作者：张华 发表于：2022-07-08
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编译ovs并启动ovs-vswitchd
#https://docs.ovn.org/en/latest/intro/install/general.html
sudo apt-get -y install build-essential fakeroot graphviz autoconf automake \
bzip2 debhelper dh-autoreconf libssl-dev libtool openssl procps sparse \
python3 wget gdb git libnetfilter-conntrack-dev libmnl-dev libelf-dev
sudo apt purge openvswitch-switch openvswitch-common python3-openvswitch -y
git clone https://github.com/openvswitch/ovs.git
cd /bak/linux/ovs
./boot.sh
#/lib/modules/5.15.0-40-generic/build is version 5.15.35, but version newer than 5.8.x is not supported
#./configure --prefix=/usr --localstatedir=/var --sysconfdir=/etc --enable-ssl --with-linux=/lib/modules/`uname -r`/build
./configure --help |grep debug
#CFLAGS="-Wall -O2 -g" ./configure --prefix=/usr --localstatedir=/var --sysconfdir=/etc --enable-ssl --with-debug
./configure CFLAGS="-g -ggdb -O0 -Wno-error -Wno-unused-function -Wno-implicit-fallthrough -Wno-missing-field-initializers" \
-prefix=/usr --localstatedir=/var --sysconfdir=/etc --enable-ssl --with-debug
make -j8
sudo make install
sudo make modules_install #but version newer than 5.8.x is not supported
sudo ovs-dpctl show
#不删除openvswitch.ko, 可能会抛出:'Unknown symbol in module'
#但删除时可能会抛出:Module openvswitch is in use,那是因为lsmod |grep openvswitch存在引用计算
#删了之后除了下列的手动安装通过'sudo make modules_install'也能安装, 这个命令不work是因为上面没有加--with-linux=/lib/modules/`uname -r`/build
#但"version 5.15.35, but version newer than 5.8.x is not supported"这个错误装不了ko, 那还是用之前deb安装的ko模块吧
./configure --help |grep debug
#sudo /usr/share/openvswitch/scripts/ovs-ctl stop && sudo ovs-dpctl del-dp ovs-system && sudo rmmod -f openvswitch.ko
# Module openvswitch is in use,Intall new module and it's depends
#sudo modinfo ./datapath/linux/openvswitch.ko |grep depends
#sudo modprobe nf_conntrack nf_nat nf_defrag_ipv6 libcrc32c nf_nat_ipv6 gre nf_nat_ipv4
#sudo insmod ./datapath/linux/openvswitch.ko
#sudo modinfo ./datapath/linux/openvswitch.ko |grep depends
#config_file="/etc/depmod.d/openvswitch.conf"
#for module in ./datapath/linux/*.ko; do
# modname="$(basename ${module})"
# echo "override ${modname%.ko} * extra" |sudo tee -a "$config_file"
# echo "override ${modname%.ko} * weak-updates" |sudo tee -a "$config_file"
#done
#sudo depmod -a
#sudo modprobe openvswitch
export PATH=$PATH:/usr/share/ovn/scripts:/usr/share/openvswitch/scripts
#start ovs-vswitchd
sudo /usr/share/openvswitch/scripts/ovs-ctl start --system-id=$(hostname)
#sudo /usr/bin/ovs-appctl -t ovsdb-server ovsdb-server/add-remote ptcp:6640:192.168.122.1 #enable remote db
#sudo ovs-vsctl show
sudo ovs-vsctl get Open_vSwitch . external-ids
#sudo cp debian/openvswitch-switch.init /etc/init.d/openvswitch-switch
#debug it
sudo cgdb -p `pidof ovs-vswitchd`
编译ovn
cd /bak/linux/
git clone https://github.com/ovn-org/ovn.git
cd ovn
./boot.sh
#configure ovn to include -g to build debug symbols and -O2 to enable optimizations,
