NPM Prometheus Update

[huntergregory]

Reason for Change:

• Encapsulates Prometheus metrics
• Fixes Prometheus IPSet metrics:
  • we were not updating metrics for operations around sets with type list
  • we were not updating metrics when all NPM ipsets are destroyed
  • metrics were sometimes being updated after error code 1
• Refactors unit testing for Prometheus metrics for ipsm, iptm, and networkPolicyController
• Fixes a faulty Prometheus HTTP handler unit test
• Updates a check for an empty response to ipset list when destroying NPM ipsets
• Removes unused clientset variable in controllers
• Fixes a copy paste error in an error message for cleanUpNetworkPolicy

Issue Fixed:

Requirements:

• uses conventional commit messages
• includes documentation
• adds unit tests

Notes:

[huntergregory]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).

[vakalapa]

We will need to create setname entry in IpsetInventory

[vakalapa]

Lgtm. Put a pin on ipset inventory creation for empty sets. I still think we will need to do it but at the moment it is not crucial.

[JungukCho]

Lgtm! Thank you for applying comments!

[rbtr]

👎🏼 don't merge with failing checks.
resolve these in a follow-up PR:

npm/nameSpaceController.go:80:144: unexported-return: exported func NewNameSpaceController returns unexported type *npm.nameSpaceController, which can be annoying to use (revive)
func NewNameSpaceController(nameSpaceInformer coreinformer.NamespaceInformer, ipsMgr *ipsm.IpsetManager, npmNamespaceCache *npmNamespaceCache) *nameSpaceController {
                                                                                                                                               ^
npm/networkPolicyController.go:46:114: unexported-return: exported func NewNetworkPolicyController returns unexported type *npm.networkPolicyController, which can be annoying to use (revive)
func NewNetworkPolicyController(npInformer networkinginformers.NetworkPolicyInformer, ipsMgr *ipsm.IpsetManager) *networkPolicyController {
                                                                                                                 ^
npm/podController.go:93:126: unexported-return: exported func NewPodController returns unexported type *npm.podController, which can be annoying to use (revive)
func NewPodController(podInformer coreinformer.PodInformer, ipsMgr *ipsm.IpsetManager, npmNamespaceCache *npmNamespaceCache) *podController {

[JungukCho]

👎🏼 don't merge with failing checks.
resolve these in a follow-up PR:

npm/nameSpaceController.go:80:144: unexported-return: exported func NewNameSpaceController returns unexported type *npm.nameSpaceController, which can be annoying to use (revive)
func NewNameSpaceController(nameSpaceInformer coreinformer.NamespaceInformer, ipsMgr *ipsm.IpsetManager, npmNamespaceCache *npmNamespaceCache) *nameSpaceController {
                                                                                                                                               ^
npm/networkPolicyController.go:46:114: unexported-return: exported func NewNetworkPolicyController returns unexported type *npm.networkPolicyController, which can be annoying to use (revive)
func NewNetworkPolicyController(npInformer networkinginformers.NetworkPolicyInformer, ipsMgr *ipsm.IpsetManager) *networkPolicyController {
                                                                                                                 ^
npm/podController.go:93:126: unexported-return: exported func NewPodController returns unexported type *npm.podController, which can be annoying to use (revive)
func NewPodController(podInformer coreinformer.PodInformer, ipsMgr *ipsm.IpsetManager, npmNamespaceCache *npmNamespaceCache) *podController {

@rbtr Thank you for reminder.
We will resolve them in a follow-up PR.