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-rw-r--r--middleware/etcd/README.md37
-rw-r--r--middleware/etcd/lookup.go22
-rw-r--r--middleware/etcd/proxy_lookup_test.go77
-rw-r--r--middleware/etcd/setup_test.go2
4 files changed, 123 insertions, 15 deletions
diff --git a/middleware/etcd/README.md b/middleware/etcd/README.md
index a424244c6..b932dc265 100644
--- a/middleware/etcd/README.md
+++ b/middleware/etcd/README.md
@@ -40,19 +40,7 @@ etcd [zones...] {
the proxy middleware.
* `tls` followed the cert, key and the CA's cert filenames.
* `debug` allow debug queries. Prefix the name with `o-o.debug.` to retrieve extra information in the
- additional section of the reply in the form of text records:
-
- skydns.test.skydns.dom.a. 300 CH TXT "127.0.0.1:0(10,0,,false)[0,]"
-
- This shows the complete key as the owername, the rdata of the TXT record has:
- `host:port(priority,weight,txt content,mail)[targetstrip,group]`.
-
- Any errors seen doing parsing will show up like this:
-
- . 0 CH TXT "/skydns/local/skydns/r/a: invalid character '.' after object key:value pair"
-
- which shows `a.r.skydns.local.` has a json encoding problem.
-
+ additional section of the reply in the form of text records.
## Examples
@@ -117,3 +105,26 @@ Or with *debug* queries enabled:
;; ADDITIONAL SECTION:
127.0.0.10.in-addr.arpa. 300 CH TXT "reverse.atoom.net.:0(10,0,,false)[0,]"
~~~
+
+## Debug queries
+
+When debug queries are enabled CoreDNS will return errors and etcd records encountered during the resolution
+process in the response. The general form looks like this:
+
+ skydns.test.skydns.dom.a. 300 CH TXT "127.0.0.1:0(10,0,,false)[0,]"
+
+ This shows the complete key as the owername, the rdata of the TXT record has:
+ `host:port(priority,weight,txt content,mail)[targetstrip,group]`.
+
+ Any errors seen doing parsing will show up like this:
+
+ . 0 CH TXT "/skydns/local/skydns/r/a: invalid character '.' after object key:value pair"
+
+ which shows `a.r.skydns.local.` has a json encoding problem.
+
+ Errors when communicating with an upstream will be returned as:
+
+ . 0 CH TXT "example.org. IN A: unreachable backend"
+
+ Signalling that an A record for example.org. was sought, but it failed
+ with that error.
diff --git a/middleware/etcd/lookup.go b/middleware/etcd/lookup.go
index f111b4240..881c43a3a 100644
--- a/middleware/etcd/lookup.go
+++ b/middleware/etcd/lookup.go
@@ -1,6 +1,7 @@
package etcd
import (
+ "errors"
"fmt"
"math"
"net"
@@ -73,7 +74,11 @@ func (e Etcd) A(zone string, state middleware.State, previousRecords []dns.RR, o
}
m1, e1 := e.Proxy.Lookup(state, target, state.QType())
if e1 != nil {
- continue
+ if opt.Debug != "" {
+ debugTxt := errorToTxt(errors.New(target + " IN " + state.Type() + ":" + e1.Error()))
+ records = append(records, debugTxt)
+ continue
+ }
}
// Len(m1.Answer) > 0 here is well?
records = append(records, newRecord)
@@ -133,6 +138,8 @@ func (e Etcd) AAAA(zone string, state middleware.State, previousRecords []dns.RR
}
m1, e1 := e.Proxy.Lookup(state, target, state.QType())
if e1 != nil {
+ debugTxt := errorToTxt(errors.New(target + " IN " + state.Type() + ": " + e1.Error()))
+ records = append(records, debugTxt)
continue
}
// Len(m1.Answer) > 0 here is well?
@@ -195,7 +202,11 @@ func (e Etcd) SRV(zone string, state middleware.State, opt Options) (records, ex
m1, e1 := e.Proxy.Lookup(state, srv.Target, dns.TypeA)
if e1 == nil {
extra = append(extra, m1.Answer...)
+ } else {
+ debugTxt := errorToTxt(errors.New(srv.Target + " IN A: " + e1.Error()))
+ extra = append(extra, debugTxt)
}
+
m1, e1 = e.Proxy.Lookup(state, srv.Target, dns.TypeAAAA)
if e1 == nil {
// If we have seen CNAME's we *assume* that they are already added.
