multi: update GetInfoResponse response

Update the output of the `commit_hash` field in the GetInfoResponse.
The `commit_hash` field will contain the most recent commit_hash that
the build was based on. If the build had uncommitted changes, this field
will contain the most recent commit hash, suffixed by "-dirty".

Note that this change also changes the output of `commit` field in the
`--version` command. The `Commit` field will now contain most recent git
commit tag.

Makefile

@@ -15,8 +15,10 @@ GOBUILD := GO111MODULE=on go build -v
 GOINSTALL := GO111MODULE=on go install -v
 GOMOD := GO111MODULE=on go mod
 
-COMMIT := $(shell git describe --abbrev=40 --dirty | sed -E 's/.*-g([0-9a-f]{40})(-dirty)?/\1\2/')
-LDFLAGS := -ldflags "-X $(PKG).Commit=$(COMMIT)"
+COMMIT := $(shell git describe --abbrev=40 --dirty --tags)
+COMMIT_HASH := $(shell git rev-parse HEAD)
+DIRTY := $(shell git diff-index --quiet HEAD -- || echo dirty)
+LDFLAGS := -ldflags "-X $(PKG).Commit=$(COMMIT) -X $(PKG).CommitHash=$(COMMIT_HASH) -X $(PKG).Dirty=$(DIRTY)"
 DEV_TAGS = dev
 
 GOFILES_NOVENDOR = $(shell find . -type f -name '*.go' -not -path "./vendor/*" -not -name "*pb.go" -not -name "*pb.gw.go" -not -name "*.pb.json.go")

loopd/swapclient_server.go

@@ -1249,9 +1249,16 @@ func (s *swapClientServer) GetInfo(ctx context.Context,
 		}
 	}
 
+	commitHash := loop.CommitHash
+	if loop.Dirty != "" {
+		// If the build was dirty, we add a "-dirty" suffix to the
+		// commit hash.
+		commitHash += "-" + loop.Dirty
+	}
+
 	return &looprpc.GetInfoResponse{
 		Version:      loop.Version(),
-		CommitHash:   loop.CommitHash(),
+		CommitHash:   commitHash,
 		Network:      s.config.Network,
 		RpcListen:    s.config.RPCListen,
 		RestListen:   s.config.RESTListen,

looprpc/client.pb.go

@@ -2737,7 +2737,9 @@ type GetInfoResponse struct {
 	LoopOutStats *LoopStats `protobuf:"bytes,7,opt,name=loop_out_stats,json=loopOutStats,proto3" json:"loop_out_stats,omitempty"`
 	// Statistics about loop ins.
 	LoopInStats *LoopStats `protobuf:"bytes,8,opt,name=loop_in_stats,json=loopInStats,proto3" json:"loop_in_stats,omitempty"`
-	// The git commit hash of the loopd binary.
+	// The Git commit hash the Loop binary build was based on. If the build had
+	// uncommited changes, this field will contain the most recent commit hash,
+	// suffixed by "-dirty".
 	CommitHash string `protobuf:"bytes,9,opt,name=commit_hash,json=commitHash,proto3" json:"commit_hash,omitempty"`
 }
 

looprpc/client.proto

@@ -1056,7 +1056,9 @@ message GetInfoResponse {
     LoopStats loop_in_stats = 8;
 
     /*
-    The git commit hash of the loopd binary.
+    The Git commit hash the Loop binary build was based on. If the build had
+    uncommited changes, this field will contain the most recent commit hash,
+    suffixed by "-dirty".
      */
     string commit_hash = 9;
 }

looprpc/client.swagger.json

@@ -986,7 +986,7 @@
         },
         "commit_hash": {
           "type": "string",
-          "description": "The git commit hash of the loopd binary."
+          "description": "The Git commit hash the Loop binary build was based on. If the build had\nuncommited changes, this field will contain the most recent commit hash,\nsuffixed by \"-dirty\"."
         }
       }
     },

version.go

@@ -12,10 +12,21 @@ import (
 	"strings"
 )
 
-// Commit stores the current commit hash of this build, this should be set
-// using the -ldflags during compilation.
+// Commit stores the current git tag of this build, when the build is based on
+// a tagged commit. If the build is based on an untagged commit or is a dirty
+// build, the Commit field stores the most recent tag suffixed by the commit
+// hash, and/or "-dirty". This should be set using the -ldflags during
+// compilation.
 var Commit string
 
+// CommitHash stores the current git commit hash of this build. This should be
+// set using the -ldflags during compilation.
+var CommitHash string
+
+// Dirty stores a "dirty" string, if the build had uncommitted changes when
+// being built. This should be set using the -ldflags during compilation.
+var Dirty string
+
 // semanticAlphabet is the allowed characters from the semantic versioning
 // guidelines for pre-release version and build metadata strings. In particular
 // they MUST only contain characters in semanticAlphabet.
@@ -52,18 +63,13 @@ func Version() string {
 }
 
 // RichVersion returns the application version as a properly formed string
-// per the semantic versioning 2.0.0 spec (http://semver.org/) and the commit
-// it was built on.
+// per the semantic versioning 2.0.0 spec (http://semver.org/), followed by the
+// most recent git tag the build was built on.
 func RichVersion() string {
-	// Append commit hash of current build to version.
+	// Append the most recent git tag of the current build to version.
 	return fmt.Sprintf("%s commit=%s", semanticVersion(), Commit)
 }
 
-// CommitHash returns the commit hash of the current build.
-func CommitHash() string {
-	return Commit
-}
-
 // UserAgent returns the full user agent string that identifies the software
 // that is submitting swaps to the loop server.
 func UserAgent(initiator string) string {