feature: kubefile CMD support ENV values with "${...}" and "$..." format

[LZiHaN]

🤖 Generated by Copilot at b065a77

Summary

🆕🛠️✅

This pull request adds new syntax options for variable expansion in the expansion package and the getGuestCmd function. It also updates the expand.go file and adds tests to the guest_test.go file to reflect the changes. The new syntaxes allow more flexibility and convenience for users who want to use variables in their cluster commands or mount images.

getGuestCmd tests
new syntax for variables
autumn of expansion

Walkthrough

• Rename constants and add new ones to support two variable expansion syntaxes: $() and ${} (link)
• Modify tryReadVariableName to use the renamed constants and handle the new syntaxes (link, link)
• Add test functions to check getGuestCmd with different variable expressions in pkg/guest/guest_test.go (link)

refer to #3853

[sealos-ci-robot]

🤖 Generated by lychee action

Summary

Status	Count
🔍 Total	932
✅ Successful	392
⏳ Timeouts	0
🔀 Redirected	0
👻 Excluded	539
❓ Unknown	0
🚫 Errors	0

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Full Github Actions output

[codecov]

Codecov Report

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[willzhang]

i have test it and it's work

# cat Kubefile 
FROM scratch
ENV VERSION=v1.0
CMD ["echo VERSION=${VERSION}"]

The result

root@kube001:~# sealos run registry.cn-shenzhen.aliyuncs.com/cnmirror/test:v1.0
2023-09-15T17:01:19 info start to install app in this cluster
2023-09-15T17:01:19 info Executing SyncStatusAndCheck Pipeline in InstallProcessor
2023-09-15T17:01:19 info Executing ConfirmOverrideApps Pipeline in InstallProcessor
2023-09-15T17:01:19 info are you sure to override these following apps? 
registry.cn-shenzhen.aliyuncs.com/cnmirror/test:v1.0
Yes [y/yes], No [n/no]: y
✔ Yes [y/yes], No [n/no]: y█
2023-09-15T17:01:21 info Executing pipeline MountRootfs in InstallProcessor.
2023-09-15T17:01:21 info Executing pipeline MirrorRegistry in InstallProcessor.
2023-09-15T17:01:21 info Executing UpgradeIfNeed Pipeline in InstallProcessor
VERSION=v1.0
2023-09-15T17:01:21 info succeeded install app in this cluster
2023-09-15T17:01:21 info no nodes that need to be scaled
2023-09-15T17:01:21 info 
      ___           ___           ___           ___       ___           ___
     /\  \         /\  \         /\  \         /\__\     /\  \         /\  \
    /::\  \       /::\  \       /::\  \       /:/  /    /::\  \       /::\  \
   /:/\ \  \     /:/\:\  \     /:/\:\  \     /:/  /    /:/\:\  \     /:/\ \  \
  _\:\~\ \  \   /::\~\:\  \   /::\~\:\  \   /:/  /    /:/  \:\  \   _\:\~\ \  \
 /\ \:\ \ \__\ /:/\:\ \:\__\ /:/\:\ \:\__\ /:/__/    /:/__/ \:\__\ /\ \:\ \ \__\
 \:\ \:\ \/__/ \:\~\:\ \/__/ \/__\:\/:/  / \:\  \    \:\  \ /:/  / \:\ \:\ \/__/
  \:\ \:\__\    \:\ \:\__\        \::/  /   \:\  \    \:\  /:/  /   \:\ \:\__\
   \:\/:/  /     \:\ \/__/        /:/  /     \:\  \    \:\/:/  /     \:\/:/  /
    \::/  /       \:\__\         /:/  /       \:\__\    \::/  /       \::/  /
     \/__/         \/__/         \/__/         \/__/     \/__/         \/__/

                  Website: https://www.sealos.io/
                  Address: github.com/labring/sealos
                  Version: untagged-0ed82702

root@kube001:~# 

[sealos-ci-robot]

/cherry-pick release-v4.4

[sealos-ci-robot]

🤖 says: cherry pick action finished successfully 🎉!
See: https://github.com/labring/sealos/actions/runs/6211427693