repmgr+PostgreSQL故障自动转移
创建dockerfile
# 使用 CentOS 7 作为基础镜像
FROM centos:7
# 设置环境变量
ENV PG_MODE=primary \
PG_USER=postgres \
PG_PASSWORD=postgres \
NODE_ROLE=master \
MASTER_NAME=master \
MASTER_PORT=5432 \
RE_USER=repmgr \
NODE_ID=1 \
#NET_SEGMENT=192.168.0 \
NODE_NAME=master1 \
PG_DATADIR=/home/postgres/pgdata \
PG_REPMGR_CONF=/home/postgres/repmgr.conf \
PG_BINDIR=/usr/pgsql-12/bin \
PG_CONFIGDIR=/home/postgres/pgdata/postgresql.conf \
PRIORITY=1 \
CONNINFO_HOST=master \
CONNINFO_PORT=5432 \
PATH="/usr/pgsql-12/bin:${PATH}"
# 创建postgres用户和组
RUN groupadd -r postgres \
&& useradd -r -g postgres postgres
# 安装所需的软件和工具
RUN yum -y install epel-release \
&& yum -y install https://download.postgresql.org/pub/repos/yum/reporpms/EL-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm \
&& yum -y install postgresql12 postgresql12-server postgresql12-contrib repmgr12 \
&& yum -y install which sudo iproute hostname \
&& yum -y clean all
# 创建脚本存放目录
RUN mkdir -p /home/runtime/ \
&& chown -R postgres:postgres /home/runtime/
# 将 functions 文件和 entrypoint.sh 添加到镜像中
#COPY functions /home/postgres/runtime/functions
COPY functions /home/runtime/functions
#COPY entrypoint.sh /home/postgres/runtime/entrypoint.sh
COPY entrypoint.sh /home/runtime/entrypoint.sh
# 修改文件权限与属性
RUN mkdir -p /home/postgres/pgdata \
&& chown -R postgres:postgres /home/postgres \
#&& chown -R postgres:postgres /home/postgres/pgdata \
#&& chown 777 /home/postgres/pgdata \
#&& chmod +x /home/postgres/runtime/entrypoint.sh \
&& chmod +x /home/runtime/entrypoint.sh \
#&& chmod +x /home/postgres/runtime/functions
&& chmod +x /home/runtime/functions
#&& usermod -a -G root postgres \
#&& chmod 770 /home/postgres
RUN echo 'postgres ALL=(ALL) NOPASSWD: /bin/chown' >> /etc/sudoers
# 切换到 postgres 用户
USER postgres
# 初始化 PostgreSQL 数据目录
#RUN initdb -D ${PG_DATADIR} -U${PG_USER}
# 暴露 PostgreSQL 端口
EXPOSE 5432
# 设置启动脚本
#ENTRYPOINT ["/home/postgres/runtime/entrypoint.sh"]
ENTRYPOINT ["/home/runtime/entrypoint.sh"]
打包成镜像
docker run build -t centos7-pgsql-repmgr:v1.0
docker-compose部署
master节点的dockercompose.yaml
version: "3"
services:
pg-master:
image: centos7-pgsql-repmgr:v1.9.27
hostname: master1
container_name: pg-master
environment:
PG_MODE: primary
PG_USER: postgres
PG_PASSWORD: postgres
NODE_ROLE: master
NODE_ID: 1
NODE_NAME: master1
#MASTER_NAME: 172.18.41.8
#MASTER_PORT: 25432
CONNINFO_HOST: 172.18.41.8
CONNINFO_PORT: 25432
PRIORITY: 10
POSTGRES_DB: repmgr
ports:
- "25432:5432"
volumes:
- ./pg-data:/home/postgres
slave节点的dockercompose.yaml
version: "3"
services:
pg-slave:
image: centos7-pgsql-repmgr:v1.9.27
container_name: pg-salve
hostname: salve1
#network_mode: host
environment:
PG_MODE: salve
PG_USER: postgres
PG_PASSWORD: postgres
PGPASSWORD: postgres
RE_USER: repmgr
NODE_ROLE: slave
MASTER_NAME: 172.18.41.8
MASTER_PORT: 25432
NODE_ID: 2
NODE_NAME: salve1
CONNINFO_HOST: 172.18.41.2
CONNINFO_PORT: 25432
PRIORITY: 15
POSTGRES_DB: repmgr
ports:
- "25432:5432"
volumes:
- ./pg-data:/home/postgres
~
master故障修复后已salve启动的dockercompose.yaml
version: "3"
