Containerd is an open-source, industry-standard container runtime designed with simplicity, robustness, and portability in mind. It acts as a core component in the container ecosystem, handling the execution and management of containers across various platforms, including Linux and Windows. Containerd's primary role is to manage the complete container lifecycle, including image transfer and storage, container execution and supervision, and low-level storage and network attachments.
While containerd is primarily a low-level runtime, here's a conceptual example of interacting with it using the Go client library:
```go package main
import (
"context" "fmt"
"github.com/containerd/containerd" "github.com/containerd/containerd/namespaces")
func main() {
// Create a new client connected to the default containerd socket
client, err := containerd.New("/run/containerd/containerd.sock")
if err != nil {
panic(err)
}
defer client.Close()
// Create a new context with a namespace ctx := namespaces.WithNamespace(context.Background(), "default")
// Pull an image from a registry
image, err := client.Pull(ctx, "docker.io/library/nginx:latest", containerd.WithPullUnpack)
if err != nil {
panic(err)
}
// Create a new container from the image
container, err := client.NewContainer(
ctx,
"my-nginx-container",
containerd.WithImage(image),
containerd.WithNewSnapshot("my-nginx-snapshot", image),
)
if err != nil {
panic(err)
}
// Create a task from the container
task, err := container.NewTask(ctx, cio.NewCreator(cio.WithStdio))
if err != nil {
panic(err)
}
// Start the task
if err := task.Start(ctx); err != nil {
panic(err)
}
// Wait for the task to complete
status, err := task.Wait(ctx)
if err != nil {
panic(err)
}
fmt.Printf("Container exited with status: %s\n", status)
}
```
Please note that this is a simplified example, and real-world usage of containerd often involves more complex configuration and interaction with other components of the container ecosystem.