[#340] Access key exclusion method

[matthewhilton]

Closes #340

Changes

• Adds access key based exclusion. Allowing optional setup of access key, which must be provided by testers via a url param to access.
• This is added in addition to the current IP restriction, i.e. if both are enabled user needs to pass both.

Note: cookie must be used since at the point where outage checks the conditions, nothing has been setup yet i.e. no $USER, $SESSION, etc...

Test plan

Test	Expected	Result
No access key setup, no IP range setup	Not blocked ever	✅ Not blocked
Access key setup, no IP range setup. Access key incorrect	Blocked	✅ Blocked
Access key setup, no IP range setup. Access key correct	Not blocked	✅ Not blocked
No Access key setup, IP range setup. Within ip range.	Not blocked	✅ Not blocked
No Access key setup, IP range setup. Outside of ip range.	Blocked	✅ Blocked
Access key setup and IP range setup. inside of ip range, access key incorrect	Blocked	✅ Blocked
Access key setup and IP range setup. inside of ip range, access key correct	Not blocked	✅ Not blocked

[rhell4]

Hey @matthewhilton what are your thoughts on adding some extra unit tests to test how the climaintenance.php file resolves with the test plan?

We would probably have to add a few if (PHPUNIT_TEST) throughout the code here so that it doesn't exit or die, and maybe echo some more stuff for testing when $blocked is false. Capture the output with ob_get_contents and then compare it with what is expected (checking the comment tags, i.e. '<!-- Your access key is allowed: ...', etc.)?

[matthewhilton]

Thanks @rhell4 good idea.

I did think of it briefly but got a bit put off of doing it because of needing to eval the php. But I ended up giving it a shot and it actually wasn't as bad as I thought. Although I did have to do some hacks to get the ip address and url params in there, will see if the CI likes it 😃

[rhell4]

Looks good, all tested okay, new unit tests added to test our new scenario and old tests amended, CI is happy, I'm happy for this change to go in.