services:
pg-slave:
image: centos7-pgsql-repmgr:v1.9.27
hostname: salve1
container_name: pg-salve
environment:
MASTER_NAME: 172.18.41.8
PGPASSWORD: postgres
MASTER_PORT: 25432
CONNINFO_HOST: 172.18.41.2
CONNINFO_PORT: 25432
NODE_ID: 1
PRIORITY: 15
POSTGRES_DB: repmgr
ports:
- "25432:5432"
volumes:
- ./pg-data:/home/postgres
注：恢复前请做好数据备份，防止数据丢失
附：functions脚本函数
#!/bin/bash
# 容器调用入口函数，根据传入命令不同，执行注册或启动主库、注册或启动备库，从新加入集群的操作。
configure_repmgr()
{
case ${NODE_ROLE} in
master)
echo 'master'
initialize_master
;;
slave)
echo 'slave'
initialize_slave
;;
# rejoin)
# echo 'rejoin'
# rejoin_node
# ;;
master_slave)
echo 'master_slave'
master_slave
;;
esac
}
# 用于设置 PostgreSQL 配置文件 'postgresql.conf' 中的参数。
# 该函数接受两个参数：参数名 (param_name) 和参数值 (param_value)，
# 并使用 'sed' 命令在 'postgresql.conf' 文件中查找以参数名开头的行
# （行前可能有一个 # 注释符号），然后用新的参数值替换该行。
set_postgresql_param() {
param_name="$1"
param_value="$2"
sed -i "/^#${param_name} =/c ${param_name} = ${param_value}" ${PG_DATADIR}/postgresql.conf
}
# 这个函数用来向 PostgreSQL 的 pg_hba.conf 文件中添加一行新的配置
# ${1}：你想要添加的配置行
# ${PG_DATADIR}：pg_hba.conf 文件的位置
set_hba_param() {
# 判断是否传入了配置行
if [ -z "${1}" ]; then
echo "No configuration line provided."
return 1
fi
# 检查 pg_hba.conf 文件是否存在
if [ ! -e "${PG_DATADIR}/pg_hba.conf" ]; then
echo "${PG_DATADIR}/pg_hba.conf does not exist."
return 1
fi
# 检查是否已经拥有写权限，如果没有则尝试获取
if [ ! -w "${PG_DATADIR}/pg_hba.conf" ]; then
chmod u+w ${PG_DATADIR}/pg_hba.conf || {
echo "Could not set write permissions on ${PG_DATADIR}/pg_hba.conf"
return 1
}
fi
# 添加配置行到 pg_hba.conf 文件
echo "${1}" >> ${PG_DATADIR}/pg_hba.conf || {
echo "Could not write to ${PG_DATADIR}/pg_hba.conf"
return 1
}
return 0
}
master_slave() {
# 检查pgdata-bak是否存在，如果存在则警告并直接启动pgsql
if [ -d "${PG_DATADIR}-bak" ]; then
echo "Warning: ${PG_DATADIR}-bak already exists. Starting pgsql directly."
pg_ctl -D $PG_DATADIR start
else
#export PGPASSFILE=~/.pgpass
#write_pgpass
IP=`ping ${MASTER_NAME} -c 1 -w 1 | sed '1{s/[^(]*(//;s/).*//;q}'`
# 1. 备份pgsql数据
mv $PG_DATADIR ${PG_DATADIR}-bak
# 2. 创建pgsql数据目录
mkdir $PG_DATADIR
# 3. 从现在的主库获取备份数据
#repmgr -f $PG_REPMGR_CONF -h ${MASTER_NAME} -U repmgr -d repmgr -D $PG_DATADIR standby clone
echo "repmgr -h ${IP} -p ${MASTER_PORT} -U repmgr -d repmgr -f ${PG_REPMGR_CONF} standby clone --dry-run"
repmgr -h ${IP} -p ${MASTER_PORT} -U repmgr -d repmgr -f ${PG_REPMGR_CONF} standby clone --dry-run
echo "repmgr -h ${IP} -p ${MASTER_PORT} -U repmgr -d repmgr -f ${PG_REPMGR_CONF} standby clone"
repmgr -h ${IP} -p ${MASTER_PORT} -U repmgr -d repmgr -f ${PG_REPMGR_CONF} standby clone
# 4. 启动pgsql
echo "pg_ctl -D $PG_DATADIR start"
pg_ctl -D $PG_DATADIR start
# 5. 重新注册节点
echo "repmgr -f $PG_REPMGR_CONF standby register --force"
repmgr -f $PG_REPMGR_CONF standby register --force
fi
echo "repmgrd -f ${PG_REPMGR_CONF} --pid-file /tmp/repmgrd.pid --daemonize=false"
repmgrd -f ${PG_REPMGR_CONF} --pid-file /tmp/repmgrd.pid --daemonize=false
}
# 注册和执行主库操作，包括修改配置文件、创建用户、数据库及插件等，并设置守护进程用于自动故障转移。
initialize_master()
{
if [[ ! -f ${PG_DATADIR}/PG_VERSION ]]; then
