mirror of https://github.com/docker/cli.git
Update Docker pull examples
The old examples no longer worked due to changes in the client and Docker Hub. This updates the "docker pull" documentation and adds more examples and explanation of the features. Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
This commit is contained in:
Sebastiaan van Stijn
Tibor Vass
parent
6bcb137d2f
commit
75bcb4f94a
|
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@ -24,31 +24,203 @@ Most of your images will be created on top of a base image from the
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[Docker Hub](https://hub.docker.com) contains many pre-built images that you
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can `pull` and try without needing to define and configure your own.
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It is also possible to manually specify the path of a registry to pull from.
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For example, if you have set up a local registry, you can specify its path to
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pull from it. A repository path is similar to a URL, but does not contain
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a protocol specifier (`https://`, for example).
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To download a particular image, or set of images (i.e., a repository),
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use `docker pull`:
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use `docker pull`.
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## Examples
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### Pull an image from Docker Hub
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To download a particular image, or set of images (i.e., a repository), use
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`docker pull`. If no tag is provided, Docker Engine uses the `:latest` tag as a
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default. This command pulls the `debian:latest` image:
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```bash
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$ docker pull debian
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# will pull the debian:latest image and its intermediate layers
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$ docker pull debian:testing
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# will pull the image named debian:testing and any intermediate
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# layers it is based on.
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$ docker pull debian@sha256:cbbf2f9a99b47fc460d422812b6a5adff7dfee951d8fa2e4a98caa0382cfbdbf
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# will pull the image from the debian repository with the digest
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# sha256:cbbf2f9a99b47fc460d422812b6a5adff7dfee951d8fa2e4a98caa0382cfbdbf
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# and any intermediate layers it is based on.
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# (Typically the empty `scratch` image, a MAINTAINER layer,
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# and the un-tarred base).
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$ docker pull --all-tags centos
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# will pull all the images from the centos repository
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$ docker pull registry.hub.docker.com/debian
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# manually specifies the path to the default Docker registry. This could
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# be replaced with the path to a local registry to pull from another source.
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# sudo docker pull myhub.com:8080/test-image
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Using default tag: latest
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latest: Pulling from library/debian
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fdd5d7827f33: Pull complete
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a3ed95caeb02: Pull complete
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Digest: sha256:e7d38b3517548a1c71e41bffe9c8ae6d6d29546ce46bf62159837aad072c90aa
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Status: Downloaded newer image for debian:latest
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```
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Docker images can consist of multiple layers. In the example above, the image
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consists of two layers; `fdd5d7827f33` and `a3ed95caeb02`.
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Layers can be reused by images. For example, the `debian:jessie` image shares
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both layers with `debian:latest`. Pulling the `debian:jessie` image therefore
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only pulls its metadata, but not its layers, because all layers are already
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present locally:
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```bash
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$ docker pull debian:jessie
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jessie: Pulling from library/debian
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fdd5d7827f33: Already exists
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a3ed95caeb02: Already exists
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Digest: sha256:a9c958be96d7d40df920e7041608f2f017af81800ca5ad23e327bc402626b58e
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Status: Downloaded newer image for debian:jessie
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```
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To see which images are present locally, use the [`docker images`](images.md)
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command:
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```bash
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$ docker images
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REPOSITORY TAG IMAGE ID CREATED SIZE
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debian jessie f50f9524513f 5 days ago 125.1 MB
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debian latest f50f9524513f 5 days ago 125.1 MB
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```
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Docker uses a content-addressable image store, and the image ID is a SHA256
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digest covering the image's configuration and layers. In the example above,
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`debian:jessie` and `debian:latest` have the same image ID because they are
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actually the *same* image tagged with different names. Because they are the
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same image, their layers are stored only once and do not consume extra disk
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space.
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For more information about images, layers, and the content-addressable store,
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refer to [understand images, containers, and storage drivers](../../userguide/storagedriver/imagesandcontainers.md).
