fix: Increasing inotify limit to 1048576 from the default 8192

[junaid-ali]

Links:

• https://linux.die.net/man/7/inotify
• https://github.com/guard/listen/wiki/Increasing-the-amount-of-inotify-watchers

Signed-off-by: Junaid Ali junaidali.yahya@gmail.com

Reason for Change:

Issue Fixed:

Requirements:

• uses conventional commit messages
• includes documentation
• adds unit tests
• tested upgrade from previous version

Notes:

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[junaid-ali]

/assign patricklang

[junaid-ali]

Backgroup for this PR: kubectl logs <pod-name> -f errors No space left on device. It appears the issue is due to inotify limit on worker nodes. Whenever more than ~15 pods are created on a node (Standard D16s v3 - 16 vcpus, 64 GiB memory), we start seeing this issue. Increasing the inotify limit from the default 8192 solves the issue.

I checked the limit on Ubuntu 18.04 and 16.04, where the limit is set to 1048576.

[mboersma]

/azp run pr-e2e

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[msftclas]

All CLA requirements met.

[junaid-ali]

/azp run pr-e2e

[azure-pipelines]

Commenter does not have sufficient privileges for PR 1801 in repo Azure/aks-engine

[junaid-ali]

@mboersma I have ran make build and make ensure-generated, pr-e2e should pass now. Also added a test for the change.

[mboersma]

/azp run pr-e2e

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[codecov]

Codecov Report

Merging #1801 into master will increase coverage by 0.24%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1801      +/-   ##
==========================================
+ Coverage   76.43%   76.67%   +0.24%     
==========================================
  Files         130      135       +5     
  Lines       19398    20542    +1144     
==========================================
+ Hits        14827    15751     +924     
- Misses       3774     3873      +99     
- Partials      797      918     +121

[junaid-ali]

@mboersma It looks like the net-config-validate.sh script is failing (please correct me if I'm wrong). I manually tested the test steps on my workstation and it seemed fine. Do you think I'm missing anything here for e2e tests?

[junaid-ali]

It looks like the updated /etc/sysctl.d/60-CIS.conf should be baked into VHD else it will use the old 60-CIS.conf which doesn't have my changes, so net-config-validate.sh will always fail. Please correct me if I'm wrong.
CC: @mboersma @jackfrancis

Ref: #999 (comment)

[CecileRobertMichon]

@junaid-ali you're correct. The fact that the k8s_non_vhd_deployment job passed confirms that E2E passes with your changes. In order to merge this change, we would need to comment out the net-config test for this change with a //TODO to re-enable when the next VHD is published (and open an issue on GitHub so we can track it on the backlog). cc @jackfrancis

[junaid-ali]

@CecileRobertMichon thanks for the update. I have commented the test case in this PR, and created an issue to re-enable it later.

[CecileRobertMichon]

/azp run pr-e2e

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[jackfrancis]

@palma21 @yangl900 @wenwu449 FYI, we will merge this pending AKS approval

[jackfrancis]

lgtm

[jackfrancis]

@yangl900 @wenwu449 ping for your thoughts on this change

[yangl900]

LGTM

[jackfrancis]

/lgtm

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