Here is my docker-compose file
version: '3'
services:
mysql:
image: mysql:5.7
command: --default-authentication-plugin=mysql_native_password
container_name: mysql
hostname: mysqlServiceHost
network_mode: bridge
ports:
- "3306:3306"
restart: on-failure
volumes:
- ./mysql_data:/var/lib/mysqldocker
- ./my.cnf:/etc/mysql/conf.d/my.cnf
- ./mysql/init:/docker-entrypoint-initdb.d/
- ./shop.sql:/docker-entrypoint-initdb.d/shop.sql
environment:
- MYSQL_ROOT_PASSWORD=a123456
- MYSQL_DATABASE=shop
redis:
image: redis:3
container_name: redis
host: redis
hostname: redisServiceHost
network_mode: bridge
restart: on-failure
ports:
- "6379:6379"
golang:
build: .
restart: always
network_mode: bridge
ports:
- "8080:8080"
depends_on:
- mysql
- redis
links:
- mysql
- redis
volumes:
- /xiangmu/go/src:/go
tty: true
This is my go language code to connect mysql：
mysqladmin="root"
mysqlpwd="a123456"
mysqldb="shop"
DB, err = gorm.Open("mysql",mysqladmin+":"+mysqlpwd+"#tcp(mysqlServiceHost)/"+mysqldb+"?charset=utf8"+"&parseTime=True&loc=Local")
This is my go language code to connect redis：
config := map[string]string{
"key": beego.AppConfig.String("redisKey"),
"conn": "redisServiceHost:6379",
"dbNum": beego.AppConfig.String("redisDbNum"),
"password": beego.AppConfig.String("redisPwd"),
}
bytes, _ := json.Marshal(config)
redisClient, err = cache.NewCache("redis", string(bytes))
they have the same problem:
dial tcp: lookup redisServiceHost on 100.100.2.136:53: no such host
dial tcp: lookup mysqlServiceHost on 100.100.2.136:53: no such host
I have successfully connected to redis once, that time I used the IP address of the redis container, but after starting docker-compose again, I can't connect to it. It seems to be a host problem. I tried many methods to no avail. .
All services in the same docker-compose file will join the same network, each container can look up service name(redis and mysql in your example) to get back the appropriate container’s IP address.
So you can use the service name, try change to:
DB, err = gorm.Open("mysql",mysqladmin+":"+mysqlpwd+"#tcp(mysql)/"+mysqldb+"?charset=utf8"+"&parseTime=True&loc=Local")
"conn": "redis:6379",
For more details, please check https://docs.docker.com/compose/networking/
Related
I am trying to setup a cassandra DB and connect to it with a golang app.
this is my docker-compose
version: "3.6"
services:
cassandra:
image: cassandra:4.0
ports:
- 9042:9042
volumes:
- ~/apps/cassandra:/var/lib/cassandra
environment:
- CASSANDRA_CLUSTER_NAME=mycluster
myapp:
...
ports:
- 4242:4242
- 4243:4243
depends_on:
- cassandra
...
networks:
default:
driver: bridge
I start the Cassandra using
docker-compose up cassandra
and then I wait it to be ready.
Then I try to connect to Cassandra in local using
> cqlsh
Connected to mycluster at 127.0.0.1:9042
and then I try to connect to it in my go app (dockerized) using gocql
cluster := gocql.NewCluster("127.0.0.1")
session, err := cluster.CreateSession()
( also tried to add element as Consistency, ProtoVersion=4 etc. same results)
it says then :
Cannot connect to db: gocql: unable to create session: unable to discover protocol version: dial tcp 127.0.0.1:9042: connect: connection refused
Do you. have any idea why it can't connect?
thanks !
Each container has its own localhost (127.0.0.1) address - you need to connect to IP address of your machine (if you use bridge), or maybe better to connect by the name (cassandra)
If both containers using bridge network you need to specify the network name in both containers and in your app container the host will be cassandra (docker) container.
services:
cassandra:
image: cassandra:4.0
container_name: cassandra
ports:
- 9042:9042
volumes:
- ~/apps/cassandra:/var/lib/cassandra
networks:
- default
environment:
- CASSANDRA_CLUSTER_NAME=mycluster
myapp:
...
ports:
- 4242:4242
- 4243:4243
depends_on:
- cassandra
networks:
- default
environment:
- HOSTS=cassandra
...
networks:
default:
driver: bridge
I have two docker containers. One backend, and the other db (postgres). They both are linked. How do I utilise the backend environment HOST variable in the golang docker container?
From my understanding, both containers have their own IP addresses. I cannot use 'localhost' in the golang container because postgres isn't on localhost, but in an isolated container.
version: "3.7"
services:
backend:
image: golang:1.16
build: ./
working_dir: /app
volumes:
- ./backend/:/app
environment:
HOST: db
command: go run main.go
ports:
- 8080:8080
depends_on:
- db
db:
image: postgres
restart: always
environment:
POSTGRES_USER: gorm
POSTGRES_PASSWORD: gorm
POSTGRES_DB: gorm
ports:
- 9920:9920
I've tried researching how to access this variable as well as check Docker tutorials/documentation, but haven't found a solution.