@@ -204,6 +215,9 @@ func (e Etcd) SRV(zone string, state middleware.State, opt Options) (records, ex
extra = append(extra, a)
}
}
+ } else {
+ debugTxt := errorToTxt(errors.New(srv.Target + " IN AAAA: " + e1.Error()))
+ extra = append(extra, debugTxt)
}
break
}
@@ -261,6 +275,9 @@ func (e Etcd) MX(zone string, state middleware.State, opt Options) (records, ext
m1, e1 := e.Proxy.Lookup(state, mx.Mx, dns.TypeA)
if e1 == nil {
extra = append(extra, m1.Answer...)
+ } else {
+ debugTxt := errorToTxt(errors.New(mx.Mx + " IN A: " + e1.Error()))
+ extra = append(extra, debugTxt)
}
m1, e1 = e.Proxy.Lookup(state, mx.Mx, dns.TypeAAAA)
if e1 == nil {
@@ -270,6 +287,9 @@ func (e Etcd) MX(zone string, state middleware.State, opt Options) (records, ext
extra = append(extra, a)
}
}
+ } else {
+ debugTxt := errorToTxt(errors.New(mx.Mx + " IN AAAA: " + e1.Error()))
+ extra = append(extra, debugTxt)
}
break
}
diff --git a/middleware/etcd/proxy_lookup_test.go b/middleware/etcd/proxy_lookup_test.go
new file mode 100644
index 000000000..868bf80d6
--- /dev/null
+++ b/middleware/etcd/proxy_lookup_test.go
@@ -0,0 +1,77 @@
+// +build etcd
+
+package etcd
+
+import (
+ "sort"
+ "testing"
+
+ "github.com/miekg/coredns/middleware"
+ "github.com/miekg/coredns/middleware/etcd/msg"
+ "github.com/miekg/coredns/middleware/proxy"
+ "github.com/miekg/coredns/middleware/test"
+
+ "github.com/miekg/dns"
+)
+
+func TestProxyLookupFailDebug(t *testing.T) {
+ for _, serv := range servicesProxy {
+ set(t, etc, serv.Key, 0, serv)
+ defer delete(t, etc, serv.Key)
+ }
+
+ prxy := etc.Proxy
+ etc.Proxy = proxy.New([]string{"127.0.0.0:154"})
+ etc.Debug = true
+
+ defer func() { etc.Debug = false }()
+ defer func() { etc.Proxy = prxy }()
+
+ for _, tc := range dnsTestCasesProxy {
+ m := tc.Msg()
+
+ rec := middleware.NewResponseRecorder(&test.ResponseWriter{})
+ _, err := etc.ServeDNS(ctxt, rec, m)
+ if err != nil {
+ t.Errorf("expected no error, got %v\n", err)
+ continue
+ }
+ resp := rec.Msg()
+
+ sort.Sort(test.RRSet(resp.Answer))
+ sort.Sort(test.RRSet(resp.Ns))
+ sort.Sort(test.RRSet(resp.Extra))
+
+ if !test.Header(t, tc, resp) {
+ t.Logf("%v\n", resp)
+ continue
+ }
+ if !test.Section(t, tc, test.Answer, resp.Answer) {
+ t.Logf("%v\n", resp)
+ }
+ if !test.Section(t, tc, test.Ns, resp.Ns) {
+ t.Logf("%v\n", resp)
+ }
+ if !test.Section(t, tc, test.Extra, resp.Extra) {
+ t.Logf("%v\n", resp)
+ }
+ }
+}
+
+// Note the key is encoded as DNS name, while in "reality" it is a etcd path.
+var servicesProxy = []*msg.Service{
+ {Host: "www.example.org", Key: "a.dom.skydns.test."},
+}
+
+var dnsTestCasesProxy = []test.Case{
+ {
+ Qname: "dom.skydns.test.", Qtype: dns.TypeSRV,
+ Answer: []dns.RR{
+ test.SRV("dom.skydns.test. 300 IN SRV 10 100 0 www.example.org."),
+ },
+ Extra: []dns.RR{
+ test.TXT(". 0 CH TXT \"www.example.org. IN A: unreachable backend\""),
+ test.TXT(". 0 CH TXT \"www.example.org. IN AAAA: unreachable backend\""),
+ },
+ },
+}
diff --git a/middleware/etcd/setup_test.go b/middleware/etcd/setup_test.go
index 5b60c6038..9391bf3c7 100644
--- a/middleware/etcd/setup_test.go
+++ b/middleware/etcd/setup_test.go
@@ -13,9 +13,9 @@ import (
"github.com/miekg/coredns/middleware/proxy"
"github.com/miekg/coredns/middleware/singleflight"
"github.com/miekg/coredns/middleware/test"
- "github.com/miekg/dns"
etcdc "github.com/coreos/etcd/client"
+ "github.com/miekg/dns"
"golang.org/x/net/context"
)
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-11 16:03:03 +0000