initdb -D /home/${PG_USER}/pgdata -U${PG_USER}
write_postgresql_config
write_pg_hba_conf
write_pgpass
pg_ctl -D /home/${PG_USER}/pgdata -w start >/dev/null
psql -U ${PG_USER} -d postgres -h localhost -c "ALTER USER ${PG_USER} WITH PASSWORD '${PG_PASSWORD}';" >/dev/null
psql -U ${PG_USER} -d postgres -h localhost -c "create database repmgr;" >/dev/null
psql -U ${PG_USER} -d postgres -h localhost -c "create extension repmgr;" >/dev/null
psql -U ${PG_USER} -d repmgr -h localhost -c "create user repmgr with superuser;" >/dev/null
psql -U ${PG_USER} -d repmgr -h localhost -c "alter user repmgr password '${PG_PASSWORD}';" >/dev/null
write_repmgr_conf
repmgr -f ${PG_REPMGR_CONF} primary register
else
pg_ctl -D /home/${PG_USER}/pgdata -w start >/dev/null
fi
repmgrd -f ${PG_REPMGR_CONF} --pid-file /tmp/repmgrd.pid --daemonize=false
}
# 注册和执行备库操作，克隆主库，加入repmgr集群，并设置守护进程用于自动故障转移。
initialize_slave()
{
if [[ ! -f ${PG_DATADIR}/PG_VERSION ]]; then
write_repmgr_conf
write_pgpass
IP=`ping ${MASTER_NAME} -c 1 -w 1 | sed '1{s/[^(]*(//;s/).*//;q}'`
repmgr -h ${IP} -p ${MASTER_PORT} -U repmgr -d repmgr -f ${PG_REPMGR_CONF} standby clone --dry-run
repmgr -h ${IP} -p ${MASTER_PORT} -U repmgr -d repmgr -f ${PG_REPMGR_CONF} standby clone
pg_ctl -D ${PG_DATADIR} -w start >/dev/null
repmgr -f ${PG_REPMGR_CONF} standby register
repmgrd -f ${PG_REPMGR_CONF} --pid-file /tmp/repmgrd.pid --daemonize=false
else
pg_ctl -D ${PG_DATADIR} -w start >/dev/null
repmgrd -f ${PG_REPMGR_CONF} --pid-file /tmp/repmgrd.pid --daemonize=false
fi
}
# 将已有节点重新加入到集群，启动守护进行用于自动切换。
rejoin_node()
{
if [[ -f ${PG_DATADIR}/PG_VERSION ]]; then
IP=`ping ${MASTER_NAME} -c 1 -w 1 | sed '1{s/[^(]*(//;s/).*//;q}'`
if [[ -d /home/${PG_USER}/pgdata-bak ]];then
rm -fr /home/${PG_USER}/pgdata-bak
fi
cp -a /home/${PG_USER}/pgdata /home/${PG_USER}/pgdata-bak
rm -fr /home/postgres/pgdata/postmaster.pid
# pg_resetwal -f /home/${PG_USER}/pgdata
repmgr node rejoin -d "host=${IP} dbname=repmgr user=repmgr" --force-rewind --config-files="postgresql.conf,postgresql.auto.conf" -f ${PG_REPMGR_CONF} --verbose --dry-run
repmgr node rejoin -d "host=${IP} dbname=repmgr user=repmgr" --force-rewind --config-files="postgresql.conf,postgresql.auto.conf" -f ${PG_REPMGR_CONF} --verbose
fi
}
# 修改postgresql.conf文件
write_postgresql_config()
{
set_postgresql_param "wal_log_hints" "on"
set_postgresql_param "archive_mode" "on"
set_postgresql_param "archive_command" "\'test ! -f /home/${PG_USER}/pgarch/%f && cp %p /home/${PG_USER}/pgarch/%f\'"
set_postgresql_param "wal_level" "hot_standby"
set_postgresql_param "listen_addresses" "\'*\'"
set_postgresql_param "hot_standby" "on"
set_postgresql_param "max_wal_senders" "10"
set_postgresql_param "wal_keep_segments" "10"
set_postgresql_param "port" "${PG_PORT:-5432}"
set_postgresql_param "max_connections " "100"
set_postgresql_param "superuser_reserved_connections" "10"
set_postgresql_param "full_page_writes" "on"
set_postgresql_param "max_replication_slots" "10"
set_postgresql_param "synchronous_commit" "on"
set_postgresql_param "shared_preload_libraries" "repmgr"