#perf should use '--call-graph dwarf' rather than '--call-graph fp' due to 'no-omit-frame-pointer'
#the error 'utilities/ovn-nbctl.c too few arguments to function ‘inet_parse_active’' will be hit with '--enable-sparse'
#'-fsanitize=address -fno-omit-frame-pointer -fno-common' will cause: LeakSanitizer does not work under ptrace (strace, gdb, etc)
#'--enable-coverage' will cause: libgconv ... overwriting an existing profile data with a different timestamp
CFLAGS="-g -O2" ./configure \
--with-ovs-source=../ovs --with-ovs-build=../ovs \
--prefix=/usr --localstatedir=/var --sysconfdir=/etc \
--enable-Werror --with-debug
CFLAGS="-g -O2" make -j8
sudo make install
#unit test
make check
启动ovn-central(ovn-northd, ovnnb, ovnsb)
export PATH=$PATH:/usr/share/ovn/scripts:/usr/share/openvswitch/scripts
sudo /usr/share/ovn/scripts/ovn-ctl stop_northd
sudo /usr/share/ovn/scripts/ovn-ctl start_northd
它等于:
sudo mkdir -p /etc/ovn
sudo mkdir -p /var/run/ovn
#sudo killall ovsdb-server && sudo rm -rf /etc/ovn/*
sudo /usr/bin/ovsdb-tool create /etc/ovn/ovnnb_db.db ovn-nb.ovsschema
sudo /usr/bin/ovsdb-tool create /etc/ovn/ovnsb_db.db ovn-sb.ovsschema
sudo /usr/sbin/ovsdb-server /etc/ovn/ovnnb_db.db --remote=punix:/var/run/ovn/ovnnb_db.sock \
--remote=db:OVN_Northbound,NB_Global,connections \
--private-key=db:OVN_Northbound,SSL,private_key \
--certificate=db:OVN_Northbound,SSL,certificate \
--bootstrap-ca-cert=db:OVN_Northbound,SSL,ca_cert \
--pidfile=/var/run/ovn/ovnnb-server.pid --detach --log-file=/var/log/ovn/ovnnb-server.log
sudo /usr/sbin/ovsdb-server /etc/ovn/ovnsb_db.db --remote=punix:/var/run/ovn/ovnsb_db.sock \
--remote=db:OVN_Southbound,SB_Global,connections \
--private-key=db:OVN_Southbound,SSL,private_key \
--certificate=db:OVN_Southbound,SSL,certificate \
--bootstrap-ca-cert=db:OVN_Southbound,SSL,ca_cert \
--pidfile=/var/run/ovn/ovnsb-server.pid --detach --log-file=/var/log/ovn/ovnsb-server.log
sudo /usr/bin/ovn-nbctl --no-wait init
sudo /usr/bin/ovn-sbctl init
#Start ovn-northd, telling it to connect to the OVN db servers same Unix domain socket
#sudo /usr/bin/ovn-northd --pidfile --detach --log-file=/var/log/ovn/ovn-northd.log
sudo /usr/bin/ovn-northd
sudo /usr/bin/ovn-nbctl set-connection ptcp:6641:0.0.0.0 -- set connection . inactivity_probe=60000
sudo /usr/bin/ovn-sbctl set-connection ptcp:6642:0.0.0.0 -- set connection . inactivity_probe=60000
sudo netstat -lntp |grep 664
启动ovn-host
#sudo /usr/bin/ovn-controller unix:/var/run/openvswitch/db.sock -vconsole:emer -vsyslog:err -vfile:info --no-chdir --log-file=/var/log/ovn/ovn-controller.log --pidfile=/var/run/ovn/ovn-controller.pid --detach --monitor
sudo /usr/share/ovn/scripts/ovn-ctl stop_controller
sudo /usr/share/ovn/scripts/ovn-ctl start_controller
然后配置它:
#on all compute chassises (we also have one chassis so it's also a compute chassis), make ovn-controller connect to southbound db.
