Python core: KSMCache ignores kms_cache_file_name override after KSM-1004

[Wade-0]

Bug Summary

After PR #1034 (KSM-1004: resolve KSMCache path lazily so KSM_CACHE_DIR is honored after import), KSMCache.kms_cache_file_name is no longer used by cache operations.

This appears to be a breaking change for consumers that override KSMCache.kms_cache_file_name programmatically instead of using KSM_CACHE_DIR.

Current Behavior

save_cache, get_cached_data, and remove_cache_file now call KSMCache.get_cache_file_path(), which always resolves the path from KSM_CACHE_DIR and the default filename:

os.path.join(os.environ.get("KSM_CACHE_DIR", ""), "ksm_cache.bin")

As a result, changing:

KSMCache.kms_cache_file_name = "/custom/path/my_cache.bin"

has no effect.

Expected Behavior

If kms_cache_file_name is kept for backward compatibility, cache operations should still honor it.

At minimum, one of these should be true:

1. kms_cache_file_name continues to override the cache file path when explicitly set, or
2. the attribute is removed or deprecated clearly as a breaking change and documented accordingly.

Why this is a problem

The PR description says:

Keep the kms_cache_file_name class attribute for backward compatibility (no longer governs behavior)

But if existing integrations depended on setting that attribute, behavior has changed incompatibly.

Reproduction

Before PR #1034, code like this worked:

from keeper_secrets_manager_core.core import KSMCache

KSMCache.kms_cache_file_name = "/tmp/custom_cache.bin"
KSMCache.save_cache(b"test")
assert KSMCache.get_cached_data() == b"test"
KSMCache.remove_cache_file()

After PR #1034, the override is ignored and the cache is written to the path derived from KSM_CACHE_DIR or the default CWD-relative location instead.

Suggested Fix

Consider updating get_cache_file_path() to preserve the legacy override behavior, for example by honoring kms_cache_file_name when it has been explicitly changed from the default value.

Alternatively, document this as a breaking change and provide a supported migration path.

Related

• PR KSM-1004: resolve KSMCache path lazily so KSM_CACHE_DIR is honored after import #1034
• Jira: KSM-1004

[mgallego-keeper]

Hi @Wade-0,

Thank you for brining this to our attention. We have opened a PR to fix this issue and will be part of our next release.