Allow restoring backups from a specific time in the past

cmd/tabacco/query.go

@@ -17,10 +17,34 @@ import (
 
 var rpcTimeout = 300 * time.Second
 
+type timeFlag time.Time
+
+func (f timeFlag) String() string {
+	return time.Time(f).Format(time.RFC3339)
+}
+
+func (f *timeFlag) Set(value string) error {
+	for _, fmt := range []string{
+		time.RFC3339,
+		time.Stamp,
+		time.Kitchen,
+		"2006/01/02",
+		"2006-01-02",
+	} {
+		if t, err := time.Parse(fmt, value); err == nil {
+			log.Printf("parsed %s as %v", value, t)
+			*f = timeFlag(t)
+			return nil
+		}
+	}
+	return errors.New("could not parse time value")
+}
+
 type queryCommand struct {
 	configPath  string
 	host        string
 	numVersions int
+	olderThan   timeFlag
 }
 
 func (c *queryCommand) Name() string     { return "query" }
@@ -36,6 +60,7 @@ func (c *queryCommand) SetFlags(f *flag.FlagSet) {
 	f.StringVar(&c.configPath, "config", "/etc/tabacco/agent.yml", "configuration `file`")
 	f.StringVar(&c.host, "host", "", "filter by host")
 	f.IntVar(&c.numVersions, "num-versions", 1, "return the most recent `N` versions")
+	f.Var(&c.olderThan, "older-than", "return a backup older than `TIME`")
 }
 
 func (c *queryCommand) buildRequest(f *flag.FlagSet) (*tabacco.FindRequest, error) {
@@ -46,6 +71,7 @@ func (c *queryCommand) buildRequest(f *flag.FlagSet) (*tabacco.FindRequest, erro
 		Pattern:     f.Arg(0),
 		Host:        c.host,
 		NumVersions: c.numVersions,
+		OlderThan:   time.Time(c.olderThan),
 	}, nil
 }
 

cmd/tabacco/restore.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"flag"
 	"log"
+	"time"
 
 	"github.com/google/subcommands"
 
@@ -16,6 +17,7 @@ type restoreCommand struct {
 	configPath string
 	httpAddr   string
 	targetDir  string
+	olderThan  timeFlag
 }
 
 func (c *restoreCommand) Name() string     { return "restore" }
@@ -32,6 +34,7 @@ func (c *restoreCommand) SetFlags(f *flag.FlagSet) {
 	f.StringVar(&c.configPath, "config", "/etc/tabacco/agent.yml", "configuration `file`")
 	f.StringVar(&c.httpAddr, "http-addr", ":5330", "listen `address` for the HTTP server exporting metrics and debugging")
 	f.StringVar(&c.targetDir, "target", ".", "target `path` for restore")
+	f.Var(&c.olderThan, "older-than", "pick the first backup older than `TIME`")
 }
 
 func (c *restoreCommand) Execute(ctx context.Context, f *flag.FlagSet, args ...interface{}) subcommands.ExitStatus {
@@ -79,7 +82,8 @@ func (c *restoreCommand) buildRestoreJob(ctx context.Context, mgr tabacco.Manage
 
 func (c *restoreCommand) newFindRequest(s string) *tabacco.FindRequest {
 	return &tabacco.FindRequest{
-		Pattern: s,
+		Pattern:   s,
+		OlderThan: time.Time(c.olderThan),
 	}
 }
 

metadb/server/service.go

@@ -222,6 +222,10 @@ func (s *Service) FindAtoms(ctx context.Context, req *tabacco.FindRequest) ([]*t
 		where = append(where, "atom_full_path LIKE ?")
 		args = append(args, strings.Replace(req.Pattern, "*", "%", -1))
 	}
+	if !req.OlderThan.IsZero() {
+		where = append(where, "backup_timestamp < ?")
+		args = append(args, req.OlderThan)
+	}
 
 	// Build the final query and execute it.
 	q := fmt.Sprintf(

types.go

@@ -94,8 +94,9 @@ type FindRequest struct {
 	Pattern   string `json:"pattern"`
 	patternRx *regexp.Regexp
 
-	Host        string `json:"host"`
-	NumVersions int    `json:"num_versions"`
+	Host        string    `json:"host"`
+	NumVersions int       `json:"num_versions"`
+	OlderThan   time.Time `json:"older_than,omitempty"`
 }
 
 func (req *FindRequest) matchPattern(s string) bool {