# lxcbr0=192.168.121.1, IP=$(ip addr show eth0| awk '$1 == "inet" {print $2}' | cut -f1 -d/)
sudo /usr/bin/ovs-vsctl set open_vswitch . \
external_ids:ovn-remote=tcp:192.168.121.1:6642 \
external_ids:ovn-encap-ip=192.168.121.1 \
external_ids:ovn-encap-type=geneve \
external_ids:system-id=ovn1
ovs-vsctl set Open_vSwitch . external-ids:ovn-cms-options=\"enable-chassis-as-gw\"
$ sudo ovs-vsctl get Open_vSwitch . external-ids
{hostname=t440p.lan, ovn-cms-options=enable-chassis-as-gw, ovn-encap-ip="192.168.121.1", ovn-encap-type=geneve, ovn-remote="tcp:192.168.121.1:6642", rundir="/var/run/openvswitch", system-id=ovn1}
sudo /usr/bin/ovs-vsctl add-br br-int
sudo /usr/bin/ovs-vsctl set bridge br-int protocols=OpenFlow10,OpenFlow11,OpenFlow12,OpenFlow13,OpenFlow14,OpenFlow15
源码调试
这里只是有源码调试, 编译时已经通过( CFLAGS=“-g -O2” )带了符号表了. 如果ovn是通过deb包装的得安装dbg后缀的符号表.
sudo /usr/share/ovn/scripts/ovn-ctl stop_controller
sudo killall ovn-controller
sudo cgdb --args /usr/bin/ovn-controller unix:/var/run/openvswitch/db.sock -vconsole:emer -vsyslog:err -vfile:info --no-chdir --log-file=/var/log/ovn/ovn-controller.log --pidfile=/var/run/ovn/ovn-controller.pid --detach --monitor
#借助 follow-fork-mode 选项，我们只能选择调试子进程还是父进程，且一经选定，调试过程中将无法改变。如果既想调试父进程，又想随时切换并调试某个子进程，就需要借助 detach-on-fork 选项
#(gdb) set detach-on-fork off #http://c.biancheng.net/view/8274.html
(gdb) set follow-fork-mode child
(gdb) b main
(gdb) b update_sb_monitors
(gdb) clear update_sb_monitors
(gdb) info b
#eg: debug 'OVNSB commit failed, force recompute next time', ovsdb_idl_loop_commit_and_wait
#这个估计这种带agent的需要设置某个超时时间来避免ovn-controller agent和SB DB的连接中断造成重计算
(gdb) b ovsdb_idl_loop_commit_and_wait
(gdb) b ovsdb_idl_wait
(gdb) r
[可选]启动一个lxd容器作为第二个节点
安装并设置lxd.
#https://blog.csdn.net/quqi99/article/details/125004749
sudo snap install lxd --classic
sudo usermod -aG $USER lxd
# MUST NOT use sudo, so must cd to home dir to run it
cd ~ && lxd init --auto
sudo chown -R $USER ~/.config/
export EDITOR=vim
#lxc storage create default dir && lxc profile device add default root disk path=/ pool=default
lxc storage show default
lxc network show lxdbr0
lxc network set lxdbr0 ipv4.address=192.168.121.1/24
lxc network set lxdbr0 ipv6.address none
ip addr show lxdbr0
sudo iptables-save |grep 192.168.121
ps -ef |grep 192.168.121
cat << EOF | tee ./lxd-profile.yaml
config:
boot.autostart: "true"
linux.kernel_modules: openvswitch,nbd,ip_tables,ip6_tables
security.nesting: "true"
security.privileged: "true"
description: ""
devices:
eth0:
mtu: "9000"
name: eth0
nictype: bridged
parent: lxdbr0
type: nic
eth1:
mtu: "9000"
name: eth1
nictype: bridged
parent: lxdbr0
type: nic
kvm:
path: /dev/kvm
type: unix-char
mem:
path: /dev/mem
type: unix-char
root:
path: /
pool: default
type: disk
tun:
path: /dev/net/tun
type: unix-char
name: juju-default
used_by: []
EOF
lxc profile create juju-default 2>/dev/null || echo "juju-default profile already exists"
cat ./lxd-profile.yaml |lxc profile edit juju-default
lxc profile show juju-default
通过一个lxd容器:
# juju-default uses eth0 so must use eth0 here as well
cat << EOF | tee network.yml
version: 1
config:
- type: physical
name: eth0
subnets:
- type: static
ipv4: true
address: 192.168.121.2
netmask: 255.255.255.0
gateway: 192.168.121.1
control: auto
- type: nameserver
address: 192.168.99.1
EOF
lxc launch ubuntu:focal ovn2 -p juju-default --config=user.network-config="$(cat network.yml)"
lxc exec `lxc list |grep ovn2 |awk -F '|' '{print $2}'` bash
为了避免版本不同我们不通过apt来安装(openvswitch-switch ovn-host),而是重复上面的步骤来源码安装OVS与OVN(scp -r /bak/linux/ov* [email protected]:/root/), 然后再按下列步骤仅启动ovs-vswitchd与ovn-controller. 为方便, 也可以试试’apt install openvswitch-switch ovn-host’的.
