docker内服务访问宿主机服务

• 1. 场景
• 2. 解决
• 4. 参考

1. 场景

使用windows， wsl2 进行日常开发测试工作。 但是wsl2经常会遇到网络问题。比如今天在测试一个项目，核心功能是

将postgres 的数据使用开源组件synch 同步到clickhouse

测试所需组件

1. postgres
2. kafka
3. zookeeper
4. redis
5. synch容器

最开始测试时，选择的方案是， 将上述五个服务使用

docker-compose

hosts

docker-compose.yaml 文件如下

version: "3"

services:
postgres:
image: failymao/postgres:12.7
container_name: postgres
restart: unless-stopped
privileged: true                                                      # 设置docker-compose env 文件
command: [ "-c", "config_file=/var/lib/postgresql/postgresql.conf", "-c", "hba_file=/var/lib/postgresql/pg_hba.conf" ]
volumes:
- ./config/postgresql.conf:/var/lib/postgresql/postgresql.conf
- ./config/pg_hba.conf:/var/lib/postgresql/pg_hba.conf
environment:
POSTGRES_PASSWORD: abc123
POSTGRES_USER: postgres
POSTGRES_PORT: 15432
POSTGRES_HOST: 127.0.0.1
healthcheck:
test: sh -c "sleep 5 && PGPASSWORD=abc123 psql -h 127.0.0.1 -U postgres -p 15432 -c '\q';"
interval: 30s
timeout: 10s
retries: 3
network_mode: "host"

zookeeper:
image: failymao/zookeeper:1.4.0
container_name: zookeeper
restart: always
network_mode: "host"

kafka:
image: failymao/kafka:1.4.0
container_name: kafka
restart: always
depends_on:
- zookeeper
environment:
KAFKA_ADVERTISED_HOST_NAME: kafka
KAFKA_ZOO
34df
KEEPER_CONNECT: localhost:2181
KAFKA_LISTENERS: PLAINTEXT://127.0.0.1:9092
KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://127.0.0.1:9092
KAFKA_BROKER_ID: 1
KAFKA_LOG_RETENTION_HOURS: 24
KAFKA_LOG_DIRS: /data/kafka-data  #数据挂载
network_mode: "host"

producer:
depends_on:
- redis
- kafka
- zookeeper
image: long2ice/synch
container_name: producer
command: sh -c "
sleep 30 &&
synch --alias pg2ch_test produce"
volumes:
- ./synch.yaml:/synch/synch.yaml
network_mode: "host"

# 一个消费者消费一个数据库
consumer:
tty: true
depends_on:
- redis
- kafka
- zookeeper
image: long2ice/synch
container_name: consumer
command: sh -c
"sleep 30 &&
synch --alias pg2ch_test consume --schema pg2ch_test"
volumes:
- ./synch.yaml:/synch/synch.yaml
network_mode: "host"

redis:
hostname: redis
container_name: redis
image: redis:latest
volumes:
- redis:/data
network_mode: "host"

volumes:
redis:
kafka:
zookeeper:

测试过程中因为要使用 postgres,

wal2json

postgres

synch

但是当重新启动服务后，synch服务一直启动不起来， 日志显示

postgres

core:
debug: true # when set True, will display sql information.
insert_num: 20000 # how many num to submit,recommend set 20000 when production
insert_interval: 60 # how many seconds to submit,recommend set 60 when production
# enable this will auto create database `synch` in ClickHouse and insert monitor data
monitoring: true

redis:
host: redis
port: 6379
db: 0
password:
prefix: synch
sentinel: false # enable redis sentinel
sentinel_hosts: # redis sentinel hosts
- 127.0.0.1:5000
sentinel_master: master
queue_max_len: 200000 # stream max len, will delete redundant ones with FIFO

source_dbs:
- db_type: postgres
alias: pg2ch_test
broker_type: kafka # current support redis and kafka
host: 127.0.0.1
port: 5433
user: postgres
password: abc123
databases:
- database: pg2ch_test
auto_create: true
tables:
- table: pgbench_accounts
auto_full_etl: true
clickhouse_engine: CollapsingMergeTree
sign_column: sign
version_column:
partition_by:
settings:

