The best Docker container connection Tutorial In 2024, In this tutorial you can learn Network Port Mapping,Docker container connection,

Docker container connection

In front of us to achieve access to the network through the port is operating in the docker container services. Let's connect to a docker container port

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Network Port Mapping

We created a python application container.

w3big@w3big:~$ docker run -d -P training/webapp python app.py
fce072cc88cee71b1cdceb57c2821d054a4a59f67da6b416fceb5593f059fc6d

In addition, we can specify the network address binding container, such as binding 127.0.0.1.

We use the -P parameter to create a container, use docker ps port 5000 is bound to see a host port 32768.

w3big@w3big:~$ docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS                     NAMES
fce072cc88ce        training/webapp     "python app.py"     4 minutes ago       Up 4 minutes        0.0.0.0:32768->5000/tcp   grave_hopper

We can also use the -p flag to specify the container port is bound to the host port.

Is the difference between the two ways:

• -P: Is mapped to the inside of the container port random high port on the host.
• -p: inside the container port is bound to the specified host port.

w3big@w3big:~$ docker run -d -p 5000:5000 training/webapp python app.py
33e4523d30aaf0258915c368e66e03b49535de0ef20317d3f639d40222ba6bc0

w3big@w3big:~$ docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS              PORTS                     NAMES
33e4523d30aa        training/webapp     "python app.py"     About a minute ago   Up About a minute   0.0.0.0:5000->5000/tcp    berserk_bartik
fce072cc88ce        training/webapp     "python app.py"     8 minutes ago        Up 8 minutes        0.0.0.0:32768->5000/tcp   grave_hopper

In addition, we can specify the network address binding container, such as binding 127.0.0.1.

w3big@w3big:~$ docker run -d -p 127.0.0.1:5001:5002 training/webapp python app.py
95c6ceef88ca3e71eaf303c2833fd6701d8d1b2572b5613b5a932dfdfe8a857c
w3big@w3big:~$ docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS                                NAMES
95c6ceef88ca        training/webapp     "python app.py"     6 seconds ago       Up 6 seconds        5000/tcp, 127.0.0.1:5001->5002/tcp   adoring_stonebraker
33e4523d30aa        training/webapp     "python app.py"     3 minutes ago       Up 3 minutes        0.0.0.0:5000->5000/tcp               berserk_bartik
fce072cc88ce        training/webapp     "python app.py"     10 minutes ago      Up 10 minutes       0.0.0.0:32768->5000/tcp              grave_hopper

So that we can access the container through the access port 127.0.0.1:5001 5002.

The above example, the default is to bind tcp port, if you want to bind UPD ports, a port in the back plus / udp.

w3big@w3big:~$ docker run -d -p 127.0.0.1:5000:5000/udp training/webapp python app.py
6779686f06f6204579c1d655dd8b2b31e8e809b245a97b2d3a8e35abe9dcd22a
w3big@w3big:~$ docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS                                NAMES
6779686f06f6        training/webapp     "python app.py"     4 seconds ago       Up 2 seconds        5000/tcp, 127.0.0.1:5000->5000/udp   drunk_visvesvaraya
95c6ceef88ca        training/webapp     "python app.py"     2 minutes ago       Up 2 minutes        5000/tcp, 127.0.0.1:5001->5002/tcp   adoring_stonebraker
33e4523d30aa        training/webapp     "python app.py"     5 minutes ago       Up 5 minutes        0.0.0.0:5000->5000/tcp               berserk_bartik
fce072cc88ce        training/webapp     "python app.py"     12 minutes ago      Up 12 minutes       0.0.0.0:32768->5000/tcp              grave_hopper

docker port command allows us to quickly and easily view the port binding information.

w3big@w3big:~$ docker port adoring_stonebraker 5002
127.0.0.1:5001

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Docker container connection

Port mapping is not the only way to connect to another docker container.

docker has a connection system allows multiple containers together, sharing the connection information.

docker connection will create a parent-child relationship, the parent container in which you can see the information of the sub container.

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Naming container

When we create a container of time, docker it will automatically be named. In addition, we can also use the --name to identify the naming container, for example:

w3big@w3big:~$  docker run -d -P --name w3big training/webapp python app.py
43780a6eabaaf14e590b6e849235c75f3012995403f97749775e38436db9a441

We can view the name of the container using a docker ps command.

w3big@w3big:~$ docker ps -l
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS                     NAMES
43780a6eabaa        training/webapp     "python app.py"     3 minutes ago       Up 3 minutes        0.0.0.0:32769->5000/tcp   w3big