From a62705101f52c74c57f0903cfefc556e75e81180 Mon Sep 17 00:00:00 2001
From: s-christoff <schristoff@hashicorp.com>
Date: Fri, 9 Oct 2020 14:57:29 -0500
Subject: [PATCH] Enhance the output of consul snapshot inspect (#8787)

---
 .changelog/8787.txt                           |   3 +
 agent/consul/fsm/fsm.go                       |  62 +++---
 agent/consul/fsm/snapshot.go                  |   8 +-
 agent/consul/fsm/snapshot_oss.go              |  44 ++--
 agent/structs/structs.go                      |  55 +++++
 agent/structs/structs_oss.go                  |   4 +
 command/snapshot/inspect/snapshot_inspect.go  | 189 +++++++++++++++++-
 .../snapshot/inspect/snapshot_inspect_test.go |  69 +++----
 .../TestSnapshotInspectCommand.golden         |  20 ++
 command/snapshot/inspect/testdata/backup.snap |   3 +
 snapshot/snapshot.go                          |  56 ++++--
 website/pages/commands/snapshot/inspect.mdx   |  16 +-
 12 files changed, 406 insertions(+), 123 deletions(-)
 create mode 100644 .changelog/8787.txt
 create mode 100644 command/snapshot/inspect/testdata/TestSnapshotInspectCommand.golden
 create mode 100644 command/snapshot/inspect/testdata/backup.snap

diff --git a/.changelog/8787.txt b/.changelog/8787.txt
new file mode 100644
index 000000000..ed42226f4
--- /dev/null
+++ b/.changelog/8787.txt
@@ -0,0 +1,3 @@
+```release-note:feature
+cli: update `snapshot inspect` command to provide more detailed snapshot data
+```
diff --git a/agent/consul/fsm/fsm.go b/agent/consul/fsm/fsm.go
index cc0cb9a07..5b0cf9630 100644
--- a/agent/consul/fsm/fsm.go
+++ b/agent/consul/fsm/fsm.go
@@ -159,28 +159,7 @@ func (c *FSM) Restore(old io.ReadCloser) error {
 	restore := stateNew.Restore()
 	defer restore.Abort()
 
-	// Create a decoder
-	dec := codec.NewDecoder(old, structs.MsgpackHandle)
-
-	// Read in the header
-	var header snapshotHeader
-	if err := dec.Decode(&header); err != nil {
-		return err
-	}
-
-	// Populate the new state
-	msgType := make([]byte, 1)
-	for {
-		// Read the message type
-		_, err := old.Read(msgType)
-		if err == io.EOF {
-			break
-		} else if err != nil {
-			return err
-		}
-
-		// Decode
-		msg := structs.MessageType(msgType[0])
+	handler := func(header *SnapshotHeader, msg structs.MessageType, dec *codec.Decoder) error {
 		switch {
 		case msg == structs.ChunkingStateType:
 			chunkState := &raftchunking.State{
@@ -194,13 +173,18 @@ func (c *FSM) Restore(old io.ReadCloser) error {
 			}
 		case restorers[msg] != nil:
 			fn := restorers[msg]
-			if err := fn(&header, restore, dec); err != nil {
+			if err := fn(header, restore, dec); err != nil {
 				return err
 			}
 		default:
 			return fmt.Errorf("Unrecognized msg type %d", msg)
 		}
+		return nil
 	}
+	if err := ReadSnapshot(old, handler); err != nil {
+		return err
+	}
+
 	if err := restore.Commit(); err != nil {
 		return err
 	}
@@ -218,3 +202,35 @@ func (c *FSM) Restore(old io.ReadCloser) error {
 	stateOld.Abandon()
 	return nil
 }
+
+// ReadSnapshot decodes each message type and utilizes the handler function to
+// process each message type individually
+func ReadSnapshot(r io.Reader, handler func(header *SnapshotHeader, msg structs.MessageType, dec *codec.Decoder) error) error {
+	// Create a decoder
+	dec := codec.NewDecoder(r, structs.MsgpackHandle)
+
+	// Read in the header
+	var header SnapshotHeader
+	if err := dec.Decode(&header); err != nil {
+		return err
+	}
+
+	// Populate the new state
+	msgType := make([]byte, 1)
+	for {
+		// Read the message type
+		_, err := r.Read(msgType)
+		if err == io.EOF {
+			return nil
+		} else if err != nil {
+			return err
+		}
+
+		// Decode
+		msg := structs.MessageType(msgType[0])
+
+		if err := handler(&header, msg, dec); err != nil {
+			return err
+		}
+	}
+}
diff --git a/agent/consul/fsm/snapshot.go b/agent/consul/fsm/snapshot.go
index 4f3c36ab1..e4c9c0bb4 100644
--- a/agent/consul/fsm/snapshot.go
+++ b/agent/consul/fsm/snapshot.go
@@ -20,8 +20,8 @@ type snapshot struct {
 	chunkState *raftchunking.State
 }
 
