Move to setting version info explicitly in linker flags

We don't have go built-in VCS information in a nix build because the git
repository isn't present. After struggling to build an overlay that
would provide it, I decided this path is easier of just injecting in the
data that we need.

Issue: #5

api/api.go

@@ -322,7 +322,7 @@ type tegolaURLs struct {
 }
 
 func getRoot(ctx context.Context, r *http.Request, q resource.QueryParams) (*about, *nhttp.ErrorWithStatus) {
-	v := version.Get()
+	v := GetVersionInfo()
 	return &about{
 		Environment: config.Environment,
 		SentryDSN:   config.SentryDSNFrontend,

api/event.go

@@ -11,7 +11,6 @@ import (
 	"source.gleipnir.technology/Gleipnir/nidus-sync/lint"
 	"source.gleipnir.technology/Gleipnir/nidus-sync/platform"
 	"source.gleipnir.technology/Gleipnir/nidus-sync/platform/event"
-	"source.gleipnir.technology/Gleipnir/nidus-sync/version"
 )
 
 var connectionsSSE map[*ConnectionSSE]bool = make(map[*ConnectionSSE]bool, 0)
@@ -41,7 +40,7 @@ type Status struct {
 
 func (c *ConnectionSSE) SendEvent(w http.ResponseWriter, m platform.Event) error {
 	if m.Type == event.EventTypeShutdown {
-		v := version.Get()
+		v := GetVersionInfo()
 		return send(w, Status{
 			BuildTime:  v.BuildTime,
 			IsModified: v.IsModified,
@@ -121,7 +120,7 @@ func streamEvents(w http.ResponseWriter, r *http.Request, u platform.User) {
 	log.Debug().Int32("org", u.Organization.ID).Int("user", u.ID).Str("id", uid.String()).Msg("connected SSE client")
 
 	// Send an initial connected event
-	v := version.Get()
+	v := GetVersionInfo()
 	status := Status{
 		BuildTime:  v.BuildTime,
 		IsModified: v.IsModified,

api/version.go

@@ -0,0 +1,16 @@
+package api
+
+import (
+	"source.gleipnir.technology/Gleipnir/nidus-sync/version"
+)
+
+var (
+	versionInfo version.VersionInfo
+)
+
+func GetVersionInfo() version.VersionInfo {
+	return versionInfo
+}
+func SetVersionInfo(v version.VersionInfo) {
+	versionInfo = v
+}