Docker Centos 7 Container

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Docker Hub repositories allow you share container images with your team,customers, or the Docker community at large.

Docker Compose is a tool used to define and run multi-container Docker applications. Users utilize this software to launch, execute, communicate, and close containers with a single coordinated command. This tutorial will show you how to install Docker Compose on CentOS 7. This tutorial aims to give you practical experience of using Docker container resource limitation functionalities on an Alibaba Cloud Elastic Compute. I am writing this tutorial using CentOS. Docker looks for centos image locally, and it is not found, it starts downloading the centos image from Docker registry. Once the image has been downloaded, it will start the container and echo the command Hello-World in the console which you can see at the end of the output. This is only available on CentOS with the following command: make FLAVORS='master,centos,7' build. Alternatively, you can build a container image based on wip-. branch: make FLAVORS='wip-nautilus-superb,centos,7' build. To build your branch on Centos 7 on the wip-nautilus-superb branch. But please make sure the branch name contains the release.

Docker images are pushed to Docker Hub through the docker pushcommand. A single Docker Hub repository can hold many Docker images (stored astags).

Creating repositories

To create a repository, sign into Docker Hub, click on Repositories thenCreate Repository:

When creating a new repository:

  • You can choose to put it in your Docker ID namespace, or in anyorganization where you are an owner.
  • The repository name needs to be unique in that namespace, can be twoto 255 characters, and can only contain lowercase letters, numbers, hyphens (-),and underscores (_).
  • The description can be up to 100 characters and is used in the search result.
  • You can link a GitHub or Bitbucket account now, or choose to do it later inthe repository settings.

After you hit the Create button, you can start using docker push to pushimages to this repository.

Pushing a Docker container image to Docker Hub

To push an image to Docker Hub, you must first name your local image using yourDocker Hub username and the repository name that you created through Docker Hubon the web.

You can add multiple images to a repository by adding a specific :<tag> tothem (for example docs/base:testing). If it’s not specified, the tag defaultsto latest.

Name your local images using one of these methods:

  • When you build them, using docker build -t <hub-user>/<repo-name>[:<tag>]
  • By re-tagging an existing local image docker tag <existing-image> <hub-user>/<repo-name>[:<tag>]
  • By using docker commit <existing-container> <hub-user>/<repo-name>[:<tag>]to commit changes

Now you can push this repository to the registry designated by its name or tag.

The image is then uploaded and available for use by your teammates and/orthe community.

Private repositories

Docker Centos 7 Container

Private repositories let you keep container images private, either to yourown account or within an organization or team.

To create a private repository, select Private when creating a repository:

You can also make an existing repository private by going to its Settings tab:

You get one private repository for free with your Docker Hub user account (notusable for organizations you’re a member of). If you need more privaterepositories for your user account, upgrade your Docker Hub plan from yourBilling Information page.

Once the private repository is created, you can push and pull images to andfrom it using Docker.

Note: You need to be signed in and have access to work with aprivate repository.

Note: Private repositories are not currently available to search throughthe top-level search or docker search. Tools for creating and maintaining an editorial calendar pdf.

You can designate collaborators and manage their access to a privaterepository from that repository’s Settings page. You can also toggle therepository’s status between public and private, if you have an availablerepository slot open. Otherwise, you can upgrade yourDocker Hub plan.

Collaborators and their role

A collaborator is someone you want to give access to a private repository. Oncedesignated, they can push and pull to your repositories. They are notallowed to perform any administrative tasks such as deleting the repository orchanging its status from private to public.


A collaborator cannot add other collaborators. Only the owner ofthe repository has administrative access.

You can also assign more granular collaborator rights (“Read”, “Write”, or“Admin”) on Docker Hub by using organizations and teams. For more informationsee the organizations documentation.

Viewing repository tags

Docker Hub’s individual repositories view shows you the available tags and thesize of the associated image. Go to the Repositories view and click on arepository to see its tags.

Image sizes are the cumulative space taken up by the image and all its parentimages. This is also the disk space used by the contents of the .tar filecreated when you docker save an image.

To view individual tags, click on the Tags tab.

An image is considered stale if there has been no push/pull activity for morethan 1 month, i.e.:

  • It has not been pulled for more than 1 month
  • And it has not been pushed for more than 1 month

A multi-architecture image is considered stale if all single-architecture imagespart of its manifest are stale.

Docker Centos 7 Container Tracking

To delete a tag, select the corresponding checkbox and select Delete from theAction drop-down list.


Only a user with administrative access (owner or team member with Adminpermission) over the repository can delete tags.

Select a tag’s digest to view details.

Searching for Repositories

You can search the Docker Hub registry through itssearch interface or by using the command line interface. Searching can findimages by image name, username, or description:

There you can see two example results: centos and ansible/centos7-ansible.The second result shows that it comes from the public repository of a user,named ansible/, while the first result, centos, doesn’t explicitly list arepository which means that it comes from the top-level namespace forofficial images. The / character separatesa user’s repository from the image name.

Once you’ve found the image you want, you can download it with docker pull <imagename>:

You now have an image from which you can run containers.

Starring Repositories

Your repositories can be starred and you can star repositories in return. Starsare a way to show that you like a repository. They are also an easy way ofbookmarking your favorites.

Service accounts

A service account is a Docker ID used by a bot for automating the build pipelinefor containerized applications. Service accounts are typically used in automatedworkflows, and do not share Docker IDs with the members in the Team plan.

To create a new service account for your Team account:

  1. Create a new Docker ID.
  2. Create a team in your organization and grant it read-only access to your private repositories.
  3. Add the new Docker ID to your organization.
  4. Add the new Docker ID to the team you created earlier.
  5. Create a new personal access token (PAT) from the user account and use it for CI.

To create a new service account for your Pro account:

  1. Create a new Docker ID.
  2. Click Repositories from the main menu.
  3. Select a repository from the list and go to the Collaborators tab.
  4. Add the new Docker ID as a collaborator.
  5. Create a new personal access token (PAT) from the user account and use it for CI.

If you want a read-only PAT just for your open source repos, or to accessofficial images and other public images, you do not have to grant any access permissions to the new Docker ID.


Service accounts are still subject to Docker’s fair pull limit policy. To learn more about these limits, see our Resource Consumption Updates FAQ.

Docker Centos 7 Container Linux

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