UnixResolverDnsServerAddressStreamProvider : unresolved DNS server address

[shivabhalla]

Getting Following exception when UnixResolverDnsServerAddressStreamProvider is trying to read from /etc/resolver.conf

java.lang.ExceptionInInitializerError: null at io.netty.resolver.dns.UnixResolverDnsServerAddressStreamProvider.parseSilently(UnixResolverDnsServerAddressStreamProvider.java:72) ~[AdExchange%23%23redisson-upgrade_9557.jar:?] at io.netty.resolver.dns.DnsServerAddressStreamProviders.<clinit>(DnsServerAddressStreamProviders.java:28) ~[AdExchange%23%23redisson-upgrade_9557.jar:?] at org.redisson.connection.MasterSlaveConnectionManager.<init>(MasterSlaveConnectionManager.java:195) ~[AdExchange%23%23redisson-upgrade_9557.jar:?] at org.redisson.connection.MasterSlaveConnectionManager.<init>(MasterSlaveConnectionManager.java:169) ~[AdExchange%23%23redisson-upgrade_9557.jar:?]

Caused by: java.lang.IllegalArgumentException: cannot use an unresolved DNS server address: nil:53 at io.netty.resolver.dns.DnsServerAddresses.sanitize(DnsServerAddresses.java:204) ~[AdExchange%23%23redisson-upgrade_9557.jar:?] at io.netty.resolver.dns.DnsServerAddresses.sequential(DnsServerAddresses.java:77) ~[AdExchange%23%23redisson-upgrade_9557.jar:?] at io.netty.resolver.dns.DefaultDnsServerAddressStreamProvider.<clinit>(DefaultDnsServerAddressStreamProvider.java:146) ~[AdExchange%23%23redisson-upgrade_9557.jar:?]

/etc/resolver.conf file contains following data ->

nameserver {A Valid IP}

nameserver {A Valid IP}

nameserver nil

Issue is resolved if we remove "nameserver nil" from file.

[normanmaurer]

@shivabhalla hmm.. why you have nameserver nil in there ? This sounds like an invalid entry.

[shivabhalla]

This is being created by some job, but I wasn't facing this issue with earlier versions of netty. Currently I shifted to 4.1.17 where I started facing this.

[normanmaurer]

@shivabhalla sure because we did not read this file in earlier releases (which was a bug). That said I wonder if we should just skip "corrupt" entries.

[normanmaurer]

@slandelle what are your thoughts on this ?

[slandelle]

Agree, we should skip invalid entries.

[normanmaurer]

@slandelle @shivabhalla PTAL #9697

[shivabhalla]

Thanks @normanmaurer 😊

[fax4ever]

I have the same issue with the following /etc/resolv.conf (I have in my VM):

# Generated by NetworkManager
search localdomain
nameserver 10.211.55.1
nameserver fe80::21c:42ff:fe00:18%enp0s5

It works commenting the IPv6 line. Is it normal?

[normanmaurer]

@fax4ever no... can you please open a issue ?

[normanmaurer]

@fax4ever I suspect the problem is that enp0s5 does not exist on the host as interface, correct ?

[fax4ever]

host as interface

[fabio@localhost infinispan]$ ip addr 
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: enp0s5: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:1c:42:32:14:87 brd ff:ff:ff:ff:ff:ff
    inet 10.211.55.25/24 brd 10.211.55.255 scope global dynamic noprefixroute enp0s5
       valid_lft 1480sec preferred_lft 1480sec
    inet6 fdb2:2c26:f4e4:0:21c:42ff:fe32:1487/64 scope global dynamic noprefixroute 
       valid_lft 2591703sec preferred_lft 604503sec
    inet6 fe80::21c:42ff:fe32:1487/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:ec:2a:d3:64 brd ff:ff:ff:ff:ff:ff

[normanmaurer]

So what exactly happens on your system ? Throws an exception when the entry is present or what ?

[fax4ever]

I opened #13612

[normanmaurer]

I opened #13612

Thanks... let's continue there.