httptransport: update discovery endpoint

This change switches to using the internal `apiError` function and
uses the "embed" package instead of generated code.

Signed-off-by: Hank Donnay <hdonnay@redhat.com>

httptransport/discoveryhandler.go

@@ -1,48 +1,42 @@
 package httptransport
 
 import (
+	"bytes"
+	_ "embed" // for json and etag
 	"errors"
 	"io"
 	"net/http"
-	"strings"
-
-	je "github.com/quay/claircore/pkg/jsonerr"
 )
 
 //go:generate go run openapigen.go
 
+var (
+	//go:embed openapi.json
+	openapiJSON []byte
+	//go:embed openapi.etag
+	openapiJSONEtag string
+)
+
 // DiscoveryHandler serves the embedded OpenAPI spec.
 func DiscoveryHandler() http.Handler {
 	allow := []string{`application/json`, `application/vnd.oai.openapi+json`}
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		if r.Method != http.MethodGet {
-			resp := &je.Response{
-				Code:    "method-not-allowed",
-				Message: "endpoint only allows GET",
-			}
-			je.Error(w, resp, http.StatusMethodNotAllowed)
+			apiError(w, http.StatusMethodNotAllowed, "endpoint only allows GET")
 			return
 		}
 		switch err := pickContentType(w, r, allow); {
 		case errors.Is(err, nil):
 		case errors.Is(err, ErrMediaType):
-			resp := &je.Response{
-				Code:    "unknown accept type",
-				Message: "endpoint only allows " + strings.Join(allow, " or "),
-			}
-			je.Error(w, resp, http.StatusUnsupportedMediaType)
+			apiError(w, http.StatusUnsupportedMediaType, "unable to negotiate common media type for %v", allow)
 			return
 		default:
-			resp := &je.Response{
-				Code:    "unknown other error",
-				Message: err.Error(),
-			}
-			je.Error(w, resp, http.StatusBadRequest)
+			apiError(w, http.StatusInternalServerError, "unexpected error: %v", err)
 			return
 		}
-		w.Header().Set("etag", _openapiJSONEtag)
+		w.Header().Set("etag", openapiJSONEtag)
 		var err error
 		defer writerError(w, &err)()
-		_, err = io.WriteString(w, _openapiJSON)
+		_, err = io.Copy(w, bytes.NewReader(openapiJSON))
 	})
 }

httptransport/discoveryhandler_test.go

@@ -2,13 +2,13 @@ package httptransport
 
 import (
 	"bytes"
-	"context"
 	"encoding/json"
 	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
 	"os"
 	"os/exec"
+	"path/filepath"
 	"strings"
 	"testing"
 
@@ -64,26 +64,32 @@ func TestDiscoveryFailure(t *testing.T) {
 }
 
 func TestEmbedding(t *testing.T) {
-	ctx, done := context.WithCancel(context.Background())
-	defer done()
-
-	var gend, written bytes.Buffer
-	cmd := exec.CommandContext(ctx, "go", "run", "openapigen.go", "-out", "/dev/stdout")
-	cmd.Stdout = &gend
+	d := t.TempDir()
+	var buf bytes.Buffer
+	cmd := exec.Command("go", "run", "openapigen.go", "-in", "../openapi.yaml", "-out", d)
+	cmd.Stdout = &buf
+	cmd.Stderr = &buf
+	t.Log(cmd.Args)
 	if err := cmd.Run(); err != nil {
-		t.Fatal(err)
-	}
-	f, err := os.Open("discoveryhandler_gen.go")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer f.Close()
-	if _, err := written.ReadFrom(f); err != nil {
-		t.Fatal(err)
+		t.Error(err)
+		t.Error(buf.String())
 	}
 
