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mw/proxy: simplify google code (#1019)

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* mw/proxy: simplify google code

Minimize bootstrap code a bit, and block on the first resolve of the
google https endpont. Add more logging and include actual error in the
returned errors.

Also re-resolve every 120 seconds, instead of 300 (might eventually make
this an option).

* fix test
This commit is contained in:
Miek Gieben 2017-09-02 18:43:52 +02:00 • committed by GitHub
parent 3a96d1ab77
commit 9bcddc5c16
5 changed files with 48 additions and 43 deletions
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13
middleware/proxy/lookup.go
View file

@ -4,6 +4,7 @@ package proxy
import (
"context"
"fmt"
"sync/atomic"
"time"
@ -14,9 +15,7 @@ import (
)
// NewLookup create a new proxy with the hosts in host and a Random policy.
func NewLookup(hosts []string) Proxy {
return NewLookupWithOption(hosts, Options{})
}
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 {
@ -95,13 +94,15 @@ func (p Proxy) lookup(state request.Request) (*dns.Msg, error) {
}
for {
start := time.Now()
reply := new(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, errUnreachable
return nil, fmt.Errorf("%s: %s", errUnreachable, "no upstream host")
}
// duplicated from proxy.go, but with a twist, we don't write the
@ -109,7 +110,7 @@ func (p Proxy) lookup(state request.Request) (*dns.Msg, error) {
atomic.AddInt64(&host.Conns, 1)
reply, backendErr := upstream.Exchanger().Exchange(context.TODO(), host.Name, state)
reply, backendErr = upstream.Exchanger().Exchange(context.TODO(), host.Name, state)
atomic.AddInt64(&host.Conns, -1)
@ -126,6 +127,6 @@ func (p Proxy) lookup(state request.Request) (*dns.Msg, error) {
atomic.AddInt32(&host.Fails, -1)
}(host, timeout)
}
return nil, errUnreachable
return nil, fmt.Errorf("%s: %s", errUnreachable, backendErr)
}
}