Add healthcheck triggered log line

Dockerfile

@@ -19,7 +19,7 @@ RUN go test ./...
 RUN go build -trimpath -ldflags="-s -w" -o app
 RUN golangci-lint run --timeout=10m
 
-FROM scratch
+FROM alpine:${ALPINE_VERSION}
 ARG BUILD_DATE
 ARG VCS_REF
 ARG VERSION

cmd/updater/main.go

@@ -150,7 +150,7 @@ func _main(ctx context.Context, timeNow func() time.Time) int {
 	go func() {
 		serverErrors <- server.RunServers(ctx,
 			server.Settings{Name: "production", Addr: "0.0.0.0:" + p.listeningPort, Handler: productionHandlerFunc},
-			server.Settings{Name: "healthcheck", Addr: "127.0.0.1:9999", Handler: healthcheckHandlerFunc},
+			server.Settings{Name: "healthcheck", Addr: "0.0.0.0:9999", Handler: healthcheckHandlerFunc},
 		)
 	}()
 

internal/healthcheck/healthcheck.go

@@ -14,6 +14,7 @@ type lookupIPFunc func(host string) ([]net.IP, error)
 
 // IsHealthy checks all the records were updated successfully and returns an error if not
 func IsHealthy(db data.Database, lookupIP lookupIPFunc, logger logging.Logger) (err error) {
+	logger.Info("Healthcheck triggered!")
 	defer func() {
 		if err != nil {
 			logger.Warn("unhealthy: %s", err)