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## Pull an image by digest (immutable identifier)
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So far, you've pulled images by their name (and "tag"). Using names and tags is
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a convenient way to work with images. When using tags, you can `docker pull` an
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image again to make sure you have the most up-to-date version of that image.
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For example, `docker pull ubuntu:14.04` pulls the latest version of the Ubuntu
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14.04 image.
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In some cases you don't want images to be updated to newer versions, but prefer
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to use a fixed version of an image. Docker enables you to pull an image by its
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*digest*. When pulling an image by digest, you specify *exactly* which version
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of an image to pull. Doing so, allows you to "pin" an image to that version,
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and guarantee that the image you're using is always the same.
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To know the digest of an image, pull the image first. Let's pull the latest
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`ubuntu:14.04` image from Docker Hub:
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```bash
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$ docker pull ubuntu:14.04
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14.04: Pulling from library/ubuntu
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5a132a7e7af1: Pull complete
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fd2731e4c50c: Pull complete
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28a2f68d1120: Pull complete
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a3ed95caeb02: Pull complete
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Digest: sha256:45b23dee08af5e43a7fea6c4cf9c25ccf269ee113168c19722f87876677c5cb2
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Status: Downloaded newer image for ubuntu:14.04
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```
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Docker prints the digest of the image after the pull has finished. In the example
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above, the digest of the image is:
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sha256:45b23dee08af5e43a7fea6c4cf9c25ccf269ee113168c19722f87876677c5cb2
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Docker also prints the digest of an image when *pushing* to a registry. This
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may be useful if you want to pin to a version of the image you just pushed.
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A digest takes the place of the tag when pulling an image, for example, to
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pull the above image by digest, run the following command:
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```bash
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$ docker pull ubuntu@sha256:45b23dee08af5e43a7fea6c4cf9c25ccf269ee113168c19722f87876677c5cb2
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sha256:45b23dee08af5e43a7fea6c4cf9c25ccf269ee113168c19722f87876677c5cb2: Pulling from library/ubuntu
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5a132a7e7af1: Already exists
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fd2731e4c50c: Already exists
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28a2f68d1120: Already exists
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a3ed95caeb02: Already exists
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Digest: sha256:45b23dee08af5e43a7fea6c4cf9c25ccf269ee113168c19722f87876677c5cb2
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Status: Downloaded newer image for ubuntu@sha256:45b23dee08af5e43a7fea6c4cf9c25ccf269ee113168c19722f87876677c5cb2
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```
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Digest can also be used in the `FROM` of a Dockerfile, for example:
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```Dockerfile
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FROM ubuntu@sha256:45b23dee08af5e43a7fea6c4cf9c25ccf269ee113168c19722f87876677c5cb2
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MAINTAINER some maintainer <maintainer@example.com>
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```
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> **Note**: Using this feature "pins" an image to a specific version in time.
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> Docker will therefore not pull updated versions of an image, which may include
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> security updates. If you want to pull an updated image, you need to change the
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> digest accordingly.
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## Pulling from a different registry
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By default, `docker pull` pulls images from Docker Hub. It is also possible to
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manually specify the path of a registry to pull from. For example, if you have
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set up a local registry, you can specify its path to pull from it. A registry
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path is similar to a URL, but does not contain a protocol specifier (`https://`).
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The following command pulls the `testing/test-image` image from a local registry
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listening on port 5000 (`myregistry.local:5000`):
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```bash
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$ docker pull myregistry.local:5000/testing/test-image
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```
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Docker uses the `https://` protocol to communicate with a registry, unless the
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registry is allowed to be accessed over an insecure connection. Refer to the
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[insecure registries](daemon.md#insecure-registries) section for more information.
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## Pull a repository with multiple images
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By default, `docker pull` pulls a *single* image from the registry. A repository
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can contain multiple images. To pull all images from a repository, provide the
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`-a` (or `--all-tags`) option when using `docker pull`.
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This command pulls all images from the `fedora` repository:
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```bash
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$ docker pull --all-tags fedora
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Pulling repository fedora
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ad57ef8d78d7: Download complete
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105182bb5e8b: Download complete
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511136ea3c5a: Download complete
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73bd853d2ea5: Download complete
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....