clickhouse:
# shard hosts when cluster, will insert by random
hosts:
- 127.0.0.1:9000
user: default
password: ''
cluster_name:  # enable cluster mode when not empty, and hosts must be more than one if enable.
distributed_suffix: _all # distributed tables suffix, available in cluster

kafka:
servers:
- 127.0.0.1:9092
topic_prefix: synch

这种情况很奇怪，首先确认

postgres

2. 解决

google 答案，参考 stackoverflow 高赞回答，问题解决，原答案如下

host.docker.internal

--add-host host.docker.internal:host-gateway

更多详情见 源贴

host 模式下 容器内服务访问宿主机服务

将postgres监听地址修改如下

host.docker.internal

/etc/hosts

root@failymao-NC:/mnt/d/pythonProject/pg_2_ch_demo# cat /etc/hosts
# This file was automatically generated by WSL. To stop automatic generation of this file, add the following entry to /etc/wsl.conf:
# [network]
# generateHosts = false
127.0.0.1       localhost

10.111.130.24    host.docker.internal

可以看到，宿主机 ip跟域名的映射. 通过访问域名，解析到宿主机ip, 访问宿主机服务。

最终启动 synch 服务配置如下

core:
debug: true # when set True, will display sql information.
insert_num: 20000 # how many num to submit,recommend set 20000 when production
insert_interval: 60 # how many seconds to submit,recommend set 60 when production
# enable this will auto create database `synch` in ClickHouse and insert monitor data
monitoring: true

redis:
host: redis
port: 6379
db: 0
password:
prefix: synch
sentinel: false # enable redis sentinel
sentinel_hosts: # redis sentinel hosts
- 127.0.0.1:5000
sentinel_master: master
queue_max_len: 200000 # stream max len, will delete redundant ones with FIFO

source_dbs:
- db_type: postgres
alias: pg2ch_test
broker_type: kafka # current support redis and kafka
host: host.docker.internal
port: 5433
user: postgres
password: abc123
databases:
- database: pg2ch_test
auto_create: true
tables:
- table: pgbench_accounts
auto_full_etl: true
clickhouse_engine: CollapsingMergeTree
sign_column: sign
version_column:
partition_by:
settings:

clickhouse:
# shard hosts when cluster, will insert by random
hosts:
- 127.0.0.1:9000
user: default
password: ''
cluster_name:  # enable cluster mode when not empty, and hosts must be more than one if enable.
distributed_suffix: _all # distributed tables suffix, available in cluster

kafka:
servers:
- 127.0.0.1:9092
topic_prefix: synch    host: host.docker.internal
core:
debug: true # when set True, will display sql information.
insert_num: 20000 # how many num to submit,recommend set 20000 when production
insert_interval: 60 # how many seconds to submit,recommend set 60 when production
# enable this will auto create database `synch` in ClickHouse and insert monitor data
monitoring: true

redis:
host: redis
port: 6379
db: 0
password:
prefix: synch
sentinel: false # enable redis sentinel
sentinel_hosts: # redis sentinel hosts
- 127.0.0.1:5000
sentinel_master: master
queue_max_len: 200000 # stream max len, will delete redundant ones with FIFO

source_dbs:
- db_type: postgres
alias: pg2ch_test
broker_type: kafka # current support redis and kafka
host:
port: 5433
user: postgres
password: abc123
databases:
- database: pg2ch_test
auto_create: true
tables:
- table: pgbench_accounts
auto_full_etl: true
clickhouse_engine: CollapsingMergeTree
sign_column: sign
version_column:
partition_by:
settings:

clickhouse:
# shard hosts when cluster, will insert by random
hosts:
- 127.0.0.1:9000
user: default
password: ''
cluster_name:  # enable cluster mode when not empty, and hosts must be more than one if enable.
distributed_suffix: _all # distributed tables suffix, available in cluster

kafka:
servers:
- 127.0.0.1:9092
topic_prefix: synch

4. 参考

1. https://stackoverflow.com/questions/24319662/from-inside-of-a-docker-container-how-do-i-connect-to-the-localhost-of-the-mach