How to install Docker CE on CentOS 7 (method 2) First remove older version of docker (if any): $ sudo yum remove docker docker-common docker-selinux docker-engine-selinux docker-engine docker-ce Next install needed packages: $ sudo yum install -y yum-utils device-mapper-persistent-data lvm2 Configure the docker-ce repo. Fix Docker For Mac unable to start in some cases: removed use of libgmp sometimes causing the vpnkit process to die. Docker Community Edition 17.09.0-ce-mac33 2017-10-03. Bug fix Do not show Toolbox migration assistant when there are existing Docker For Mac data. Docker Community Edition 17.09.0-ce-mac32 2017-10-02.
-->This section lists terms and definitions you should be familiar with before getting deeper into Docker. For further definitions, see the extensive glossary provided by Docker.
Container image: A package with all the dependencies and information needed to create a container. An image includes all the dependencies (such as frameworks) plus deployment and execution configuration to be used by a container runtime. Usually, an image derives from multiple base images that are layers stacked on top of each other to form the container's filesystem. An image is immutable once it has been created.
Dockerfile: A text file that contains instructions for building a Docker image. It's like a batch script, the first line states the base image to begin with and then follow the instructions to install required programs, copy files, and so on, until you get the working environment you need.
Build: The action of building a container image based on the information and context provided by its Dockerfile, plus additional files in the folder where the image is built. You can build images with the following Docker command:
Container: An instance of a Docker image. A container represents the execution of a single application, process, or service. It consists of the contents of a Docker image, an execution environment, and a standard set of instructions. When scaling a service, you create multiple instances of a container from the same image. Or a batch job can create multiple containers from the same image, passing different parameters to each instance.
Volumes: Offer a writable filesystem that the container can use. Since images are read-only but most programs need to write to the filesystem, volumes add a writable layer, on top of the container image, so the programs have access to a writable filesystem. The program doesn't know it's accessing a layered filesystem, it's just the filesystem as usual. Volumes live in the host system and are managed by Docker.
Tag: A mark or label you can apply to images so that different images or versions of the same image (depending on the version number or the target environment) can be identified.
Multi-stage Build: Is a feature, since Docker 17.05 or higher, that helps to reduce the size of the final images. In a few sentences, with multi-stage build you can use, for example, a large base image, containing the SDK, for compiling and publishing the application and then using the publishing folder with a small runtime-only base image, to produce a much smaller final image.
Repository (repo): A collection of related Docker images, labeled with a tag that indicates the image version. Some repos contain multiple variants of a specific image, such as an image containing SDKs (heavier), an image containing only runtimes (lighter), etc. Those variants can be marked with tags. A single repo can contain platform variants, such as a Linux image and a Windows image.
Registry: A service that provides access to repositories. The default registry for most public images is Docker Hub (owned by Docker as an organization). A registry usually contains repositories from multiple teams. Companies often have private registries to store and manage images they've created. Azure Container Registry is another example.
Multi-arch image: For multi-architecture, it's a feature that simplifies the selection of the appropriate image, according to the platform where Docker is running. For example, when a Dockerfile requests a base image mcr.microsoft.com/dotnet/sdk:5.0 from the registry, it actually gets 5.0-nanoserver-1909, 5.0-nanoserver-1809 or 5.0-buster-slim, depending on the operating system and version where Docker is running.
Docker Hub: A public registry to upload images and work with them. Docker Hub provides Docker image hosting, public or private registries, build triggers and web hooks, and integration with GitHub and Bitbucket.
Azure Container Registry: A public resource for working with Docker images and its components in Azure. This provides a registry that's close to your deployments in Azure and that gives you control over access, making it possible to use your Azure Active Directory groups and permissions.
Docker Trusted Registry (DTR): A Docker registry service (from Docker) that can be installed on-premises so it lives within the organization's datacenter and network. It's convenient for private images that should be managed within the enterprise. Docker Trusted Registry is included as part of the Docker Datacenter product. For more information, see Docker Trusted Registry (DTR).