-	if got, want := gend.String(), written.String(); !cmp.Equal(got, want) {
-		t.Error(cmp.Diff(got, want, cmpopts.AcyclicTransformer("normalizeWhitespace", func(s string) []string { return strings.Split(s, "\n") })))
-		t.Log("\n\tYou probably edited the openapi.yaml and forgot to run `go generate` here.")
+	for _, n := range []string{
+		"openapi.json", "openapi.etag"} {
+		new, err := os.ReadFile(filepath.Join(d, n))
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+		old, err := os.ReadFile(n)
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+		if got, want := string(new), string(old); !cmp.Equal(got, want) {
+			t.Error(cmp.Diff(got, want, cmpopts.AcyclicTransformer("normalizeWhitespace", func(s string) []string { return strings.Split(s, "\n") })))
+			t.Log("\n\tYou probably edited the openapi.yaml and forgot to run `go generate` here.")
+		}
 	}
 }

httptransport/openapi.etag

@@ -0,0 +1 @@
+"eee376f6eb502c8b9e413b131b81d700d185927f607474fdf80a237a1cc5294d"

httptransport/openapigen.go

@@ -1,41 +1,27 @@
+//go:build tools
 // +build tools
 
 // Openapigen is a script to take the OpenAPI YAML file, turn it into a JSON
-// document, and embed it into a source file for easy deployment.
+// document, and write out files for use with the "embed" package.
 package main
 
 import (
+	"bytes"
 	"crypto/sha256"
 	"encoding/json"
 	"flag"
 	"fmt"
-	"go/ast"
-	"go/format"
-	"go/parser"
-	"go/token"
+	"io"
 	"log"
 	"os"
 	"path/filepath"
-	"strings"
 
 	"gopkg.in/yaml.v3"
 )
 
-const template = `
-// Code generated by openapigen.go DO NOT EDIT.
-
-package main
-
-const (
-	_openapiJSON     = ""
-	_openapiJSONEtag = ""
-)
-`
-
 func main() {
 	inFile := flag.String("in", "../openapi.yaml", "input YAML file")
-	outFile := flag.String("out", "discoveryhandler_gen.go", "output go file")
-	pkgName := flag.String("name", "httptransport", "package name for generated file")
+	outDir := flag.String("out", ".", "output directory")
 	flag.Parse()
 
 	inF, err := os.Open(*inFile)
@@ -56,40 +42,20 @@ func main() {
 	}
 	ck := sha256.Sum256(embed)
 
-	fs := token.NewFileSet()
-	file, err := parser.ParseFile(fs, filepath.Base(*outFile), strings.NewReader(template), parser.ParseComments)
+	outF, err := os.OpenFile(filepath.Join(*outDir, `openapi.json`), os.O_WRONLY|os.O_TRUNC|os.O_CREATE, 0644)
 	if err != nil {
 		log.Fatal(err)
 	}
-	ast.Inspect(file, func(n ast.Node) bool {
-		switch x := n.(type) {
-		case *ast.File:
-			x.Name = ast.NewIdent(*pkgName)
-		case *ast.ValueSpec:
-			id := x.Names[0]
-			var v string
-			switch id.Name {
-			case "_openapiJSON":
-				v = fmt.Sprintf("%#q", string(embed))
-			case "_openapiJSONEtag":
-				v = fmt.Sprintf("`\"%x\"`", ck)
-			default:
-				return true
-			}
-			x.Values = []ast.Expr{&ast.BasicLit{
-				Kind:  token.STRING,
-				Value: v,
-			}}
-		}
-		return true
-	})
-
-	outF, err := os.OpenFile(*outFile, os.O_WRONLY|os.O_TRUNC|os.O_CREATE, 0644)
+	defer outF.Close()
+	if _, err := io.Copy(outF, bytes.NewReader(embed)); err != nil {
+		log.Fatal(err)
+	}
+	outF, err = os.OpenFile(filepath.Join(*outDir, `openapi.etag`), os.O_WRONLY|os.O_TRUNC|os.O_CREATE, 0644)
 	if err != nil {
 		log.Fatal(err)
 	}
 	defer outF.Close()
-	if err := format.Node(outF, fs, file); err != nil {
+	if _, err := fmt.Fprintf(outF, `"%x"`, ck); err != nil {
 		log.Fatal(err)
 	}
 }