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Status: Downloaded newer image for fedora
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```
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After the pull has completed use the `docker images` command to see the
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images that were pulled. The example below shows all the `fedora` images
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that are present locally:
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```bash
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$ docker images fedora
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REPOSITORY TAG IMAGE ID CREATED SIZE
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fedora rawhide ad57ef8d78d7 5 days ago 359.3 MB
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fedora 20 105182bb5e8b 5 days ago 372.7 MB
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fedora heisenbug 105182bb5e8b 5 days ago 372.7 MB
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fedora latest 105182bb5e8b 5 days ago 372.7 MB
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```
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## Canceling a pull
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Killing the `docker pull` process, for example by pressing `CTRL-c` while it is
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running in a terminal, will terminate the pull operation.
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```bash
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$ docker pull fedora
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Using default tag: latest
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latest: Pulling from library/fedora
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a3ed95caeb02: Pulling fs layer
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236608c7b546: Pulling fs layer
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^C
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```
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> **Note**: Technically, the Engine terminates a pull operation when the
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> connection between the Docker Engine daemon and the Docker Engine client
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> initiating the pull is lost. If the connection with the Engine daemon is
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> lost for other reasons than a manual interaction, the pull is also aborted.
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@ -27,58 +27,185 @@ registry located at `registry-1.docker.io` by default.
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**--help**
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Print usage statement
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# EXAMPLE
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# EXAMPLES
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## Pull a repository with multiple images with the -a|--all-tags option set to true.
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Note that if the image is previously downloaded then the status would be
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`Status: Image is up to date for fedora`.
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### Pull an image from Docker Hub
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To download a particular image, or set of images (i.e., a repository), use
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`docker pull`. If no tag is provided, Docker Engine uses the `:latest` tag as a
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default. This command pulls the `debian:latest` image:
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$ docker pull debian
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Using default tag: latest
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latest: Pulling from library/debian
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fdd5d7827f33: Pull complete
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a3ed95caeb02: Pull complete
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Digest: sha256:e7d38b3517548a1c71e41bffe9c8ae6d6d29546ce46bf62159837aad072c90aa
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Status: Downloaded newer image for debian:latest
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Docker images can consist of multiple layers. In the example above, the image
|
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consists of two layers; `fdd5d7827f33` and `a3ed95caeb02`.
|
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|
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Layers can be reused by images. For example, the `debian:jessie` image shares
|
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both layers with `debian:latest`. Pulling the `debian:jessie` image therefore
|
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only pulls its metadata, but not its layers, because all layers are already
|
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present locally:
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$ docker pull debian:jessie
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jessie: Pulling from library/debian
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fdd5d7827f33: Already exists
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a3ed95caeb02: Already exists
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Digest: sha256:a9c958be96d7d40df920e7041608f2f017af81800ca5ad23e327bc402626b58e
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Status: Downloaded newer image for debian:jessie
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To see which images are present locally, use the **docker-images(1)**
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command:
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$ docker images
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REPOSITORY TAG IMAGE ID CREATED SIZE
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debian jessie f50f9524513f 5 days ago 125.1 MB
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debian latest f50f9524513f 5 days ago 125.1 MB
|
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|
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Docker uses a content-addressable image store, and the image ID is a SHA256
|
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digest covering the image's configuration and layers. In the example above,
|
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`debian:jessie` and `debian:latest` have the same image ID because they are
|
||||
actually the *same* image tagged with different names. Because they are the
|
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same image, their layers are stored only once and do not consume extra disk
|
||||
space.
|
||||
|
||||
For more information about images, layers, and the content-addressable store,
|
||||
refer to [understand images, containers, and storage drivers](https://docs.docker.com/engine/userguide/storagedriver/imagesandcontainers/)
|
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in the online documentation.
