revise failover scenario

[zhzhuang-zju]

revise failover scenario

/hold for #11

test link: https://killercoda.com/zhzhuang-zju/scenario/karmada-Failover-example

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[gemini-code-assist]

Summary of Changes

Hello @zhzhuang-zju, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request refines the Karmada failover scenario examples, ensuring proper setup and clearer demonstration of multi-cluster failover capabilities. It integrates necessary SSH key management for inter-cluster communication and explicitly enables the Failover feature gate along with eviction mechanisms in the Karmada initialization process. The changes also enhance the user experience by providing more descriptive guidance and robust verification steps within the example documentation.

Highlights

• SSH known_hosts Initialization: Added ssh-keyscan commands to foreground.sh scripts across karmada-CLI-installtion-example, karmada-Failover-example, karmada-HA-workload-example1, and karmada-HA-workload-example2 to properly initialize known_hosts for secure SSH connections between member and host clusters.
• Karmada Failover Feature Activation: Modified the karmadactl init command in karmada-Failover-example/foreground.sh to explicitly enable the Failover feature gate and the enable-no-execute-taint-eviction feature, which are crucial for simulating failover scenarios.
• Enhanced Failover Example Documentation: Updated karmada-Failover-example/index.json and karmada-Failover-example/intro.md to provide clearer descriptions and more detailed explanations of the multi-cluster failover scenario, including a link to official documentation.
• Improved Failover Scenario Verification: Revised karmada-Failover-example/step2/text.md, karmada-Failover-example/step3/verify.sh, and karmada-Failover-example/step4/text.md to include more precise instructions for checking pod distribution, a script to verify taint application, and a detailed explanation of pod eviction and rescheduling during failover.

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[zhzhuang-zju]

Please take a look @XiShanYongYe-Chang

[gemini-code-assist]

Code Review

This pull request revises the Karmada failover scenario. My review has identified a critical issue with command-line arguments that would prevent the failover feature from enabling correctly. I have also provided suggestions to improve the robustness of a verification script, pointed out a recurring security weakness in the use of ssh-keyscan across several example scripts, and corrected a minor typo. Overall, the changes improve the failover example, but the identified issues should be addressed to ensure correctness and security best practices.

[XiShanYongYe-Chang]

Thanks @zhzhuang-zju
Let me make a test.

[XiShanYongYe-Chang]

test link: https://killercoda.com/zhzhuang-zju/scenario/karmada-Failover-example

It test well, thanks~

[zhzhuang-zju]

/hold cancel

[zhzhuang-zju]

cc @XiShanYongYe-Chang @RainbowMango

[XiShanYongYe-Chang]

Hi @zhzhuang-zju, compared to previous submissions, are there any adjustments to the demonstration behavior in the example?

[zhzhuang-zju]

Hi @zhzhuang-zju, compared to previous submissions, are there any adjustments to the demonstration behavior in the example?

No, there were just some rebasing operations.