go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/config_service/internal/schema/schema.go (about)

     1  // Copyright 2023 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  // Package schema handles config schema lookup
    16  package schema
    17  
    18  import (
    19  	"context"
    20  	"fmt"
    21  	"net/http"
    22  	"strings"
    23  
    24  	"go.chromium.org/luci/common/logging"
    25  	cfgcommonpb "go.chromium.org/luci/common/proto/config"
    26  	"go.chromium.org/luci/server/router"
    27  
    28  	"go.chromium.org/luci/config_service/internal/common"
    29  )
    30  
    31  // InstallHandler installs handler for schema redirection.
    32  func InstallHandler(r *router.Router) {
    33  	r.GET("/schemas/*SchemaName", nil, func(c *router.Context) {
    34  		ctx := c.Request.Context()
    35  		schemaName := strings.Trim(c.Params.ByName("SchemaName"), "/")
    36  		switch url, err := lookupSchemaURL(ctx, schemaName); {
    37  		case err != nil:
    38  			logging.Errorf(ctx, "failed to find schema url for %q: %s", schemaName, err)
    39  			http.Error(c.Writer, fmt.Sprintf("failed to find corresponding schema url for %q", schemaName), http.StatusInternalServerError)
    40  		case url == "":
    41  			http.Error(c.Writer, fmt.Sprintf("%q has no corresponding schema url", schemaName), http.StatusNotFound)
    42  		default:
    43  			http.Redirect(c.Writer, c.Request, url, http.StatusFound)
    44  		}
    45  	})
    46  }
    47  
    48  func lookupSchemaURL(ctx context.Context, name string) (string, error) {
    49  	schemaCfg := &cfgcommonpb.SchemasCfg{}
    50  	if err := common.LoadSelfConfig(ctx, common.SchemaConfigFilePath, schemaCfg); err != nil {
    51  		return "", err
    52  	}
    53  	for _, schema := range schemaCfg.GetSchemas() {
    54  		if schema.GetName() == name {
    55  			return schema.Url, nil
    56  		}
    57  	}
    58  	return "", nil
    59  }