feat(cache): generate a shell-format runtime config alongside runtime.json

[btxu-db]

Ⅰ. Describe what this PR does

Phase 1 of #6176: generate runtime.sh into the runtime ConfigMap alongside runtime.json, so that a cache system without a FUSE client (Mooncake is the motivating case) can source its runtime configuration instead of parsing JSON.

generateRuntimeConfigData now returns both keys, built from the same CacheRuntimeConfig, so the two files cannot drift apart. The script flattens the config into shell exports following the naming convention in #6176:

export RUNTIME_TARGETPATH='/runtime-mnt/cache/default/demo'
export MOUNTS_COUNT='1'
export MOUNT_0_NAME='mc'
export MASTER_ENABLED='true'
export MASTER_NAME='demo-master'
export MASTER_OPTIONS='{"k":"v"}'
export WORKER_TIEREDSTORE_LEVEL_0_QUOTAS_COUNT='1'
export WORKER_TIEREDSTORE_LEVEL_0_QUOTA_0='4Gi'
export CLIENT_ENABLED='false'
...

A few choices worth calling out, since some differ from the example in the issue:

• Single quotes, not double. The example in the issue uses export KEY="VALUE". Values here are single-quoted with '\'' escaping, so the shell takes them literally: a $, a backtick or a quote in a dataset option cannot expand or execute when the script is sourced.
• String slices are indexed, not joined. Access modes, tier mount paths and tier quotas are exported as a count plus one variable per element, the same way mounts are. Joining on a comma would be ambiguous, since a host path may legally contain one, and paths and quotas are paired by position, so a stray separator would shift the pairing silently.
• An absent component still exports every variable, from a zero value. When the topology leaves a component out (the client, in the client-less case), its variables are present and empty, so a consumer running under set -u can read any of them. <COMPONENT>_ENABLED alone tells an absent component from a present one.
• Maps stay JSON, as the issue specifies. json.Marshal sorts map keys, so the script is byte-stable across reconciles and does not rewrite the ConfigMap on every sync.

The volume, setup and client code needed no change for the client-disabled path. The second commit adds tests that pin the existing behaviour there rather than altering it.

Ⅱ. Does this pull request fix one issue?

Part of #6176 (phase 1). I have not marked it as fixing the issue, because phase 2, the webhook plugin that injects runtime.sh into application Pods, is still to come.

Ⅲ. List the added test cases (unit test/integration test) if any, please explain if no tests are needed.

cm_test.go:

• TestGenerateRuntimeConfigDataIncludesRuntimeSh: both keys are generated, and the script agrees with the JSON field by field.
• TestRuntimeShCoversEveryConfigField: walks every field reachable from CacheRuntimeConfig and fails if one is not exported to runtime.sh, or if the export table names a field that no longer exists. Adding a field to the config without exporting it fails this test.
• TestRuntimeShExportsEveryComponentAlike: the master and the worker, populated identically, export the same variables.
• TestRuntimeShExportsAbsentComponentsUnderNounset: an absent component exports the same variables as a present one, and the script can be sourced and read under set -u.
• TestGenerateRuntimeShQuotesHostileValues: quotes, $, backticks, spaces and newlines round-trip through a real sh.
• TestGenerateRuntimeShIsDeterministic, TestGenerateRuntimeShWithoutAnyEnabledComponent, TestGenerateRuntimeShExportsTieredStoreLevels.

volume_test.go: TestCreateVolumeWithClientDisabled, the PV and PVC are still created when the client is disabled.

sync_test.go: three specs covering how the creation and sync paths treat a disabled client.

The tests that source the script shell out to sh, and skip if it is not available.

Ⅳ. Describe how to verify it

go test ./pkg/ddc/cache/engine/ -run 'RuntimeSh|RuntimeConfigData|ClientDisabled' -count=1

On a cluster, create a CacheRuntime with spec.client.disabled: true and read the script back:

kubectl get cm fluid-runtime-config-<name> -o jsonpath='{.data.runtime\.sh}'

Ⅴ. Special notes for reviews

The in-Pod path of runtime.sh is not defined here. It is left to phase 2, together with its first consumer, the injector.

[fluid-e2e-bot]

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[fluid-e2e-bot]

Hi @btxu-db. Thanks for your PR.

I'm waiting for a fluid-cloudnative member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[codecov]

Codecov Report

❌ Patch coverage is 80.00000% with 18 lines in your changes missing coverage. Please review.
✅ Project coverage is 65.40%. Comparing base (54a41cd) to head (9c06a62).

Files with missing lines	Patch %	Lines
pkg/ddc/cache/engine/cm.go	79.54%	12 Missing and 6 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6191      +/-   ##
==========================================
+ Coverage   65.24%   65.40%   +0.16%     
==========================================
  Files         486      486              
  Lines       34194    34284      +90     
==========================================
+ Hits        22309    22423     +114     
+ Misses      10135    10097      -38     
- Partials     1750     1764      +14     

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[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
3.4% Duplication on New Code

See analysis details on SonarQube Cloud