kubernetes

Documentation

Overview

Package kubernetes is our main interface on top of the Kubernetes API Currently, we directly control Pods. Alternatively we may opt for the Kubernetes Job abstraction if it provides enough low-level access today

Index

• func CopyFileFromPod(ctx context.Context, podName string, containerName string, sourcePath string, ...) error
• func CopyFileToPod(ctx context.Context, podName string, containerName string, sourcePath string, ...) error
• func CreatePod(ctx context.Context, pod *apiv1.Pod) (*apiv1.Pod, error)
• func DeletePod(ctx context.Context, podName string) error
• func ExecBashInContainer(ctx context.Context, nameSpace, podName, containerName, cmd string) (string, string, error)
• func ExecCommandInContainer(ctx context.Context, nameSpace, podName, containerName string, cmd ...string) (string, string, error)
• func ExecShellInContainer(ctx context.Context, nameSpace, podName, containerName, cmd string) (string, string, error)
• func ExecShellInContainerWithEnvVars(ctx context.Context, namespace string, podName string, containerName string, ...) (string, string, error)
• func ExecWithOptions(options ExecOptions) (string, string, error)
• func Init(ctx context.Context) error
• func PodExists(ctx context.Context, podName string) (bool, error)
• func WatchErrors() <-chan error
• type ExecOptions
• type PodWatcher
  • func NewPodWatcher(podsClient v1.PodInterface) PodWatcher
  • func (pw *PodWatcher) Start(ctx context.Context) <-chan error
  • func (pw *PodWatcher) WaitForPodReady(ctx context.Context, podName string) (*apiv1.Pod, error)
  • func (pw *PodWatcher) WatchPods(ctx context.Context) error
• type RunningPodSpec
  • func CreateReadyPod(ctx context.Context, pod *apiv1.Pod) (RunningPodSpec, error)
  • func SetPodSpec(pod *apiv1.Pod) RunningPodSpec

Functions

func CopyFileFromPod

func CopyFileFromPod(ctx context.Context, podName string, containerName string, sourcePath string, destPath string, keepFile bool) error

CopyFileFromPod is a function that copies a file from a specified Pod and container to the local filesystem. Parameters:

• podName: A string containing the name of the Pod from which the file should be copied.
• containerName: A string containing the name of the container from which the file should be copied.
• sourcePath: A string containing the path to the file in the Pod that should be copied.
• destPath: A string containing the path to the destination file on the local filesystem.
• keepFile: A boolean value indicating whether the file should be kept in the Pod after copying.

Returns:

• An error if there were any issues encountered during the file copy process.

func CopyFileToPod

func CopyFileToPod(ctx context.Context, podName string, containerName string, sourcePath string, destPath string) error

CopyFileToPod is a function that copies a file to a specified Pod and container from the local filesystem. Parameters:

• podName: A string containing the name of the Pod to which the file should be copied.
• containerName: A string containing the name of the container to which the file should be copied.
• sourcePath: A string containing the path to the source file on the local filesystem.
• destPath: A string containing the path to the destination file in the Pod.

Returns:

• An error if there were any issues encountered during the file copy process.

func CreatePod

func CreatePod(ctx context.Context, pod *apiv1.Pod) (*apiv1.Pod, error)

CreatePod is a function that takes a pointer to a Kubernetes Pod object as input. It uses the Kubernetes client to create the new Pod, and returns the new Pod object along with any errors encountered during the creation process.

Parameters:

• pod: A pointer to the Kubernetes Pod object that needs to be created.

Returns:

• A pointer to the new Kubernetes Pod object that was created by the function.
• An error if there were any issues encountered during the creation process.

func DeletePod

func DeletePod(ctx context.Context, podName string) error

DeletePod is a function that takes a string containing the name of a Pod as input. It deletes the specified Pod from the Kubernetes cluster using the Kubernetes client.

Parameters:

• podName: A string containing the name of the Pod that needs to be deleted.

Returns:

• An error if there were any issues encountered during the Pod deletion process.

func ExecBashInContainer

func ExecBashInContainer(ctx context.Context, nameSpace, podName, containerName, cmd string) (string, string, error)

ExecShellInContainer is a function that launches a command in the specified container using sh. It takes the namespace, pod name, container name, and command as input parameters and returns the stdout and stderr outputs of the command. This function is used in the main function.

Parameters:

• nameSpace: A string containing the name of the namespace in which the pod is running.
• podName: A string containing the name of the pod in which the container is running.
• containerName: A string containing the name of the container in which the command is to be executed.
• cmd: A string containing the command to be executed using sh.

Returns:

• stdout: A string containing the standard output of the executed command.
• stderr: A string containing the standard error output of the executed command.

func ExecCommandInContainer

func ExecCommandInContainer(ctx context.Context, nameSpace, podName, containerName string, cmd ...string) (string, string, error)

ExecCommandInContainerWithFullOutput is a function that executes a command in a specified container and returns the stdout, stderr, and error using the Kubernetes client. It uses the ExecWithOptions function to execute the command at the API level. The function takes the namespace, pod name, container name, and command as input parameters.

