Docker-compose Networks and Volumes

Using docker-compose yaml file, we can create multiple networks and volume in an application.

The below code shows how to create networks using YAML file 

version
:
 
'3'
services
:
  
web
:
    
build
:
      
context
:
 
.
      
dockerfile
:
 
Dockerfile
      
args
:
        
-
 
PYTHON_VERSION=3.4-alpine
    
image
:
 
coolgourav147/python-redis
    
ports
:
      
-
 
"5000:5000"
    
networks
:
      
-
 
appnetwork
  
redis
:
    
image
:
 
"redis:alpine"
    
volumes
:
      
-
 
myredisdata:/data
    
networks
:
      
-
 
appnetwork

  
redis2
:
    
image
:
 
"redis:alpine"
    
volumes
:
      
-
 
myredisdata2:/data
    
networks
:
      
-
 
appnetwork2
networks
:
  
appnetwork
:
  
appnetwork2
:

volumes
:
  
myredisdata
:
  
myredisdata2
:

We have defined 3 containers inside services, each container is using network and volume. At the end network is the property/field which will create 2 networks appnetwork and appnetwork2,likewise, volumes are the property to create volume inside the container.Users can attach the network with any container if and only if it has been created in YAML file.

Before running the docker-compose up -d command ,there are no networks and new volumes created. 

gaurav
@learning
-
ocean:
~/
python_redis$ docker container ls
CONTAINER ID   IMAGE     COMMAND   CREATED   STATUS    PORTS     NAMES
gaurav
@learning
-
ocean:
~/
python_redis$ docker volume ls
DRIVER    VOLUME NAME
gaurav
@learning
-
ocean:
~/
python_redis$ docker network ls
NETWORK ID     NAME      DRIVER    
SCOPE
0022
a9f511fe   bridge    bridge    
local
3
a33f83c3663   host      host      
local
e4ebd601732c   
none
      
null
      
local

let run docker-compose up

[email protected]:~$ docker-compose up -d
Creating network 
"docker-volumes_appnetwork"
 
with
 the 
default
 
driver
Creating network 
"docker-volumes_default"
 
with
 the 
default
 
driver
Building web
Sending build context 
to
 Docker daemon  
5.632
kB

let check network, volume and containers again

[email protected]:~$ docker container ls
CONTAINER ID   IMAGE                        COMMAND                  CREATED         STATUS         PORTS                    NAMES
d0df46f4f293   redis:alpine                 
"docker-entrypoint.s…"
   
9
 
seconds
 ago   Up 
7
 
seconds
   
6379
/tcp                 docker-networks_redis_1
11
f7d05376d2   coolgourav147/python-redis   
"python app.py"
          
9
 
seconds
 ago   Up 
6
 
seconds
   
0.0.0.0
:
5000
->
5000
/tcp   docker-networks_web_1
5
f9d87371ad6   redis:alpine                 
"docker-entrypoint.s…"
   
9
 
seconds
 ago   Up 
6
 
seconds
   
6379
/tcp                 docker-networks_redis2_1
[email protected]:$ docker volume ls
DRIVER    VOLUME NAME
local
     docker-networks_myredisdata
local
     docker-networks_myredisdata2
[email protected]:~$ docker network ls
NETWORK ID     NAME                          DRIVER    SCOPE
0022
a9f511fe   bridge                        bridge    
local
4
dd17646884a   docker-networks_appnetwork    bridge    
local
d124edf4aa4c   docker-networks_appnetwork2   bridge    
local
3
a33f83c3663   host                          host      
local
e4ebd601732c   
none
                          
null
      
local
[email protected]:~$