Start work on lua based plugin system

plugins/init.go

@@ -0,0 +1,62 @@
+package plugins
+
+import (
+	"fmt"
+
+	"git.mstar.dev/mstar/goutils/other"
+	"github.com/PeerDB-io/gluabit32"
+	"github.com/cjoudrey/gluahttp"
+	"github.com/cosmotek/loguago"
+	"github.com/kohkimakimoto/gluatemplate"
+	gluajson "github.com/layeh/gopher-json"
+	"github.com/rs/zerolog/log"
+	"github.com/yuin/gluare"
+	lua "github.com/yuin/gopher-lua"
+
+	webshared "git.mstar.dev/mstar/linstrom/web/shared"
+)
+
+// "github.com/CuberL/glua-async" // For async support, see module readme for how to
+// Use "github.com/layeh/gopher-luar" for implementing interface
+
+// Create a new "blank" lua state for future use.
+// Each created state has to be properly closed.
+// A "blank" state has the base libraries preloaded and is technically ready to use.
+// Plugin specific functions and data is not yet included
+func NewBlankState() (*lua.LState, error) {
+	l := lua.NewState()
+	for _, pair := range []struct {
+		n string
+		f lua.LGFunction
+	}{
+		{lua.LoadLibName, lua.OpenPackage}, // Must always be first
+		{lua.BaseLibName, lua.OpenBase},
+		{lua.TabLibName, lua.OpenTable},
+		// {lua.IoLibName, lua.OpenIo},
+		{lua.OsLibName, lua.OpenOs},
+		{lua.StringLibName, lua.OpenString},
+		{lua.MathLibName, lua.OpenMath},
+		// {lua.DebugLibName, lua.OpenDebug},
+		{lua.ChannelLibName, lua.OpenChannel},
+		{lua.CoroutineLibName, lua.OpenCoroutine},
+		{"bit32", gluabit32.Loader},
+		{"json", gluajson.Loader},
+		{"log", loguago.NewLogger(log.Logger).Loader},                     // TODO: Decide if used logger should be passed in via context
+		{"http", gluahttp.NewHttpModule(&webshared.RequestClient).Loader}, // TODO: Modify this to support signing
+		{"re", gluare.Loader},
+		{"texttemplate", gluatemplate.Loader}, // TODO: Copy this lib, but modify to use html/template instead
+	} {
+		if err := l.CallByParam(lua.P{
+			Fn:      l.NewFunction(pair.f),
+			NRet:    0,
+			Protect: true,
+		}, lua.LString(pair.n)); err != nil {
+			return nil, other.Error(
+				"plugins",
+				fmt.Sprintf("Failed to preload lua library %q into state", pair.n),
+				err,
+			)
+		}
+	}
+	return l, nil
+}