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a320d70614
In some containers, /etc/resolv.conf is a bind-mount from outside the container. This prevents renaming to or from /etc/resolv.conf, because it's on a different filesystem from linux's perspective. It also prevents removing /etc/resolv.conf, because doing so would break the bind-mount. If we find ourselves within this environment, fall back to using copy+delete when renaming to /etc/resolv.conf, and copy+truncate when renaming from /etc/resolv.conf. Fixes #3000 Co-authored-by: Denton Gentry <dgentry@tailscale.com> Signed-off-by: David Anderson <danderson@tailscale.com>
41 lines
981 B
Go
41 lines
981 B
Go
// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package dns
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import (
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"fmt"
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"io/ioutil"
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"os"
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"tailscale.com/types/logger"
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)
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func NewOSConfigurator(logf logger.Logf, _ string) (OSConfigurator, error) {
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bs, err := ioutil.ReadFile("/etc/resolv.conf")
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if os.IsNotExist(err) {
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return newDirectManager(logf), nil
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}
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if err != nil {
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return nil, fmt.Errorf("reading /etc/resolv.conf: %w", err)
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}
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switch resolvOwner(bs) {
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case "resolvconf":
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switch resolvconfStyle() {
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case "":
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return newDirectManager(logf), nil
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case "debian":
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return newDebianResolvconfManager(logf)
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case "openresolv":
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return newOpenresolvManager()
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default:
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logf("[unexpected] got unknown flavor of resolvconf %q, falling back to direct manager", resolvconfStyle())
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return newDirectManager(logf), nil
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}
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default:
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return newDirectManager(logf), nil
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}
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}
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