containerd/namespaces/context.go
Stephen J Day 5380585e21
namespaces: enforce a character set for namespaces
Signed-off-by: Stephen J Day <stephen.day@docker.com>
2017-06-21 17:31:25 -07:00

70 lines
1.7 KiB
Go

package namespaces
import (
"os"
"github.com/pkg/errors"
"golang.org/x/net/context"
)
const (
namespaceEnvVar = "CONTAINERD_NAMESPACE"
defaultNamespace = "default"
)
var (
errNamespaceRequired = errors.New("namespace is required")
)
type namespaceKey struct{}
// WithNamespace sets a given namespace on the context
func WithNamespace(ctx context.Context, namespace string) context.Context {
ctx = context.WithValue(ctx, namespaceKey{}, namespace) // set our key for namespace
// also store on the grpc headers so it gets picked up by any clients that
// are using this.
return withGRPCNamespaceHeader(ctx, namespace)
}
// NamespaceFromEnv uses the namespace defined in CONTAINERD_NAMESPACE or
// default
func NamespaceFromEnv(ctx context.Context) context.Context {
namespace := os.Getenv(namespaceEnvVar)
if namespace == "" {
namespace = defaultNamespace
}
return WithNamespace(ctx, namespace)
}
// Namespace returns the namespace from the context.
//
// The namespace is not guaranteed to be valid.
func Namespace(ctx context.Context) (string, bool) {
namespace, ok := ctx.Value(namespaceKey{}).(string)
if !ok {
return fromGRPCHeader(ctx)
}
return namespace, ok
}
// IsNamespaceRequired returns whether an error is caused by a missing namespace
func IsNamespaceRequired(err error) bool {
return errors.Cause(err) == errNamespaceRequired
}
// NamespaceRequired returns the valid namepace from the context or an error.
func NamespaceRequired(ctx context.Context) (string, error) {
namespace, ok := Namespace(ctx)
if !ok || namespace == "" {
return "", errNamespaceRequired
}
if err := Validate(namespace); err != nil {
return "", err
}
return namespace, nil
}