嵌入式Linux内核修改转发skb网络数据包

实际的项目软件开过程中，碰到一个需求，需要修改以太网接收到的数据包，主要有两点需求：

  • L2层特定自定义协议包修改目的MAC地址
  • 针对特定端口的UDP包，修改其目的IP后，再接交给上层（或在Bridge转发之前）处理

方案评估

第一点需求，修改L2层的MAC地址，可采用：

  • 采用ebtable的DNAT修改L2层MAC地址
  • 通过网络驱动传参修改

第二点需求，修改Bridge转发之前的特定端口包目的IP，可采用：

  • 用iptables的INT_NET_PREROUTING Hook，结合br_netfilter模块的bridge-nf-call-iptables功能实现

    /proc/sys/net/bridge/bridge-nf-call-iptables
  • 编写一个netfilter hook内核模块，通过bridge NF_BR_PRE_ROUTING hook点特殊处理

最终采用的方案

上述两点的两个方案，理论上都是第一条比较优雅，但是现实总是残酷的，在嵌入式系统上，芯片资源有限，CPU\RAM\Flash资源受限的情况下，无论是ebtables或是iptables都太重了，特别还要考虑转发执行效率尽量的减少CPU处理，最终都采用了第二种策略。

实现注意点

  • 网络驱动的代码netif_rx(skb);都处于中断的下半区，代码需要高效简短，否则严重影响CPU。
  • 编写netfilter hook模块时，挂载在NF_BR_PRE_ROUTING hook处理节点，处于L2层，收到的skb数据包，无论是网络层、还是传输层指针都是无效的，不能直接引用

  • 挂载点协议选择NFPROTO_BRIDGE

    static struct nf_hook_ops nfho = {
  .hook = hook_func,
  .hooknum = NF_BR_PRE_ROUTING,
  .pf = NFPROTO_BRIDGE,
  .priority = NF_BR_PRI_FIRST,
};
  • 修改了UDP包的目的IP后，需要重新计算UDP及IP Header的checksum；此外，这里仅修改目的IP，不需要重新全部计算，可以使用inet_proto_csum_replace4只作替代更新，提高效率
  • 目的IP如果修改为组播或广播包，则需要对应的修改eth header的目的MAC地址，否则包不会经过Bridge广播，从L2层上看还是会传给NF_BR_LOCAL_IN

参考代码及资料

  1. 参考代码1

    /*
 * Copyright (c) 2007-2012 Nicira, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/skbuff.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/openvswitch.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/in6.h>
#include <linux/if_arp.h>
#include <linux/if_vlan.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/checksum.h>
#include <net/dsfield.h>

#include "checksum.h"
#include "datapath.h"
#include "vlan.h"
#include "vport.h"

static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
               const struct nlattr *attr, int len,
               struct ovs_key_ipv4_tunnel *tun_key, bool keep_skb);

static int make_writable(struct sk_buff *skb, int write_len)
{
 if (!skb_cloned(skb) || skb_clone_writable(skb, write_len))
     return 0;

 return pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
}

/* remove VLAN header from packet and update csum accordingly. */
static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
{
 struct vlan_hdr *vhdr;
 int err;

 err = make_writable(skb, VLAN_ETH_HLEN);
 if (unlikely(err))
     return err;

 if (get_ip_summed(skb) == OVS_CSUM_COMPLETE)
     skb->csum = csum_sub(skb->csum, csum_partial(skb->data
                 + ETH_HLEN, VLAN_HLEN, 0));

 vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
 *current_tci = vhdr->h_vlan_TCI;

 memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
 __skb_pull(skb, VLAN_HLEN);

 vlan_set_encap_proto(skb, vhdr);
 skb->mac_header += VLAN_HLEN;
 skb_reset_mac_len(skb);

 return 0;
}

static int pop_vlan(struct sk_buff *skb)
{
 __be16 tci;
 int err;

