mirror of https://github.com/k3s-io/k3s
24 lines
1.4 KiB
Markdown
24 lines
1.4 KiB
Markdown
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# Images
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Each container in a pod has its own image. Currently, the only type of image supported is a [Docker Image](https://docs.docker.com/userguide/dockerimages/).
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You create your Docker image and push it to a registry before referring to it in a kubernetes pod.
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The `image` property of a container supports the same syntax as the `docker` command does, including private registries and tags.
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## Using a Private Registry
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Keys for private registries are stored in a `.dockercfg` file. Create a config file by running `docker login <registry>.<domain>` and then copying the resulting `.dockercfg` file to the kubelet working dir.
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The kubelet working dir varies by cloud provider. It is `/` on GCE and `/home/core` on CoreOS. You can determine the working dir by running this command:
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`sudo ls -ld /proc/$(pidof kubelet)/cwd` on a kNode.
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All users of the cluster will have access to any private registry in the `.dockercfg`.
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## Preloading Images
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Be default, the kubelet will try to pull each image from the specified registry.
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However, if the `imagePullPolicy` property of the container is set to `PullIfNotPresent` or `PullNever`,
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then a local image is used (preferentially or exclusively, respectively).
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This can be used to preload certain images for speed or as an alternative to authenticating to a private registry.
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Pull Policy is per-container, but any user of the cluster will have access to all local images.
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