consul dns 轉發配置

 測試使用dnsmasq。

 優勢：可以方便的進行應該編碼，進行動態域名解析，容錯處理。

  因為consul 預設的dns 為127.0.0.1 8600

 所以配置如下：

 檔案目錄：

1. /etc/dnsmasq.d ### 目錄下

1. # Enable forward lookup of the 'consul' domain:
2. server=/consul/127.0.0.1#8600
4. # Uncomment and modify as appropriate to enable reverse DNS lookups for
5. # common netblocks found in RFC 1918, 5735, and 6598:
6. #rev-server=0.0.0.0/8,127.0.0.1#8600
7. #rev-server=10.0.0.0/8,127.0.0.1#8600
8. #rev-server=100.64.0.0/10,127.0.0.1#8600
9. #rev-server=127.0.0.1/8,127.0.0.1#8600
10. #rev-server=169.254.0.0/16,127.0.0.1#8600
11. #rev-server=172.16.0.0/12,127.0.0.1#8600
12. #rev-server=192.168.0.0/16,127.0.0.1#8600
13. #rev-server=224.0.0.0/4,127.0.0.1#8600
14. #rev-server=240.0.0.0/4,127.0.0.1#8600

一些額外的配置

1. # Accept DNS queries only from hosts whose address is on a local subnet.
2. #local-service
4. # Don't poll /etc/resolv.conf for changes.
5. #no-poll
7. # Don't read /etc/resolv.conf. Get upstream servers only from the command
8. # line or the dnsmasq configuration file (see the "server" directive below).
9. #no-resolv
11. # Specify IP address(es) of other DNS servers for queries not handled
12. # directly by consul. There is normally one 'server' entry set for every
13. # 'nameserver' parameter found in '/etc/resolv.conf'. See dnsmasq(8)'s
14. # 'server' configuration option for details.
15. #server=1.2.3.4
16. #server=208.67.222.222
17. #server=8.8.8.8
19. # Set the size of dnsmasq's cache. The default is 150 names. Setting the
20. # cache size to zero disables caching.
21. #cache-size=65536

nginx 做為負載均使用的方式

使用nginx  的 resolver  

1. resolver 127.0.0.1:8600;
2. set $backend "nginx.service.consul";
3. location / {
4. proxy_pass http://$backend;
5. }

詳細參考：https://www.consul.io/docs/guides/forwarding.html