[GitHub] [trafficcontrol] rob05c commented on a change in pull request #3360: Cache Config Parser

[GitBox <gi...@apache.org>]

rob05c commented on a change in pull request #3360: Cache Config Parser
URL: https://github.com/apache/trafficcontrol/pull/3360#discussion_r262680077
 
 

 ##########
 File path: traffic_ops/testing/api/v14/config/cache_config/cache_config.go
 ##########
 @@ -0,0 +1,265 @@
+/*
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package cache_config
+
+import (
+	"regexp"
+	"strings"
+
+	. "github.com/apache/trafficcontrol/traffic_ops/testing/api/v14/config"
+	"github.com/apache/trafficcontrol/traffic_ops/traffic_ops_golang/test"
+	"github.com/go-ozzo/ozzo-validation/is"
+)
+
+// ParseCacheConfig takes a string presumed to be an ATS cache.config and validates
+// it is syntatically correct.
+//
+// The general format of a cache config is three types of labels separated by spaces:
+//
+//  primary_destination=value secondary_specifier=value action=value
+//
+// For a full description of how to format a cache config, refer to the ATS documentation
+// for the cache config:
+// https://docs.trafficserver.apache.org/en/latest/admin-guide/files/cache.config.en.html
+//
+func ParseCacheConfig(config string) test.Error {
+	lines := strings.Split(config, "\n")
+
+	if len(lines) == 1 {
+		return parseConfigRule(lines[0])
+	}
+
+	for i, ln := range lines {
+		err := parseConfigRule(ln)
+		if err != nil {
+			return err.Prepend("error on line %d: ", i+1)
+		}
+	}
+
+	return nil
+}
+
+func parsePrimaryDestinations(lhs string, rhs string) test.Error {
+
+	switch lhs {
+	case "dest_domain":
+		// dest_host is an alias for dest_domain
+		fallthrough
+	case "dest_host":
+		if err := is.Host.Validate(rhs); err != nil {
+			return ErrorContext.NewError(InvalidHost, `"%s" %v`, rhs, err)
+		}
+	case "dest_ip":
+		if err := is.IP.Validate(rhs); err != nil {
+			return ErrorContext.NewError(InvalidIP, `"%s" %v`, rhs, err)
+		}
+	case "host_regex":
+		fallthrough
+	case "url_regex":
+		// only makes sure the regex compiles, not that the regex generates anything valid
+		if _, err := regexp.Compile(rhs); err != nil {
+			return ErrorContext.NewError(InvalidRegex, "%v", err)
+		}
+	default:
+		return ErrorContext.NewError(InvalidLabel)
+	}
+
+	return nil
+}
+
+func parseSecondarySpecifiers(lhs string, rhs string) test.Error {
+
+	switch lhs {
+	case "port":
+		if err := is.Port.Validate(rhs); err != nil {
+			return ErrorContext.AddErrorCode(InvalidPort, err)
+		}
+	case "scheme":
+		if rhs != "http" && rhs != "https" {
+			return ErrorContext.NewError(InvalidHTTPScheme)
+		}
+	case "prefix":
+		// idk what validation to do on this
+		// does a path prefix contain '/' at the start of it?
+		// ignore..
+		//	Same cross platform problem as below?
+	case "suffix":
+		// examples: gif jpeg
+		// pure syntax: xxx.1 is a valid file name
+		//	I doubt there is anything in a validation package for this.
+		//	Even if there was, it would be silly since different platforms
+		//	have difference specifications for file suffixes.
+	case "method":
+		// assuming all methods are valid
+		// see RFC 2616-9 for list of all methods
+		// PURGE and PUSH are specific to ATS
+		switch rhs {
 
 Review comment:
   I'm not sure if methods in the ATS config are case-insensitive. But they're _not_ in the RFC, and they're defined to be uppercase. So, this should either call `rhs = strings.ToLower(rhs)`, or the methods below changed to uppercase.
   
   If the latter, they can use the `net/http` constants, `case http.MethodGet:` etc.

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