HAProxy router fix for ip whitelist exceeding max config arguments that haproxy allows.

[ramr]

Changes to use a file based acl if the annotation for the ip whitelist exceeds the max haproxy config line arguments.

fixes bugz #1598738

/cc @openshift/sig-network-edge

[Miciah]

/lgtm

But... How much would it hurt performance (a) to use a file always and (b) to write the file using the template? Doing so could simplify the code, obviate the need for validateHAProxyWhiteList, and increase re-usability for other template-based routers.

Edit: By "always", I mean for any positive number of whitelist entries, but not if there are zero entries.

[ramr]

@Miciah yeah agree using a file always would be simpler. Bu it does come with a performance effect if a lot of routes use that annotation - does mean more IO + the processing is sequential so it makes for a slower startup. If there's not a lot of routes using that annotation, then it would be ok.

[imcsk8]

LGTM

[ironcladlou]

/approve

[ironcladlou]

/lgtm

[pravisankar]

/lgtm
Thanks Ram.

[openshift-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ironcladlou, Miciah, pravisankar, ramr

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[ramr]

/retest

[ramr]

/retest