Provide static IP to docker containers via docker-compose - docker

Question

I'm trying to provide static IP address to containers. I understand that I have to create a custom network. I create it and the bridge interface is up on the host machine (Ubuntu 16.x). The containers get IP from this subnet but not the static I provided.
Here is my docker-compose.yml:
version: '2'
services:
mysql:
container_name: mysql
image: mysql:latest
restart: always
environment:
- MYSQL_ROOT_PASSWORD=root
ports:
- "3306:3306"
networks:
- vpcbr
apigw-tomcat:
container_name: apigw-tomcat
build: tomcat/.
ports:
- "8080:8080"
- "8009:8009"
networks:
- vpcbr
depends_on:
- mysql
networks:
vpcbr:
driver: bridge
ipam:
config:
- subnet: 10.5.0.0/16
gateway: 10.5.0.1
aux_addresses:
mysql: 10.5.0.5
apigw-tomcat: 10.5.0.6
The containers get 10.5.0.2 and 10.5.0.3, instead of 5 and 6.

Answer 1

Note that I don't recommend a fixed IP for containers in Docker unless you're doing something that allows routing from outside to the inside of your container network (e.g. macvlan). DNS is already there for service discovery inside of the container network and supports container scaling. And outside the container network, you should use exposed ports on the host. With that disclaimer, here's the compose file you want:
version: '2'
services:
mysql:
container_name: mysql
image: mysql:latest
restart: always
environment:
- MYSQL_ROOT_PASSWORD=root
ports:
- "3306:3306"
networks:
vpcbr:
ipv4_address: 10.5.0.5
apigw-tomcat:
container_name: apigw-tomcat
build: tomcat/.
ports:
- "8080:8080"
- "8009:8009"
networks:
vpcbr:
ipv4_address: 10.5.0.6
depends_on:
- mysql
networks:
vpcbr:
driver: bridge
ipam:
config:
- subnet: 10.5.0.0/16
gateway: 10.5.0.1

Answer 2

I was facing some difficulties with an environment variable that is with custom name (not with container name /port convention for KAPACITOR_BASE_URL and KAPACITOR_ALERTS_ENDPOINT). If we give service name in this case it wouldn't resolve the ip as
KAPACITOR_BASE_URL: http://kapacitor:9092
In above http://[**kapacitor**]:9092 would not resolve to http://172.20.0.2:9092
I resolved the static IPs issues using subnetting configurations.
version: "3.3"
networks:
frontend:
ipam:
config:
- subnet: 172.20.0.0/24
services:
db:
image: postgres:9.4.4
networks:
frontend:
ipv4_address: 172.20.0.5
ports:
- "5432:5432"
volumes:
- postgres_data:/var/lib/postgresql/data
redis:
image: redis:latest
networks:
frontend:
ipv4_address: 172.20.0.6
ports:
- "6379"
influxdb:
image: influxdb:latest
ports:
- "8086:8086"
- "8083:8083"
volumes:
- ../influxdb/influxdb.conf:/etc/influxdb/influxdb.conf
- ../influxdb/inxdb:/var/lib/influxdb
networks:
frontend:
ipv4_address: 172.20.0.4
environment:
INFLUXDB_HTTP_AUTH_ENABLED: "false"
INFLUXDB_ADMIN_ENABLED: "true"
INFLUXDB_USERNAME: "db_username"
INFLUXDB_PASSWORD: "12345678"
INFLUXDB_DB: db_customers
kapacitor:
image: kapacitor:latest
ports:
- "9092:9092"
networks:
frontend:
ipv4_address: 172.20.0.2
depends_on:
- influxdb
volumes:
- ../kapacitor/kapacitor.conf:/etc/kapacitor/kapacitor.conf
- ../kapacitor/kapdb:/var/lib/kapacitor
environment:
KAPACITOR_INFLUXDB_0_URLS_0: http://influxdb:8086
web:
build: .
environment:
RAILS_ENV: $RAILS_ENV
command: bundle exec rails s -b 0.0.0.0
ports:
- "3000:3000"
networks:
frontend:
ipv4_address: 172.20.0.3
links:
- db
- kapacitor
depends_on:
- db
volumes:
- .:/var/app/current
environment:
DATABASE_URL: postgres://postgres#db
DATABASE_USERNAME: postgres
DATABASE_PASSWORD: postgres
INFLUX_URL: http://influxdb:8086
INFLUX_USER: db_username
INFLUX_PWD: 12345678
KAPACITOR_BASE_URL: http://172.20.0.2:9092
KAPACITOR_ALERTS_ENDPOINT: http://172.20.0.3:3000
volumes:
postgres_data:

Answer 3

If you are never seeing the static IP address set, perhaps it could be because you are using "docker compose up". Try using "docker-compose up".
When I use "docker-compose up" (with the hyphen) I now see the static IPs assigned.
networks:
hfnet:
driver: bridge
ipam:
driver: default
config:
- subnet: 192.168.55.0/24
gateway: 192.168.55.1
services:
web:
image: 'mycompany/webserver:latest'
hostname: www
domainname: mycompany.com
stdin_open: true # docker run -i
tty: true # docker run -t
networks:
hfnet:
ipv4_address: 192.168.55.10
ports:
- '80:80'
- '443:443'
volumes:
- '../honeyfund:/var/www/html'
I wasted a lot of time to figure that one out. :(

Answer 4

I realized, that the more convenient and meaningful way is to give the container a container-name.
You can use the name in the same docker network as source.
This helped me because the docker-containers had changing IPs and by this I can communicate with another container with a static name that I can use in config-files.