{"version":"1.0","provider_name":"Jui-Nan Lin's Blog","provider_url":"https:\/\/jnlin.org","author_name":"jnlin","author_url":"https:\/\/jnlin.org\/author\/jnlin\/","title":"\u7528 pf + relayd \u67b6\u8a2d Layer 4 Switch (Server Load Balancer)","html":"\u6e90\u65bc OpenBSD\uff0cport \u5230 FreeBSD \u7684 pf<\/a> \u672c\u8eab\u5c31\u53ef\u4ee5\u4f5c load balancer\uff0c\u4f46\u662f\u4e0d\u80fd\u4f5c healthy check\u3002\u8981\u4f5c healthy check \u7684\u8a71\uff0c\u5fc5\u9808\u52a0\u4e0a relayd<\/a>\u3002\u53e6\u5916\u7528 CARP(4)<\/a> \u8207 PFSYNC(4)<\/a> \u53ef\u4ee5\u505a\u5230 Active-Standby \u7684 Redundancy HA\uff0c\u4e5f\u5c31\u662f\u7576\u4e00\u53f0 SLB (Server Load Balancer) \u6b7b\u6389\u7684\u6642\u5019\uff0c\u53e6\u4e00\u53f0\u6703\u81ea\u52d5\u8d77\u4f86\u63d0\u4f9b\u670d\u52d9\u3002\u8a73\u7d30\u7684\u4f5c\u6cd5\u5728\u53c3\u8003\u8cc7\u6599\u6709\uff0c\u56e0\u6b64\u9019\u88e1\u4e0d\u8d05\u8ff0\u3002\u57fa\u672c\u7684\u60f3\u6cd5\u70ba\uff1a
  1. \u7528 pf \u8a2d\u5b9a\u9632\u706b\u7246\u8207 NAT\uff0c\u628a incoming port 80 \u7684 destination \u63db\u6210 server pool \u5167\u7684\u4efb\u4e00\u53f0\u3002<\/li>
  2. \u7528 carp \u4f86\u4fdd\u8b49 HA\u3002<\/li>
  3. \u7528 pfsync \u4f86 sync \u5169\u53f0 SLB \u4e4b\u9593\u7684 pf firewall state\u3002<\/li>
  4. \u7528 relayd \u4f86\u6aa2\u67e5 server \u7684\u72c0\u614b\uff0c\u5982\u679c\u4e0d\u80fd\u9023\u7dda\u7684\u6642\u5019\uff0c\u628a server \u5f9e pool \u5167\u62ff\u6389\u3002<\/li> <\/ol>

    \u9019\u6a23\u5c31\u53ef\u4ee5\u9054\u5230 Layer 4 Switch \u7684\u529f\u80fd\uff0c\u5728 relayd \u88e1\u9762\u7a31\u70ba REDIRECT \u6a21\u5f0f\uff0c\u7f3a\u9ede\u662f pool \u5167\u6240\u6709\u7684 server \u90fd\u5fc5\u9808\u628a default gateway \u8a2d\u70ba SLB\u3002
    \u53e6\u5916 relayd \u4e5f\u53ef\u4ee5\u63a1\u7528\u985e\u4f3c     haproxy<\/a> \u7684\u65b9\u5f0f\uff0c\u7531 relayd \u8ddf client \u8207 server \u5404\u5efa\u7acb\u4e00\u500b\u9023\u7dda\uff0c\u4f5c Layer 7 \u7684 forwarding\u3002\u9019\u5728 relayd \u88e1\u9762\u7a31\u70ba RELAY \u6a21\u5f0f\u3002
    \u8a2d\u5b9a relay \u6a21\u5f0f\u7684\u6642\u5019\uff0c\u53ef\u4ee5\u5c0d HTTP Header \u4f5c\u4fee\u6539\uff0c\u4f8b\u5982\u52a0\u4e0a X-Forwarded-For Header\uff0c\u6216\u662f\u6839\u64da Host Header \u6216\u8005 URI \u4f86\u6c7a\u5b9a\u8981\u5206\u914d\u5230\u7684 Pool\u3002\u53e6\u5916 healthy check \u4e5f\u53ef\u4ee5\u7531\u7ba1\u7406\u8005\u81ea\u884c\u64b0\u5beb script\uff0c\u56e0\u6b64\u53ef\u4ee5\u4f5c\u6bd4\u8f03\u8907\u96dc\u7684\u6aa2\u67e5\u3002\u8a2d\u5b9a\u65b9\u5f0f\u53ef\u4ee5\u53c3\u8003     RELAYD.CONF(5)<\/a>\u3002<\/p>

    \u6bd4\u8d77 haproxy \u4f86\u8aaa\uff0crelayd \u53ef\u4ee5\u8f15\u6613\u7684\u9054\u5230 Full Transparent Proxy \uff08\u5f8c\u7aef\u7684 Server \u770b\u5230\u7684 source ip \u662f\u771f\u6b63\u7684 ip\uff09\u7684\u529f\u80fd\u800c\u4e0d\u9700\u8981 patch kernel\uff0c\u800c\u4e14\u4e5f\u53ef\u4ee5\u4f5c graceful restart\uff08 haproxy \u5728 restart \u7684\u6642\u5019\u670d\u52d9\u6703\u4e2d\u65b7\uff09\uff1b\u4e0d\u904e haproxy \u6709\u8a31\u591a\u7684\u5be6\u4f8b\u5df2\u7d93\u9a57\u8b49\u904e\u5b83\u7684\u6548\u80fd\uff0c\u53ef\u4ee5\u5403\u6eff 10Gbps \u7db2\u8def\uff0c\u4f46 relayd \u5728 RELAY \u6a21\u5f0f\u7684 \u6548\u80fd\u9084\u662f\u672a\u77e5\u6578\u3002\u53e6\u5916\uff0c\u7531\u65bc relayd \u8207 pf \u7d81\u7684\u5f88\u7dca\uff0c\u56e0\u6b64\u76ee\u524d\u53ea\u6709 OpenBSD \u8207 FreeBSD \u7248\uff0c\u4e0d\u80fd\u5728 Linux \u4e0a\u57f7\u884c\u3002<\/p>

    \u53c3\u8003\u8cc7\u6599\uff1a<\/p>