Arch Linux resolvendo problemas

Question

Eu tenho um Rasberry Pi executando o Arch e estou encontrando um comportamento de resolução estranho. Resumindo, dig e nslookup podem resolver nomes de host, curl , wget , pacman não. Se eu adicionar um host em /etc/hosts , tudo funcionará bem para esse host.

Aqui está a saída de algumas soluções de problemas:

1. resolv.conf existe e é legível:

   $ ls -l /etc/resolv.conf
   -rw-r--r-- 1 root root 19 Apr 28 10:45 /etc/resolv.conf
   

2. Eu tenho um servidor de nomes:

   $ cat /etc/resolv.conf
   nameserver 8.8.8.8
   

3. nslookup funciona:

   $ nslookup google.com
   Server:         8.8.8.8
   Address:        8.8.8.8#53
   
   Non-authoritative answer:
   Name:   google.com
   Address: 92.87.11.30
   Name:   google.com
   Address: 92.87.11.54
   Name:   google.com
   Address: 92.87.11.49
   Name:   google.com
   Address: 92.87.11.45
   ...
   

4. dig funciona:

   $ dig google.com
   
   ; <<>> DiG 9.11.0-P3 <<>> google.com
   ;; global options: +cmd
   ;; Got answer:
   ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20686
   ;; flags: qr rd ra; QUERY: 1, ANSWER: 16, AUTHORITY: 0, ADDITIONAL: 1
   
   ;; OPT PSEUDOSECTION:
   ; EDNS: version: 0, flags:; udp: 512
   ;; QUESTION SECTION:
   ;google.com.                    IN      A
   
   ;; ANSWER SECTION:
   google.com.             299     IN      A       92.87.175.49
   google.com.             299     IN      A       92.87.175.50
   google.com.             299     IN      A       92.87.175.48
   google.com.             299     IN      A       92.87.175.44
   google.com.             299     IN      A       92.87.175.42
   google.com.             299     IN      A       92.87.175.41
   google.com.             299     IN      A       92.87.175.51
   google.com.             299     IN      A       92.87.175.36
   google.com.             299     IN      A       92.87.175.39
   google.com.             299     IN      A       92.87.175.45
   google.com.             299     IN      A       92.87.175.37
   google.com.             299     IN      A       92.87.175.40
   google.com.             299     IN      A       92.87.175.38
   google.com.             299     IN      A       92.87.175.47
   google.com.             299     IN      A       92.87.175.43
   google.com.             299     IN      A       92.87.175.46
   
   ;; Query time: 40 msec
   ;; SERVER: 8.8.8.8#53(8.8.8.8)
   ;; WHEN: Fri Apr 28 11:37:32 EEST 2017
   ;; MSG SIZE  rcvd: 295
   

5. Eu posso ping de um dos IPs:

   $ ping 92.87.175.49
   PING 92.87.175.49 (92.87.175.49) 56(84) bytes of data.
   64 bytes from 92.87.175.49: icmp_seq=1 ttl=54 time=3.75 ms
   64 bytes from 92.87.175.49: icmp_seq=2 ttl=54 time=3.71 ms
   
   --- 92.87.175.49 ping statistics ---
   2 packets transmitted, 2 received, 0% packet loss, time 1001ms
   rtt min/avg/max/mdev = 3.711/3.734/3.758/0.065 ms
   

6. wget falha:

   $ wget https://google.com
   --2017-04-28 11:39:31--  https://google.com/
   Loaded CA certificate '/etc/ssl/certs/ca-certificates.crt'
   Resolving google.com... failed: Name or service not known.
   wget: unable to resolve host address 'google.com'
   

7. curl falha:

   $ curl https://google.com
   curl: (6) Could not resolve host: google.com
   

O que eu estou sentindo falta?! ...

Editar:

$ cat /etc/hosts
#
# /etc/hosts: static lookup table for host names
#

#<ip-address>   <hostname.domain.org>   <hostname>
127.0.0.1       localhost.localdomain   localhost
::1             localhost.localdomain   localhost

# End of file

$ cat /etc/nsswitch.conf
# Begin /etc/nsswitch.conf

passwd: compat mymachines systemd
group: compat mymachines systemd
shadow: compat

publickey: files

hosts: files mymachines resolve [!UNAVAIL=return] dns myhostname
networks: files

protocols: files
services: files
ethers: files
rpc: files

netgroup: files

# End /etc/nsswitch.conf

Parece que tem algo a ver com systemd-resolvd . Se eu pará-lo ou remover resolve [!UNAVAIL=return] de /etc/nsswitch.conf , a resolução funciona bem para cada aplicativo, se eu iniciá-lo novamente ou deixar /etc/nsswitch.conf como está, a resolução funciona apenas para nslookup & dig .