Register a callback that tries to load other versions Open LDAP library if the default is failed

[buyaa-n]

Register a callback that tries to load other versions of Open LDAP library if the default is failed

Open LDAP library version is hardcoded in runtime and used for native calls

runtime/src/libraries/Common/src/Interop/Linux/Interop.Libraries.cs

Line 9 in b12e288

internal const string OpenLdap = "libldap-2.4.so.2";

From Ubuntu 22.04 only the new version of the library (libldap-2.5.so.0) is included in OS, so System.DirectoryServices.Protocols.LdapConnection fails to find the new version of the LDAP library as mentioned in the issue.

@AaronRobinsonMSFT pointed out that we can register a callback to AssemblyLoadContext.Default.ResolvingUnmanagedll event. This event is raised if the native library could not be resolved via the default resolution logic.

The PR doesn't include a specific test, I don't think I can test the logic added here specifically, let me know if you have a testing idea. Though all existing tests that connects to LDAP server would test this, run the tests locally on Ubuntu 22.04, after the fix all tests that require LDAP server passed. (No CI test runs LDAP server so they are skipped in CI)

Fixes #69456

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Issue Details

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Register a callback that tries to load other versions of Open LDAP library if the default is failed

Open LDAP library version is hardcoded in runtime and used for native calls

runtime/src/libraries/Common/src/Interop/Linux/Interop.Libraries.cs

Line 9 in b12e288

internal const string OpenLdap = "libldap-2.4.so.2";

From Ubuntu 22.04 only the new version of the library (libldap-2.5.so.0) is included in OS, so System.DirectoryServices.Protocols.LdapConnection fails to find the new version of the LDAP library as mentioned in the issue.

@AaronRobinsonMSFT pointed out that we can register a callback to AssemblyLoadContext.Default.ResolvingUnmanagedll event. This event is raised if the native library could not be resolved via the default resolution logic.

The PR doesn't include a specific test, I don't think I can test the logic added here specifically, let me know if you have a testing idea. Though all existing tests that connects to LDAP server would test this run the tests locally, all passes. (No CI test runs LDAP server so they are skipped in CI)

Fixes #69456

Author:	buyaa-n
Assignees:	-
Labels:	area-System.DirectoryServices
Milestone:	-

[joperezr]

Thanks for doing this @buyaa-n. Changes LGTM but I'll defer to @AaronRobinsonMSFT and @elinor-fung for what the best approach to hook to that event is.

[steveharter]

LGTM pending question on patch versions

[buyaa-n]

Failures unrelated and known