feat: add a simple version resolver api (#25)

* feat: add a simple version resolver api

* feat: simple rate limiter addition for the same

Author: barelyhuman

cmd/goblin-api/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bytes"
+	"encoding/json"
 	"errors"
 	"flag"
 	"fmt"
@@ -19,11 +20,42 @@ import (
 	"github.com/barelyhuman/goblin/resolver"
 	"github.com/barelyhuman/goblin/storage"
 	"github.com/joho/godotenv"
+	"go.uber.org/ratelimit"
 )
 
 var shTemplates *template.Template
 var serverURL string
 var storageClient storage.Storage
+var rateLimiter ratelimit.Limiter
+
+type ErrorJSON struct {
+	Success bool   `json:"success"`
+	Message string `json:"message"`
+}
+
+func (ej ErrorJSON) toJSONString() (string, error) {
+	marshaled, err := json.Marshal(ej)
+	if err != nil {
+		return "", err
+	}
+	return string(marshaled), nil
+}
+
+type VersionJSON struct {
+	Success         bool   `json:"success"`
+	Package         string `json:"package"`
+	Binary          string `json:"binary"`
+	OriginalVersion string `json:"originalVersion"`
+	Version         string `json:"version"`
+}
+
+func (ej VersionJSON) toJSONString() (string, error) {
+	marshaled, err := json.Marshal(ej)
+	if err != nil {
+		return "", err
+	}
+	return string(marshaled), nil
+}
 
 func HandleRequest(rw http.ResponseWriter, req *http.Request) {
 	path := req.URL.Path
@@ -41,6 +73,13 @@ func HandleRequest(rw http.ResponseWriter, req *http.Request) {
 		return
 	}
 
+	if strings.HasPrefix(path, "/version") {
+		log.Println("Resolving version")
+		rateLimiter.Take()
+		resolveVersionJSON(rw, req)
+		return
+	}
+
 	if strings.HasPrefix(path, "/binary") {
 		log.Print("handle binary")
 		fetchBinary(rw, req)
@@ -75,6 +114,9 @@ func main() {
 
 	flag.Parse()
 
+	// starting off with 250 since there's only one operation that's being rate limited
+	rateLimiter = ratelimit.New(250)
+
 	if _, err := os.Stat(*envFile); !errors.Is(err, os.ErrNotExist) {
 		err := godotenv.Load()
 		if err != nil {
@@ -225,6 +267,36 @@ func fetchInstallScript(rw http.ResponseWriter, req *http.Request) {
 	})
 }
 
+func resolveVersionJSON(rw http.ResponseWriter, req *http.Request) {
+	// only reply in JSON
+	rw.Header().Set("Content-Type", "application/json")
+
+	pkg := strings.TrimPrefix(req.URL.Path, "/version")
+	pkg, _, version, name := parsePackage(pkg)
+	v := &resolver.Resolver{
+		Pkg: pkg,
+	}
+	v.ParseVersion(version)
+	resolvedVersion, err := v.ResolveVersion()
+	if err != nil || len(resolvedVersion) == 0 {
+		errorJson, _ := ErrorJSON{Success: false, Message: "Failed to resolve version:" + version}.toJSONString()
+		rw.Write([]byte(errorJson))
+		return
+	}
+
+	responseJson, _ := VersionJSON{
+		Success:         true,
+		Package:         pkg,
+		Binary:          name,
+		OriginalVersion: version,
+		Version:         resolvedVersion,
+	}.toJSONString()
+
+	rw.Write([]byte(responseJson))
+	return
+
+}
+
 func fetchBinary(rw http.ResponseWriter, req *http.Request) {
 	pkg := strings.TrimPrefix(req.URL.Path, "/binary/")
 

go.mod

@@ -9,11 +9,13 @@ require (
 	github.com/joho/godotenv v1.5.1
 	github.com/minio/minio-go v6.0.14+incompatible
 	github.com/tj/go-semver v1.0.0
+	go.uber.org/ratelimit v0.3.1
 	golang.org/x/oauth2 v0.16.0
 )
 
 require (
 	github.com/ProtonMail/go-crypto v1.0.0 // indirect
+	github.com/benbjohnson/clock v1.3.0 // indirect
 	github.com/cloudflare/circl v1.3.7 // indirect
 	github.com/go-ini/ini v1.67.0 // indirect
 	github.com/golang/protobuf v1.5.3 // indirect

go.sum

@@ -4,6 +4,8 @@ github.com/ProtonMail/go-crypto v1.0.0 h1:LRuvITjQWX+WIfr930YHG2HNfjR1uOfyf5vE0k
 github.com/ProtonMail/go-crypto v1.0.0/go.mod h1:EjAoLdwvbIOoOQr3ihjnSoLZRtE8azugULFRteWMNc0=
 github.com/barelyhuman/go v0.2.2 h1:Lpk1XrlP40F3II8BibVzViZUOJ1GgDdzXUBb8ENwb0U=
 github.com/barelyhuman/go v0.2.2/go.mod h1:hox2iDYZAarjpS7jKQeYIi2F+qMA8KLMtCws++L2sSY=
+github.com/benbjohnson/clock v1.3.0 h1:ip6w0uFQkncKQ979AypyG0ER7mqUSBdKLOgAle/AT8A=
+github.com/benbjohnson/clock v1.3.0/go.mod h1:J11/hYXuz8f4ySSvYwY0FKfm+ezbsZBKZxNJlLklBHA=
 github.com/bwesterb/go-ristretto v1.2.3/go.mod h1:fUIoIZaG73pV5biE2Blr2xEzDoMj7NFEuV9ekS419A0=
 github.com/cloudflare/circl v1.3.3/go.mod h1:5XYMA4rFBvNIrhs50XuiBJ15vF2pZn4nnUKZrLbUZFA=
 github.com/cloudflare/circl v1.3.7 h1:qlCDlTPz2n9fu58M0Nh1J/JzcFpfgkFHHX3O35r5vcU=
@@ -45,6 +47,9 @@ github.com/tj/assert v0.0.0-20190920132354-ee03d75cd160/go.mod h1:mZ9/Rh9oLWpLLD
 github.com/tj/go-semver v1.0.0 h1:vpn6Jmn6Hi3QSmrP1PzYcqScop9IZiGCVOSn18wzu8w=
 github.com/tj/go-semver v1.0.0/go.mod h1:YZuwVc013rh7KDV0k6tPbWrFeEHBHcp8amfJL+nHzjM=
 github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
+go.uber.org/atomic v1.7.0 h1:ADUqmZGgLDDfbSL9ZmPxKTybcoEYHgpYfELNoN+7hsw=
+go.uber.org/ratelimit v0.3.1 h1:K4qVE+byfv/B3tC+4nYWP7v/6SimcO7HzHekoMNBma0=
+go.uber.org/ratelimit v0.3.1/go.mod h1:6euWsTB6U/Nb3X++xEUXA8ciPJvr19Q/0h1+oDcJhRk=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
 golang.org/x/crypto v0.3.1-0.20221117191849-2c476679df9a/go.mod h1:hebNnKkNXi2UzZN1eVRvBB7co0a+JxK6XbPiWVs/3J4=