1/*
2   Copyright The containerd Authors.
3
4   Licensed under the Apache License, Version 2.0 (the "License");
5   you may not use this file except in compliance with the License.
6   You may obtain a copy of the License at
7
8       http://www.apache.org/licenses/LICENSE-2.0
9
10   Unless required by applicable law or agreed to in writing, software
11   distributed under the License is distributed on an "AS IS" BASIS,
12   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   See the License for the specific language governing permissions and
14   limitations under the License.
15*/
16
17package containerd
18
19import (
20	"context"
21
22	diffapi "github.com/containerd/containerd/api/services/diff/v1"
23	"github.com/containerd/containerd/api/types"
24	"github.com/containerd/containerd/diff"
25	"github.com/containerd/containerd/errdefs"
26	"github.com/containerd/containerd/mount"
27	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
28)
29
30// DiffService handles the computation and application of diffs
31type DiffService interface {
32	diff.Comparer
33	diff.Applier
34}
35
36// NewDiffServiceFromClient returns a new diff service which communicates
37// over a GRPC connection.
38func NewDiffServiceFromClient(client diffapi.DiffClient) DiffService {
39	return &diffRemote{
40		client: client,
41	}
42}
43
44type diffRemote struct {
45	client diffapi.DiffClient
46}
47
48func (r *diffRemote) Apply(ctx context.Context, desc ocispec.Descriptor, mounts []mount.Mount, opts ...diff.ApplyOpt) (ocispec.Descriptor, error) {
49	var config diff.ApplyConfig
50	for _, opt := range opts {
51		if err := opt(ctx, desc, &config); err != nil {
52			return ocispec.Descriptor{}, err
53		}
54	}
55	req := &diffapi.ApplyRequest{
56		Diff:     fromDescriptor(desc),
57		Mounts:   fromMounts(mounts),
58		Payloads: config.ProcessorPayloads,
59	}
60	resp, err := r.client.Apply(ctx, req)
61	if err != nil {
62		return ocispec.Descriptor{}, errdefs.FromGRPC(err)
63	}
64	return toDescriptor(resp.Applied), nil
65}
66
67func (r *diffRemote) Compare(ctx context.Context, a, b []mount.Mount, opts ...diff.Opt) (ocispec.Descriptor, error) {
68	var config diff.Config
69	for _, opt := range opts {
70		if err := opt(&config); err != nil {
71			return ocispec.Descriptor{}, err
72		}
73	}
74	req := &diffapi.DiffRequest{
75		Left:      fromMounts(a),
76		Right:     fromMounts(b),
77		MediaType: config.MediaType,
78		Ref:       config.Reference,
79		Labels:    config.Labels,
80	}
81	resp, err := r.client.Diff(ctx, req)
82	if err != nil {
83		return ocispec.Descriptor{}, errdefs.FromGRPC(err)
84	}
85	return toDescriptor(resp.Diff), nil
86}
87
88func toDescriptor(d *types.Descriptor) ocispec.Descriptor {
89	return ocispec.Descriptor{
90		MediaType:   d.MediaType,
91		Digest:      d.Digest,
92		Size:        d.Size_,
93		Annotations: d.Annotations,
94	}
95}
96
97func fromDescriptor(d ocispec.Descriptor) *types.Descriptor {
98	return &types.Descriptor{
99		MediaType:   d.MediaType,
100		Digest:      d.Digest,
101		Size_:       d.Size,
102		Annotations: d.Annotations,
103	}
104}
105
106func fromMounts(mounts []mount.Mount) []*types.Mount {
107	apiMounts := make([]*types.Mount, len(mounts))
108	for i, m := range mounts {
109		apiMounts[i] = &types.Mount{
110			Type:    m.Type,
111			Source:  m.Source,
112			Options: m.Options,
113		}
114	}
115	return apiMounts
116}
117