Automatic Keyboard in Input with Ionic

I need a routine on Ionic that calls the cellphone's Keyboard to an Ion-input as it enters the page.

An example page would be:

<ion-content padding>
  <form>
    <ion-row>
      <ion-col>
        <ion-input #user name="user" type="text" placeholder="Usuário"></ion-input>
      </ion-col>
    </ion-row>
  </form>
</ion-content>

What I want is to use the Navigating Lifecycle from Ionic (I believe that in this case using the ionViewDidEnter) to bring the focus and the Keyboard in the field automatically, I've already tried some codes but unfortunately sometimes it works and sometimes not, thanks since already.