Allow additional CIDRs to be excluded from SNAT#520
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mogren merged 4 commits intoaws:masterfrom Jul 11, 2019
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Introduces a mechanism to provide an exclusion list of CIDRs that should not be SNATed. Adds an environment variable `AWS_VPC_K8S_CNI_EXCLUDE_SNAT_CIDRS` to provide a comma separated list of ipv4 CIDRs to exclude from SNAT. The value of this environment variable will only be use when `AWS_VPC_K8S_CNI_EXTERNALSNAT` is false. The SNAT exclusion CIDRs will be used to: - Generate `iptable` rules to prevent SNATing for packets directed to the excluded CIDRs - Generate `ip rule` entries to route packets directed to the excluded CIDRs through the pod's `eni`. These configuration is done both at the `cni` plugin level via the `rpc_handler`, and the runtime `network` api. Given that the list of excluded CIDRs may vary by configuration it was necessary to include a mechanism to clean up stale SNAT rules. If a CIDR is removed from the exclusion list, the corresponding `iptable` rule will be removed as well, and the chain will be adjusted. Connects aws#469 Co-authored-by: @rewiko Co-authored-by: @yorg1st
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Hi @mogren , do you think this PR could be looked at? |
mogren
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Nice work, thanks a lot for adding this.
Just a few small nitpicks to fix and I'd be happy to merge it.
`format` applies formatting to the project's go files. `check-format` checks that no files require formatting; if they do it will fail the command. It adds the `check-format` target to the travis build so that CI fails if files are not properly formatted.
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Looks great, thanks again!
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Thanks @mogren ! |
This was referenced Sep 18, 2019
This was referenced Sep 28, 2019
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Connects to #469
Introduces a mechanism to provide an exclusion list of CIDRs that should
not be SNATed.
Adds an environment variable
AWS_VPC_K8S_CNI_EXCLUDE_SNAT_CIDRStoprovide a comma separated list of ipv4 CIDRs to exclude from SNAT.
The value of this environment variable will only be use when
AWS_VPC_K8S_CNI_EXTERNALSNATis false.The SNAT exclusion CIDRs will be used to:
iptablerules to prevent SNATing for packets directed tothe excluded CIDRs
ip ruleentries to route packets directed to the excludedCIDRs through the pod's
eni. This configuration is done both at thecniplugin level via therpc_handler, and the runtimenetworkapi.Given that the list of excluded CIDRs may vary by configuration it was
necessary to include a mechanism to clean up stale SNAT rules. If a
CIDR is removed from the exclusion list, the corresponding
iptablerule will be removed as well, and the chain will be adjusted.
By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
Co-authored-by: @rewiko
Co-authored-by: @yorg1st