buildkit/client/connhelper/kubepod/kubepod.go

79 lines
2.4 KiB
Go

// Package kubepod provides connhelper for kube-pod://<pod>
package kubepod
import (
"context"
"net"
"net/url"
"regexp"
"github.com/docker/cli/cli/connhelper/commandconn"
"github.com/moby/buildkit/client/connhelper"
"github.com/pkg/errors"
)
func init() {
connhelper.Register("kube-pod", Helper)
}
// Helper returns helper for connecting to a Kubernetes pod.
// Requires BuildKit v0.5.0 or later in the pod.
func Helper(u *url.URL) (*connhelper.ConnectionHelper, error) {
sp, err := SpecFromURL(u)
if err != nil {
return nil, err
}
return &connhelper.ConnectionHelper{
ContextDialer: func(ctx context.Context, addr string) (net.Conn, error) {
// using background context because context remains active for the duration of the process, after dial has completed
return commandconn.New(context.Background(), "kubectl", "--context="+sp.Context, "--namespace="+sp.Namespace,
"exec", "--container="+sp.Container, "-i", sp.Pod, "--", "buildctl", "dial-stdio")
},
}, nil
}
// Spec
type Spec struct {
Context string
Namespace string
Pod string
Container string
}
// SpecFromURL creates Spec from URL.
// URL is like kube-pod://<pod>?context=<context>&namespace=<namespace>&container=<container> .
// Only <pod> part is mandatory.
func SpecFromURL(u *url.URL) (*Spec, error) {
q := u.Query()
sp := Spec{
Context: q.Get("context"),
Namespace: q.Get("namespace"),
Pod: u.Hostname(),
Container: q.Get("container"),
}
if sp.Context != "" && !validKubeIdentifier(sp.Context) {
return nil, errors.Errorf("unsupported context name: %q", sp.Context)
}
if sp.Namespace != "" && !validKubeIdentifier(sp.Namespace) {
return nil, errors.Errorf("unsupported namespace name: %q", sp.Namespace)
}
if sp.Pod == "" {
return nil, errors.New("url lacks pod name")
}
if !validKubeIdentifier(sp.Pod) {
return nil, errors.Errorf("unsupported pod name: %q", sp.Pod)
}
if sp.Container != "" && !validKubeIdentifier(sp.Container) {
return nil, errors.Errorf("unsupported container name: %q", sp.Container)
}
return &sp, nil
}
var kubeIdentifierRegexp = regexp.MustCompile(`^[-a-z0-9.]+$`)
// validKubeIdentifier: https://kubernetes.io/docs/concepts/overview/working-with-objects/names/#names
// The length is not checked because future version of Kube may support longer identifiers.
func validKubeIdentifier(s string) bool {
return kubeIdentifierRegexp.MatchString(s)
}