Docker Community Edition (CE): Development tools for Windows and macOS for building, running, and testing containers locally. Docker CE for Windows provides development environments for both Linux and Windows Containers. The Linux Docker host on Windows is based on a Hyper-V virtual machine. The host for Windows Containers is directly based on Windows. Docker CE for Mac is based on the Apple Hypervisor framework and the xhyve hypervisor, which provides a Linux Docker host virtual machine on macOS X. Docker CE for Windows and for Mac replaces Docker Toolbox, which was based on Oracle VirtualBox.
Docker Enterprise Edition (EE): An enterprise-scale version of Docker tools for Linux and Windows development.
Compose: A command-line tool and YAML file format with metadata for defining and running multi-container applications. You define a single application based on multiple images with one or more .yml files that can override values depending on the environment. After you've created the definitions, you can deploy the whole multi-container application with a single command (docker-compose up) that creates a container per image on the Docker host.
Cluster: A collection of Docker hosts exposed as if it were a single virtual Docker host, so that the application can scale to multiple instances of the services spread across multiple hosts within the cluster. Docker clusters can be created with Kubernetes, Azure Service Fabric, Docker Swarm and Mesosphere DC/OS.
Orchestrator: A tool that simplifies management of clusters and Docker hosts. Orchestrators enable you to manage their images, containers, and hosts through a command-line interface (CLI) or a graphical UI. You can manage container networking, configurations, load balancing, service discovery, high availability, Docker host configuration, and more. An orchestrator is responsible for running, distributing, scaling, and healing workloads across a collection of nodes. Typically, orchestrator products are the same products that provide cluster infrastructure, like Kubernetes and Azure Service Fabric, among other offerings in the market.
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Welcome to Docker Desktop! The Docker Desktop for Mac user manual provides information on how to configure and manage your Docker Desktop settings.
For information about Docker Desktop download, system requirements, and installation instructions, see Install Docker Desktop.
Preferences
The Docker Preferences menu allows you to configure your Docker settings such as installation, updates, version channels, Docker Hub login,and more.
Choose the Docker menu > Preferences from themenu bar and configure the runtime options described below.
General
On the General tab, you can configure when to start and update Docker:
Start Docker Desktop when you log in: Automatically starts Docker Desktop when you open your session.
Include VM in Time Machine backups: Select this option to back up the Docker Desktop virtual machine. This option is disabled by default.
Securely store Docker logins in macOS keychain: Docker Desktop stores your Docker login credentials in macOS keychain by default.
Send usage statistics: Docker Desktop sends diagnostics, crash reports, and usage data. This information helps Docker improve and troubleshoot the application. Clear the check box to opt out.
Resources
The Resources tab allows you to configure CPU, memory, disk, proxies, network, and other resources.
Advanced
On the Advanced tab, you can limit resources available to Docker.
Advanced settings are:
CPUs: By default, Docker Desktop is set to use half the number of processorsavailable on the host machine. To increase processing power, set this to ahigher number; to decrease, lower the number.
Memory: By default, Docker Desktop is set to use 2 GB runtime memory,allocated from the total available memory on your Mac. To increase the RAM, set this to a higher number. To decrease it, lower the number.
Swap: Configure swap file size as needed. The default is 1 GB.
Disk image size: Specify the size of the disk image.
Disk image location: Specify the location of the Linux volume where containers and images are stored.
You can also move the disk image to a different location. If you attempt to move a disk image to a location that already has one, you get a prompt asking if you want to use the existing image or replace it.
File sharing
Use File sharing to allow local directories on the Mac to be shared with Linux containers.This is especially useful forediting source code in an IDE on the host while running and testing the code in a container.By default the /Users, /Volume, /private, /tmp and /var/folders directory are shared. If your project is outside this directory then it must be addedto the list. Otherwise you may get Mounts denied or cannot start service errors at runtime.
File share settings are:
Add a Directory: Click
+and navigate to the directory you want to add.Apply & Restart makes the directory available to containers using Docker’sbind mount (
-v) feature.
Tips on shared folders, permissions, and volume mounts
Share only the directories that you need with the container. File sharing introduces overhead as any changes to the files on the host need to be notified to the Linux VM. Sharing too many files can lead to high CPU load and slow filesystem performance.