 if (likely(vlan_tx_tag_present(skb))) {
     vlan_set_tci(skb, 0);
 } else {
     if (unlikely(skb->protocol != htons(ETH_P_8021Q) ||
              skb->len < VLAN_ETH_HLEN))
         return 0;

     err = __pop_vlan_tci(skb, &tci);
     if (err)
         return err;
 }
 /* move next vlan tag to hw accel tag */
 if (likely(skb->protocol != htons(ETH_P_8021Q) ||
        skb->len < VLAN_ETH_HLEN))
     return 0;

 err = __pop_vlan_tci(skb, &tci);
 if (unlikely(err))
     return err;

 __vlan_hwaccel_put_tag(skb, ntohs(tci));
 return 0;
}

static int push_vlan(struct sk_buff *skb, const struct ovs_action_push_vlan *vlan)
{
 if (unlikely(vlan_tx_tag_present(skb))) {
     u16 current_tag;

     /* push down current VLAN tag */
     current_tag = vlan_tx_tag_get(skb);

     if (!__vlan_put_tag(skb, current_tag))
         return -ENOMEM;

     if (get_ip_summed(skb) == OVS_CSUM_COMPLETE)
         skb->csum = csum_add(skb->csum, csum_partial(skb->data
                 + ETH_HLEN, VLAN_HLEN, 0));

 }
 __vlan_hwaccel_put_tag(skb, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
 return 0;
}

static int set_eth_addr(struct sk_buff *skb,
         const struct ovs_key_ethernet *eth_key)
{
 int err;
 err = make_writable(skb, ETH_HLEN);
 if (unlikely(err))
     return err;

 memcpy(eth_hdr(skb)->h_source, eth_key->eth_src, ETH_ALEN);
 memcpy(eth_hdr(skb)->h_dest, eth_key->eth_dst, ETH_ALEN);

 return 0;
}

static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
             __be32 *addr, __be32 new_addr)
{
 int transport_len = skb->len - skb_transport_offset(skb);

 if (nh->protocol == IPPROTO_TCP) {
     if (likely(transport_len >= sizeof(struct tcphdr)))
         inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
                      *addr, new_addr, 1);
 } else if (nh->protocol == IPPROTO_UDP) {
     if (likely(transport_len >= sizeof(struct udphdr))) {
         struct udphdr *uh = udp_hdr(skb);

         if (uh->check ||
             get_ip_summed(skb) == OVS_CSUM_PARTIAL) {
             inet_proto_csum_replace4(&uh->check, skb,
                          *addr, new_addr, 1);
             if (!uh->check)
                 uh->check = CSUM_MANGLED_0;
         }
     }
 }

 csum_replace4(&nh->check, *addr, new_addr);
 skb_clear_rxhash(skb);
 *addr = new_addr;
}

static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
              __be32 addr[4], const __be32 new_addr[4])
{
 int transport_len = skb->len - skb_transport_offset(skb);

 if (l4_proto == IPPROTO_TCP) {
     if (likely(transport_len >= sizeof(struct tcphdr)))
         inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
                       addr, new_addr, 1);
 } else if (l4_proto == IPPROTO_UDP) {
     if (likely(transport_len >= sizeof(struct udphdr))) {
         struct udphdr *uh = udp_hdr(skb);

         if (uh->check ||
             get_ip_summed(skb) == OVS_CSUM_PARTIAL) {
             inet_proto_csum_replace16(&uh->check, skb,
                           addr, new_addr, 1);
             if (!uh->check)
                 uh->check = CSUM_MANGLED_0;
         }
     }
 }
}

static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
           __be32 addr[4], const __be32 new_addr[4],
           bool recalculate_csum)
{
 if (recalculate_csum)
     update_ipv6_checksum(skb, l4_proto, addr, new_addr);

