Merge pull request #34 from stealthrocket/timecraft-export

timecraft: add export command

internal/cmd/describe.go

@@ -63,29 +63,22 @@ func describe(ctx context.Context, args []string) error {
  if len(args) == 0 {
  return errors.New(`expected a resource type as argument`)
  }
- resourceTypeLookup := args[0]
- resourceIDs := args[1:]
-
- resource, ok := findResource(resourceTypeLookup, resources[:])
- if !ok {
- matchingResources := findMatchingResources(resourceTypeLookup, resources[:])
- if len(matchingResources) == 0 {
- return fmt.Errorf(`no resources matching '%s'`+useGet(), resourceTypeLookup)
- }
- return fmt.Errorf(`no resources matching '%s'
 
-Did you mean?%s`, resourceTypeLookup, joinResourceTypes(matchingResources, "\n "))
- }
-
- registry, err := openRegistry(registryPath)
+ resource, err := findResource("describe", args[0])
  if err != nil {
  return err
  }
 
+ resourceIDs := args[1:]
  if len(resourceIDs) == 0 {
  return fmt.Errorf(`no resources were specified, use 'timecraft describe %s <resources ids...>'`, resource.typ)
  }
 
+ registry, err := openRegistry(registryPath)
+ if err != nil {
+ return err
+ }
+
  var lookup func(context.Context, *timemachine.Registry, string) (any, error)
  var writer stream.WriteCloser[any]
  switch output {

internal/cmd/export.go

@@ -0,0 +1,98 @@
+package cmd
+
+import (
+ "context"
+ "errors"
+ "io"
+ "os"
+
+ "github.com/google/uuid"
+ "github.com/stealthrocket/timecraft/format"
+ "github.com/stealthrocket/timecraft/internal/print/human"
+)
+
+const exportUsage = `
+Usage: timecraft export <resource type> <resource id> <output file>
+
+ The export command reads resources from the time machine registry and writes
+ them to local files. This command is useful to extract data generated by
+ timecraft and visualize it with other tools.
+
+ The last argument is the location where the resource is exported, typically
+ a path on the file system. The special value "-" may be set to write the
+ resource to stdout.
+
+Options:
+ -h, --help Show this usage information
+ -r, --registry path Path to the timecraft registry (default to ~/.timecraft)
+`
+
+func export(ctx context.Context, args []string) error {
+ var (
+ registryPath = human.Path("~/.timecraft")
+ )
+
+ flagSet := newFlagSet("timecraft export", exportUsage)
+ customVar(flagSet, &registryPath, "r", "registry")
+ args = parseFlags(flagSet, args)
+
+ if len(args) != 3 {
+ return errors.New(`expected resource type, id, and output file as argument` + useCmd("export"))
+ }
+
+ resource, err := findResource("describe", args[0])
+ if err != nil {
+ return err
+ }
+
+ registry, err := openRegistry(registryPath)
+ if err != nil {
+ return err
+ }
+
+ if resource.typ == "log" {
+ // How should we handle logs?
+ // - write the manifest.json + segments to a tar archive?
+ // - combines the segments into a single log file?
+ // - ???
+ return errors.New(`TODO`)
+ }
+
+ var hash format.Hash
+ if resource.typ == "process" {
+ processID, err := uuid.Parse(args[1])
+ if err != nil {
+ return errors.New(`malformed process id (not a UUID)`)
+ }
+ manifest, err := registry.LookupLogManifest(ctx, processID)
+ if err != nil {
+ return err
+ }
+ hash = manifest.Process.Digest
+ } else {
+ desc, err := registry.LookupDescriptor(ctx, format.ParseHash(args[1]))
+ if err != nil {
+ return err
+ }
+ hash = desc.Digest
+ }
+
+ r, err := registry.LookupResource(ctx, hash)
+ if err != nil {
+ return err
+ }
+ defer r.Close()
+
+ w := io.Writer(os.Stdout)
+ if outputFile := args[2]; outputFile != "-" {
+ f, err := os.Create(outputFile)
+ if err != nil {
+ return err
+ }
+ defer f.Close()
+ w = f
+ }
+
+ _, err = io.Copy(w, r)
+ return err
+}

internal/cmd/get.go

@@ -127,18 +127,11 @@ func get(ctx context.Context, args []string) error {
  args = parseFlags(flagSet, args)
 
  if len(args) != 1 {
- return errors.New(`expected exactly one resource type as argument` + useGet())
+ return errors.New(`expected exactly one resource type as argument` + useCmd("get"))
  }
- resourceTypeLookup := args[0]
- resource, ok := findResource(resourceTypeLookup, resources[:])
- if !ok {
- matchingResources := findMatchingResources(resourceTypeLookup, resources[:])
- if len(matchingResources) == 0 {
- return fmt.Errorf(`no resources matching '%s'`+useGet(), resourceTypeLookup)
- }
- return fmt.Errorf(`no resources matching '%s'
-
-Did you mean?%s`, resourceTypeLookup, joinResourceTypes(matchingResources, "\n "))
+ resource, err := findResource("get", args[0])
+ if err != nil {
+ return err
  }
 
  registry, err := openRegistry(registryPath)
@@ -348,27 +341,35 @@ func newTableWriter[T1, T2 any](w io.Writer, orderBy func(T1, T1) bool, conv fun
  return stream.NewWriteCloser(cw, tw)
 }
 