Docker compose does DNS resolution. You should be able to access your database by name.
Remove:
environment:
HOST: db
Correct the postgres port to 5432:
db:
...
ports:
- 5432:5432
You must be able to connect like so:
db := pg.Connect(&pg.Options{
Addr: "db:5432",
User: "gorm",
Database: "gorm",
Password: "gorm",
})
As for environment variables, you can declare and access them like this:
backend:
environment:
POSTGRES_USER: gorm
...
os.Getenv("POSTGRES_USER")
Docker compose will create a network for your containers where they can communicate and reach each other.
You can make a simple change to your docker compose file by adding a name to your services which will make sure they get the same name each time.
version: "3.7"
services:
backend:
image: golang:1.16
build: ./
container_name: backend
working_dir: /app
volumes:
- ./backend/:/app
command: go run main.go
ports:
- "8080:8080"
depends_on:
- db
db:
image: postgres
restart: always
container_name: db
environment:
POSTGRES_USER: gorm
POSTGRES_PASSWORD: gorm
POSTGRES_DB: gorm
ports:
- "9920:5432"
The default port for Postgres is 5432, so I mapped it to your 9920. Then, you can access the db container from the backend container by specifying:
db:9920
I am having a problem connecting my compiled Spring-Boot app to the database that I have running on another container on my server.
I have tried different configurations, changing from localhost to the IP address of my server for the connection. I also double checked that the credentials matched by logging in via Adminer. Finally, I did a rebuild of the compose and image files several times to ensure that I have all the latest versions.
Compose file:
version: '3.1'
services:
db:
image: mariadb
restart: always
environment:
MYSQL_ROOT_PASSWORD: mypassword
MYSQL_DATABASE: marketingappdb
ports:
- "3306:3306"
expose:
- 3306
volumes:
- ./mariadbvolume:/var/lib/mariadb
networks:
- marketingapp
adminer:
image: adminer
restart: always
ports:
- "8086:8080"
expose:
- 8086
depends_on:
- db
networks:
- marketingapp
springserver:
image: marketingapp
restart: always
ports:
- "8091:8091"
expose:
- 8091
depends_on:
- db
networks:
- marketingapp
networks:
marketingapp:
Spring Server Image:
FROM openjdk:latest
COPY /marketing-app-final.jar .
EXPOSE 8091
ENTRYPOINT ["java", "-jar", "marketing-app-final.jar"]
Application properties for Spring:
server.port = 8091
spring.datasource.url=jdbc:mariadb://0.0.0.0:3306/marketingappdb
spring.datasource.username=root
spring.datasource.password=mypassword
spring.datasource.driver-class-name=org.mariadb.jdbc.Driver
spring.jpa.hibernate.ddl-auto=update
I can connect from my PC to the database using the app from the remote same configuration (obviously replacing localhost with the IP) and don't see why I shouldn't be able to do the same from the actual server. Thanks in advance for any help!
Use the docker dns to connect your spring App to the mariabd:
jdbc:mariadb://db:3306/marketingappdb
Just a few other hints: you don't need to expose port 3306, you already bind it to 3306 on Host (if you just want to use it from within the docker Services you don't need to bind/expose it at all). And the mariabd persistent storage is var/lib/mysql and not var/lib/mariadb
I have this docker-compose file:
networks:
default:
ipam:
config:
- subnet: 10.48.0.0/16
gateway: 10.48.0.1
services:
haproxy:
build: haproxy
container_name: haproxy
volumes:
- ./haproxy/conf/:/usr/local/etc/haproxy/
- ./haproxy/ssl/:/etc/ssl/xip.io/
ports:
- "80:80"
- "443:443"
networks:
default:
ipv4_address: 10.48.0.2
server:
build: server
container_name: server
restart: always
environment:
- ENV=env=production db=true
ports:
- "8081:8081"
volumes:
- ./server/config:/usr/src/app/config
depends_on:
- haproxy
networks:
default:
ipv4_address: 10.48.0.4
frontend:
build: frontend
container_name: frontend
restart: always
ports:
- "8080:8080"
volumes:
- ./frontend/config:/usr/src/app/config
depends_on:
- server
networks:
default:
ipv4_address: 10.48.0.5
version: '2'
In order to deploy a backend server and a frontend interface inside a subnet defined in the range 10.48.0.0/16.
So I tried to assign fixed ip to each container. On Linux everything is ok, so I can reach 10.48.0.4_8081/api, but on MacOS when I try to do the same thing, I have ERR_CONNECTION_REFUSED.
If I try to connect without using IP, but with localhost:8081/api, this is ok. But with multiple containers, I have to access directly with the IP.
