Adds JSON support for the snapshots command

doc/Manual.md

@@ -77,6 +77,7 @@ Available Commands:
   version       Print version information
 
 Flags:
+      --json                   set output mode to JSON for commands that support it
       --no-lock                do not lock the repo, this allows some operations on read-only repos
   -p, --password-file string   read the repository password from a file
   -q, --quiet                  do not output comprehensive progress report
@@ -110,6 +111,7 @@ Flags:
       --tag tag                 add a tag for the new snapshot (can be specified multiple times)
 
 Global Flags:
+      --json                   set output mode to JSON for commands that support it
       --no-lock                do not lock the repo, this allows some operations on read-only repos
   -p, --password-file string   read the repository password from a file
   -q, --quiet                  do not output comprehensive progress report
@@ -739,3 +741,10 @@ enter password for repository:
   "gid": 20
 }
 ```
+
+# Scripting restic
+
+Restic supports the output of some commands in JSON format. The JSON flag ```--json``` is currently supported only by ```restic snapshots```.
+
+```console
+$ restic -r /tmp/backup snapshots --json```

src/cmds/restic/cmd_snapshots.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/spf13/cobra"
 
+	"encoding/json"
 	"restic"
 )
 
@@ -56,10 +57,6 @@ func runSnapshots(opts SnapshotOptions, gopts GlobalOptions, args []string) erro
 		}
 	}
 
-	tab := NewTable()
-	tab.Header = fmt.Sprintf("%-8s  %-19s  %-10s  %-10s  %-3s %s", "ID", "Date", "Host", "Tags", "", "Directory")
-	tab.RowFormat = "%-8s  %-19s  %-10s  %-10s  %-3s %s"
-
 	done := make(chan struct{})
 	defer close(done)
 
@@ -87,6 +84,25 @@ func runSnapshots(opts SnapshotOptions, gopts GlobalOptions, args []string) erro
 
 	}
 
+	if gopts.JSON {
+		err := printSnapshotsJSON(list)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "error printing snapshot: %v\n", err)
+		}
+		return nil
+	}
+	printSnapshotsReadable(list)
+
+	return nil
+}
+
+// printSnapshotsReadable prints a text table of the snapshots in list to stdout.
+func printSnapshotsReadable(list []*restic.Snapshot) {
+
+	tab := NewTable()
+	tab.Header = fmt.Sprintf("%-8s  %-19s  %-10s  %-10s  %-3s %s", "ID", "Date", "Host", "Tags", "", "Directory")
+	tab.RowFormat = "%-8s  %-19s  %-10s  %-10s  %-3s %s"
+
 	for _, sn := range list {
 		if len(sn.Paths) == 0 {
 			continue
@@ -132,5 +148,30 @@ func runSnapshots(opts SnapshotOptions, gopts GlobalOptions, args []string) erro
 
 	tab.Write(os.Stdout)
 
-	return nil
+	return
+}
+
+// Snapshot helps to print Snaphots as JSON
+type Snapshot struct {
+	*restic.Snapshot
+
+	ID string `json:"id"`
+}
+
+// printSnapshotsJSON writes the JSON representation of list to stdout.
+func printSnapshotsJSON(list []*restic.Snapshot) error {
+
+	var snapshots []Snapshot
+
+	for _, sn := range list {
+
+		k := Snapshot{
+			Snapshot: sn,
+			ID:       sn.ID().String(),
+		}
+		snapshots = append(snapshots, k)
+	}
+
+	return json.NewEncoder(os.Stdout).Encode(snapshots)
+
 }

src/cmds/restic/global.go

@@ -31,6 +31,7 @@ type GlobalOptions struct {
 	PasswordFile string
 	Quiet        bool
 	NoLock       bool
+	JSON         bool
 
 	password string
 	stdout   io.Writer
@@ -53,6 +54,7 @@ func init() {
 	f.StringVarP(&globalOptions.PasswordFile, "password-file", "p", "", "read the repository password from a file")
 	f.BoolVarP(&globalOptions.Quiet, "quiet", "q", false, "do not output comprehensive progress report")
 	f.BoolVar(&globalOptions.NoLock, "no-lock", false, "do not lock the repo, this allows some operations on read-only repos")
+	f.BoolVarP(&globalOptions.JSON, "json", "", false, "set output mode to JSON for commands that support it")
 
 	restoreTerminal()
 }