Bug 1461492 - inet:gethostbyname returns IPv4 results when IPv6 is configured [OSP-11]
inet:gethostbyname returns IPv4 results when IPv6 is configured [OSP-11]
Product: Red Hat OpenStack
Classification: Red Hat
Component: erlang (Show other bugs)
11.0 (Ocata)
Unspecified Unspecified
high Severity high
: z2
: 11.0 (Ocata)
Assigned To: Peter Lemenkov
: Triaged, ZStream
Depends On:
  Show dependency treegraph
Reported: 2017-06-14 11:10 EDT by John Eckersberg
Modified: 2017-09-13 17:50 EDT (History)
9 users (show)

See Also:
Fixed In Version: erlang-
Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: 1461190
Last Closed: 2017-09-13 17:50:42 EDT
Type: Bug
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

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External Trackers
Tracker ID Priority Status Summary Last Updated
Github erlang/otp/pull/1065 None None None 2017-06-14 11:10 EDT

  None (edit)
Description John Eckersberg 2017-06-14 11:10:26 EDT
+++ This bug was initially created as a clone of Bug #1461190 +++

Description of problem:
If IPv6 is configured via proto_dist and/or inetrc, inet:gethostbyname will still prefer IPv4 addresses.  This breaks epmd lookups if epmd is forced to listen only on IPv6.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
[root@rhel7 ~]# env | grep ERL                                                                                                                                                                                       
[root@rhel7 ~]# cat /root/inetrc
{inet6, true}.
[root@rhel7 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 52:54:00:13:f6:0e brd ff:ff:ff:ff:ff:ff
    inet brd scope global dynamic eth0
       valid_lft 2881sec preferred_lft 2881sec
    inet6 fd00::1/128 scope global 
       valid_lft forever preferred_lft forever
    inet6 fe80::5054:ff:fe13:f60e/64 scope link 
       valid_lft forever preferred_lft forever
[root@rhel7 ~]# cat /etc/hosts   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
fd00::1     rhel7

Actual results:
[root@rhel7 ~]# erl -sname foo -proto_dist inet6_tcp
Erlang/OTP 18 [erts-] [source] [64-bit] [async-threads:10] [hipe] [kernel-poll:false]

Eshell V7.3.1.2  (abort with ^G)
(foo@rhel7)1> inet:gethostbyname("rhel7").
inet_gethost[7615] (DEBUG):Saved domainname .
inet_gethost[7615] (DEBUG):Saved domainname .
inet_gethost[7616] (DEBUG):Worker got request, op = 1, proto = 1, data = rhel7.
inet_gethost[7616] (DEBUG):Starting gethostbyname(rhel7)
inet_gethost[7616] (DEBUG):gethostbyname OK

Expected results:
[root@rhel7 ~]# erl -sname foo -proto_dist inet6_tcp
Erlang/OTP 18 [erts-] [source] [64-bit] [async-threads:10] [hipe] [kernel-poll:false]

Eshell V7.3.1.2  (abort with ^G)
(foo@rhel7)1> inet:gethostbyname("rhel7").
inet_gethost[7694] (DEBUG):Saved domainname .
inet_gethost[7694] (DEBUG):Created worker[7695] with fd 3
inet_gethost[7694] (DEBUG):Saved domainname .
inet_gethost[7695] (DEBUG):Worker got request, op = 1, proto = 2, data = rhel7.
inet_gethost[7695] (DEBUG):Starting getaddrinfo(rhel7, ...)
inet_gethost[7695] (DEBUG):getaddrinfo returned 0

Additional info:
Upstream fix on OTP 19 - https://github.com/erlang/otp/commit/5d7dcfc2e0de7e93b29d01f07a2f970720d62f9d
Backport for OTP - https://github.com/jeckersb/otp/commit/5ceafb8276b2d920abb3724450e87d8724d21f8e
Comment 1 Peter Lemenkov 2017-07-14 11:20:05 EDT
Different build (against RHEL 7.3) - erlang-
Comment 4 pkomarov 2017-09-03 09:23:35 EDT
Verified : on Ver. :erlang-

Steps taken: 

erlang ver. check: 

[root@controller-0 ~]#yum  list *erlang*|grep '18'|awk '{print $2}'|uniq 

prepare env. for erlang run: 

[root@controller-0 ~]#export ERL_INET_GETHOST_DEBUG=5
[root@controller-0 ~]#export ERL_INETRC=/root/inetrc
[root@controller-0 ~]#export ERL_EPMD_ADDRESS=$(grep `hostname -s`\.localdomain /etc/hosts|awk '{print $1}')
[root@controller-0 ~]#echo "{inet6, true}.">>/root/inetrc

[root@controller-0 ~]#pcs cluster stop --all
[root@controller-0 ~]#killall epmd

Test execution: 
Expected results are validated - we get ipv6 output from "net:gethostbyname"

[root@controller-0 ~]# erl -sname foo -proto_dist inet6_tcp
inet_gethost[932209] (DEBUG):Saved domainname .
inet_gethost[932209] (DEBUG):Created worker[932210] with fd 3
inet_gethost[932209] (DEBUG):Saved domainname .
inet_gethost[932210] (DEBUG):Worker got request, op = 1, proto = 1, data = controller-0.
inet_gethost[932210] (DEBUG):Starting gethostbyname(controller-0)
inet_gethost[932210] (DEBUG):gethostbyname OK
inet_gethost[932209] (DEBUG):End of file while reading from pipe.
inet_gethost[932209] (DEBUG):Erlang has closed.
Erlang/OTP 18 [erts-] [source] [64-bit] [smp:12:12] [async-threads:10] [hipe] [kernel-poll:false]

Eshell V7.3.1.3  (abort with ^G)
(foo@controller-0)1> inet:gethostbyname("controller-0").
inet_gethost[932308] (DEBUG):Saved domainname .
inet_gethost[932308] (DEBUG):Created worker[932309] with fd 3
inet_gethost[932308] (DEBUG):Saved domainname .
inet_gethost[932309] (DEBUG):Worker got request, op = 1, proto = 2, data = controller-0.
inet_gethost[932309] (DEBUG):Starting getaddrinfo(controller-0, ...)
inet_gethost[932309] (DEBUG):getaddrinfo returned 0
Comment 6 errata-xmlrpc 2017-09-13 17:50:42 EDT
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.


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