How to create a new partition with Ansible

By default, Ansible executes /bin/sh shell.
For example, if /bin/sh is linked to dash, it's built echo is different to the one in bash or GNU echo; so you end up with -e characters fed into fdisk.

Try:

- name: partition new disk
  shell: echo -e "n\np\n1\n\n\nw" | sudo fdisk /dev/sdb
  args:
    executable: /bin/bash

Or:

- name: partition new disk
  shell: /bin/echo -e "n\np\n1\n\n\nw" | sudo fdisk /dev/sdb

With Ansible 2.3 and above, you can use parted module to create partitions from a block device. For example:

 - parted:
     device: /dev/sdb
     number: 1
     flags: [ lvm ]
     state: present

To format the partition just use filesystem module as shown below:

 - filesystem:
     fstype: ext2
     dev: /dev/sdb1

To mount the partition to, let's say, /work folder just use mount module as shown below:

- mount:
    fstype: ext2
    src: /dev/sdb1
    path: /work
    state: mounted