Add version info to common package and -version flag to CLI

.changelog/128.feature.1.md

@@ -0,0 +1,4 @@
+common: Add package implementing common things for Oasis Core Rosetta Gateway
+
+Initially, it stores the versions of the Rosetta API, Go toolchain and the
+Oasis Core Rosetta Gateway itself.

.changelog/128.feature.2.md

@@ -0,0 +1 @@
+cli: Add `-version` flag to `oasis-core-rosetta-gateway` binary

.changelog/128.internal.2.md

@@ -0,0 +1 @@
+cli: Extract port setting steps to `getPortOrExit()` function

.changelog/128.internal.md

@@ -0,0 +1 @@
+Make: Add reproducibility and version info flags to Go builds

Makefile

@@ -16,18 +16,23 @@ $(error Please install wget or curl)
 endif
 endif
 
+# Check if Go's linkers flags are set in common.mk and add them as extra flags.
+ifneq ($(GOLDFLAGS),)
+	GO_EXTRA_FLAGS += -ldflags $(GOLDFLAGS)
+endif
+
 ROOT := $(shell dirname $(realpath $(firstword $(MAKEFILE_LIST))))
 
 all: build
 	@$(ECHO) "$(CYAN)*** Everything built successfully!$(OFF)"
 
 build:
 	@$(ECHO) "$(CYAN)*** Building...$(OFF)"
-	@$(GO) build
+	@$(GO) build $(GOFLAGS) $(GO_EXTRA_FLAGS)
 
 build-tests:
 	@$(ECHO) "$(CYAN)*** Building tests...$(OFF)"
-	@$(GO) build ./tests/...
+	@$(GO) build $(GOFLAGS) $(GO_EXTRA_FLAGS) ./tests/...
 
 tests/oasis_core_release.tar.gz:
 	@$(ECHO) "$(MAGENTA)*** Downloading oasis-core release $(OASIS_RELEASE)...$(OFF)"

common.mk

@@ -127,6 +127,16 @@ export OASIS_GO ?= go
 # Go command prefix to use in all Go commands.
 GO := env -u GOPATH $(OASIS_GO)
 
+# NOTE: The -trimpath flag strips all host dependent filesystem paths from
+# binaries which is required for deterministic builds.
+GOFLAGS ?= -trimpath -v
+
+# Project's version as the linker's string value definition.
+export GOLDFLAGS_VERSION := -X github.com/oasisprotocol/oasis-core-rosetta-gateway/common.SoftwareVersion=$(VERSION)
+
+# Go's linker flags.
+export GOLDFLAGS ?= "$(GOLDFLAGS_VERSION)"
+
 # Helper that ensures the git workspace is clean.
 define ENSURE_GIT_CLEAN =
 	if [[ ! -z `git status --porcelain` ]]; then \

common/version.go

@@ -0,0 +1,20 @@
+// Package common implements common things for Oasis Core Rosetta Gateway.
+package common
+
+import (
+	"runtime"
+	"strings"
+)
+
+var (
+	// SoftwareVersion represents the Oasis Core Rosetta Gateway's version and
+	// should be set by the linker.
+	SoftwareVersion = "0.0.0-unset"
+
+	// RosettaAPIVersion represents the Rosetta API version with which the
+	// Oasis Core Rosetta Gateway is guaranteed to be compatible with.
+	RosettaAPIVersion = "1.4.1"
+
+	// ToolchainVersion is the version of the Go compiler/standard library.
+	ToolchainVersion = strings.TrimPrefix(runtime.Version(), "go")
+)

main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"flag"
 	"fmt"
 	"net/http"
 	"os"
@@ -15,6 +16,7 @@ import (
 	"github.com/oasisprotocol/oasis-core/go/common/crypto/signature"
 	"github.com/oasisprotocol/oasis-core/go/common/logging"
 
