[Dnsmasq-discuss] CNAME caching issue in Dnsmasq(2.76)

[Yossi Boaron]

Hi All,
I have the following DNS topology (In my Openstack deployment):
VM --> DNSMASQ --> external DNS server
domain name= shiftstack.com, and Dnsmasq 2.76 is used at this Openstack
deployment.

I run the following test:
1. Define CNAME record at external DNS server

ostest-etcd-5.shiftstack.com.     IN   CNAME        ostest-master-2

2. while 'ostest-master-2' is defined in --addn-hosts at Dnsmasq:
the relevant entry:
10.0.1.214      ostest-master-2.shiftstack.com. ostest-master-2

3. next step, I tried to resolve 'ostest-etcd-5.shiftstack.com.' from the
VM.
I expected that dig ostest-etcd-5.shiftstack.com. should be replied with
the ostest-master-2 IP (10.0.1.214).

Actual behavior:
When I run dig (see 1)  just for type A, Dnsmasq replied only with the
CNAME entry and doesn't return ostest-master-2 IP address.

But when I run dig (see 2) for types AAAA and A (at this order), I can see
that Dnsmasq resolves  ostest-master-2 IP address as expected.

It seems to me like an issue of CNAME caching  at Dnsmasq (2.76),
Is it a known issue?

Thanks in advance
Yossi


[1]
$ dig +noedns  ostest-etcd-5.shiftstack.com.  A

; <<>> DiG 9.9.4-RedHat-9.9.4-72.el7 <<>> +noedns
ostest-etcd-5.shiftstack.com. A
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 13837
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;ostest-etcd-5.shiftstack.com.  IN      A

;; ANSWER SECTION:
ostest-etcd-5.shiftstack.com. 3600 IN   CNAME
ostest-master-2.shiftstack.com.

;; Query time: 2 msec
;; SERVER: 10.0.0.2#53(10.0.0.2)
;; WHEN: Sun Jan 20 09:52:48 UTC 2019
;; MSG SIZE  rcvd: 118

$

[2]
$ dig +noedns ostest-etcd-5.shiftstack.com. AAAA
ostest-etcd-5.shiftstack.com.  A

; <<>> DiG 9.9.4-RedHat-9.9.4-72.el7 <<>> +noedns
ostest-etcd-5.shiftstack.com. AAAA ostest-etcd-5.shiftstack.com. A
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 63573
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;ostest-etcd-5.shiftstack.com.  IN      AAAA

;; ANSWER SECTION:
ostest-etcd-5.shiftstack.com. 3600 IN   CNAME
ostest-master-2.shiftstack.com.

;; Query time: 3 msec
;; SERVER: 10.0.0.2#53(10.0.0.2)
;; WHEN: Sun Jan 20 09:53:59 UTC 2019
;; MSG SIZE  rcvd: 118

;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 15671
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;ostest-etcd-5.shiftstack.com.  IN      A

;; ANSWER SECTION:
ostest-etcd-5.shiftstack.com. 3600 IN   CNAME
ostest-master-2.shiftstack.com.
ostest-master-2.shiftstack.com. 0 IN    A       10.0.1.214

;; Query time: 0 msec
;; SERVER: 10.0.0.2#53(10.0.0.2)
;; WHEN: Sun Jan 20 09:53:59 UTC 2019
;; MSG SIZE  rcvd: 106

$
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