[NO TESTS NEEDED] Vendor in containers/buildah v1.20.0

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

vendor/github.com/containers/buildah/define/namespace.go

@@ -0,0 +1,87 @@
+package define
+
+import (
+	"fmt"
+)
+
+// NamespaceOption controls how we set up a namespace when launching processes.
+type NamespaceOption struct {
+	// Name specifies the type of namespace, typically matching one of the
+	// ...Namespace constants defined in
+	// github.com/opencontainers/runtime-spec/specs-go.
+	Name string
+	// Host is used to force our processes to use the host's namespace of
+	// this type.
+	Host bool
+	// Path is the path of the namespace to attach our process to, if Host
+	// is not set.  If Host is not set and Path is also empty, a new
+	// namespace will be created for the process that we're starting.
+	// If Name is specs.NetworkNamespace, if Path doesn't look like an
+	// absolute path, it is treated as a comma-separated list of CNI
+	// configuration names which will be selected from among all of the CNI
+	// network configurations which we find.
+	Path string
+}
+
+// NamespaceOptions provides some helper methods for a slice of NamespaceOption
+// structs.
+type NamespaceOptions []NamespaceOption
+
+// Find the configuration for the namespace of the given type.  If there are
+// duplicates, find the _last_ one of the type, since we assume it was appended
+// more recently.
+func (n *NamespaceOptions) Find(namespace string) *NamespaceOption {
+	for i := range *n {
+		j := len(*n) - 1 - i
+		if (*n)[j].Name == namespace {
+			return &((*n)[j])
+		}
+	}
+	return nil
+}
+
+// AddOrReplace either adds or replaces the configuration for a given namespace.
+func (n *NamespaceOptions) AddOrReplace(options ...NamespaceOption) {
+nextOption:
+	for _, option := range options {
+		for i := range *n {
+			j := len(*n) - 1 - i
+			if (*n)[j].Name == option.Name {
+				(*n)[j] = option
+				continue nextOption
+			}
+		}
+		*n = append(*n, option)
+	}
+}
+
+// NetworkConfigurationPolicy takes the value NetworkDefault, NetworkDisabled,
+// or NetworkEnabled.
+type NetworkConfigurationPolicy int
+
+const (
+	// NetworkDefault is one of the values that BuilderOptions.ConfigureNetwork
+	// can take, signalling that the default behavior should be used.
+	NetworkDefault NetworkConfigurationPolicy = iota
+	// NetworkDisabled is one of the values that BuilderOptions.ConfigureNetwork
+	// can take, signalling that network interfaces should NOT be configured for
+	// newly-created network namespaces.
+	NetworkDisabled
+	// NetworkEnabled is one of the values that BuilderOptions.ConfigureNetwork
+	// can take, signalling that network interfaces should be configured for
+	// newly-created network namespaces.
+	NetworkEnabled
+)
+
+// String formats a NetworkConfigurationPolicy as a string.
+func (p NetworkConfigurationPolicy) String() string {
+	switch p {
+	case NetworkDefault:
+		return "NetworkDefault"
+	case NetworkDisabled:
+		return "NetworkDisabled"
+	case NetworkEnabled:
+		return "NetworkEnabled"
+	}
+	return fmt.Sprintf("unknown NetworkConfigurationPolicy %d", p)
+}