-// snapshotHeader is the first entry in our snapshot
-type snapshotHeader struct {
+// SnapshotHeader is the first entry in our snapshot
+type SnapshotHeader struct {
 	// LastIndex is the last index that affects the data.
 	// This is used when we do the restore for watchers.
 	LastIndex uint64
@@ -40,7 +40,7 @@ func registerPersister(fn persister) {
 }
 
 // restorer is a function used to load back a snapshot of the FSM state.
-type restorer func(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error
+type restorer func(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error
 
 // restorers is a map of restore functions by message type.
 var restorers map[structs.MessageType]restorer
@@ -62,7 +62,7 @@ func (s *snapshot) Persist(sink raft.SnapshotSink) error {
 	defer metrics.MeasureSince([]string{"fsm", "persist"}, time.Now())
 
 	// Write the header
-	header := snapshotHeader{
+	header := SnapshotHeader{
 		LastIndex: s.state.LastIndex(),
 	}
 	encoder := codec.NewEncoder(sink, structs.MsgpackHandle)
diff --git a/agent/consul/fsm/snapshot_oss.go b/agent/consul/fsm/snapshot_oss.go
index 683982606..f6bc29d9f 100644
--- a/agent/consul/fsm/snapshot_oss.go
+++ b/agent/consul/fsm/snapshot_oss.go
@@ -506,7 +506,7 @@ func (s *snapshot) persistIndex(sink raft.SnapshotSink, encoder *codec.Encoder)
 	return nil
 }
 
-func restoreRegistration(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreRegistration(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.RegisterRequest
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -517,7 +517,7 @@ func restoreRegistration(header *snapshotHeader, restore *state.Restore, decoder
 	return nil
 }
 
-func restoreKV(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreKV(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.DirEntry
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -528,7 +528,7 @@ func restoreKV(header *snapshotHeader, restore *state.Restore, decoder *codec.De
 	return nil
 }
 
-func restoreTombstone(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreTombstone(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.DirEntry
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -547,7 +547,7 @@ func restoreTombstone(header *snapshotHeader, restore *state.Restore, decoder *c
 	return nil
 }
 
-func restoreSession(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreSession(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.Session
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -558,7 +558,7 @@ func restoreSession(header *snapshotHeader, restore *state.Restore, decoder *cod
 	return nil
 }
 
-func restoreACL(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreACL(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.ACL
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -571,7 +571,7 @@ func restoreACL(header *snapshotHeader, restore *state.Restore, decoder *codec.D
 }
 
 // DEPRECATED (ACL-Legacy-Compat) - remove once v1 acl compat is removed
-func restoreACLBootstrap(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreACLBootstrap(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.ACLBootstrap
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -582,7 +582,7 @@ func restoreACLBootstrap(header *snapshotHeader, restore *state.Restore, decoder
 	return restore.IndexRestore(&state.IndexEntry{Key: "acl-token-bootstrap", Value: req.ModifyIndex})
 }
 
-func restoreCoordinates(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreCoordinates(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.Coordinates
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -593,7 +593,7 @@ func restoreCoordinates(header *snapshotHeader, restore *state.Restore, decoder
 	return nil
 }
 
-func restorePreparedQuery(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restorePreparedQuery(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.PreparedQuery
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -604,7 +604,7 @@ func restorePreparedQuery(header *snapshotHeader, restore *state.Restore, decode
 	return nil
 }
 
-func restoreAutopilot(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreAutopilot(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req autopilot.Config
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -615,7 +615,7 @@ func restoreAutopilot(header *snapshotHeader, restore *state.Restore, decoder *c
 	return nil
 }
 