export PATH=$PATH:/usr/share/ovn/scripts:/usr/share/openvswitch/scripts
#start ovs-vswitchd
sudo /usr/share/openvswitch/scripts/ovs-ctl start --system-id=$(hostname)
#start ovn-controller
ovs-vsctl add-br br-int
ovs-vsctl set bridge br-int protocols=OpenFlow10,OpenFlow11,OpenFlow12,OpenFlow13,OpenFlow14,OpenFlow15
ovs-vsctl set open_vswitch . \
external_ids:ovn-remote=tcp:192.168.122.1:6642 \
external_ids:ovn-encap-ip=$(ip addr show eth0| awk '$1 == "inet" {print $2}' | cut -f1 -d/) \
external_ids:ovn-encap-type=geneve \
external_ids:system-id=$(hostname)
ovs-vsctl set Open_vSwitch . external-ids:ovn-cms-options=\"enable-chassis-as-gw\"
root@ovn2:~/ovn# ovs-vsctl get Open_vSwitch . external-ids
{hostname=ovn2, ovn-cms-options=enable-chassis-as-gw, ovn-encap-ip="192.168.121.2", ovn-encap-type=geneve, ovn-remote="tcp:192.168.122.1:6642", rundir="/var/run/openvswitch", system-id=ovn2}
搭建一个小ovn环境测试
#https://blog.russellbryant.net/2016/11/11/ovn-logical-flows-and-ovn-trace/
# Create the first logical switch and its two ports.
sudo ovn-nbctl ls-add sw0
sudo ovn-nbctl lsp-add sw0 sw0-port1
sudo ovn-nbctl lsp-set-addresses sw0-port1 "00:00:00:00:00:01 10.0.0.51"
sudo ovn-nbctl lsp-set-port-security sw0-port1 "00:00:00:00:00:01 10.0.0.51"
sudo ovn-nbctl lsp-add sw0 sw0-port2
sudo ovn-nbctl lsp-set-addresses sw0-port2 "00:00:00:00:00:02 10.0.0.52"
sudo ovn-nbctl lsp-set-port-security sw0-port2 "00:00:00:00:00:02 10.0.0.52"
# Create the second logical switch and its two ports.
sudo ovn-nbctl ls-add sw1
sudo ovn-nbctl lsp-add sw1 sw1-port1
sudo ovn-nbctl lsp-set-addresses sw1-port1 "00:00:00:00:00:03 192.168.1.51"
sudo ovn-nbctl lsp-set-port-security sw1-port1 "00:00:00:00:00:03 192.168.1.51"
sudo ovn-nbctl lsp-add sw1 sw1-port2
sudo ovn-nbctl lsp-set-addresses sw1-port2 "00:00:00:00:00:04 192.168.1.52"
sudo ovn-nbctl lsp-set-port-security sw1-port2 "00:00:00:00:00:04 192.168.1.52"
# Create a logical router between sw0 and sw1.
sudo ovn-nbctl create Logical_Router name=lr0
sudo ovn-nbctl lrp-add lr0 lrp0 00:00:00:00:ff:01 10.0.0.1/24
sudo ovn-nbctl lsp-add sw0 sw0-lrp0 \
-- set Logical_Switch_Port sw0-lrp0 type=router \
options:router-port=lrp0 addresses='"00:00:00:00:ff:01"'
sudo ovn-nbctl lrp-add lr0 lrp1 00:00:00:00:ff:02 192.168.1.1/24
sudo ovn-nbctl lsp-add sw1 sw1-lrp1 \
-- set Logical_Switch_Port sw1-lrp1 type=router \
options:router-port=lrp1 addresses='"00:00:00:00:ff:02"'
sudo ovn-sbctl lflow-list
但是它报了下列错, 为什么呢?