set_postgresql_param "log_destination" "csvlog"
set_postgresql_param "logging_collector" "on"
set_postgresql_param "log_directory" "on"
set_postgresql_param "log_filename" "postgresql-%Y-%m-%d_%H%M%S"
set_postgresql_param "log_rotation_age" "1d"
set_postgresql_param "log_rotation_size" "10MB"
set_postgresql_param "log_statement" "mod"
#set_postgresql_param "data_directory" "/home/pgsqlData"
}
# 修改repmgr.conf文件
write_repmgr_conf()
{
echo "node_id=${NODE_ID}" > ${PG_REPMGR_CONF}
echo "node_name='${NODE_NAME}'" >> ${PG_REPMGR_CONF}
#echo "conninfo='host=${CONNINFO_HOST} user=repmgr dbname=repmgr connect_timeout=2'" >> ${PG_REPMGR_CONF}
echo "conninfo='host=${CONNINFO_HOST} port=${CONNINFO_PORT} user=repmgr dbname=repmgr connect_timeout=2'" >> ${PG_REPMGR_CONF}
echo "data_directory='${PG_DATADIR}'" >> ${PG_REPMGR_CONF}
echo "config_directory='${PG_CONFIGDIR}'" >> ${PG_REPMGR_CONF}
echo "use_replication_slots=true" >> ${PG_REPMGR_CONF}
echo "reconnect_attempts=4" >> ${PG_REPMGR_CONF}
echo "reconnect_interval=5" >> ${PG_REPMGR_CONF}
echo "monitor_interval_secs=2" >> ${PG_REPMGR_CONF}
echo "retry_promote_interval_secs=300" >> ${PG_REPMGR_CONF}
echo "pg_bindir='${PG_BINDIR}'" >> ${PG_REPMGR_CONF}
echo "log_level='INFO'" >> ${PG_REPMGR_CONF}
echo "log_status_interval=300" >> ${PG_REPMGR_CONF}
echo "log_facility='STDERR'" >> ${PG_REPMGR_CONF}
#echo "event_notification_command='${PG_EVENT_NOTIFICATION_SCRIPT}'" >> ${PG_REPMGR_CONF}
echo "promote_command='repmgr standby promote -f ${PG_REPMGR_CONF}'" >> ${PG_REPMGR_CONF}
echo "follow_command='repmgr standby follow -f ${PG_REPMGR_CONF} -W --log-to-file'" >> ${PG_REPMGR_CONF}
echo "failover='automatic'" >> ${PG_REPMGR_CONF}
echo "priority=${PRIORITY}" >> ${PG_REPMGR_CONF}
echo "degraded_monitoring_timeout=-1" >> ${PG_REPMGR_CONF}
}
# 修改pg_hba.conf文件
write_pg_hba_conf()
{
set_hba_param " local replication ${PG_USER} trust "
set_hba_param " host replication ${PG_USER} 127.0.0.1/32 trust "
set_hba_param " local repmgr ${PG_USER} trust "
set_hba_param " host repmgr ${PG_USER} 127.0.0.1/32 trust "
#set_hba_param " host replication ${PG_USER} ${NET_SEGMENT}/24 md5 "
#set_hba_param " host repmgr ${PG_USER} ${NET_SEGMENT}/24 md5 "
#set_hba_param " host repmgr repmgr ${NET_SEGMENT}/24 md5 "
set_hba_param " host replication ${RE_USER} 0.0.0.0/0 md5 "
set_hba_param " host repmgr ${PG_USER} 0.0.0.0/0 md5 "
set_hba_param " host repmgr repmgr 0.0.0.0/0 md5 "
set_hba_param " host all all 0.0.0.0/0 md5 "
}
# 修改.pgpass文件
write_pgpass()
{
if [ -f ~/.pgpass ]
then
rm -f ~/.pgpass
fi
echo "*:*:*:${PG_USER}:${PG_PASSWORD}" >> ~/.pgpass
echo "*:*:repmgr:repmgr:${PG_PASSWORD}" >> ~/.pgpass
chmod 600 ~/.pgpass
}
附2：entrypoint.sh
#!/bin/bash
set -e
# shellcheck source=runtime/functions
#source "/home/postgres/runtime/functions"
source "/home/runtime/functions"
sudo chown -R postgres:postgres /home/postgres
if [ ! -d /home/postgres/pgarch/ ];then
mkdir -p /home/postgres/pgarch/
fi
if [ -f /tmp/repmgrd.pid ];then
rm -fr /tmp/repmgrd.pid
fi
#运行repmgr
configure_repmgr