env PILOSA_TXSRC is reinjected into the env if pilosa server --tx overrides it. fixes #575

1. Tests can choose the Tx engine desired by setting the PILOSA_TXSRC
      env variable. For example:

         PILOSA_TXSRC=badger go test -v -run TestImportClearRestart

   2. pilosa server --tx is enabled now.

     Examples:
      pilosa server --tx roaring    # gives the legacy approach.
      pilosa server --tx rbf        # will activate RBF
      pilosa server --tx badger     # will activate BadgerDB
      pilosa server --tx badger_rbf # will run Blue-Green badger to RBF comparisons.

      and so forth. See pilosa server -h or txfactory.go for all valid --tx choices.

   3. Mechanism that makes both tests(1) and pilosa server(2) work at once:
       pilosa/server/server.go injects PILOSA_TXSRC into env to
       communicate with NewIndex in pilosa/index.go.

Makefile

@@ -178,6 +178,9 @@ golangci-lint: require-golangci-lint
 # Alias
 linter: golangci-lint
 
+# Better alias
+ocd: golangci-lint
+
 # Run gometalinter with custom flags
 gometalinter: require-gometalinter vendor
 	GO111MODULE=off gometalinter --vendor --disable-all \

ctl/server.go

@@ -87,5 +87,5 @@ func BuildServerFlags(cmd *cobra.Command, srv *server.Command) {
 	flags.IntVar(&srv.Config.Profile.MutexFraction, "profile.mutex-fraction", srv.Config.Profile.MutexFraction, "Sampling fraction for mutex contention profiling. Sample 1/<rate> of events.")
 
 	// Transactional storage engine
-	flags.StringVarP(&srv.Config.Txsrc, "tx", "", "roaring", "transaction/storage to use: one of roaring, rbf, badger, rbf_roaring, roaring_rbf, badger_roaring, roaring_badger, badger_rbf, or rbf_badger")
+	flags.StringVarP(&srv.Config.Txsrc, "tx", "", "", "transaction/storage to use: one of roaring, rbf, badger, rbf_roaring, roaring_rbf, badger_roaring, roaring_badger, badger_rbf, or rbf_badger (default roaring)")
 }

index.go

@@ -78,9 +78,25 @@ func NewIndex(holder *Holder, path, name string) (*Index, error) {
 	// Emulate what the spf13/cobra does, letting env vars override
 	// the defaults, because we may be under a simple "go test" run where
 	// not all that command line machinery has been spun up.
+
+	// needed for the tests:
 	txsrc := os.Getenv("PILOSA_TXSRC")
+
+	// Warning: won't work for the tests to say:
+	// txsrc := holder.Opts.Txsrc // WILL BREAK TESTS
+
 	if txsrc == "" {
-		txsrc = DefaultTxsrc
+		// nothing in the env for PILOSA_TXSRC; therefore not running under a "make topt.badger" for example.
+		if holder.Opts.Txsrc != "" {
+			// most of the tests and production run, we expect that if holder.opts.Txsrc is set, it
+			// will be the exact same as PILOSA_TXSRC. Unfortunately there are tests where that won't hold.
+			// So if the env var PILOSA_TXSRC *is* set, we always give it precedence.
+			// This lets `PILOSA_TXSRC=rbf go test -v -run "one_of_my_RBF_tests"` succeed.
+			//
+			txsrc = holder.Opts.Txsrc
+		} else {
+			txsrc = DefaultTxsrc
+		}
 	}
 	txf, err := newTxFactory(txsrc, path)
 	if err != nil {

server/server.go

@@ -240,6 +240,29 @@ func (m *Command) SetupServer() error {
 
 	m.logger.Printf("%s", pilosa.VersionInfo())
 
+	// If the pilosa command line uses -tx to override the
+	// PILOSA_TXSRC env variable, then we must also correct
+	// the environment, so that pilosa/txfactory.go can determine the
+	// desired Tx engine. This enables "go test" testing in pilosa that
+	// does not spin up a full server, while still respecting the pilosa
+	// server's choice when run full in production.
+	envTxsrc := os.Getenv("PILOSA_TXSRC")
+	if m.Config.Txsrc == "" {
+		// INVAR: No -tx flag on the command line.
+		// We defer to the environment, and then the DefaultTxsrc
+		if envTxsrc == "" {
+			// no env variable requested either.
+			m.Config.Txsrc = pilosa.DefaultTxsrc
+		} else {
+			// Tell the "regular" prod server what to use.
+			m.Config.Txsrc = envTxsrc
+		}
+	}
+	// INVAR: m.Config.Txsrc is valid and not "", but pilosa.DefaultTxsrc could be bad.
+	txty := pilosa.MustTxsrcToTxtype(m.Config.Txsrc) // will panic on unknown Txsrc.
+	os.Setenv("PILOSA_TXSRC", m.Config.Txsrc)
+	m.logger.Printf("using Txsrc '%v'/%v", m.Config.Txsrc, txty)
+
 	// validateAddrs sets the appropriate values for Bind and Advertise
 	// based on the inputs. It is not responsible for applying defaults, although
 	// it does provide a non-zero port (10101) in the case where no port is specified.
@@ -353,6 +376,7 @@ func (m *Command) SetupServer() error {
 		pilosa.OptServerInternalClient(http.NewInternalClientFromURI(uri, c)),
 		pilosa.OptServerClusterDisabled(m.Config.Cluster.Disabled, m.Config.Cluster.Hosts),
 		pilosa.OptServerSerializer(proto.Serializer{}),
+		pilosa.OptServerTxsrc(m.Config.Txsrc),
 		coordinatorOpt,
 	}
 

txfactory.go

@@ -85,7 +85,7 @@ const (
 	blueGreenRBFBadger txtype = 9
 )
 
-func txsrcToTxtype(txsrc string) txtype {
+func MustTxsrcToTxtype(txsrc string) txtype {
 	switch txsrc {
 	case RoaringTxn: // "roaring"
 		return roaringFragmentFilesTxn
@@ -110,10 +110,11 @@ func txsrcToTxtype(txsrc string) txtype {
 }
 
 func newTxFactory(txsrc string, path string) (f *TxFactory, err error) {
-	ty := txsrcToTxtype(txsrc)
+	ty := MustTxsrcToTxtype(txsrc)
 	if ty < 1 || ty > 9 {
 		panic(fmt.Sprintf("invalid txtype '%v'", int(ty)))
 	}
+
 	var bw *BadgerDBWrapper
 	if ty == badgerTxn || ty == 4 || ty == 5 || ty == 8 || ty == 9 {
 		bw, err = openBadgerDBWrapper(path)