Use IOptionsSnapshot instead of IOptions

[msmolka]

It would be useful to settings be dynamically read when changed, so usage of IOptionsSnapshot could be used instead of IOptions

[justmara]

to dynamically read one must support IOptionsMonitor, because IOptionsSnapshot is read once on class activation via DI, while Monitor can be dynamically changed in the same class instance.

[cristipufu]

I am not quite sure what value will this enhancement bring (considering the possible consequences..).

What options would you want to change at runtime?

[msmolka]

Using IOptions causes configuration read once at startup. Using IOptionsSnapshot cause configuration read every DI resolve Using IOptionsMonitor allow change configuration dynamically without restart application.

[minhdanghuu]

@msmolka Since MemoryCacheIpPolicyStore provide some method of which you can re set your policies by your self. MemoryCacheIpPolicyStore is singleton too, have a worker watch for option change, you can achive dynamic policies.