ctr

Documentation

Overview

Package ctr provides invoking a “ctr” command inside a Docker container containing containerd and ctr.

Due to some design decisions on containerd's native API any client that wants to pull images and then deploy them as containers has to be inside the same kernel namespaces as the containerd daemon. It is unclear as to which namespace types need to be the same, but assumed to be the same mount and user namespaces. This affects both tools such as “cri” as well as the generic API client.

Successfully will fail the current test in case “ctr” either cannot be started or exits with a non-zero result code.

In contrast, Exec will only fail the current test in case “ctr” cannot be started at all, but otherwise will gladly accept all exit code outcomes and report them back.

Putting these functions into their own public package allows for re-use and maintaining them in one central place.

Index

• func Exec(cntr *dockertest.Resource, args ...string) int
• func Successfully(cntr *dockertest.Resource, args ...string)

Functions

func Exec

func Exec(cntr *dockertest.Resource, args ...string) int

Exec runs a "ctr" command inside the specified Docker container that not only contains a containerd but also a ctr binary, returning ctr's exit code.

func Successfully

func Successfully(cntr *dockertest.Resource, args ...string)

Successfully runs a "ctr” command inside the specified Docker container that not only contains a containerd but also a ctr binary, expecting the command to succeed without any error and a zero exit code.