Initial Swagger compatibility proposal

generate/main.go

@@ -0,0 +1,205 @@
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+	"os/exec"
+	"path"
+	"regexp"
+	"strings"
+)
+
+// ServerVersion : the version from the upstream repository
+var ServerVersion = getDefaultVersion()
+
+// GrafeasRepository : the repository of the Grafeas server to use for downloading Swagger files
+var GrafeasRepository = "https://github.com/grafeas/grafeas"
+
+// Reference : the commit, branch, or tag to use for downloading Swagger files from the defined Grafeas repo
+var Reference = "master"
+
+// APIVersion : the version of the Grafeas API per the Google Cloud scheme - https://github.com/grafeas/grafeas/blob/master/docs/versioning.md#api
+var APIVersion = "v1beta1"
+
+// SwaggerCodegenVersion : the version of the Swagger CodeGen CLI to download
+var SwaggerCodegenVersion = "2.4.5"
+
+// MergedClient : whether to keep the generated Swagger clients separate or to merge the paths
+// TODO: implement function that merges the paths of each Swagger spec into one file before running codegen
+var MergedClient = false
+
+// trimVersionTag : remove the "v" prefix from the version tag string
+func trimVersionTag(tag string) string {
+	if strings.HasPrefix(tag, "v") {
+		return strings.TrimPrefix(tag, "v")
+	}
+	return tag
+}
+
+func getDefaultVersion() string {
+	version := os.Getenv("VERSION")
+	if version == "" {
+		tag := getMostRecentTag()
+		trimmedVersion := trimVersionTag(tag)
+		version = trimmedVersion
+	}
+	return version
+}
+
+func getMostRecentTag() string {
+	tagsBytes, _ := get("https://api.github.com/repos/grafeas/grafeas/tags")
+	var tags []map[string]interface{}
+	json.Unmarshal(tagsBytes, &tags)
+	return tags[0]["name"].(string)
+}
+
+func swaggerCompatibility(jsonInput string) string {
+	re := regexp.MustCompile(`\/{.*(=.*)}`)
+	jsonOutput := re.ReplaceAllStringFunc(jsonInput, func(substringMatch string) string {
+		return strings.Split(substringMatch, "=")[0] + "}"
+	})
+	return jsonOutput
+}
+
+func get(url string) ([]byte, error) {
+	var responseData []byte
+	resp, err := http.Get(url)
+	if err != nil {
+		return responseData, err
+	}
+	defer resp.Body.Close()
+
+	responseData, err = ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return responseData, err
+	}
+	return responseData, err
+}
+
+func downloadCompatibleSwaggerSpec(url string, filename string) error {
+	if filename == "" {
+		filename = path.Base(url)
+	}
+	responseBytes, err := get(url)
+	if err != nil {
+		return err
+	}
+
+	swaggerString := swaggerCompatibility(string(responseBytes))
+
+	f, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	responseReader := bytes.NewReader([]byte(swaggerString))
+
+	_, err = io.Copy(f, responseReader)
+	return err
+}
+
+func downloadFile(url string, filename string) error {
+	if filename == "" {
+		filename = path.Base(url)
+	}
+	responseBytes, err := get(url)
+	if err != nil {
+		return err
+	}
+
+	f, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	responseReader := bytes.NewReader(responseBytes)
+
+	_, err = io.Copy(f, responseReader)
+	return err
+}
+
+type swaggerCodegenConfig struct {
+	language        string
+	inputSpec       string
+	outputDirectory string
+	configFile      string
+	jar             string
+}
+
+func stringOrDefault(currentValue string, defaultValue string) string {
+	if currentValue == "" {
+		return defaultValue
+	}
+	return currentValue
+}
+
+func (c *swaggerCodegenConfig) generate() {
+	c.language = stringOrDefault(c.language, "go")
+	c.jar = stringOrDefault(c.jar, "./swagger-codegen-cli.jar")
+	c.configFile = stringOrDefault(c.configFile, "./config.go.json")
+	c.outputDirectory = stringOrDefault(c.outputDirectory, ServerVersion)
+	args := []string{"-jar", c.jar, "generate", "-i", c.inputSpec, "-l", c.language, "-o", c.outputDirectory, "-c", c.configFile}
+	log.Println("[CMD] java " + strings.Join(args, " "))
+	cmd := exec.Command("java", args...)
+
+	stderr, _ := cmd.StderrPipe()
+	cmd.Start()
+
+	scanner := bufio.NewScanner(stderr)
+	scanner.Split(bufio.ScanLines)
+	for scanner.Scan() {
+		m := scanner.Text()
+		fmt.Println(m)
+	}
+	cmd.Wait()
+}
+
+func downloadSwaggerCodegenCli(version string) {
+	downloadURL := fmt.Sprintf("https://repo1.maven.org/maven2/io/swagger/swagger-codegen-cli/%s/swagger-codegen-cli-%s.jar", version, version)
+	downloadFile(downloadURL, "swagger-codegen-cli.jar")
+}
+
+func getSwaggerNames() []string {
+	return []string{"grafeas.swagger.json", "project.swagger.json"}
+}
+
+func swaggerGenerate(mergedClient bool) {
+	swaggerSpecNames := getSwaggerNames()
+	for _, swaggerSpecName := range swaggerSpecNames {
+		swaggerSpecURL := strings.Join([]string{GrafeasRepository, "/raw/", Reference, "/proto/", APIVersion, "/swagger/", swaggerSpecName}, "")
+		log.Printf("[DOWNLOAD] %s\n", swaggerSpecURL)
+		downloadCompatibleSwaggerSpec(swaggerSpecURL, "")
+		fileBasename := strings.Split(swaggerSpecName, ".")[0]
+		outputDirectory := strings.Join([]string{ServerVersion, fileBasename}, "/")
+		if fileBasename == "grafeas" && !mergedClient {
+			outputDirectory = ServerVersion
+		}
+		swaggerCodeGen := swaggerCodegenConfig{
+			inputSpec:       swaggerSpecName,
+			outputDirectory: outputDirectory,
+		}
+		swaggerCodeGen.generate()
+	}
+}
+
+func main() {
+	log.Printf(
+		`
+
+Grafeas Repository: 	 %s
+Reference:		 %s
+Server Version:     	 %s
+API Version:    	 %s
+Swagger Codegen Version: %s
+
+`, GrafeasRepository, Reference, ServerVersion, APIVersion, SwaggerCodegenVersion)
+	downloadSwaggerCodegenCli(SwaggerCodegenVersion)
+	swaggerGenerate(MergedClient)
+}

generate_client.go

@@ -1,8 +1,6 @@
 // Downloads v1beta1 grafeas.swagger.json, swagger-codegen CLI tool,
 // and generates Go client library from the downloaded Swagger spec.
 
-//go:generate wget https://github.com/grafeas/grafeas/raw/master/proto/v1beta1/swagger/grafeas.swagger.json
-//go:generate wget https://repo1.maven.org/maven2/io/swagger/swagger-codegen-cli/2.4.5/swagger-codegen-cli-2.4.5.jar -O swagger-codegen-cli.jar
-//go:generate java -jar ./swagger-codegen-cli.jar generate -i ./grafeas.swagger.json -l go -o 0.1.0 -c ./config.go.json
+//go:generate go run generate/main.go
 
 package generate_client