-func restoreLegacyIntention(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreLegacyIntention(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.Intention
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -627,7 +627,7 @@ func restoreLegacyIntention(header *snapshotHeader, restore *state.Restore, deco
 	return nil
 }
 
-func restoreConnectCA(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreConnectCA(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.CARoot
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -638,7 +638,7 @@ func restoreConnectCA(header *snapshotHeader, restore *state.Restore, decoder *c
 	return nil
 }
 
-func restoreConnectCAProviderState(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreConnectCAProviderState(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.CAConsulProviderState
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -649,7 +649,7 @@ func restoreConnectCAProviderState(header *snapshotHeader, restore *state.Restor
 	return nil
 }
 
-func restoreConnectCAConfig(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreConnectCAConfig(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.CAConfiguration
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -660,7 +660,7 @@ func restoreConnectCAConfig(header *snapshotHeader, restore *state.Restore, deco
 	return nil
 }
 
-func restoreIndex(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreIndex(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req state.IndexEntry
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -668,7 +668,7 @@ func restoreIndex(header *snapshotHeader, restore *state.Restore, decoder *codec
 	return restore.IndexRestore(&req)
 }
 
-func restoreToken(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreToken(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.ACLToken
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -688,7 +688,7 @@ func restoreToken(header *snapshotHeader, restore *state.Restore, decoder *codec
 	return restore.ACLToken(&req)
 }
 
-func restorePolicy(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restorePolicy(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.ACLPolicy
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -696,7 +696,7 @@ func restorePolicy(header *snapshotHeader, restore *state.Restore, decoder *code
 	return restore.ACLPolicy(&req)
 }
 
-func restoreConfigEntry(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreConfigEntry(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.ConfigEntryRequest
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -704,7 +704,7 @@ func restoreConfigEntry(header *snapshotHeader, restore *state.Restore, decoder
 	return restore.ConfigEntry(req.Entry)
 }
 
-func restoreRole(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreRole(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.ACLRole
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -712,7 +712,7 @@ func restoreRole(header *snapshotHeader, restore *state.Restore, decoder *codec.
 	return restore.ACLRole(&req)
 }
 
-func restoreBindingRule(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreBindingRule(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.ACLBindingRule
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -720,7 +720,7 @@ func restoreBindingRule(header *snapshotHeader, restore *state.Restore, decoder
 	return restore.ACLBindingRule(&req)
 }
 
-func restoreAuthMethod(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreAuthMethod(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.ACLAuthMethod
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -728,7 +728,7 @@ func restoreAuthMethod(header *snapshotHeader, restore *state.Restore, decoder *
 	return restore.ACLAuthMethod(&req)
 }
 
-func restoreFederationState(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreFederationState(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.FederationStateRequest
 	if err := decoder.Decode(&req); err != nil {
 		return err
@@ -736,7 +736,7 @@ func restoreFederationState(header *snapshotHeader, restore *state.Restore, deco
 	return restore.FederationState(req.State)
 }
 
-func restoreSystemMetadata(header *snapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
+func restoreSystemMetadata(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
 	var req structs.SystemMetadataEntry
 	if err := decoder.Decode(&req); err != nil {
 		return err
diff --git a/agent/structs/structs.go b/agent/structs/structs.go
index 4797bc4a8..46a6ba399 100644
--- a/agent/structs/structs.go
+++ b/agent/structs/structs.go
@@ -72,6 +72,46 @@ const (
 	SystemMetadataRequestType                   = 31
 )
 