$ sudo ovn-nbctl lsp-set-addresses sw0-port1 "00:00:00:00:00:01 10.0.0.51"
ovn-nbctl: 10.0.0.51: Invalid address format. See ovn-nb(5). Hint: An Ethernet address must be listed before an IP address, together as a single argument.
下面gdb调试显示是因为sudo上的双引号被吃了.
$ sudo cgdb ovn-nbctl
...
(gdb) run lsp-set-addresses sw0-port1 "00:00:00:00:00:03 10.0.0.5"
Starting program: /usr/bin/ovn-nbctl lsp-set-addresses sw0-port1 "00:00:00:00:00:03 10.0.0.5"
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Inferior 1 (process 110752) exited normally]
(gdb) run lsp-set-addresses sw0-port1 00:00:00:00:00:03 10.0.0.5
Starting program: /usr/bin/ovn-nbctl lsp-set-addresses sw0-port1 00:00:00:00:00:03 10.0.0.5
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
ovn-nbctl: 10.0.0.5: Invalid address format. See ovn-nb(5). Hint: An Ethernet address must be listed before an IP address, together as a single argument.
[Inferior 1 (process 110859) exited with code 01]
使用下面方法双引号也会被吃.
sudo cgdb --args ovn-nbctl lsp-set-addresses sw0-port1 "00:00:00:00:00:03 10.0.0.4"
用root用户或者将命令写在脚本里然后再运行"sudo bash test.sh"不会被吃. 遇到了类似的问题(https://stackoverflow.com/questions/10835933/how-can-i-preserve-quotes-in-printing-a-bash-scripts-arguments)
OVS DB CLI
#ovsdb-client只可以查看数据, 默认是使用unix:/var/run/openvswitch/db.sock查看ovs-server DB，也可以切换如unix:/var/run/ovn/ovnsb_db.sock查看OVN SBDB
cat /etc/openvswitch/conf.db
sudo ovsdb-client dump
sudo ovsdb-client list-dbs
sudo ovsdb-client list-tables Open_vSwitch
sudo ovsdb-client list-columns Open_vSwitch Port
#sudo ovsdb-client dump Open_vSwitch Port
#sudo ovsdb-client dump unix:/var/run/openvswitch/db.sock
sudo ovsdb-client dump unix:/var/run/ovn/ovnsb_db.sock
sudo ovsdb-client list-dbs unix:/var/run/ovn/ovnsb_db.sock
sudo ovsdb-client list-tables unix:/var/run/ovn/ovnsb_db.sock |grep Encap
sudo ovsdb-client dump unix:/var/run/ovn/ovnsb_db.sock OVN_Southbound Encap
#修改ovs-server DB的数据可以使用ovs-vsctl
sudo ovs-vsctl list Port
sudo ovs-vsctl --columns=_uuid,external_ids,name list Port
sudo ovs-vsctl --if-exists set Port b8e62998-5560-4eff-972a-01eed8d20bf6 external_ids:quqi='test'
sudo ovs-vsctl --if-exists get Port b8e62998-5560-4eff-972a-01eed8d20bf6 external_ids:quqi
sudo ovs-vsctl --if-exists remove Port b8e62998-5560-4eff-972a-01eed8d20bf6 external_ids quqi='test'
sudo ovs-vsctl --if-exists add Port b8e62998-5560-4eff-972a-01eed8d20bf6 external_ids quqi2='test2'
sudo ovs-vsctl --if-exists remove Port b8e62998-5560-4eff-972a-01eed8d20bf6 external_ids quqi2='test2'
#修改OVN SBDB的数据可不是用ovs-vsctl哦，而是使用ovn-sbctl
sudo ovs-sbctl list Chassis
sudo ovn-sbctl destroy Chassis 9d9ff1ce-f611-4ac3-96ea-25722c6cfd1c