Inside each container, if I try to ping the other ip address (example from container frontend with IP 10.48.0.5 I try to ping 10.48.0.4) everything is OK.
So my question is, How can I do in order make an http call to an api that is on another service? thanks for your help.
I've read everywhere that is a well know situation under windows and mac, but not on linux, where is possible from the client side making request directly on the ip address of the container. This is not possible on mac and is still open an issue on github.
In this case, I've used haproxy in order to proxy requests to each container.
I'm using an application hosted on a docker container.
This application executes bash scripts / instructions to send mails.
I made another container which executes Postfix as a SMTP Relay.
I want to send mails from my application container by using a bash script using my Postfix container as a relay.
I tried to connect with SSH from my application container to my Postfix container. But that doesn't seem to work.
How can i make it so a script executed in my application container can use my Postfix relay while not allowing anything outside of the docker network, or even better, to only allow some containers, to send mails from this relay.
EDIT 1 : Docker-compose files
Application docker compose :
version: "3.4"
volumes:
[...]
services:
application:
restart: always
build: ./application
depends_on:
- mariadb
container_name: application
volumes:
[...]
ports:
- "80:80"
- "443:443"
- "5669:5669"
deploy:
restart_policy:
window: 300s
links:
- mariadb
external_links:
- smtp-server
mariadb:
restart: always
image: mariadb
command: mysqld --sql-mode=ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
container_name: application-mariadb
volumes:
[...]
environment:
MYSQL_RANDOM_ROOT_PASSWORD: "yes"
deploy:
restart_policy:
window: 300s
Here's my docker compose for my SMTP server :
version: "3.4"
services:
postfix:
restart: always
build: ./postfix
container_name: smtp-server
deploy:
restart_policy:
window: 300s
{a quick response, because I "cicle" in my work ... and I'm taking 10 minutes of clear my mint, I hope it serves you}
Are you using "docker-compose" ?, could you give an example of your YML file? (a little more context)
[you can not connect to by ssh to a container unless you have "supervisor" installed,which I do not recommend at all.]
from what I see, you only need to make private networks; You could use this:
https://docs.docker.com/compose/networking/
to hide everything, I also recommend using a load balancer / Inverse Proxy like TRAEFIK (if they have access to port 80 or 443 in some clear way this ...)
so you only expose 1/2 port(s) (80 + 443 for example) and everything else is protected by your reverse proxy
Watch as I separate the networks as you need the different containers.
bash have access to db and smtp
db does not have access smtp neither nginx
nginx have access to bash
nginx have access to proxy network to expose 80 and 443
no other container is exposed to the outside more than nginx
--
version: "3"
services:
bash:
####### use hostname "smtp" as SMTP server
image: bash
depends_on:
- db
networks:
- smtp_internal_network
- internal_network
- data_network
volumes:
- ../html:/var/www/html
restart: always
db:
image: percona:5.7
# ports: # for debug connections and querys
# - 3306:3306
volumes:
- ../db_data:/var/lib/mysql
environment:
MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD}
MYSQL_DATABASE: ${MYSQL_DATABASE}
MYSQL_USER: ${MYSQL_USER}
MYSQL_PASSWORD: ${MYSQL_PASSWORD}
networks:
- data_network
restart: always
smtp:
image: mwader/postfix-relay
environment:
- POSTFIX_myhostname=smtp.domain.tld
networks:
- smtp_internal_network
restart: always
nginx:
image: nginx
volumes:
- ../html:/var/www/html
networks:
- external_network
- internal_network
labels:
- "traefik.backend=nginx_${COMPOSE_PROJECT_NAME}"
- "traefik.port=80"
- "traefik.frontend.rule=Host:${FRONTEND_RULE}"
- "traefik.frontend.passHostHeader=true"
- "traefik.enable=true"
- "traefik.docker.network=traefik_proxy"
restart: always
depends_on:
- db
- bash
networks:
external_network:
external:
name: traefik_proxy
internal_network:
driver: bridge
smtp_internal_network:
driver: bridge
data_network:
driver: bridge
Edit:
version: "3"
volumes:
[...]
services:
####### use hostname "smtp" as SMTP server in your application
application:
restart: always
build: ./application
depends_on:
- mariadb
volumes:
[...]
ports:
- "80:80"
- "443:443"
- "5669:5669"
deploy:
restart_policy:
window: 300s
networks:
- smtp_external_network
- data_network
mariadb:
restart: always
image: mariadb
command: mysqld --sql-mode=ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
networks:
- data_network
volumes:
[...]
environment:
MYSQL_RANDOM_ROOT_PASSWORD: "yes"
deploy:
restart_policy:
window: 300s
networks:
smtp_external_network:
external:
name: [ReplaceForFolderParentNameOfSmtpYmlWithoutSquareBrackets]_smtp
data_network:
driver: bridge
--- (in your other file)
services:
smtp:
restart: always
build: ./postfix
networks:
- smtp
deploy:
restart_policy:
window: 300s
networks:
smpt:
driver: bridge