+// if a new request type is added above it must be
+// added to the map below
+
+// requestTypeStrings is used for snapshot enhance
+// any new request types added must be placed here
+var requestTypeStrings = map[MessageType]string{
+	RegisterRequestType:             "Register",
+	DeregisterRequestType:           "Deregister",
+	KVSRequestType:                  "KVS",
+	SessionRequestType:              "Session",
+	ACLRequestType:                  "ACL", // DEPRECATED (ACL-Legacy-Compat)
+	TombstoneRequestType:            "Tombstone",
+	CoordinateBatchUpdateType:       "CoordinateBatchUpdate",
+	PreparedQueryRequestType:        "PreparedQuery",
+	TxnRequestType:                  "Txn",
+	AutopilotRequestType:            "Autopilot",
+	AreaRequestType:                 "Area",
+	ACLBootstrapRequestType:         "ACLBootstrap",
+	IntentionRequestType:            "Intention",
+	ConnectCARequestType:            "ConnectCA",
+	ConnectCAProviderStateType:      "ConnectCAProviderState",
+	ConnectCAConfigType:             "ConnectCAConfig", // FSM snapshots only.
+	IndexRequestType:                "Index",           // FSM snapshots only.
+	ACLTokenSetRequestType:          "ACLToken",
+	ACLTokenDeleteRequestType:       "ACLTokenDelete",
+	ACLPolicySetRequestType:         "ACLPolicy",
+	ACLPolicyDeleteRequestType:      "ACLPolicyDelete",
+	ConnectCALeafRequestType:        "ConnectCALeaf",
+	ConfigEntryRequestType:          "ConfigEntry",
+	ACLRoleSetRequestType:           "ACLRole",
+	ACLRoleDeleteRequestType:        "ACLRoleDelete",
+	ACLBindingRuleSetRequestType:    "ACLBindingRule",
+	ACLBindingRuleDeleteRequestType: "ACLBindingRuleDelete",
+	ACLAuthMethodSetRequestType:     "ACLAuthMethod",
+	ACLAuthMethodDeleteRequestType:  "ACLAuthMethodDelete",
+	ChunkingStateType:               "ChunkingState",
+	FederationStateRequestType:      "FederationState",
+	SystemMetadataRequestType:       "SystemMetadata",
+}
+
 const (
 	// IgnoreUnknownTypeFlag is set along with a MessageType
 	// to indicate that the message type can be safely ignored
@@ -2442,6 +2482,21 @@ func (r *KeyringResponses) New() interface{} {
 	return new(KeyringResponses)
 }
 
+// String converts message type int to string
+func (m MessageType) String() string {
+	s, ok := requestTypeStrings[m]
+	if ok {
+		return s
+	}
+
+	s, ok = enterpriseRequestType(m)
+	if ok {
+		return s
+	}
+	return "Unknown(" + strconv.Itoa(int(m)) + ")"
+
+}
+
 // UpstreamDownstream pairs come from individual proxy registrations, which can be updated independently.
 type UpstreamDownstream struct {
 	Upstream   ServiceName
diff --git a/agent/structs/structs_oss.go b/agent/structs/structs_oss.go
index 6ecb6783c..522e2f0ff 100644
--- a/agent/structs/structs_oss.go
+++ b/agent/structs/structs_oss.go
@@ -131,6 +131,10 @@ func (_ *HealthCheck) Validate() error {
 	return nil
 }
 
+func enterpriseRequestType(m MessageType) (string, bool) {
+	return "", false
+}
+
 // CheckIDs returns the IDs for all checks associated with a session, regardless of type
 func (s *Session) CheckIDs() []types.CheckID {
 	// Merge all check IDs into a single slice, since they will be handled the same way
diff --git a/command/snapshot/inspect/snapshot_inspect.go b/command/snapshot/inspect/snapshot_inspect.go
index e7a38315b..85e6c895f 100644
--- a/command/snapshot/inspect/snapshot_inspect.go
+++ b/command/snapshot/inspect/snapshot_inspect.go
@@ -4,11 +4,20 @@ import (
 	"bytes"
 	"flag"
 	"fmt"
+	"io"
 	"os"
+	"sort"
+	"strconv"
+	"strings"
 	"text/tabwriter"
 
+	"github.com/hashicorp/consul/agent/consul/fsm"
+	"github.com/hashicorp/consul/agent/structs"
 	"github.com/hashicorp/consul/command/flags"
 	"github.com/hashicorp/consul/snapshot"
+	"github.com/hashicorp/go-hclog"
+	"github.com/hashicorp/go-msgpack/codec"
+	"github.com/hashicorp/raft"
 	"github.com/mitchellh/cli"
 )
 
@@ -31,12 +40,13 @@ func (c *cmd) init() {
 
 func (c *cmd) Run(args []string) int {
 	if err := c.flags.Parse(args); err != nil {
+		c.UI.Error(err.Error())
 		return 1
 	}
 
 	var file string
-
 	args = c.flags.Args()
+
 	switch len(args) {
 	case 0:
 		c.UI.Error("Missing FILE argument")
@@ -56,12 +66,45 @@ func (c *cmd) Run(args []string) int {
 	}
 	defer f.Close()
 