Shared folders are designed to allow application code to be edited on the host while being executed in containers. For non-code items such as cache directories or databases, the performance will be much better if they are stored in the Linux VM, using a data volume (named volume) or data container.
If you share the whole of your home directory into a container, MacOS may prompt you to give Docker access to personal areas of your home directory such as your Reminders or Downloads.
By default, Mac file systems are case-insensitive while Linux is case-sensitive. On Linux, it is possible to create 2 separate files:
testandTest, while on Mac these filenames would actually refer to the same underlying file. This can lead to problems where an app works correctly on a Mac (where the file contents are shared) but fails when run in Linux in production (where the file contents are distinct). To avoid this, Docker Desktop insists that all shared files are accessed as their original case. Therefore, if a file is created calledtest, it must be opened astest. Attempts to openTestwill fail with the errorNo such file or directory. Similarly, once a file calledtestis created, attempts to create a second file calledTestwill fail. For more information, see Volume mounting requires file sharing for any project directories outside of/Users.)
Proxies
Docker Desktop detects HTTP/HTTPS Proxy Settings from macOS and automaticallypropagates these to Docker. For example, if you set yourproxy settings to http://proxy.example.com, Docker uses this proxy whenpulling containers.
Your proxy settings, however, will not be propagated into the containers you start.If you wish to set the proxy settings for your containers, you need to defineenvironment variables for them, just like you would do on Linux, for example:
For more information on setting environment variables for running containers,see Set environment variables.
Network
You can configure Docker Desktop networking to work on a virtual private network (VPN). Specify a network address translation (NAT) prefix and subnet mask to enable Internet connectivity.
Docker Engine
The Docker Engine page allows you to configure the Docker daemon to determine how your containers run.
Type a JSON configuration file in the box to configure the daemon settings. For a full list of options, see the Docker Enginedockerd commandline reference.
Click Apply & Restart to save your settings and restart Docker Desktop.
Command Line
On the Command Line page, you can specify whether or not to enable experimental features.
Docker Ce For Mac
Experimental features provide early access to future product functionality.These features are intended for testing and feedback only as they may changebetween releases without warning or can be removed entirely from a futurerelease. Experimental features must not be used in production environments.Docker does not offer support for experimental features.
For a list of current experimental features in the Docker CLI, see Docker CLI Experimental features.
You can toggle the experimental features on and off in Docker Desktop. If you toggle the experimental features off, Docker Desktop uses the current generally available release of Docker Engine.
You can see whether you are running experimental mode at the command line. IfExperimental is true, then Docker is running in experimental mode, as shownhere. (If false, Experimental mode is off.)
Kubernetes
Docker Desktop includes a standalone Kubernetes server that runs on your Mac, sothat you can test deploying your Docker workloads on Kubernetes. To enable Kubernetes support and install a standalone instance of Kubernetes running as a Docker container, select Enable Kubernetes.
For more information about using the Kubernetes integration with Docker Desktop, see Deploy on Kubernetes.
Reset
Reset and Restart options
On Docker Desktop Mac, the Restart Docker Desktop, Reset to factory defaults, and other reset options are available from the Troubleshoot menu.
For information about the reset options, see Logs and Troubleshooting.
Dashboard
Docker Ce For Mac Os
The Docker Desktop Dashboard enables you to interact with containers and applications and manage the lifecycle of your applications directly from your machine. The Dashboard UI shows all running, stopped, and started containers with their state. It provides an intuitive interface to perform common actions to inspect and manage containers and existing Docker Compose applications. For more information, see Docker Desktop Dashboard.
Add TLS certificates
You can add trusted Certificate Authorities (CAs) (used to verify registryserver certificates) and client certificates (used to authenticate toregistries) to your Docker daemon.
Add custom CA certificates (server side)
All trusted CAs (root or intermediate) are supported. Docker Desktop creates acertificate bundle of all user-trusted CAs based on the Mac Keychain, andappends it to Moby trusted certificates. So if an enterprise SSL certificate istrusted by the user on the host, it is trusted by Docker Desktop.