|
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|
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|
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## Pull an image by digest (immutable identifier)
|
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|
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So far, you've pulled images by their name (and "tag"). Using names and tags is
|
||||
a convenient way to work with images. When using tags, you can `docker pull` an
|
||||
image again to make sure you have the most up-to-date version of that image.
|
||||
For example, `docker pull ubuntu:14.04` pulls the latest version of the Ubuntu
|
||||
14.04 image.
|
||||
|
||||
In some cases you don't want images to be updated to newer versions, but prefer
|
||||
to use a fixed version of an image. Docker enables you to pull an image by its
|
||||
*digest*. When pulling an image by digest, you specify *exactly* which version
|
||||
of an image to pull. Doing so, allows you to "pin" an image to that version,
|
||||
and guarantee that the image you're using is always the same.
|
||||
|
||||
To know the digest of an image, pull the image first. Let's pull the latest
|
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`ubuntu:14.04` image from Docker Hub:
|
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|
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$ docker pull ubuntu:14.04
|
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|
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14.04: Pulling from library/ubuntu
|
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5a132a7e7af1: Pull complete
|
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fd2731e4c50c: Pull complete
|
||||
28a2f68d1120: Pull complete
|
||||
a3ed95caeb02: Pull complete
|
||||
Digest: sha256:45b23dee08af5e43a7fea6c4cf9c25ccf269ee113168c19722f87876677c5cb2
|
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Status: Downloaded newer image for ubuntu:14.04
|
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|
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Docker prints the digest of the image after the pull has finished. In the example
|
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above, the digest of the image is:
|
||||
|
||||
sha256:45b23dee08af5e43a7fea6c4cf9c25ccf269ee113168c19722f87876677c5cb2
|
||||
|
||||
Docker also prints the digest of an image when *pushing* to a registry. This
|
||||
may be useful if you want to pin to a version of the image you just pushed.
|
||||
|
||||
A digest takes the place of the tag when pulling an image, for example, to
|
||||
pull the above image by digest, run the following command:
|
||||
|
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$ docker pull ubuntu@sha256:45b23dee08af5e43a7fea6c4cf9c25ccf269ee113168c19722f87876677c5cb2
|
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|
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sha256:45b23dee08af5e43a7fea6c4cf9c25ccf269ee113168c19722f87876677c5cb2: Pulling from library/ubuntu
|
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5a132a7e7af1: Already exists
|
||||
fd2731e4c50c: Already exists
|
||||
28a2f68d1120: Already exists
|
||||
a3ed95caeb02: Already exists
|
||||
Digest: sha256:45b23dee08af5e43a7fea6c4cf9c25ccf269ee113168c19722f87876677c5cb2
|
||||
Status: Downloaded newer image for ubuntu@sha256:45b23dee08af5e43a7fea6c4cf9c25ccf269ee113168c19722f87876677c5cb2
|
||||
|
||||
Digest can also be used in the `FROM` of a Dockerfile, for example:
|
||||
|
||||
FROM ubuntu@sha256:45b23dee08af5e43a7fea6c4cf9c25ccf269ee113168c19722f87876677c5cb2
|
||||
MAINTAINER some maintainer <maintainer@example.com>
|
||||
|
||||
> **Note**: Using this feature "pins" an image to a specific version in time.
|
||||
> Docker will therefore not pull updated versions of an image, which may include
|
||||
> security updates. If you want to pull an updated image, you need to change the
|
||||
> digest accordingly.
|
||||
|
||||
## Pulling from a different registry
|
||||
|
||||
By default, `docker pull` pulls images from Docker Hub. It is also possible to
|
||||
manually specify the path of a registry to pull from. For example, if you have
|
||||
set up a local registry, you can specify its path to pull from it. A registry
|
||||
path is similar to a URL, but does not contain a protocol specifier (`https://`).
|
||||
|
||||
The following command pulls the `testing/test-image` image from a local registry
|
||||
listening on port 5000 (`myregistry.local:5000`):
|
||||
|
||||
$ docker pull myregistry.local:5000/testing/test-image
|
||||
|
||||
Docker uses the `https://` protocol to communicate with a registry, unless the
|
||||
registry is allowed to be accessed over an insecure connection. Refer to the
|
||||
[insecure registries](https://docs.docker.com/engine/reference/commandline/daemon/#insecure-registries)
|
||||
section in the online documentation for more information.