#同时，修改OVN SBDB的数据使用ovn-nbctl
ovn-nbctl --help
#ovs-appctl通过传不同的unixctl文件，可以同时操作ovsdb-server, ovs-vswitchd, ovnnb, ovnsb等进程
ls /var/run/openvswitch/*ctl
ls /var/run/ovn/*.ctl
#sudo ovs-appctl -t ovsdb-server list-commands
sudo ovs-appctl -t /var/run/openvswitch/ovsdb-server.21606.ctl list-commands
sudo ovs-appctl -t /var/run/openvswitch/ovs-vswitchd.21623.ctl list-commands
sudo ovs-appctl -t /var/run/ovn/ovnnb_db.ctl list-commands
sudo ovs-appctl -t /var/run/ovn/ovn-northd.21745.ctl list-commands
sudo ovs-appctl -t /var/run/ovn/ovnnb_db.ctl list-commands
sudo ovs-appctl -t /var/run/ovn/ovnsb_db.ctl list-commands
sudo ovs-appctl -t /var/run/ovn/ovn-controller.21762.ctl list-commands
#ovn-controller.log is too big
sudo ovs-appctl -t /var/run/ovn/ovn-controller*.ctl list-commands
sudo ovs-appctl -t /var/run/ovn/ovn-controller*.ctl vlog/list-pattern
sudo ovs-appctl -t /var/run/ovn/ovn-controller*.ctl vlog/list
sudo ovs-appctl -t /var/run/ovn/ovn-controller*.ctl vlog/list |grep chassis
sudo ovs-appctl -t /var/run/ovn/ovn-controller*.ctl vlog/set chassis:file:dbg
sudo ovs-appctl -t /var/run/ovn/ovn-controller*.ctl vlog/set ANY:ANY:err
#其他
other_config : stats-update-interval #将统计信息写入数据库的间隔时间
other_config : flow-limit #在flow table中flow entry的数量
other_config : n-handler-threads #用于处理新flow的线程数
other_config : n-revalidator-threads ：用于验证flow的线程数.
other_config : enable-statistics
ovs-vsctl set-manager ptcp:8881 #Manager表用于配置ovsdb-server
#ovs-vsctl del-manager
#ovs-vsctl set-manager pssl:8881
#ovs-vsctl set-ssl private.key cert.pem ca.pem
OVS/OVN Trace
linuxbridge，是纯粹根据MAC转发，桥内的转发问题通常我们看看fdb表项正确，ebtables、iptables是否做了拦截就能解决大部分问题了. 而ovs使用openflow 流表转发报文，情况就复杂的多，特别在使用多个datapath bridge、多级流表的情况下，通过肉眼看流表还是很费力的. OVS/OVN Trace则方便来定位问题.
- ovn-trace, 只能用于ovn，在Centrial节点执行，跟踪OVN托管的datapath，显示内容和ovn逻辑配置对应，可读性好。
- ovs-appctl ofproto/trace, 可以在非central节点执行，而且可以跟踪non-ovn托管的datapath，但显示内容更加抽象，可读性差；
- 它们都是通过查询ovs流表整理出路径，并非构造真实报文。 二者可以相互转换(ovs-appctl ofproto/trace “xxxx” > tmp && ovn-detrace < tmp).
另外需要依赖外部模块时，可能就无法使用。比如，如果pipeline 中用到ct，是无法真正进入ct模块做报文修改，如nat修改，就会造成trace失效，所以使用起来还是有一定限制的。
可参考我之前关于ovn的一些博客, 或者: https://www.jianshu.com/p/c308ecc3b191
根据unit test + gdb来理解ovs代码
根据单元测试代码(Documentation/topics/testing.rst) + gdb来一步步调试理解代码：
1, 以下列test-ovsdb log-io为例
#make check TESTSUITEFLAGS=--help
#make check TESTSUITEFLAGS='-k ovsdb'
#./tests/testsuite -h
./tests/testsuite -C tests -v AUTOTEST_PATH=utilities:vswitchd:ovsdb:vtep:tests::ovn/controller-vtep:ovn/northd:ovn/utilities:ovn/controller -k ovsdb > test.txt
241 1329. ovsdb-log.at:3: testing create empty, reread ...
