mirror of https://github.com/knative/caching.git
53 lines
1.6 KiB
Go
53 lines
1.6 KiB
Go
/*
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Copyright 2019 The Knative Authors
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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// spoof contains logic to make polling HTTP requests against an endpoint with optional host spoofing.
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package spoof
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import (
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"net"
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"strings"
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)
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func isTCPTimeout(e error) bool {
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err, ok := e.(net.Error)
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return err != nil && ok && err.Timeout()
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}
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func isDNSError(err error) bool {
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if err == nil {
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return false
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}
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// Checking by casting to url.Error and casting the nested error
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// seems to be not as robust as string check.
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msg := strings.ToLower(err.Error())
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// Example error message:
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// > Get http://this.url.does.not.exist: dial tcp: lookup this.url.does.not.exist on 127.0.0.1:53: no such host
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return strings.Contains(msg, "no such host") || strings.Contains(msg, ":53")
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}
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func isTCPConnectRefuse(err error) bool {
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// The alternative for the string check is:
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// errNo := (((err.(*url.Error)).Err.(*net.OpError)).Err.(*os.SyscallError).Err).(syscall.Errno)
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// if errNo == syscall.Errno(0x6f) {...}
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// But with assertions, of course.
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if err != nil && strings.Contains(err.Error(), "connect: connection refused") {
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return true
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}
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return false
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}
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