Enable snapshots in dev mode (#2453)

consul/server.go

@@ -386,7 +386,7 @@ func (s *Server) setupRaft() error {
 		s.raftInmem = store
 		stable = store
 		log = store
-		snap = raft.NewDiscardSnapshotStore()
+		snap = raft.NewInmemSnapshotStore()
 	} else {
 		// Create the base raft path.
 		path := filepath.Join(s.config.DataDir, raftState)

consul/snapshot_endpoint.go

@@ -20,12 +20,6 @@ import (
 	"github.com/hashicorp/go-msgpack/codec"
 )
 
-const (
-	// noSnapshotsInDevMode indicates that snapshots aren't available for a
-	// server in dev mode.
-	noSnapshotsInDevMode = "Snapshot operations not available in dev mode"
-)
-
 // dispatchSnapshotRequest takes an incoming request structure with possibly some
 // streaming data (for a restore) and returns possibly some streaming data (for
 // a snapshot save). We can't use the normal RPC mechanism in a streaming manner
@@ -52,13 +46,6 @@ func (s *Server) dispatchSnapshotRequest(args *structs.SnapshotRequest, in io.Re
 		}
 	}
 
-	// Snapshots don't work in dev mode because we need Raft's snapshots to
-	// be readable. Better to present a clear error than one from deep down
-	// in the Raft snapshot store.
-	if s.config.DevMode {
-		return nil, errors.New(noSnapshotsInDevMode)
-	}
-
 	// Verify token is allowed to operate on snapshots. There's only a
 	// single ACL sense here (not read and write) since reading gets you
 	// all the ACLs and you could escalate from there.

consul/snapshot_endpoint_test.go

@@ -391,26 +391,3 @@ func TestSnapshot_AllowStale(t *testing.T) {
 		}
 	}
 }
-
-func TestSnapshot_DevMode(t *testing.T) {
-	dir1, s1 := testServerWithConfig(t, func(c *Config) {
-		c.DevMode = true
-	})
-	defer os.RemoveAll(dir1)
-	defer s1.Shutdown()
-	codec := rpcClient(t, s1)
-	defer codec.Close()
-
-	testutil.WaitForLeader(t, s1.RPC, "dc1")
-
-	args := structs.SnapshotRequest{
-		Datacenter: s1.config.Datacenter,
-		Op:         structs.SnapshotSave,
-	}
-	var reply structs.SnapshotResponse
-	_, err := SnapshotRPC(s1.connPool, s1.config.Datacenter, s1.config.RPCAddr,
-		&args, bytes.NewReader([]byte("")), &reply)
-	if err == nil || !strings.Contains(err.Error(), noSnapshotsInDevMode) {
-		t.Fatalf("err: %v", err)
-	}
-}

vendor/github.com/hashicorp/raft/inmem_snapshot.go

@@ -0,0 +1,93 @@
+package raft
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+)
+
+// InmemSnapshotStore implements the SnapshotStore interface and
+// retains only the most recent snapshot
+type InmemSnapshotStore struct {
+	latest      *InmemSnapshotSink
+	hasSnapshot bool
+}
+
+// InmemSnapshotSink implements SnapshotSink in memory
+type InmemSnapshotSink struct {
+	meta     SnapshotMeta
+	contents *bytes.Buffer
+}
+
+// NewInmemSnapshotStore creates a blank new InmemSnapshotStore
+func NewInmemSnapshotStore() *InmemSnapshotStore {
+	return &InmemSnapshotStore{
+		latest: &InmemSnapshotSink{
+			contents: &bytes.Buffer{},
+		},
+	}
+}
+
+// Create replaces the stored snapshot with a new one using the given args
+func (m *InmemSnapshotStore) Create(version SnapshotVersion, index, term uint64,
+	configuration Configuration, configurationIndex uint64, trans Transport) (SnapshotSink, error) {
+	// We only support version 1 snapshots at this time.
+	if version != 1 {
+		return nil, fmt.Errorf("unsupported snapshot version %d", version)
+	}
+
+	name := snapshotName(term, index)
+
+	sink := m.latest
+	sink.meta = SnapshotMeta{
+		Version:            version,
+		ID:                 name,
+		Index:              index,
+		Term:               term,
+		Peers:              encodePeers(configuration, trans),
+		Configuration:      configuration,
+		ConfigurationIndex: configurationIndex,
+	}
+	sink.contents = &bytes.Buffer{}
+	m.hasSnapshot = true
+
+	return sink, nil
+}
+
+// List returns the latest snapshot taken
+func (m *InmemSnapshotStore) List() ([]*SnapshotMeta, error) {
+	if !m.hasSnapshot {
+		return []*SnapshotMeta{}, nil
+	}
+	return []*SnapshotMeta{&m.latest.meta}, nil
+}
+
+// Open wraps an io.ReadCloser around the snapshot contents
+func (m *InmemSnapshotStore) Open(id string) (*SnapshotMeta, io.ReadCloser, error) {
+	if m.latest.meta.ID != id {
+		return nil, nil, fmt.Errorf("[ERR] snapshot: failed to open snapshot id: %s", id)
+	}
+
+	return &m.latest.meta, ioutil.NopCloser(m.latest.contents), nil
+}
+
+// Write appends the given bytes to the snapshot contents
+func (s *InmemSnapshotSink) Write(p []byte) (n int, err error) {
+	written, err := io.Copy(s.contents, bytes.NewReader(p))
+	s.meta.Size += written
+	return int(written), err
+}
+
+// Close updates the Size and is otherwise a no-op
+func (s *InmemSnapshotSink) Close() error {
+	return nil
+}
+
+func (s *InmemSnapshotSink) ID() string {
+	return s.meta.ID
+}
+
+func (s *InmemSnapshotSink) Cancel() error {
+	return nil
+}

vendor/vendor.json

@@ -350,10 +350,10 @@
 			"revisionTime": "2015-11-16T02:03:38Z"
 		},
 		{
-			"checksumSHA1": "tHzyGCXkf8PnmBrTk1Z01JIv/5Q=",
+			"checksumSHA1": "ed1YY/S0BSb57IRRSDUbFp7r0IE=",
 			"path": "github.com/hashicorp/raft",
-			"revision": "e1d3debe52b9152e8db5c3a77b7f7cf9b2a8b404",
-			"revisionTime": "2016-10-26T00:17:15Z"
+			"revision": "def7451ceceb8a919cbb1f6d1c0f7648e9311879",
+			"revisionTime": "2016-10-31T16:57:40Z"
 		},
 		{
 			"checksumSHA1": "QAxukkv54/iIvLfsUP6IK4R0m/A=",

website/source/docs/agent/http/snapshot.html.markdown

@@ -34,9 +34,6 @@ The endpoints support the use of ACL Tokens. Because snapshots contain all
 server state, including ACLs, a management token is required to perform snapshot
 operations is ACLs are enabled.
 
--> Snapshot operations are not available for servers running in
-   [dev mode](/docs/agent/options.html#_dev).
-
 ### <a name="snapshot"></a> /v1/snapshot
 
 The snapshot endpoint supports the `GET` and `PUT` methods.