/*
Copyright 2019 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package docker

import (
	"fmt"
	"strings"

	log "github.com/sirupsen/logrus"

	"sigs.k8s.io/kind/pkg/container/cri"
)

/*
This is adapated from:
https://github.com/kubernetes/kubernetes/blob/07a5488b2a8f67add543da72e8819407d8314204/pkg/kubelet/dockershim/helpers.go#L115-L155
*/
// generateMountBindings converts the mount list to a list of strings that
// can be understood by docker.
// '<HostPath>:<ContainerPath>[:options]', where 'options'
// is a comma-separated list of the following strings:
// 'ro', if the path is read only
// 'Z', if the volume requires SELinux relabeling
func generateMountBindings(mounts ...cri.Mount) []string {
	result := make([]string, 0, len(mounts))
	for _, m := range mounts {
		bind := fmt.Sprintf("%s:%s", m.HostPath, m.ContainerPath)
		var attrs []string
		if m.Readonly {
			attrs = append(attrs, "ro")
		}
		// Only request relabeling if the pod provides an SELinux context. If the pod
		// does not provide an SELinux context relabeling will label the volume with
		// the container's randomly allocated MCS label. This would restrict access
		// to the volume to the container which mounts it first.
		if m.SelinuxRelabel {
			attrs = append(attrs, "Z")
		}
		switch m.Propagation {
		case cri.MountPropagationNone:
			// noop, private is default
		case cri.MountPropagationBidirectional:
			attrs = append(attrs, "rshared")
		case cri.MountPropagationHostToContainer:
			attrs = append(attrs, "rslave")
		default:
			log.Warningf("unknown propagation mode for hostPath %q", m.HostPath)
			// Falls back to "private"
		}

		if len(attrs) > 0 {
			bind = fmt.Sprintf("%s:%s", bind, strings.Join(attrs, ","))
		}
		// our specific modification is the following line: make this a docker flag
		bind = fmt.Sprintf("--volume=%s", bind)
		result = append(result, bind)
	}
	return result
}
