diff options
| author | Adin Scannell <ascannell@google.com> | 2020-02-19 18:27:48 -0800 |
|---|---|---|
| committer | Copybara-Service <copybara-worker@google.com> | 2020-02-19 18:28:42 -0800 |
| commit | ec5630527bc4473081048d2d13d1dcfadc6c7cdd (patch) | |
| tree | ac8922a25edcd7271f6978f82b85c8a1c698791b /runsc/cmd/statefile.go | |
| parent | 30794512d3977ebb2b185e5e9cfb969d558a07a4 (diff) | |
Add statefile command to runsc.
PiperOrigin-RevId: 296105337
Diffstat (limited to 'runsc/cmd/statefile.go')
| -rw-r--r-- | runsc/cmd/statefile.go | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/runsc/cmd/statefile.go b/runsc/cmd/statefile.go new file mode 100644 index 000000000..e6f1907da --- /dev/null +++ b/runsc/cmd/statefile.go @@ -0,0 +1,143 @@ +// Copyright 2020 The gVisor 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 cmd + +import ( + "context" + "fmt" + "os" + + "github.com/google/subcommands" + "gvisor.dev/gvisor/pkg/state" + "gvisor.dev/gvisor/pkg/state/statefile" + "gvisor.dev/gvisor/runsc/flag" +) + +// Statefile implements subcommands.Command for the "statefile" command. +type Statefile struct { + list bool + get string + key string + output string + html bool +} + +// Name implements subcommands.Command. +func (*Statefile) Name() string { + return "state" +} + +// Synopsis implements subcommands.Command. +func (*Statefile) Synopsis() string { + return "shows information about a statefile" +} + +// Usage implements subcommands.Command. +func (*Statefile) Usage() string { + return `statefile [flags] <statefile>` +} + +// SetFlags implements subcommands.Command. +func (s *Statefile) SetFlags(f *flag.FlagSet) { + f.BoolVar(&s.list, "list", false, "lists the metdata in the statefile.") + f.StringVar(&s.get, "get", "", "extracts the given metadata key.") + f.StringVar(&s.key, "key", "", "the integrity key for the file.") + f.StringVar(&s.output, "output", "", "target to write the result.") + f.BoolVar(&s.html, "html", false, "outputs in HTML format.") +} + +// Execute implements subcommands.Command.Execute. +func (s *Statefile) Execute(_ context.Context, f *flag.FlagSet, args ...interface{}) subcommands.ExitStatus { + // Check arguments. + if s.list && s.get != "" { + Fatalf("error: can't specify -list and -get simultaneously.") + } + + // Setup output. + var output = os.Stdout // Default. + if s.output != "" { + f, err := os.OpenFile(s.output, os.O_WRONLY|os.O_TRUNC|os.O_CREATE, 0644) + if err != nil { + Fatalf("error opening output: %v", err) + } + defer func() { + if err := f.Close(); err != nil { + Fatalf("error flushing output: %v", err) + } + }() + output = f + } + + // Open the file. + if f.NArg() != 1 { + f.Usage() + return subcommands.ExitUsageError + } + input, err := os.Open(f.Arg(0)) + if err != nil { + Fatalf("error opening input: %v\n", err) + } + + if s.html { + fmt.Fprintf(output, "<html><body>\n") + defer fmt.Fprintf(output, "</body></html>\n") + } + + // Dump the full file? + if !s.list && s.get == "" { + var key []byte + if s.key != "" { + key = []byte(s.key) + } + rc, _, err := statefile.NewReader(input, key) + if err != nil { + Fatalf("error parsing statefile: %v", err) + } + if err := state.PrettyPrint(output, rc, s.html); err != nil { + Fatalf("error printing state: %v", err) + } + return subcommands.ExitSuccess + } + + // Load just the metadata. + metadata, err := statefile.MetadataUnsafe(input) + if err != nil { + Fatalf("error reading metadata: %v", err) + } + + // Is it a single key? + if s.get != "" { + val, ok := metadata[s.get] + if !ok { + Fatalf("metadata key %s: not found", s.get) + } + fmt.Fprintf(output, "%s\n", val) + return subcommands.ExitSuccess + } + + // List all keys. + if s.html { + fmt.Fprintf(output, " <ul>\n") + defer fmt.Fprintf(output, " </ul>\n") + } + for key := range metadata { + if s.html { + fmt.Fprintf(output, " <li>%s</li>\n", key) + } else { + fmt.Fprintf(output, "%s\n", key) + } + } + return subcommands.ExitSuccess +} |