 skb_clear_rxhash(skb);
 memcpy(addr, new_addr, sizeof(__be32[4]));
}

static void set_ipv6_tc(struct ipv6hdr *nh, u8 tc)
{
 nh->priority = tc >> 4;
 nh->flow_lbl[0] = (nh->flow_lbl[0] & 0x0F) | ((tc & 0x0F) << 4);
}

static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl)
{
 nh->flow_lbl[0] = (nh->flow_lbl[0] & 0xF0) | (fl & 0x000F0000) >> 16;
 nh->flow_lbl[1] = (fl & 0x0000FF00) >> 8;
 nh->flow_lbl[2] = fl & 0x000000FF;
}

static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl)
{
 csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
 nh->ttl = new_ttl;
}

static int set_ipv4(struct sk_buff *skb, const struct ovs_key_ipv4 *ipv4_key)
{
 struct iphdr *nh;
 int err;

 err = make_writable(skb, skb_network_offset(skb) +
              sizeof(struct iphdr));
 if (unlikely(err))
     return err;

 nh = ip_hdr(skb);

 if (ipv4_key->ipv4_src != nh->saddr)
     set_ip_addr(skb, nh, &nh->saddr, ipv4_key->ipv4_src);

 if (ipv4_key->ipv4_dst != nh->daddr)
     set_ip_addr(skb, nh, &nh->daddr, ipv4_key->ipv4_dst);

 if (ipv4_key->ipv4_tos != nh->tos)
     ipv4_change_dsfield(nh, 0, ipv4_key->ipv4_tos);

 if (ipv4_key->ipv4_ttl != nh->ttl)
     set_ip_ttl(skb, nh, ipv4_key->ipv4_ttl);

 return 0;
}

static int set_ipv6(struct sk_buff *skb, const struct ovs_key_ipv6 *ipv6_key)
{
 struct ipv6hdr *nh;
 int err;
 __be32 *saddr;
 __be32 *daddr;

 err = make_writable(skb, skb_network_offset(skb) +
             sizeof(struct ipv6hdr));
 if (unlikely(err))
     return err;

 nh = ipv6_hdr(skb);
 saddr = (__be32 *)&nh->saddr;
 daddr = (__be32 *)&nh->daddr;

 if (memcmp(ipv6_key->ipv6_src, saddr, sizeof(ipv6_key->ipv6_src)))
     set_ipv6_addr(skb, ipv6_key->ipv6_proto, saddr,
               ipv6_key->ipv6_src, true);

 if (memcmp(ipv6_key->ipv6_dst, daddr, sizeof(ipv6_key->ipv6_dst))) {
     unsigned int offset = 0;
     int flags = OVS_IP6T_FH_F_SKIP_RH;
     bool recalc_csum = true;

     if (ipv6_ext_hdr(nh->nexthdr))
         recalc_csum = ipv6_find_hdr(skb, &offset,
                         NEXTHDR_ROUTING, NULL,
                         &flags) != NEXTHDR_ROUTING;

     set_ipv6_addr(skb, ipv6_key->ipv6_proto, daddr,
               ipv6_key->ipv6_dst, recalc_csum);
 }

 set_ipv6_tc(nh, ipv6_key->ipv6_tclass);
 set_ipv6_fl(nh, ntohl(ipv6_key->ipv6_label));
 nh->hop_limit = ipv6_key->ipv6_hlimit;

 return 0;
}

/* Must follow make_writable() since that can move the skb data. */
static void set_tp_port(struct sk_buff *skb, __be16 *port,
          __be16 new_port, __sum16 *check)
{
 inet_proto_csum_replace2(check, skb, *port, new_port, 0);
 *port = new_port;
 skb_clear_rxhash(skb);
}

static void set_udp_port(struct sk_buff *skb, __be16 *port, __be16 new_port)
{
 struct udphdr *uh = udp_hdr(skb);

 if (uh->check && get_ip_summed(skb) != OVS_CSUM_PARTIAL) {
     set_tp_port(skb, port, new_port, &uh->check);