-	meta, err := snapshot.Verify(f)
+	readFile, meta, err := snapshot.Read(hclog.New(nil), f)
 	if err != nil {
-		c.UI.Error(fmt.Sprintf("Error verifying snapshot: %s", err))
+		c.UI.Error(fmt.Sprintf("Error reading snapshot: %s", err))
+	}
+	defer func() {
+		if err := readFile.Close(); err != nil {
+			c.UI.Error(fmt.Sprintf("Failed to close temp snapshot: %v", err))
+		}
+		if err := os.Remove(readFile.Name()); err != nil {
+			c.UI.Error(fmt.Sprintf("Failed to clean up temp snapshot: %v", err))
+		}
+	}()
+
+	stats, totalSize, err := enhance(readFile)
+	if err != nil {
+		c.UI.Error(fmt.Sprintf("Error extracting snapshot data: %s", err))
 		return 1
 	}
+	// Outputs the original style of inspect information
+	legacy, err := c.legacyStats(meta)
+	if err != nil {
+		c.UI.Error(fmt.Sprintf("Error outputting snapshot data: %s", err))
+	}
+	c.UI.Info(legacy.String())
 
+	// Outputs the more detailed snapshot information
+	enhanced, err := c.readStats(stats, totalSize)
+	if err != nil {
+		c.UI.Error(fmt.Sprintf("Error outputting enhanced snapshot data: %s", err))
+		return 1
+	}
+	c.UI.Info(enhanced.String())
+
+	return 0
+}
+
+// legacyStats outputs the expected stats from the original snapshot
+// inspect command
+func (c *cmd) legacyStats(meta *raft.SnapshotMeta) (bytes.Buffer, error) {
 	var b bytes.Buffer
 	tw := tabwriter.NewWriter(&b, 0, 2, 6, ' ', 0)
 	fmt.Fprintf(tw, "ID\t%s\n", meta.ID)
@@ -69,14 +112,142 @@ func (c *cmd) Run(args []string) int {
 	fmt.Fprintf(tw, "Index\t%d\n", meta.Index)
 	fmt.Fprintf(tw, "Term\t%d\n", meta.Term)
 	fmt.Fprintf(tw, "Version\t%d\n", meta.Version)
-	if err = tw.Flush(); err != nil {
-		c.UI.Error(fmt.Sprintf("Error rendering snapshot info: %s", err))
-		return 1
+	if err := tw.Flush(); err != nil {
+		return b, err
+	}
+	return b, nil
+}
+
+type typeStats struct {
+	Name  string
+	Sum   int
+	Count int
+}
+
+// countingReader helps keep track of the bytes we have read
+// when reading snapshots
+type countingReader struct {
+	wrappedReader io.Reader
+	read          int
+}
+
+func (r *countingReader) Read(p []byte) (n int, err error) {
+	n, err = r.wrappedReader.Read(p)
+	if err == nil {
+		r.read += n
+	}
+	return n, err
+}
+
+// enhance utilizes ReadSnapshot to populate the struct with
+// all of the snapshot's itemized data
+func enhance(file io.Reader) (map[structs.MessageType]typeStats, int, error) {
+	stats := make(map[structs.MessageType]typeStats)
+	cr := &countingReader{wrappedReader: file}
+	totalSize := 0
+	handler := func(header *fsm.SnapshotHeader, msg structs.MessageType, dec *codec.Decoder) error {
+		name := structs.MessageType.String(msg)
+		s := stats[msg]
+		if s.Name == "" {
+			s.Name = name
+		}
+		var val interface{}
+		err := dec.Decode(&val)
+		if err != nil {
+			return fmt.Errorf("failed to decode msg type %v, error %v", name, err)
+		}
+
+		size := cr.read - totalSize
+		s.Sum += size
+		s.Count++
+		totalSize = cr.read
+		stats[msg] = s
+		return nil
+	}
+	if err := fsm.ReadSnapshot(cr, handler); err != nil {
+		return nil, 0, err
+	}
+	return stats, totalSize, nil
+
+}
+
+// readStats takes the information generated from enhance and creates human
+// readable output from it
+func (c *cmd) readStats(stats map[structs.MessageType]typeStats, totalSize int) (bytes.Buffer, error) {
+	// Output stats in size-order
+	ss := make([]typeStats, 0, len(stats))
+
+	for _, s := range stats {
+		ss = append(ss, s)
 	}
 