Parameters:

• nameSpace: A string representing the namespace of the pod.
• podName: A string representing the name of the pod.
• containerName: A string representing the name of the container.
• cmd: A variadic parameter of strings representing the command to be executed in the container.

Returns:

• stdout: A string containing the standard output of the executed command.
• stderr: A string containing the standard error output of the executed command.
• error: An error object indicating any errors encountered while executing the command.

func ExecShellInContainer

func ExecShellInContainer(ctx context.Context, nameSpace, podName, containerName, cmd string) (string, string, error)

ExecShellInContainer is a function that launches a command in the specified container using sh. It takes the namespace, pod name, container name, and command as input parameters and returns the stdout and stderr outputs of the command. This function is used in the main function.

Parameters:

• nameSpace: A string containing the name of the namespace in which the pod is running.
• podName: A string containing the name of the pod in which the container is running.
• containerName: A string containing the name of the container in which the command is to be executed.
• cmd: A string containing the command to be executed using sh.

Returns:

• stdout: A string containing the standard output of the executed command.
• stderr: A string containing the standard error output of the executed command.

func ExecShellInContainerWithEnvVars

func ExecShellInContainerWithEnvVars(ctx context.Context, namespace string, podName string, containerName string, cmd string, envVars map[string]string) (string, string, error)

func ExecWithOptions

func ExecWithOptions(options ExecOptions) (string, string, error)

ExecWithOptions is a function that executes a command in a specified container using the Kubernetes API. The function takes an ExecOptions struct as input, which includes the name of the Pod and Container to execute the command in, the command to execute, and additional options such as whether to capture stdout and stderr, whether to preserve whitespace in output, and whether to use a TTY.

Parameters:

• options: an ExecOptions struct containing the necessary information to execute the command.

Returns:

• stdout: a string containing the standard output of the command execution.
• stderr: a string containing the standard error of the command execution.
• err: an error object that indicates whether an error occurred while executing the command.

func Init

func Init(ctx context.Context) error

Init initializes the Kubernetes API clients and starts the shared pod watcher.

func PodExists

func PodExists(ctx context.Context, podName string) (bool, error)

PodExists checks if a Pod with the specified name exists in the cluster using the Kubernetes client. If the Pod exists, the function returns true. If the Pod does not exist, the function returns false.

Parameters:

• podName: A string containing the name of the Pod whose existence needs to be checked.

Returns:

• A boolean value indicating whether the specified Pod exists or not.
• An error if there were any issues encountered during the existence check process.

func WatchErrors

func WatchErrors() <-chan error

WatchErrors returns asynchronous pod watcher failures.

Types

type ExecOptions

type ExecOptions struct {
	Context            context.Context
	Command            []string
	Namespace          string
	PodName            string
	ContainerName      string
	Stdin              io.Reader
	CaptureStdout      bool
	CaptureStderr      bool
	PreserveWhitespace bool // If false, whitespace in std{err,out} will be removed.
}

type PodWatcher

type PodWatcher struct {
	// contains filtered or unexported fields
}

func NewPodWatcher

func NewPodWatcher(podsClient v1.PodInterface) PodWatcher

func (*PodWatcher) Start

func (pw *PodWatcher) Start(ctx context.Context) <-chan error

func (*PodWatcher) WaitForPodReady

func (pw *PodWatcher) WaitForPodReady(ctx context.Context, podName string) (*apiv1.Pod, error)

WaitForPodReady blocks until the pod is in the running phase and all the containers are ready.

First it adds the pod with a corresponding channel to the eventsChans map for PodWatcher. Then it waits for updates from the PodWatcher for the desired phase to be reached.

func (*PodWatcher) WatchPods

func (pw *PodWatcher) WatchPods(ctx context.Context) error

WatchPods watches all pods in the namespace and sends events to the corresponding channels.

type RunningPodSpec

type RunningPodSpec struct {
	PodName        string
	ContainerImage string
	ContainerName  string
	PodIP          string
}

func CreateReadyPod

func CreateReadyPod(ctx context.Context, pod *apiv1.Pod) (RunningPodSpec, error)

CreateReadyPod is a function that creates a Kubernetes Pod and waits for the Pod to be ready using the PodWatcher. The function returns a PodSpec containing the relevant specifications of the created Pod.

Parameters:

• pod: A pointer to the Kubernetes Pod object that needs to be created.

Returns:

• A PodSpec struct containing the specifications of the created Pod.
• An error if there were any issues encountered during the Pod creation process.

func SetPodSpec

func SetPodSpec(pod *apiv1.Pod) RunningPodSpec

SetPodSpec is a helper function that returns a structured object that contains some of the relevant specifications of the given Kubernetes Pod. It extracts the Pod's name, container imag, container name, and Pod IP from the provided Pod variable, and organizes them into a flat struct of type RunningPodSpec.

Parameters:

• pod: A pointer to the Kubernetes Pod whose specifications are to be extracted.

Returns:

• A PodSpec object containing the specifications of the given Pod.