https://www.linux-toys.com/?p=435
This is a followup on how to use Docker after building a Swarm cluster. I think it is important for people to understand the different ways to create containers and choose the best way for their needs.This blog post will explain docker-compose, docker engine, and how to do persistent storage.
[Docker Compose]
Let’s begin with docker-compose. This utility allows a user to create a manifest file of all the containers needed and how they communicate with each other. This example will show you how to create a MySQL container and connect it to a web application called nodechat.
Download the sample docker-compose.yml in a new directory. Below is the contents of the file for reference. Since YAML files are space sensitive and not easy share in a blog post, please do not copy and paste the contents below.
docker-compose.yml:
Type the following command to create the containers.
This is how you can stop and remove your running containers built with the compose file:
Pull the image from the repository:
Find out what host is running nodechat with “docker ps” and use your web browser to navigate to the host running nodechat on port 8080
[Dockerfile’s]
Dockerfile’s contain all of the steps needed to create a container such as adding files, defining volumes, installing software, and setting environment variables. The following steps will explain how to create persistent storage for containers by creating a container to share volumes with other containers.
Create a directory called “fileserver” with a file called “Dockerfile” with the following contents:
Now we have a container named fileserver that can share volumes with other containers. The files will be store locally in the data directory. To create a client, create a directory called “fileserver-client” with a file called “Dockerfile” with the following contents:
Run another fileserver-client container to see list of files on the fileserver.
This is a followup on how to use Docker after building a Swarm cluster. I think it is important for people to understand the different ways to create containers and choose the best way for their needs.This blog post will explain docker-compose, docker engine, and how to do persistent storage.
[Docker Compose]
Let’s begin with docker-compose. This utility allows a user to create a manifest file of all the containers needed and how they communicate with each other. This example will show you how to create a MySQL container and connect it to a web application called nodechat.
Download the sample docker-compose.yml in a new directory. Below is the contents of the file for reference. Since YAML files are space sensitive and not easy share in a blog post, please do not copy and paste the contents below.
docker-compose.yml:
Type the following command to create the containers.
This is how you can stop and remove your running containers built with the compose file:
Pull the image from the repository:
Find out what host is running nodechat with “docker ps” and use your web browser to navigate to the host running nodechat on port 8080
[Dockerfile’s]
Dockerfile’s contain all of the steps needed to create a container such as adding files, defining volumes, installing software, and setting environment variables. The following steps will explain how to create persistent storage for containers by creating a container to share volumes with other containers.
Create a directory called “fileserver” with a file called “Dockerfile” with the following contents:
Now we have a container named fileserver that can share volumes with other containers. The files will be store locally in the data directory. To create a client, create a directory called “fileserver-client” with a file called “Dockerfile” with the following contents:
Run another fileserver-client container to see list of files on the fileserver.
This is a followup on how to use Docker after building a Swarm cluster. I think it is important for people to understand the different ways to create containers and choose the best way for their needs.This blog post will explain docker-compose, docker engine, and how to do persistent storage.
[Docker Compose]
Let’s begin with docker-compose. This utility allows a user to create a manifest file of all the containers needed and how they communicate with each other. This example will show you how to create a MySQL container and connect it to a web application called nodechat.
Download the sample docker-compose.yml in a new directory. Below is the contents of the file for reference. Since YAML files are space sensitive and not easy share in a blog post, please do not copy and paste the contents below.
docker-compose.yml:
mysql:
image: rusher81572/mysql
restart: always
nodechat:
image: rusher81572/nodechat
restart: always
ports:
– 8080:8080
links:
– mysql:mysql
Type the following command to create the containers.
docker-compose upA lot of output will be displayed on the screen next and may not bring you back to a terminal prompt. It is safe to press ctrl+c when you see the following:
nodechat_1 |Now that the containers have been created, it is time to start them.
nodechat_1 | listening on *:8080
nodechat_1 | Creating Database…..
nodechat_1 | Creating Table……
docker-compose startRun the following command to find out which host is running nodechat with:
docker ps
Use your web browser to navigate to the host running nodechat on port 8080. Feel free to chat with yourself =)
This is how you can stop and remove your running containers built with the compose file:
docker-compose stop
docker-compose rm -f
[Docker Engine]
Now let’s run the equivalent Docker engine commands to accomplish the
same result as the docker-compose file so you will have a better
understanding on how Docker works.Pull the image from the repository:
docker pull rusher81572/mysqlRun the containers in daemon mode (In the background) with -d. The -p argument exposes a port for outside access. The format for -p is outside_port:inside_port. The “name” argument specifies a container name. This will allow us to link the nodechat application to the MySQL container simply by using a name. The”link” argument links the MySQL container to Nodechat using the container name. This will allow connectivity between nodechat and MySQL to store the chat data. The format for “link” is: container_name:link_name.
docker pull rusher81572/nodechat
docker run -d –name mysql rusher81572/mysql(If you have any issues copying and pasting the above commands….There should be two “-” before name and link. For some reason, WordPress changes them to a single minus sign)
docker run -d –link mysql:mysql -p 8080:8080 rusher81572/nodechat
Find out what host is running nodechat with “docker ps” and use your web browser to navigate to the host running nodechat on port 8080
[Dockerfile’s]
Dockerfile’s contain all of the steps needed to create a container such as adding files, defining volumes, installing software, and setting environment variables. The following steps will explain how to create persistent storage for containers by creating a container to share volumes with other containers.
Create a directory called “fileserver” with a file called “Dockerfile” with the following contents:
FROM ubuntuBuild the filesever container. The -t argument specifies the tag for the container which is basically a name for it.
