1. docker
  2. Commit 5fb7f9b29e9a85f36d02c4ecec6c04498fdb4315
Browse code

Suppress "IPv4 forwarding" warning for --net=host

Containers using the host network stack (--net=host)
are not affected by "ip-forwarding" being disabled,
so there's not need to show a warning.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Sebastiaan van Stijn authored on 2016/05/19 03:10:31
Showing 2 changed files
daemon/daemon_unix.go
History View file @ 5fb7f9b
... ... 
@@ -488,7 +488,9 @@ func verifyPlatformContainerSettings(daemon *Daemon, hostConfig *containertypes.
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 	if hostConfig.OomScoreAdj < -1000 || hostConfig.OomScoreAdj > 1000 {
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 		return warnings, fmt.Errorf("Invalid value %d, range for oom score adj is [-1000, 1000]", hostConfig.OomScoreAdj)
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 	}
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-	if sysInfo.IPv4ForwardingDisabled {
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+
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+	// ip-forwarding does not affect container with '--net=host'
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+	if sysInfo.IPv4ForwardingDisabled && !hostConfig.NetworkMode.IsHost() {
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 		warnings = append(warnings, "IPv4 forwarding is disabled. Networking will not work.")
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 		logrus.Warnf("IPv4 forwarding is disabled. Networking will not work")
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 	}
docs/userguide/networking/default_network/container-communication.md
History View file @ 5fb7f9b
... ... 
@@ -37,6 +37,9 @@ or to turn it on manually:
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   net.ipv4.conf.all.forwarding = 1
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 ```
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+> **Note**: this setting does not affect containers that use the host
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+> network stack (`--net=host`).
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+
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 Many using Docker will want `ip_forward` to be on, to at least make
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 communication _possible_ between containers and the wider world. May also be
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 needed for inter-container communication if you are in a multiple bridge setup.