-	c.UI.Info(b.String())
+	// Sort the stat slice
+	sort.Slice(ss, func(i, j int) bool { return ss[i].Sum > ss[j].Sum })
 
-	return 0
+	var b bytes.Buffer
+
+	tw := tabwriter.NewWriter(&b, 8, 8, 6, ' ', 0)
+	fmt.Fprintln(tw, "\n Type\tCount\tSize\t")
+	fmt.Fprintf(tw, " %s\t%s\t%s\t", "----", "----", "----")
+	// For each different type generate new output
+	for _, s := range ss {
+		fmt.Fprintf(tw, "\n %s\t%d\t%s\t", s.Name, s.Count, ByteSize(uint64(s.Sum)))
+	}
+	fmt.Fprintf(tw, "\n %s\t%s\t%s\t", "----", "----", "----")
+	fmt.Fprintf(tw, "\n Total\t\t%s\t", ByteSize(uint64(totalSize)))
+
+	if err := tw.Flush(); err != nil {
+		c.UI.Error(fmt.Sprintf("Error rendering snapshot info: %s", err))
+		return b, err
+	}
+
+	return b, nil
+
+}
+
+// ByteSize returns a human-readable byte string of the form 10MB, 12.5KB, and so forth.  The following units are available:
+//	TB: Terabyte
+//	GB: Gigabyte
+//	MB: Megabyte
+//	KB: Kilobyte
+//	B: Byte
+// The unit that results in the smallest number greater than or equal to 1 is always chosen.
+// From https://github.com/cloudfoundry/bytefmt/blob/master/bytes.go
+
+const (
+	BYTE = 1 << (10 * iota)
+	KILOBYTE
+	MEGABYTE
+	GIGABYTE
+	TERABYTE
+)
+
+func ByteSize(bytes uint64) string {
+	unit := ""
+	value := float64(bytes)
+
+	switch {
+	case bytes >= TERABYTE:
+		unit = "TB"
+		value = value / TERABYTE
+	case bytes >= GIGABYTE:
+		unit = "GB"
+		value = value / GIGABYTE
+	case bytes >= MEGABYTE:
+		unit = "MB"
+		value = value / MEGABYTE
+	case bytes >= KILOBYTE:
+		unit = "KB"
+		value = value / KILOBYTE
+	case bytes >= BYTE:
+		unit = "B"
+	case bytes == 0:
+		return "0"
+	}
+
+	result := strconv.FormatFloat(value, 'f', 1, 64)
+	result = strings.TrimSuffix(result, ".0")
+	return result + unit
 }
 
 func (c *cmd) Synopsis() string {
@@ -96,6 +267,6 @@ Usage: consul snapshot inspect [options] FILE
   To inspect the file "backup.snap":
 
     $ consul snapshot inspect backup.snap
-
+  
   For a full list of options and examples, please see the Consul documentation.
 `
diff --git a/command/snapshot/inspect/snapshot_inspect_test.go b/command/snapshot/inspect/snapshot_inspect_test.go
index eab43a8f4..e04494c10 100644
--- a/command/snapshot/inspect/snapshot_inspect_test.go
+++ b/command/snapshot/inspect/snapshot_inspect_test.go
@@ -1,17 +1,36 @@
 package inspect
 
 import (
-	"io"
-	"os"
+	"flag"
+	"io/ioutil"
 	"path/filepath"
 	"strings"
 	"testing"
 
-	"github.com/hashicorp/consul/agent"
-	"github.com/hashicorp/consul/sdk/testutil"
 	"github.com/mitchellh/cli"
+	"github.com/stretchr/testify/require"
 )
 