VOLUME /share
CMD sleep infinity
docker build -t fileserver .Run the container in daemon mode. The -v argument allows you to share a local directory inside the container as a volume. Replace location_to_data_dir with the full path to the data directory created in the previous step.
mkdir data
docker run -d -v location_to_data_dir:/share –name fileserver fileserver(If you have any issues copying and pasting the above command….There should be two “-” before name)
Now we have a container named fileserver that can share volumes with other containers. The files will be store locally in the data directory. To create a client, create a directory called “fileserver-client” with a file called “Dockerfile” with the following contents:
FROM ubuntuBuild the fileserver-client container image.
CMD sleep infinity
docker build -t fileserver-client .Now let’s run the fileserver-client container in interactive mode to create a test file. Interactive mode runs a container in the foreground so you can see what is happening and even interact with the shell. The argument “volumes-from” will mount all of the volumes from the container specified. Please note that the container will stop and return you to the shell after running the command.
docker run -it –volumes-from fileserver fileserver-client touch /share/foo.txt(If you have any issues copying and pasting the above command….There should be two “-” before volumes-from)
Run another fileserver-client container to see list of files on the fileserver.
docker run -it –volumes-from fileserver fileserver-client ls /shareCheck to ensure that the files are being stored locally.
ls location_to_data_dir/dataThe file should be displayed in the terminal. Feel free to play around with this more. I hope that you learned something new today.
This is a followup on how to use Docker after building a Swarm cluster. I think it is important for people to understand the different ways to create containers and choose the best way for their needs.This blog post will explain docker-compose, docker engine, and how to do persistent storage.
[Docker Compose]
Let’s begin with docker-compose. This utility allows a user to create a manifest file of all the containers needed and how they communicate with each other. This example will show you how to create a MySQL container and connect it to a web application called nodechat.
Download the sample docker-compose.yml in a new directory. Below is the contents of the file for reference. Since YAML files are space sensitive and not easy share in a blog post, please do not copy and paste the contents below.
docker-compose.yml:
mysql:
image: rusher81572/mysql
restart: always
nodechat:
image: rusher81572/nodechat
restart: always
ports:
– 8080:8080
links:
– mysql:mysql
Type the following command to create the containers.
docker-compose upA lot of output will be displayed on the screen next and may not bring you back to a terminal prompt. It is safe to press ctrl+c when you see the following:
nodechat_1 |Now that the containers have been created, it is time to start them.
nodechat_1 | listening on *:8080
nodechat_1 | Creating Database…..
nodechat_1 | Creating Table……
docker-compose startRun the following command to find out which host is running nodechat with:
docker ps
Use your web browser to navigate to the host running nodechat on port 8080. Feel free to chat with yourself =)
This is how you can stop and remove your running containers built with the compose file:
docker-compose stop
docker-compose rm -f
[Docker Engine]
Now let’s run the equivalent Docker engine commands to accomplish the
same result as the docker-compose file so you will have a better
understanding on how Docker works.Pull the image from the repository:
docker pull rusher81572/mysqlRun the containers in daemon mode (In the background) with -d. The -p argument exposes a port for outside access. The format for -p is outside_port:inside_port. The “name” argument specifies a container name. This will allow us to link the nodechat application to the MySQL container simply by using a name. The”link” argument links the MySQL container to Nodechat using the container name. This will allow connectivity between nodechat and MySQL to store the chat data. The format for “link” is: container_name:link_name.
docker pull rusher81572/nodechat
docker run -d –name mysql rusher81572/mysql(If you have any issues copying and pasting the above commands….There should be two “-” before name and link. For some reason, WordPress changes them to a single minus sign)
docker run -d –link mysql:mysql -p 8080:8080 rusher81572/nodechat
Find out what host is running nodechat with “docker ps” and use your web browser to navigate to the host running nodechat on port 8080
[Dockerfile’s]
Dockerfile’s contain all of the steps needed to create a container such as adding files, defining volumes, installing software, and setting environment variables. The following steps will explain how to create persistent storage for containers by creating a container to share volumes with other containers.
Create a directory called “fileserver” with a file called “Dockerfile” with the following contents:
FROM ubuntuBuild the filesever container. The -t argument specifies the tag for the container which is basically a name for it.
VOLUME /share
CMD sleep infinity
docker build -t fileserver .Run the container in daemon mode. The -v argument allows you to share a local directory inside the container as a volume. Replace location_to_data_dir with the full path to the data directory created in the previous step.
mkdir data
docker run -d -v location_to_data_dir:/share –name fileserver fileserver(If you have any issues copying and pasting the above command….There should be two “-” before name)
Now we have a container named fileserver that can share volumes with other containers. The files will be store locally in the data directory. To create a client, create a directory called “fileserver-client” with a file called “Dockerfile” with the following contents:
FROM ubuntuBuild the fileserver-client container image.
CMD sleep infinity
docker build -t fileserver-client .Now let’s run the fileserver-client container in interactive mode to create a test file. Interactive mode runs a container in the foreground so you can see what is happening and even interact with the shell. The argument “volumes-from” will mount all of the volumes from the container specified. Please note that the container will stop and return you to the shell after running the command.
docker run -it –volumes-from fileserver fileserver-client touch /share/foo.txt(If you have any issues copying and pasting the above command….There should be two “-” before volumes-from)
Run another fileserver-client container to see list of files on the fileserver.
docker run -it –volumes-from fileserver fileserver-client ls /shareCheck to ensure that the files are being stored locally.
ls location_to_data_dir/dataThe file should be displayed in the terminal. Feel free to play around with this more. I hope that you learned something new today.
No comments:
Post a Comment