mirror of https://github.com/k3s-io/k3s
150 lines
5.1 KiB
Go
150 lines
5.1 KiB
Go
/*
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Copyright 2016 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package dockershim
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import (
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"fmt"
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"math/rand"
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"strconv"
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"strings"
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runtimeapi "k8s.io/kubernetes/pkg/kubelet/apis/cri/runtime/v1alpha2"
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"k8s.io/kubernetes/pkg/kubelet/leaky"
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)
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// Container "names" are implementation details that do not concern
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// kubelet/CRI. This CRI shim uses names to fulfill the CRI requirement to
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// make sandbox/container creation idempotent. CRI states that there can
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// only exist one sandbox/container with the given metadata. To enforce this,
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// this shim constructs a name using the fields in the metadata so that
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// docker will reject the creation request if the name already exists.
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//
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// Note that changes to naming will likely break the backward compatibility.
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// Code must be added to ensure the shim knows how to recognize and extract
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// information the older containers.
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//
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// TODO: Add code to handle backward compatibility, i.e., making sure we can
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// recognize older containers and extract information from their names if
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// necessary.
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const (
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// kubePrefix is used to identify the containers/sandboxes on the node managed by kubelet
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kubePrefix = "k8s"
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// sandboxContainerName is a string to include in the docker container so
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// that users can easily identify the sandboxes.
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sandboxContainerName = leaky.PodInfraContainerName
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// Delimiter used to construct docker container names.
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nameDelimiter = "_"
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// DockerImageIDPrefix is the prefix of image id in container status.
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DockerImageIDPrefix = "docker://"
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// DockerPullableImageIDPrefix is the prefix of pullable image id in container status.
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DockerPullableImageIDPrefix = "docker-pullable://"
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)
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func makeSandboxName(s *runtimeapi.PodSandboxConfig) string {
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return strings.Join([]string{
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kubePrefix, // 0
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sandboxContainerName, // 1
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s.Metadata.Name, // 2
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s.Metadata.Namespace, // 3
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s.Metadata.Uid, // 4
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fmt.Sprintf("%d", s.Metadata.Attempt), // 5
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}, nameDelimiter)
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}
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func makeContainerName(s *runtimeapi.PodSandboxConfig, c *runtimeapi.ContainerConfig) string {
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return strings.Join([]string{
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kubePrefix, // 0
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c.Metadata.Name, // 1:
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s.Metadata.Name, // 2: sandbox name
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s.Metadata.Namespace, // 3: sandbox namesapce
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s.Metadata.Uid, // 4 sandbox uid
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fmt.Sprintf("%d", c.Metadata.Attempt), // 5
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}, nameDelimiter)
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}
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// randomizeName randomizes the container name. This should only be used when we hit the
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// docker container name conflict bug.
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func randomizeName(name string) string {
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return strings.Join([]string{
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name,
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fmt.Sprintf("%08x", rand.Uint32()),
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}, nameDelimiter)
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}
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func parseUint32(s string) (uint32, error) {
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n, err := strconv.ParseUint(s, 10, 32)
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if err != nil {
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return 0, err
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}
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return uint32(n), nil
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}
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// TODO: Evaluate whether we should rely on labels completely.
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func parseSandboxName(name string) (*runtimeapi.PodSandboxMetadata, error) {
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// Docker adds a "/" prefix to names. so trim it.
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name = strings.TrimPrefix(name, "/")
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parts := strings.Split(name, nameDelimiter)
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// Tolerate the random suffix.
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// TODO(random-liu): Remove 7 field case when docker 1.11 is deprecated.
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if len(parts) != 6 && len(parts) != 7 {
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return nil, fmt.Errorf("failed to parse the sandbox name: %q", name)
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}
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if parts[0] != kubePrefix {
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return nil, fmt.Errorf("container is not managed by kubernetes: %q", name)
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}
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attempt, err := parseUint32(parts[5])
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if err != nil {
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return nil, fmt.Errorf("failed to parse the sandbox name %q: %v", name, err)
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}
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return &runtimeapi.PodSandboxMetadata{
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Name: parts[2],
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Namespace: parts[3],
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Uid: parts[4],
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Attempt: attempt,
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}, nil
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}
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// TODO: Evaluate whether we should rely on labels completely.
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func parseContainerName(name string) (*runtimeapi.ContainerMetadata, error) {
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// Docker adds a "/" prefix to names. so trim it.
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name = strings.TrimPrefix(name, "/")
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parts := strings.Split(name, nameDelimiter)
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// Tolerate the random suffix.
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// TODO(random-liu): Remove 7 field case when docker 1.11 is deprecated.
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if len(parts) != 6 && len(parts) != 7 {
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return nil, fmt.Errorf("failed to parse the container name: %q", name)
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}
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if parts[0] != kubePrefix {
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return nil, fmt.Errorf("container is not managed by kubernetes: %q", name)
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}
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attempt, err := parseUint32(parts[5])
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if err != nil {
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return nil, fmt.Errorf("failed to parse the container name %q: %v", name, err)
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}
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return &runtimeapi.ContainerMetadata{
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Name: parts[1],
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Attempt: attempt,
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}, nil
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}
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