified with upstream.go's NewStaticUpstreams, caddy uses NewHost - // we should copy/make something similar. - upstream := &staticUpstream{ - from: ".", - HealthCheck: healthcheck.HealthCheck{ - FailTimeout: 5 * time.Second, - MaxFails: 3, - }, - ex: newDNSExWithOption(opts), - } - upstream.Hosts = make([]*healthcheck.UpstreamHost, len(hosts)) - - for i, host := range hosts { - uh := &healthcheck.UpstreamHost{ - Name: host, - FailTimeout: upstream.FailTimeout, - CheckDown: checkDownFunc(upstream), - } - - upstream.Hosts[i] = uh - } - p.Upstreams = &[]Upstream{upstream} - return p -} - -// Lookup will use name and type to forge a new message and will send that upstream. It will -// set any EDNS0 options correctly so that downstream will be able to process the reply. -func (p Proxy) Lookup(state request.Request, name string, typ uint16) (*dns.Msg, error) { - req := new(dns.Msg) - req.SetQuestion(name, typ) - state.SizeAndDo(req) - - state2 := request.Request{W: state.W, Req: req} - - return p.lookup(state2) -} - -// Forward forward the request in state as-is. Unlike Lookup that adds EDNS0 suffix to the message. -func (p Proxy) Forward(state request.Request) (*dns.Msg, error) { - return p.lookup(state) -} - -func (p Proxy) lookup(state request.Request) (*dns.Msg, error) { - upstream := p.match(state) - if upstream == nil { - return nil, errInvalidDomain - } - for { - start := time.Now() - var reply *dns.Msg - var backendErr error - - // Since Select() should give us "up" hosts, keep retrying - // hosts until timeout (or until we get a nil host). - for time.Since(start) < tryDuration { - host := upstream.Select() - if host == nil { - return nil, fmt.Errorf("%s: %s", errUnreachable, "no upstream host") - } - - // duplicated from proxy.go, but with a twist, we don't write the - // reply back to the client, we return it and there is no monitoring to update here. - - atomic.AddInt64(&host.Conns, 1) - - reply, backendErr = upstream.Exchanger().Exchange(context.TODO(), host.Name, state) - - atomic.AddInt64(&host.Conns, -1) - - if backendErr == nil { - - if !state.Match(reply) { - return state.ErrorMessage(dns.RcodeFormatError), nil - } - - return reply, nil - } - - if oe, ok := backendErr.(*net.OpError); ok { - if oe.Timeout() { // see proxy.go for docs. - continue - } - } - - timeout := host.FailTimeout - if timeout == 0 { - timeout = defaultFailTimeout - } - - atomic.AddInt32(&host.Fails, 1) - fails := atomic.LoadInt32(&host.Fails) - - go func(host *healthcheck.UpstreamHost, timeout time.Duration) { - time.Sleep(timeout) - atomic.AddInt32(&host.Fails, -1) - if fails%failureCheck == 0 { // Kick off healthcheck on eveyry third failure. - host.HealthCheckURL() - } - }(host, timeout) - } - return nil, fmt.Errorf("%s: %s", errUnreachable, backendErr) - } -} |