     if (!uh->check)
         uh->check = CSUM_MANGLED_0;
 } else {
     *port = new_port;
     skb_clear_rxhash(skb);
 }
}

static int set_udp(struct sk_buff *skb, const struct ovs_key_udp *udp_port_key)
{
 struct udphdr *uh;
 int err;

 err = make_writable(skb, skb_transport_offset(skb) +
              sizeof(struct udphdr));
 if (unlikely(err))
     return err;

 uh = udp_hdr(skb);
 if (udp_port_key->udp_src != uh->source)
     set_udp_port(skb, &uh->source, udp_port_key->udp_src);

 if (udp_port_key->udp_dst != uh->dest)
     set_udp_port(skb, &uh->dest, udp_port_key->udp_dst);

 return 0;
}

static int set_tcp(struct sk_buff *skb, const struct ovs_key_tcp *tcp_port_key)
{
 struct tcphdr *th;
 int err;

 err = make_writable(skb, skb_transport_offset(skb) +
              sizeof(struct tcphdr));
 if (unlikely(err))
     return err;

 th = tcp_hdr(skb);
 if (tcp_port_key->tcp_src != th->source)
     set_tp_port(skb, &th->source, tcp_port_key->tcp_src, &th->check);

 if (tcp_port_key->tcp_dst != th->dest)
     set_tp_port(skb, &th->dest, tcp_port_key->tcp_dst, &th->check);

 return 0;
}

static int do_output(struct datapath *dp, struct sk_buff *skb, int out_port)
{
 struct vport *vport;

 if (unlikely(!skb))
     return -ENOMEM;

 vport = ovs_vport_rcu(dp, out_port);
 if (unlikely(!vport)) {
     kfree_skb(skb);
     return -ENODEV;
 }

 ovs_vport_send(vport, skb);
 return 0;
}

static int output_userspace(struct datapath *dp, struct sk_buff *skb,
             const struct nlattr *attr)
{
 struct dp_upcall_info upcall;
 const struct nlattr *a;
 int rem;

 upcall.cmd = OVS_PACKET_CMD_ACTION;
 upcall.key = &OVS_CB(skb)->flow->key;
 upcall.userdata = NULL;
 upcall.pid = 0;

 for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
      a = nla_next(a, &rem)) {
     switch (nla_type(a)) {
     case OVS_USERSPACE_ATTR_USERDATA:
         upcall.userdata = a;
         break;

     case OVS_USERSPACE_ATTR_PID:
         upcall.pid = nla_get_u32(a);
         break;
     }
 }

 return ovs_dp_upcall(dp, skb, &upcall);
}

static int sample(struct datapath *dp, struct sk_buff *skb,
       const struct nlattr *attr,
       struct ovs_key_ipv4_tunnel *tun_key)
{
 const struct nlattr *acts_list = NULL;
 const struct nlattr *a;
 int rem;

 for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
      a = nla_next(a, &rem)) {
     switch (nla_type(a)) {
     case OVS_SAMPLE_ATTR_PROBABILITY:
         if (net_random() >= nla_get_u32(a))
             return 0;
         break;

     case OVS_SAMPLE_ATTR_ACTIONS:
         acts_list = a;
         break;
     }
 }

 return do_execute_actions(dp, skb, nla_data(acts_list),
               nla_len(acts_list), tun_key, true);
}

static int execute_set_action(struct sk_buff *skb,
              const struct nlattr *nested_attr,
              struct ovs_key_ipv4_tunnel *tun_key)
{
 int err = 0;

 switch (nla_type(nested_attr)) {
 case OVS_KEY_ATTR_PRIORITY:
     skb->priority = nla_get_u32(nested_attr);
     break;

 case OVS_KEY_ATTR_TUN_ID:
     /* If we're only using the TUN_ID action, store the value in a
      * temporary instance of struct ovs_key_ipv4_tunnel on the stack.
      * If both IPV4_TUNNEL and TUN_ID are being used together we
      * can't write into the IPV4_TUNNEL action, so make a copy and
      * write into that version.
      */
     if (!OVS_CB(skb)->tun_key)
         memset(tun_key, 0, sizeof(*tun_key));
     else if (OVS_CB(skb)->tun_key != tun_key)
         memcpy(tun_key, OVS_CB(skb)->tun_key, sizeof(*tun_key));
     OVS_CB(skb)->tun_key = tun_key;