242 ./ovsdb-log.at:6: test-ovsdb log-io file create
243 stderr:
244 ./ovsdb-log.at:10: test-ovsdb log-io file read-only read
245 stderr:
246 ./ovsdb-log.at:15: test -f .file.~lock~
247 1329. ovsdb-log.at:3: ok
2, 相应的调用代码如下， 是调用了＂test-ovsdb log-io file create＂
grep -r 'test-ovsdb log-io file create' ./tests/testsuite
...
335117 printf "%s\n" "$at_srcdir/ovsdb-log.at:6: test-ovsdb log-io file create"
335118 at_fn_check_prepare_trace "ovsdb-log.at:6"
335119 ( $at_check_trace; test-ovsdb log-io file create
335120 ) >>"$at_stdout" 2>>"$at_stderr" 5>&-
335121 at_status=$? at_failed=false
335122 $at_check_filter
335123 echo stderr:; cat "$at_stderr"
335124 echo >>"$at_stdout"; printf "%s\n" "file: open successful
335125 " | \
335126 $at_diff - "$at_stdout" || at_failed=:
335127 at_fn_check_status 0 $at_status "$at_srcdir/ovsdb-log.at:6"
335128 $at_failed && at_fn_log_failure \
335129 "log"
335130 $at_traceon; }
3, gdb debug test-ovsdb
hua@t440p:/bak/linux/ovs$ gdb ./tests/test-ovsdb
Reading symbols from ./tests/test-ovsdb...
(gdb) b do_log_io
Breakpoint 1 at 0xedad: file tests/test-ovsdb.c, line 324.
(gdb) run log-io file create
Starting program: /bak/linux/ovs/tests/test-ovsdb log-io file create
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Breakpoint 1, do_log_io (ctx=0x7fffffffd920) at tests/test-ovsdb.c:324
324 {
快速重启
可通过下列三个命令快速重启这个ovn测试环境
sudo /usr/share/openvswitch/scripts/ovs-ctl stop --system-id=$(hostname) && sudo /usr/share/openvswitch/scripts/ovs-ctl start --system-id=$(hostname)
sudo /usr/share/ovn/scripts/ovn-ctl stop_northd && sudo /usr/share/ovn/scripts/ovn-ctl start_northd
sudo /usr/share/ovn/scripts/ovn-ctl stop_controller && sudo /usr/share/ovn/scripts/ovn-ctl start_controller
有时候ovn-controller.log文件会非常大，原因是会因为这个错误＂Could not find Chassis, will create it. Transaction causes multiple rows in “Encap” table to have identical values＂产生很多recompute的日志．所以并不是调日志级别可以解决的：
sudo ovs-appctl -t /var/run/ovn/ovn-controller*.ctl vlog/set ANY:ANY:err
直接删除Encap (sudo ovn-sbctl destroy Encap xxx)是删不掉的，因为它关联chassis，所以删除chassis(sudo ovn-sbctl destroy chassis xxx)能将chassis与encap一起删除再自动新建一个新的，然后看到这个日志似乎不报了．
源码
ovn-controller源码分析 - https://blog.csdn.net/fengcai_ke/article/details/125710004
ovn-northd 源码分析 - http://events.jianshu.io/p/e2139ecd0463
Referecne
[1] https://github.com/lishuhuakai/ovs_reading/blob/master/Document/Openvswtich%E5%AE%9E%E9%AA%8C%E6%95%99%E7%A8%8B.pdf
[2] https://github.com/lishuhuakai/ovs_reading/blob/master/Document/Openvswitch%E6%BA%90%E7%A0%81%E9%98%85%E8%AF%BB%E7%AC%94%E8%AE%B0.pdf