|
||||
|
||||
|
||||
## Pull a repository with multiple images
|
||||
|
||||
By default, `docker pull` pulls a *single* image from the registry. A repository
|
||||
can contain multiple images. To pull all images from a repository, provide the
|
||||
`-a` (or `--all-tags`) option when using `docker pull`.
|
||||
|
||||
This command pulls all images from the `fedora` repository:
|
||||
|
||||
$ docker pull --all-tags fedora
|
||||
|
||||
Pulling repository fedora
|
||||
ad57ef8d78d7: Download complete
|
||||
105182bb5e8b: Download complete
|
||||
511136ea3c5a: Download complete
|
||||
73bd853d2ea5: Download complete
|
||||
....
|
||||
|
||||
Status: Downloaded newer image for fedora
|
||||
|
||||
$ docker images
|
||||
After the pull has completed use the `docker images` command to see the
|
||||
images that were pulled. The example below shows all the `fedora` images
|
||||
that are present locally:
|
||||
|
||||
$ docker images fedora
|
||||
|
||||
REPOSITORY TAG IMAGE ID CREATED SIZE
|
||||
fedora rawhide ad57ef8d78d7 5 days ago 359.3 MB
|
||||
fedora 20 105182bb5e8b 5 days ago 372.7 MB
|
||||
fedora heisenbug 105182bb5e8b 5 days ago 372.7 MB
|
||||
fedora latest 105182bb5e8b 5 days ago 372.7 MB
|
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|
||||
## Pull a repository with the -a|--all-tags option set to false (this is the default).
|
||||
|
||||
$ docker pull debian
|
||||
## Canceling a pull
|
||||
|
||||
Killing the `docker pull` process, for example by pressing `CTRL-c` while it is
|
||||
running in a terminal, will terminate the pull operation.
|
||||
|
||||
$ docker pull fedora
|
||||
|
||||
Using default tag: latest
|
||||
latest: Pulling from library/debian
|
||||
2c49f83e0b13: Pull complete
|
||||
4a5e6db8c069: Pull complete
|
||||
latest: Pulling from library/fedora
|
||||
a3ed95caeb02: Pulling fs layer
|
||||
236608c7b546: Pulling fs layer
|
||||
^C
|
||||
|
||||
Status: Downloaded newer image for debian:latest
|
||||
|
||||
$ docker images
|
||||
REPOSITORY TAG IMAGE ID CREATED SIZE
|
||||
debian latest 4a5e6db8c069 5 days ago 125.1 MB
|
||||
|
||||
|
||||
## Pull an image, manually specifying path to Docker's public registry and tag
|
||||
Note that if the image is previously downloaded then the status would be
|
||||
`Status: Image is up to date for registry.hub.docker.com/fedora:20`
|
||||
|
||||
$ docker pull registry.hub.docker.com/fedora:20
|
||||
Pulling repository fedora
|
||||
3f2fed40e4b0: Download complete
|
||||
511136ea3c5a: Download complete
|
||||
fd241224e9cf: Download complete
|
||||
|
||||
Status: Downloaded newer image for registry.hub.docker.com/fedora:20
|
||||
|
||||
$ docker images
|
||||
REPOSITORY TAG IMAGE ID CREATED SIZE
|
||||
fedora 20 3f2fed40e4b0 4 days ago 372.7 MB
|
||||
> **Note**: Technically, the Engine terminates a pull operation when the
|
||||
> connection between the Docker Engine daemon and the Docker Engine client
|
||||
> initiating the pull is lost. If the connection with the Engine daemon is
|
||||
> lost for other reasons than a manual interaction, the pull is also aborted.
|
||||
|
||||
|
||||
# HISTORY
|
||||
|
|
|
|||
Loading…
Reference in New Issue