     OVS_CB(skb)->tun_key->tun_id = nla_get_be64(nested_attr);
     break;

 case OVS_KEY_ATTR_IPV4_TUNNEL:
     OVS_CB(skb)->tun_key = nla_data(nested_attr);
     break;

 case OVS_KEY_ATTR_ETHERNET:
     err = set_eth_addr(skb, nla_data(nested_attr));
     break;

 case OVS_KEY_ATTR_IPV4:
     err = set_ipv4(skb, nla_data(nested_attr));
     break;

 case OVS_KEY_ATTR_IPV6:
     err = set_ipv6(skb, nla_data(nested_attr));
     break;

 case OVS_KEY_ATTR_TCP:
     err = set_tcp(skb, nla_data(nested_attr));
     break;

 case OVS_KEY_ATTR_UDP:
     err = set_udp(skb, nla_data(nested_attr));
     break;
 }

 return err;
}

/* Execute a list of actions against 'skb'. */
static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
         const struct nlattr *attr, int len,
         struct ovs_key_ipv4_tunnel *tun_key, bool keep_skb)
{
 /* Every output action needs a separate clone of 'skb', but the common
  * case is just a single output action, so that doing a clone and
  * then freeing the original skbuff is wasteful.  So the following code
  * is slightly obscure just to avoid that. */
 int prev_port = -1;
 const struct nlattr *a;
 int rem;

 for (a = attr, rem = len; rem > 0;
      a = nla_next(a, &rem)) {
     int err = 0;

     if (prev_port != -1) {
         do_output(dp, skb_clone(skb, GFP_ATOMIC), prev_port);
         prev_port = -1;
     }

     switch (nla_type(a)) {
     case OVS_ACTION_ATTR_OUTPUT:
         prev_port = nla_get_u32(a);
         break;

     case OVS_ACTION_ATTR_USERSPACE:
         output_userspace(dp, skb, a);
         break;

     case OVS_ACTION_ATTR_PUSH_VLAN:
         err = push_vlan(skb, nla_data(a));
         if (unlikely(err)) /* skb already freed. */
             return err;
         break;

     case OVS_ACTION_ATTR_POP_VLAN:
         err = pop_vlan(skb);
         break;

     case OVS_ACTION_ATTR_SET:
         err = execute_set_action(skb, nla_data(a), tun_key);
         break;

     case OVS_ACTION_ATTR_SAMPLE:
         err = sample(dp, skb, a, tun_key);
         break;
     }

     if (unlikely(err)) {
         kfree_skb(skb);
         return err;
     }
 }

 if (prev_port != -1) {
     if (keep_skb)
         skb = skb_clone(skb, GFP_ATOMIC);

     do_output(dp, skb, prev_port);
 } else if (!keep_skb)
     consume_skb(skb);

 return 0;
}

/* We limit the number of times that we pass into execute_actions()
 * to avoid blowing out the stack in the event that we have a loop. */
#define MAX_LOOPS 5

struct loop_counter {
 u8 count;        /* Count. */
 bool looping;        /* Loop detected? */
};

static DEFINE_PER_CPU(struct loop_counter, loop_counters);

static int loop_suppress(struct datapath *dp, struct sw_flow_actions *actions)
{
 if (net_ratelimit())
     pr_warn("%s: flow looped %d times, dropping\n",
             ovs_dp_name(dp), MAX_LOOPS);
 actions->actions_len = 0;
 return -ELOOP;
}