+// update allows golden files to be updated based on the current output.
+var update = flag.Bool("update", false, "update golden files")
+
+// golden reads and optionally writes the expected data to the golden file,
+// returning the contents as a string.
+func golden(t *testing.T, name, got string) string {
+	t.Helper()
+
+	golden := filepath.Join("testdata", name+".golden")
+	if *update && got != "" {
+		err := ioutil.WriteFile(golden, []byte(got), 0644)
+		require.NoError(t, err)
+	}
+
+	expected, err := ioutil.ReadFile(golden)
+	require.NoError(t, err)
+
+	return string(expected)
+}
+
 func TestSnapshotInspectCommand_noTabs(t *testing.T) {
 	t.Parallel()
 	if strings.ContainsRune(New(cli.NewMockUi()).Help(), '\t') {
@@ -60,53 +79,19 @@ func TestSnapshotInspectCommand_Validation(t *testing.T) {
 }
 
 func TestSnapshotInspectCommand(t *testing.T) {
-	t.Parallel()
-	a := agent.NewTestAgent(t, ``)
-	defer a.Shutdown()
-	client := a.Client()
 
-	dir := testutil.TempDir(t, "snapshot")
-	file := filepath.Join(dir, "backup.tgz")
-
-	// Save a snapshot of the current Consul state
-	f, err := os.Create(file)
-	if err != nil {
-		t.Fatalf("err: %v", err)
-	}
-
-	snap, _, err := client.Snapshot().Save(nil)
-	if err != nil {
-		f.Close()
-		t.Fatalf("err: %v", err)
-	}
-	if _, err := io.Copy(f, snap); err != nil {
-		f.Close()
-		t.Fatalf("err: %v", err)
-	}
-	if err := f.Close(); err != nil {
-		t.Fatalf("err: %v", err)
-	}
+	filepath := "./testdata/backup.snap"
 
 	// Inspect the snapshot
 	ui := cli.NewMockUi()
 	c := New(ui)
-	args := []string{file}
+	args := []string{filepath}
 
 	code := c.Run(args)
 	if code != 0 {
 		t.Fatalf("bad: %d. %#v", code, ui.ErrorWriter.String())
 	}
 
-	output := ui.OutputWriter.String()
-	for _, key := range []string{
-		"ID",
-		"Size",
-		"Index",
-		"Term",
-		"Version",
-	} {
-		if !strings.Contains(output, key) {
-			t.Fatalf("bad %#v, missing %q", output, key)
-		}
-	}
+	want := golden(t, t.Name(), ui.OutputWriter.String())
+	require.Equal(t, want, ui.OutputWriter.String())
 }
diff --git a/command/snapshot/inspect/testdata/TestSnapshotInspectCommand.golden b/command/snapshot/inspect/testdata/TestSnapshotInspectCommand.golden
new file mode 100644
index 000000000..bb176a6e5
--- /dev/null
+++ b/command/snapshot/inspect/testdata/TestSnapshotInspectCommand.golden
@@ -0,0 +1,20 @@
+ID           2-13-1602222343947
+Size         5141
+Index        13
+Term         2
+Version      1
+
+
+ Type                        Count      Size       
+ ----                        ----       ----       
+ Register                    3          1.7KB      
+ ConnectCA                   1          1.2KB      
+ ConnectCAProviderState      1          1.1KB      
+ Index                       12         344B       
+ Autopilot                   1          199B       
+ ConnectCAConfig             1          197B       
+ FederationState             1          139B       
+ SystemMetadata              1          68B        
+ ChunkingState               1          12B        
+ ----                        ----       ----       
+ Total                                  5KB
diff --git a/command/snapshot/inspect/testdata/backup.snap b/command/snapshot/inspect/testdata/backup.snap
new file mode 100644
index 000000000..ee15817a7
--- /dev/null
+++ b/command/snapshot/inspect/testdata/backup.snap
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a285e148fd8ce77abc949bb4e502dfe8dcadcc8c7ba976ad2e71637d8a1d2001
+size 2842
diff --git a/snapshot/snapshot.go b/snapshot/snapshot.go
index bc2827ebd..9437cfa11 100644
--- a/snapshot/snapshot.go
+++ b/snapshot/snapshot.go
@@ -160,13 +160,12 @@ func concludeGzipRead(decomp *gzip.Reader) error {
 	return nil
 }
 