-func findResource(typ string, options []resource) (resource, bool) {
- for _, option := range options {
- if option.typ == typ {
- return option, true
+func findResource(cmd, typ string) (*resource, error) {
+ for i, resource := range resources {
+ if resource.typ == typ {
+ return &resources[i], nil
  }
- for _, alt := range option.alt {
+ for _, alt := range resource.alt {
  if alt == typ {
- return option, true
+ return &resources[i], nil
  }
  }
  }
- return resource{}, false
-}
 
-func findMatchingResources(typ string, options []resource) (matches []resource) {
- for _, option := range options {
- if prefixLength(option.typ, typ) > 1 || prefixLength(typ, option.typ) > 1 {
- matches = append(matches, option)
+ var matchingResources []*resource
+ for i, resource := range resources {
+ if prefixLength(resource.typ, typ) > 1 || prefixLength(typ, resource.typ) > 1 {
+ matchingResources = append(matchingResources, &resources[i])
  }
  }
- return matches
+ if len(matchingResources) == 0 {
+ return nil, fmt.Errorf(`no resources matching '%s'%s`, typ, useCmd(cmd))
+ }
+
+ var resourceTypes strings.Builder
+ for _, r := range matchingResources {
+ resourceTypes.WriteString("\n ")
+ resourceTypes.WriteString(r.typ)
+ }
+
+ return nil, fmt.Errorf("no resources matching '%s'\n\nDid you mean?%s", typ, &resourceTypes)
 }
 
 func prefixLength(base, prefix string) int {
@@ -379,19 +380,10 @@ func prefixLength(base, prefix string) int {
  return n
 }
 
-func joinResourceTypes(resources []resource, prefix string) string {
- s := new(strings.Builder)
- for _, r := range resources {
- s.WriteString(prefix)
- s.WriteString(r.typ)
- }
- return s.String()
-}
-
-func useGet() string {
+func useCmd(cmd string) string {
  s := new(strings.Builder)
  s.WriteString("\n\n")
- s.WriteString(`Use 'timecraft get <resource type>' where the supported resource types are:`)
+ s.WriteString(`Use 'timecraft ` + cmd + ` <resource type>' where the supported resource types are:`)
  for _, r := range resources {
  s.WriteString("\n ")
  s.WriteString(r.typ)

internal/cmd/help.go

@@ -10,6 +10,7 @@ Usage: timecraft <command> [options]
 
 Registry Commands:
  describe Show detailed information about specific resources
+ export Export resources to local files
  get Display resources from the time machine registry
 
 Runtime Commands:
@@ -28,6 +29,9 @@ For a description of each command, run 'timecraft help <command>'.`
 func help(ctx context.Context, args []string) error {
  flagSet := newFlagSet("timecraft help", helpUsage)
  args = parseFlags(flagSet, args)
+ if len(args) == 0 {
+ args = []string{"help"}
+ }
 
  for i, cmd := range args {
  var msg string
@@ -39,9 +43,11 @@ func help(ctx context.Context, args []string) error {
  switch cmd {
  case "describe":
  msg = describeUsage
+ case "export":
+ msg = exportUsage
  case "get":
  msg = getUsage
- case "help", "":
+ case "help":
  msg = helpUsage
  case "profile":
  msg = profileUsage

internal/cmd/root.go

@@ -80,6 +80,8 @@ func Root(ctx context.Context, args ...string) int {
  switch cmd {
  case "describe":
  err = describe(ctx, args)
+ case "export":
+ err = export(ctx, args)
  case "get":
  err = get(ctx, args)
  case "help":

internal/timemachine/registry.go

@@ -153,6 +153,10 @@ func (reg *Registry) LookupDescriptor(ctx context.Context, hash format.Hash) (*f
  return reg.lookupDescriptor(ctx, hash)
 }
 
+func (reg *Registry) LookupResource(ctx context.Context, hash format.Hash) (io.ReadCloser, error) {
+ return reg.Store.ReadObject(ctx, reg.objectKey(hash))
+}
+
 func (reg *Registry) ListModules(ctx context.Context, timeRange TimeRange, tags ...object.Tag) stream.ReadCloser[*format.Descriptor] {
  return reg.listObjects(ctx, format.TypeTimecraftModule, timeRange, tags)
 }