/* Execute a list of actions against 'skb'. */
int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb)
{
 struct sw_flow_actions *acts = rcu_dereference(OVS_CB(skb)->flow->sf_acts);
 struct loop_counter *loop;
 int error;
 struct ovs_key_ipv4_tunnel tun_key;

 /* Check whether we've looped too much. */
 loop = &__get_cpu_var(loop_counters);
 if (unlikely(++loop->count > MAX_LOOPS))
     loop->looping = true;
 if (unlikely(loop->looping)) {
     error = loop_suppress(dp, acts);
     kfree_skb(skb);
     goto out_loop;
 }

 OVS_CB(skb)->tun_key = NULL;
 error = do_execute_actions(dp, skb, acts->actions,
                  acts->actions_len, &tun_key, false);

 /* Check whether sub-actions looped too much. */
 if (unlikely(loop->looping))
     error = loop_suppress(dp, acts);

out_loop:
 /* Decrement loop counter. */
 if (!--loop->count)
     loop->looping = false;

 return error;
}

  2. 独立内核模块示例代码

    #include <linux/module.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv4.h>
#include <linux/ip.h>
#include <linux/udp.h>
#include <linux/skbuff.h>

#define TARGET_PORT 12345  // 设置特定的目的端口
#define MULTICAST_IP "224.0.0.1"  // 指定的组播IP地址

// Netfilter钩子函数，用于处理入站的数据包
static unsigned int hook_func(void *priv, struct sk_buff *skb, const struct nf_hook_state *state)
{
 struct iphdr *ip_header;
 struct udphdr *udp_header;

 // 检查skb包是否为空
 if (!skb)
     return NF_ACCEPT;

 // 检查skb包是否包含IP头部
 if (!skb_network_header(skb))
     return NF_ACCEPT;

 // 获取IP头部和UDP头部
 ip_header = ip_hdr(skb);
 udp_header = (struct udphdr *)(skb_transport_header(skb) + ip_hdrlen(skb));

 // 检查是否为UDP协议和特定目的端口
 if (ip_header->protocol == IPPROTO_UDP && ntohs(udp_header->dest) == TARGET_PORT) {
     // 修改目的IP地址为指定的组播IP
     ip_header->daddr = in_aton(MULTICAST_IP);

     // 重新计算校验值
     udp_header->check = 0;
     udp_header->check = csum_tcpudp_magic(ip_header->saddr, ip_header->daddr,
                                            skb->len - ip_hdrlen(skb), IPPROTO_UDP, csum_partial(udp_header, skb->len - ip_hdrlen(skb), 0));

     // 更新校验和
     skb->ip_summed = CHECKSUM_NONE;
     skb->pkt_type = PACKET_MULTICAST;

     // 让tcp/ip协议栈处理skb包
     return NF_ACCEPT;
 }

 return NF_ACCEPT;
}

// 初始化和清理模块
static struct nf_hook_ops nfho = {
 .hook = hook_func,
 .hooknum = NF_BR_PRE_ROUTING,
 .pf = NFPROTO_BRIDGE,
 .priority = NF_BR_PRI_FIRST,
};

static int __init my_module_init(void)
{
 return nf_register_hook(&nfho);
}

static void __exit my_module_exit(void)
{
 nf_unregister_hook(&nfho);
}

module_init(my_module_init);
module_exit(my_module_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Kimson");
  3. linux内核中如何修改skb报文
  4. linux-2-6-network-stack-paper.pdf
  5. skbuff.pdf

