|
| 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 | + |
| 17 | +package containerd |
| 18 | + |
| 19 | +import ( |
| 20 | + "context" |
| 21 | + "encoding/json" |
| 22 | + "fmt" |
| 23 | + "strconv" |
| 24 | + "strings" |
| 25 | + "syscall" |
| 26 | + |
| 27 | + "github.com/containerd/containerd/content" |
| 28 | + "github.com/containerd/containerd/images" |
| 29 | + "github.com/opencontainers/image-spec/specs-go/v1" |
| 30 | +) |
| 31 | + |
| 32 | +// StopSignalLabel is a well-known containerd label for storing the stop |
| 33 | +// signal specified in the OCI image config |
| 34 | +const StopSignalLabel = "io.containerd.image.config.stop-signal" |
| 35 | + |
| 36 | +// GetStopSignal retrieves the container stop signal, specified by the |
| 37 | +// well-known containerd label (StopSignalLabel) |
| 38 | +func GetStopSignal(ctx context.Context, container Container, defaultSignal syscall.Signal) (syscall.Signal, error) { |
| 39 | + labels, err := container.Labels(ctx) |
| 40 | + if err != nil { |
| 41 | + return -1, err |
| 42 | + } |
| 43 | + |
| 44 | + if stopSignal, ok := labels[StopSignalLabel]; ok { |
| 45 | + return ParseSignal(stopSignal) |
| 46 | + } |
| 47 | + |
| 48 | + return defaultSignal, nil |
| 49 | +} |
| 50 | + |
| 51 | +// GetOCIStopSignal retrieves the stop signal specified in the OCI image config |
| 52 | +func GetOCIStopSignal(ctx context.Context, image Image, defaultSignal string) (string, error) { |
| 53 | + _, err := ParseSignal(defaultSignal) |
| 54 | + if err != nil { |
| 55 | + return "", err |
| 56 | + } |
| 57 | + ic, err := image.Config(ctx) |
| 58 | + if err != nil { |
| 59 | + return "", err |
| 60 | + } |
| 61 | + var ( |
| 62 | + ociimage v1.Image |
| 63 | + config v1.ImageConfig |
| 64 | + ) |
| 65 | + switch ic.MediaType { |
| 66 | + case v1.MediaTypeImageConfig, images.MediaTypeDockerSchema2Config: |
| 67 | + p, err := content.ReadBlob(ctx, image.ContentStore(), ic) |
| 68 | + if err != nil { |
| 69 | + return "", err |
| 70 | + } |
| 71 | + |
| 72 | + if err := json.Unmarshal(p, &ociimage); err != nil { |
| 73 | + return "", err |
| 74 | + } |
| 75 | + config = ociimage.Config |
| 76 | + default: |
| 77 | + return "", fmt.Errorf("unknown image config media type %s", ic.MediaType) |
| 78 | + } |
| 79 | + |
| 80 | + if config.StopSignal == "" { |
| 81 | + return defaultSignal, nil |
| 82 | + } |
| 83 | + |
| 84 | + return config.StopSignal, nil |
| 85 | +} |
| 86 | + |
| 87 | +// ParseSignal parses a given string into a syscall.Signal |
| 88 | +// it checks that the signal exists in the platform-appropriate signalMap |
| 89 | +func ParseSignal(rawSignal string) (syscall.Signal, error) { |
| 90 | + s, err := strconv.Atoi(rawSignal) |
| 91 | + if err == nil { |
| 92 | + sig := syscall.Signal(s) |
| 93 | + for _, msig := range signalMap { |
| 94 | + if sig == msig { |
| 95 | + return sig, nil |
| 96 | + } |
| 97 | + } |
| 98 | + return -1, fmt.Errorf("unknown signal %q", rawSignal) |
| 99 | + } |
| 100 | + signal, ok := signalMap[strings.TrimPrefix(strings.ToUpper(rawSignal), "SIG")] |
| 101 | + if !ok { |
| 102 | + return -1, fmt.Errorf("unknown signal %q", rawSignal) |
| 103 | + } |
| 104 | + return signal, nil |
| 105 | +} |
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