Enabled the dynamic reload of GeoIP data

[Stono]

Hey,
This attempts to fix #2100

In summary I have:

• Moved the geoip data to /etc/nginx/geoip
• Added Filesystem watchers on each of the files in that directory.

Things I don't like:

• I've hard coded the files in /etc/nginx/geoip, it'd be nice to probably just enumerate the files in that directory and watch them all (in case they change name/are added/removed)
• I've probably wrote terrible golang, this is literally my first golang change PR ever - so I apologise!

I've tested it on my controller, this was me modifying each file:

I0216 19:46:45.439078       7 nginx.go:158] Triggering NGINX reload
I0216 19:46:50.054260       7 controller.go:180] ingress backend successfully reloaded...
I0216 19:47:05.182746       7 nginx.go:158] Triggering NGINX reload
I0216 19:47:05.183088       7 controller.go:171] backend reload required
I0216 19:47:09.787091       7 controller.go:180] ingress backend successfully reloaded...
I0216 19:47:14.246166       7 nginx.go:158] Triggering NGINX reload
I0216 19:47:14.246540       7 controller.go:171] backend reload required
I0216 19:47:19.135127       7 controller.go:180] ingress backend successfully reloaded...

[k8s-reviewable]

This change is 

[Stono]

/assign @aledbf

[aledbf]

good idea 👍

[Stono]

I couldn't work out how to define a function with parameters!? hence why I had to do variables, set them, and invoke the function. It works, but it doesn't feel right?

[Stono]

It'd be nice to enumerate the directory instead of hard coding files, as I couldn't sus our how to recursively watch a folder

[aledbf]

@Stono how about

		_, err = watch.NewFileWatcher(tmplPath, onChange)
		if err != nil {
			glog.Fatalf("unexpected error creating file watcher: %v", err)
		}

		filesToWatch := []string{}
		err := filepath.Walk("/etc/nginx/geoip/", func(path string, info os.FileInfo, err error) error {
			if info.IsDir() {
				return nil
			}

			filesToWatch = append(filesToWatch, path)
			return nil
		})

		if err != nil {
			glog.Fatalf("unexpected error creating file watcher: %v", err)
		}

		for _, f := range filesToWatch {
			_, err = watch.NewFileWatcher(f, func() {
				glog.Info("file %v changed. Reloading NGINX")
				n.SetForceReload(true)
			})
			if err != nil {
				glog.Fatalf("unexpected error creating file watcher: %v", err)
			}
		}

(inside the else)

[Stono]

@aledbf thanks! I had to change: glog.Info("file %v changed. Reloading NGINX") to glog.Info("file %v changed. Reloading NGINX", f) as the log was coming out as: I0216 20:31:49.852270 7 nginx.go:208] file %v changed. Reloading NGINX but other than that it worked a treat!

[Stono]

@aledbf are the e2e tests flakey?

Not sure how this change would have caused:

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x20 pc=0x116038f]

[aledbf]

Not sure how this change would have caused:

The update of the nginx image will solve this issue.

[aledbf]

/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: aledbf, Stono

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