1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
|
// Copyright (c) 2022, Sylabs Inc. All rights reserved.
// This software is licensed under a 3-clause BSD license. Please consult the
// LICENSE.md file distributed with the sources of this project regarding your
// rights to use or distribute this software.
package oci
import (
"fmt"
"path/filepath"
"strings"
"time"
imgspecv1 "github.com/opencontainers/image-spec/specs-go/v1"
runtimespec "github.com/opencontainers/runtime-spec/specs-go"
"github.com/sylabs/singularity/v4/internal/pkg/runtime/launcher"
"github.com/sylabs/singularity/v4/internal/pkg/util/rootless"
"github.com/sylabs/singularity/v4/pkg/sylog"
)
// defaultNamespaces matching native runtime with --compat / --containall, except PID which can be disabled.
var defaultNamespaces = []runtimespec.LinuxNamespace{
{
Type: runtimespec.IPCNamespace,
},
{
Type: runtimespec.MountNamespace,
},
}
// defaultResources - an empty set, no resource limits
var defaultResources = runtimespec.LinuxResources{}
// minimalSpec returns an OCI runtime spec with a minimal OCI configuration that
// is a starting point for compatibility with Singularity's native launcher in
// `--compat` mode.
func minimalSpec() runtimespec.Spec {
config := runtimespec.Spec{
Version: runtimespec.Version,
}
config.Root = &runtimespec.Root{
Path: "rootfs",
Readonly: false,
}
config.Process = &runtimespec.Process{
Terminal: true,
// Default fallback to a shell at / - will generally be overwritten by
// the launcher.
Args: []string{"sh"},
Cwd: "/",
}
config.Process.User = runtimespec.User{}
config.Process.Env = []string{
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
}
// All mounts are added by the launcher, as it must handle flags.
config.Mounts = []runtimespec.Mount{}
config.Linux = &runtimespec.Linux{
Namespaces: defaultNamespaces,
// Ensure this is not nil to work around crun bug.
// https://github.com/containers/crun/issues/1402
Resources: &defaultResources,
}
return config
}
// addNamespaces adds requested namespace, if appropriate, to an existing spec.
// It is assumed that spec contains at least the defaultNamespaces.
func addNamespaces(spec *runtimespec.Spec, ns launcher.Namespaces) error {
if ns.IPC {
sylog.Infof("--oci runtime always uses an IPC namespace, ipc flag is redundant.")
}
// Currently supports only `--network none`, i.e. isolated loopback only.
// Launcher.checkopts enforces this.
if ns.Net {
spec.Linux.Namespaces = append(
spec.Linux.Namespaces,
runtimespec.LinuxNamespace{Type: runtimespec.NetworkNamespace},
)
}
if ns.PID {
sylog.Infof("--oci runtime uses a PID namespace by default, pid flag is redundant.")
}
if !ns.NoPID {
spec.Linux.Namespaces = append(
spec.Linux.Namespaces,
runtimespec.LinuxNamespace{Type: runtimespec.PIDNamespace},
)
}
if ns.User {
uid, err := rootless.Getuid()
if err != nil {
return err
}
if uid == 0 {
spec.Linux.Namespaces = append(
spec.Linux.Namespaces,
runtimespec.LinuxNamespace{Type: runtimespec.UserNamespace},
)
} else {
sylog.Infof("The --oci runtime always creates a user namespace when run as non-root, --userns / -u flag is redundant.")
}
}
if ns.UTS {
spec.Linux.Namespaces = append(
spec.Linux.Namespaces,
runtimespec.LinuxNamespace{Type: runtimespec.UTSNamespace},
)
}
return nil
}
// addAnnotations adds the required annotations to the runtime-spec, based on an image-spec.
// See https://github.com/opencontainers/image-spec/blob/main/conversion.md
func addAnnotations(rSpec *runtimespec.Spec, iSpec *imgspecv1.Image) error {
if rSpec == nil {
return fmt.Errorf("runtime spec is required")
}
if iSpec == nil {
return nil
}
if rSpec.Annotations == nil {
rSpec.Annotations = map[string]string{}
}
if iSpec.OS != "" {
rSpec.Annotations["org.opencontainers.image.os"] = iSpec.OS
}
if iSpec.Architecture != "" {
rSpec.Annotations["org.opencontainers.image.architecture"] = iSpec.Architecture
}
if iSpec.Variant != "" {
rSpec.Annotations["org.opencontainers.image.variant"] = iSpec.Variant
}
if iSpec.OSVersion != "" {
rSpec.Annotations["org.opencontainers.image.os.version"] = iSpec.OSVersion
}
if iSpec.OSFeatures != nil {
rSpec.Annotations["org.opencontainers.image.os.features"] = strings.Join(iSpec.OSFeatures, ",")
}
if iSpec.Author != "" {
rSpec.Annotations["org.opencontainers.image.author"] = iSpec.Author
}
if iSpec.Created != nil {
rSpec.Annotations["org.opencontainers.image.created"] = iSpec.Created.Format(time.RFC3339)
}
if iSpec.Config.StopSignal != "" {
rSpec.Annotations["org.opencontainers.image.stopSignal"] = iSpec.Config.StopSignal
}
// Note: Explicit Config.Labels take precedence over the above.
for k, v := range iSpec.Config.Labels {
rSpec.Annotations[k] = v
}
return nil
}
// noSetgroupsAnnotation will set the `run.oci.keep_original_groups=1` annotation
// to disable the setgroups call when entering the container. Supported by crun, but not runc.
func noSetgroupsAnnotation(rSpec *runtimespec.Spec) error {
runtime, err := Runtime()
if err != nil {
return err
}
if filepath.Base(runtime) != "crun" {
return fmt.Errorf("runtime '%q' does not support --no-setgroups", runtime)
}
if rSpec.Annotations == nil {
rSpec.Annotations = map[string]string{}
}
rSpec.Annotations["run.oci.keep_original_groups"] = "1"
return nil
}
|