-// Restore takes the snapshot from the reader and attempts to apply it to the
-// given Raft instance.
-func Restore(logger hclog.Logger, in io.Reader, r *raft.Raft) error {
+// Read a snapshot into a temporary file. The caller is responsible for removing the file.
+func Read(logger hclog.Logger, in io.Reader) (*os.File, *raft.SnapshotMeta, error) {
 	// Wrap the reader in a gzip decompressor.
 	decomp, err := gzip.NewReader(in)
 	if err != nil {
-		return fmt.Errorf("failed to decompress snapshot: %v", err)
+		return nil, nil, fmt.Errorf("failed to decompress snapshot: %v", err)
 	}
 	defer func() {
 		if err := decomp.Close(); err != nil {
@@ -178,9 +177,37 @@ func Restore(logger hclog.Logger, in io.Reader, r *raft.Raft) error {
 	// we can avoid buffering in memory.
 	snap, err := ioutil.TempFile("", "snapshot")
 	if err != nil {
-		return fmt.Errorf("failed to create temp snapshot file: %v", err)
+		return nil, nil, fmt.Errorf("failed to create temp snapshot file: %v", err)
 	}
+
+	// Read the archive.
+	var metadata raft.SnapshotMeta
+	if err := read(decomp, &metadata, snap); err != nil {
+		return nil, nil, fmt.Errorf("failed to read snapshot file: %v", err)
+	}
+
+	if err := concludeGzipRead(decomp); err != nil {
+		return nil, nil, err
+	}
+
+	// Sync and rewind the file so it's ready to be read again.
+	if err := snap.Sync(); err != nil {
+		return nil, nil, fmt.Errorf("failed to sync temp snapshot: %v", err)
+	}
+	if _, err := snap.Seek(0, 0); err != nil {
+		return nil, nil, fmt.Errorf("failed to rewind temp snapshot: %v", err)
+	}
+	return snap, &metadata, nil
+}
+
+// Restore takes the snapshot from the reader and attempts to apply it to the
+// given Raft instance.
+func Restore(logger hclog.Logger, in io.Reader, r *raft.Raft) error {
+	snap, metadata, err := Read(logger, in)
 	defer func() {
+		if snap == nil {
+			return
+		}
 		if err := snap.Close(); err != nil {
 			logger.Error("Failed to close temp snapshot", "error", err)
 		}
@@ -188,27 +215,12 @@ func Restore(logger hclog.Logger, in io.Reader, r *raft.Raft) error {
 			logger.Error("Failed to clean up temp snapshot", "error", err)
 		}
 	}()
-
-	// Read the archive.
-	var metadata raft.SnapshotMeta
-	if err := read(decomp, &metadata, snap); err != nil {
-		return fmt.Errorf("failed to read snapshot file: %v", err)
-	}
-
-	if err := concludeGzipRead(decomp); err != nil {
+	if err != nil {
 		return err
 	}
 
-	// Sync and rewind the file so it's ready to be read again.
-	if err := snap.Sync(); err != nil {
-		return fmt.Errorf("failed to sync temp snapshot: %v", err)
-	}
-	if _, err := snap.Seek(0, 0); err != nil {
-		return fmt.Errorf("failed to rewind temp snapshot: %v", err)
-	}
-
 	// Feed the snapshot into Raft.
-	if err := r.Restore(&metadata, snap, 0); err != nil {
+	if err := r.Restore(metadata, snap, 0); err != nil {
 		return fmt.Errorf("Raft error when restoring snapshot: %v", err)
 	}
 
diff --git a/website/pages/commands/snapshot/inspect.mdx b/website/pages/commands/snapshot/inspect.mdx
index 474303140..37398d5bb 100644
--- a/website/pages/commands/snapshot/inspect.mdx
+++ b/website/pages/commands/snapshot/inspect.mdx
@@ -41,7 +41,21 @@ Size         667
 Index        5
 Term         2
 Version      1
+
+ Type                        Count      Size
+ ----                        ----       ----
+ Register                    3          1.7KB
+ ConnectCA                   1          1.2KB
+ ConnectCAProviderState      1          1.1KB
+ Index                       12         344B
+ AutopilotRequest            1          199B
+ ConnectCAConfig             1          197B
+ FederationState             1          139B
+ SystemMetadata              1          68B
+ ChunkingState               1          12B
+ ----                        ----       ----
+ Total                                   5KB
 ```
 
 Please see the [HTTP API](/api/snapshot) documentation for
-more details about snapshot internals.
+more details about snapshot internals.
\ No newline at end of file