add docker log in

docs/playbooks/set_dockerhub_credentials2.yml

+---
+- hosts: all
+  tasks:
+  - name: Update aptitude
+    apt: {name: aptitude}
+    become: true
+    register: result  
+    
+  - name: update and upgrade
+    apt: {update_cache: true, upgrade: true, autoremove: true, force: true}
+    become: true
+    register: result   
+    
+  - name: install pre-req
+    apt: name="{{ item }}" state=latest
+    with_items: [python, curl, python-pip, apt-transport-https, linux-image-extra-virtual,
+      linux-image-extra-4.4.0-97-generic, ca-certificates, software-properties-common]
+    become: true
+    register: result
+    
+  - name: Add key
+    apt_key: {url: 'https://download.docker.com/linux/ubuntu/gpg', state: present}
+    become: true
+    register: result  
+    
+  - name: add repo
+    apt_repository: {repo: 'deb https://download.docker.com/linux/ubuntu xenial stable', state: present}
+    become: true
+    register: result   
+    
+  - name: update and upgrade
+    apt: {update_cache: true, upgrade: true, autoremove: true, force: true}
+    become: true
+    register: result  
+    
+  - name: install docker-ce
+    apt: name="{{ item }}" state=latest
+    with_items: [docker-ce]
+    become: true
+    
+  - {name: run, command: "docker login -u USER -p PASS", become: true}