+	"github.com/oasisprotocol/oasis-core-rosetta-gateway/common"
 	"github.com/oasisprotocol/oasis-core-rosetta-gateway/oasis"
 	"github.com/oasisprotocol/oasis-core-rosetta-gateway/services"
 )
@@ -30,7 +32,11 @@ const GatewayPortEnvVar = "OASIS_ROSETTA_GATEWAY_PORT"
 // Don't forget to set services.OfflineModeChainIDEnvVar as well.
 const OfflineModeEnvVar = "OASIS_ROSETTA_GATEWAY_OFFLINE_MODE"
 
-var logger = logging.GetLogger("oasis-rosetta-gateway")
+var (
+	logger = logging.GetLogger("oasis-rosetta-gateway")
+
+	versionFlag = flag.Bool("version", false, "Print version and exit")
+)
 
 // NewBlockchainRouter returns a Mux http.Handler from a collection of
 // Rosetta service controllers.
@@ -113,29 +119,50 @@ func getEnvVarOrExit(name string) string {
 	return value
 }
 
-func main() {
-	// Initialize logging.
-	if err := logging.Initialize(os.Stdout, logging.FmtLogfmt, logging.LevelDebug, nil); err != nil {
-		fmt.Fprintf(os.Stderr, "ERROR: Unable to initialize logging: %v\n", err)
-		os.Exit(1)
-	}
-
-	// Get server port from environment variable or use the default.
-	port := os.Getenv(GatewayPortEnvVar)
-	if port == "" {
-		port = "8080"
+// Return the server port that should be used or exit if it is malformed.
+func getPortOrExit() int {
+	portStr := os.Getenv(GatewayPortEnvVar)
+	if portStr == "" {
+		portStr = "8080"
 	}
-	nPort, err := strconv.Atoi(port)
+	port, err := strconv.Atoi(portStr)
 	if err != nil {
 		logger.Error("malformed environment variable",
 			"err", err,
 			"name", GatewayPortEnvVar,
 		)
 		os.Exit(1)
 	}
+	return port
+}
+
+// Print version information.
+func printVersionInfo() {
+	fmt.Printf("Software version: %s\n", common.SoftwareVersion)
+	fmt.Printf("Rosetta API version: %s\n", common.RosettaAPIVersion)
+	fmt.Printf("Go toolchain version: %s\n", common.ToolchainVersion)
+}
+
+func main() {
+	// Initialize logging.
+	if err := logging.Initialize(os.Stdout, logging.FmtLogfmt, logging.LevelDebug, nil); err != nil {
+		fmt.Fprintf(os.Stderr, "ERROR: Unable to initialize logging: %v\n", err)
+		os.Exit(1)
+	}
+
+	// Print version info if -version flag is passed.
+	flag.Parse()
+	if *versionFlag {
+		printVersionInfo()
+		return
+	}
+
+	// Get server port.
+	port := getPortOrExit()
 
 	var chainID string
 	var oasisClient oasis.Client
+	var err error
 
 	// Check if we should run in offline mode.
 	offlineMode := os.Getenv(OfflineModeEnvVar) != ""
@@ -197,8 +224,8 @@ func main() {
 	}
 
 	// Start the server.
-	logger.Info("Oasis Rosetta Gateway listening", "port", nPort)
-	err = http.ListenAndServe(fmt.Sprintf(":%d", nPort), router)
+	logger.Info("Oasis Rosetta Gateway listening", "port", port)
+	err = http.ListenAndServe(fmt.Sprintf(":%d", port), router)
 	if err != nil {
 		logger.Error("Oasis Rosetta Gateway server exited",
 			"err", err,

services/network.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/oasisprotocol/oasis-core/go/common/logging"
 
+	"github.com/oasisprotocol/oasis-core-rosetta-gateway/common"
 	"github.com/oasisprotocol/oasis-core-rosetta-gateway/oasis"
 )
 
@@ -132,7 +133,7 @@ func (s *networkAPIService) NetworkOptions(
 
 	return &types.NetworkOptionsResponse{
 		Version: &types.Version{
-			RosettaVersion: "1.4.0",
+			RosettaVersion: common.RosettaAPIVersion,
 			NodeVersion:    status.SoftwareVersion,
 		},
 		Allow: &types.Allow{