To manually add a custom, self-signed certificate, start by adding thecertificate to the macOS keychain, which is picked up by Docker Desktop. Here isan example:
Or, if you prefer to add the certificate to your own local keychain only (ratherthan for all users), run this command instead:
See also, Directory structures forcertificates.
Note: You need to restart Docker Desktop after making any changes to thekeychain or to the ~/.docker/certs.d directory in order for the changes totake effect.
For a complete explanation of how to do this, see the blog post AddingSelf-signed Registry Certs to Docker & Docker Desktop forMac.
Add client certificates
You can put your client certificates in~/.docker/certs.d/<MyRegistry>:<Port>/client.cert and~/.docker/certs.d/<MyRegistry>:<Port>/client.key.
When the Docker Desktop application starts, it copies the ~/.docker/certs.dfolder on your Mac to the /etc/docker/certs.d directory on Moby (the DockerDesktop xhyve virtual machine).
You need to restart Docker Desktop after making any changes to the keychainor to the
~/.docker/certs.ddirectory in order for the changes to takeeffect.The registry cannot be listed as an insecure registry (see DockerEngine. Docker Desktop ignores certificates listedunder insecure registries, and does not send client certificates. Commandslike
docker runthat attempt to pull from the registry produce errormessages on the command line, as well as on the registry.
Directory structures for certificates
If you have this directory structure, you do not need to manually add the CAcertificate to your Mac OS system login:
The following further illustrates and explains a configuration with customcertificates:
You can also have this directory structure, as long as the CA certificate isalso in your keychain.
To learn more about how to install a CA root certificate for the registry andhow to set the client TLS certificate for verification, seeVerify repository client with certificatesin the Docker Engine topics.
Install shell completion
Docker Desktop comes with scripts to enable completion for the docker and docker-compose commands. The completion scripts may befound inside Docker.app, in the Contents/Resources/etc/ directory and can beinstalled both in Bash and Zsh.
Bash
Bash has built-in support forcompletion To activate completion for Docker commands, these files need to becopied or symlinked to your bash_completion.d/ directory. For example, if youinstalled bash via Homebrew:
Add the following to your ~/.bash_profile:
OR
Zsh
In Zsh, the completionsystemtakes care of things. To activate completion for Docker commands,these files need to be copied or symlinked to your Zsh site-functions/directory. For example, if you installed Zsh via Homebrew:
Fish-Shell
Fish-shell also supports tab completion completionsystem. To activate completion for Docker commands,these files need to be copied or symlinked to your Fish-shell completions/directory.
Create the completions directory:
Now add fish completions from docker.
Give feedback and get help
To get help from the community, review current user topics, join or start adiscussion, log on to our Docker Desktop for Macforum.
To report bugs or problems, log on to Docker Desktop for Mac issues onGitHub,where you can review community reported issues, and file new ones. SeeLogs and Troubleshooting for more details.
For information about providing feedback on the documentation or update it yourself, see Contribute to documentation.
Docker Hub
Select Sign in /Create Docker ID from the Docker Desktop menu to access your Docker Hub account. Once logged in, you can access your Docker Hub repositories and organizations directly from the Docker Desktop menu.
For more information, refer to the following Docker Hub topics:
Two-factor authentication
Docker Desktop enables you to sign into Docker Hub using two-factor authentication. Two-factor authentication provides an extra layer of security when accessing your Docker Hub account.
You must enable two-factor authentication in Docker Hub before signing into your Docker Hub account through Docker Desktop. For instructions, see Enable two-factor authentication for Docker Hub.
After you have enabled two-factor authentication:
Go to the Docker Desktop menu and then select Sign in / Create Docker ID.
Enter your Docker ID and password and click Sign in.
After you have successfully signed in, Docker Desktop prompts you to enter the authentication code. Enter the six-digit code from your phone and then click Verify.
After you have successfully authenticated, you can access your organizations and repositories directly from the Docker Desktop menu.
Where to go next
Try out the walkthrough at Get Started.
Dig in deeper with Docker Labs examplewalkthroughs and source code.
For a summary of Docker command line interface (CLI) commands, seeDocker CLI Reference Guide.
Check out the blog post, What’s New in Docker 17.06 Community Edition(CE).