因为历史原因，很多工具还需要32位库，Debian/Ubuntu默认未开启支持，直接安装会提示失败，如：
2023-05-30T02:39:18.png

开启i386库支持

sudo dpkg --add-architecture i386
sudo apt update

这样就可以愉快的安装了。

从搭建Blog开始

近期抽空注册了一个免费的VPS，本着不浪费的原则，考虑顺手搭建个Blog，虽然很老土，但还是有不少收获，至少可以解决几点关键需求：

  • 个人技术存档
  • 工具类后台需要
  • 练练手，动动脑

技术方案选型

考虑几点关键需求：

  • 支持HTTPS，证书注册及维护简单
  • 有管理后台，支持Markdown，方便编写文档
  • 小小简单，快速，对VPS要求低
  • 整个站点维护简单，移机轻松

综合上述需求，对应的技术方案：

  • Caddy 支持免费HTTPS证书自动注册及续期
  • typecho 小小简单，支持Markdown

  • Dockers+Docker-compose 实现快速部署，并解决后期的维护问题
    所以综合建立3个docker，分别是：

    Caddy2 + php8 + mysql8

VPS及域名

  • VPS
    VPS有太多的选择，个人注册了Oracle Cloud免费版，可以参考这篇文章，获取高性价比VPS：高性价比VPS整理
  • 域名
    域名注册推荐: Namesilo 或者 Freenom

Docker-compose

Docker-compose.yml:

version: '3'

services:

    caddy:
        image: caddy
        ports:
            - "80:80"
            - "443:443"
            - "443:443/udp"
        volumes:
            - /path_to_your/Caddyfile:/etc/caddy/Caddyfile
            - /path_to_your/caddy_data:/data
            - /path_to_your/caddy_config:/config
#Caddy requires write access to two locations: a data directory, and a configuration directory.
            - /path_to_your/site:/srv
        restart: unless-stopped
        networks:
            - frontend
    db:
        image: mysql
        volumes:
            - /path_to_your/database:/var/lib/mysql
            - /path_to_your/mysql_logs:/var/log/mysql
            - /path_to_your/mysql_conf:/etc/mysql/conf.d
        restart: always
        expose:
            - "3306"
        environment:
            - MYSQL_ROOT_PASSWORD=your_root_password
            - MYSQL_DATABASE=typecho
            - MYSQL_USER=typecho
            - MYSQL_PASSWORD=your_user_password
            - TZ=Asia/Shanghai
        networks:
            - frontend
    php:
      #image: php:fpm
        build: .
        volumes:
            - /path_to_your/site:/var/www/html
        restart: always
        expose:
            - "9000"
        environment:
          - TZ=Asia/Shanghai
        depends_on:
            - db
            - caddy
        networks:
            - frontend
networks:
    frontend:

Caddy配置

Caddyfile：

v365.life www.v365.life {
    encode gzip
    tls [email protected]
    php_fastcgi php:9000 {
        root /var/www/html
    }
    file_server
    log {
      output file /data/log/web.log
    }
}

PHP docker

dockerfile:

FROM php:fpm
RUN docker-php-ext-install mysqli pdo pdo_mysql && docker-php-ext-enable pdo_mysql

typecho

下载最新的typecho zip包，并解压到目录：/path_to_your/site下面

运行

执行如下命令，启动服务：

sudo docker-compose up -d

启动后根据typecho安装页面提示进行配置，在数据库界面选择pdo Mysql数据接口，需要根据配置填写：

  • 用户名: 根据配置MYSQL_USER=typecho
  • 密码: 根据配置MYSQL_PASSWORD=your_user_password
  • 数据库路径: db (默认的localhost需要修改）
  • 数据库名: typecho

注意点

  • Caddy V2与V1配置文件不兼容，有一些细节关键字段有差异，可以参考：Caddy2文档 及 CaddyV2配置文件解析
  • PHP、Caddy及Mysql都在不同的Dockers内，不同于单机部署，需要通过bridge互相访问，即通过docker名+端口号形式，在配置文件时需要特别注意
  • Mysql /var/lib/mysql映射的数据库所在目录，第一次需确保里面为空，这样才能根据ENV变量自动创建MYSQL_DATABASE
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