HW5: Ansible Exercise

Note

Replace mongodb.yml to site.yml in hw5.sh, if you failed running hw5.sh with the incorrect filename. If you recently pulled hw5 branch in your private repository, you don’t need this fix.

Guidelines

  • Assignments must be completed individually.
  • Discussion is allowed (e.g. via Slack) but the submission should be made by yourself. Acknowledge your helpers/collaborators name in the submission if you discussed or got help from anyone.
  • Use an individual github repository. A repository in FutureSystems will be given later.

Use hw5 branch

  • Login https://github.iu.edu with your IU Username and Password (It is a same IU Credential that you use on other IU sites e.g. one.iu.edu)
  • Checkout hw5 branch

MongoDB Ansible Role

Writing Mongodb playbook is taught in the Ansible lessons. You write MongoDB Ansible role in this assignment. Submit inventory, main playbook, command script and your role including sub-directories.

Requirements

The following files should be included in your submission

  • inventory file
  • site.yml the main playbook file
  • mongodb directory (which is ansible role for mongodb)
  • hw5-cmd.script file

Preparation

  • Login to india.futuresystems.org

  • Use the same bdossp-sp16 virtualenv used in hw3

  • Install ansible to the bodssp-sp16 virtualenv via python package manager

  • Change a directory to your IU GitHub repository where you work on hw5

  • Create a new branch hw5 by:

    git checkout -b hw5

  • Pull hw5 template files by:

    git pull git@github.iu.edu:bdossp-sp16/assignments.git hw5

  • Sync to remote by:

    git push origin hw5

  • Start working on hw5

HW5 Tasks

You need to write an Ansible role to install mongodb on your vm instance hw3-$USER. Ansible Playbook for MongoDB installation is given in the Ansible lessons. You may start from there but you need to install MongoDB on Ubuntu 15.10 at this time. Systemd is a main init system in Ubuntu 15.10 and you need to locate a service file using Ansible modules. Certain conditions should be met in your submission, see the requirements below:

  • create a new Ansible role where
    • mongodb is a role name
  • Describe tasks in tasks directory
    • Add the MongoDB public GPG key from:
      • hkp://keyserver.ubuntu.com:80
      • Use EA312927 as MongoDB public GPG Key ID when Ubuntu package management imports a key (apt-key)

    • Install mongodb-org with 3.2 Community Edition for Ubuntu Trusty 14.04 LTS by adding a MongoDB repository from:

      • deb http://repo.mongodb.org/apt/ubuntu trusty/mongodb-org/3.2 multiverse

  • Define those as Ansible variables in defaults directory, at least the four variable names below should be used:

    • mongodb_keyserver (to store hkp://...)
    • mongodb_gpgkey_id (to store EA312...)
    • mongodb_repository_list (to store deb http://...)
    • monogodb_package_name (use ‘mongodb’)
    • (more vars can be defined)
  • Two handlers
    • one for starting mongodb
    • one for restarting mongodb
  • Locate a service file where:
    • destination is /lib/systemd/system/mongodb.service
    • owner/group of the destination file is root
    • mode of the file is 0644
    • reload mongodb after adding this file to remote
    • You can find mongodb.service.j2 template file in your hw5 branch
  • Write a main playbook:
    • to include your new role
    • in site.yml file

  • Run hw5.sh to record your outputs in hw5-cmd.script file

Grading Guidelines

  • Existence of required files/directories (15%)
    • inventory
    • site.yml
    • (role) directory including subdirectories
    • hw5-cmd.script

  • Proper use of Ansible Variables (15%)

  • Proper use of Ansible Tasks (15%)

  • Proper use of Ansible Templates (15%)

  • Proper use of Ansible Handlers (15%)

  • General understanding of Ansible Roles (20%)

  • Successful Execution (5%)

FAQ

  1. How do I avoid typing SSH passphrase while current session is alive?

  1. Use ssh-agent like this:

    eval `ssh-agent`
ssh-add
  1. Where should I run Ansible Playbooks or Roles?
  1. It is on india.futuresystems.org, not on your VM instance.
  1. I see mongodb.service.j2 template file but don’t exactly know what to do.
  1. Once you installed a mongodb server to a destination, you may need to register a mongodb server as a service. In Ubuntu 15.10, systemd is a main init system and you need to locate a service file to register. Explore Ansible template module which is useful to locate a file with variables. See documentation here: http://docs.ansible.com/ansible/template_module.html
  1. Permission denied on git pull git@github.iu.edu:bdossp-sp16/assignments.git hw5
  1. Try https or register your ssh key at IU GitHub. Using https URL is like:
git pull https://github.iu.edu/bdossp-sp16/assignments.git hw5

Submission via IU GitHub (github.iu.edu)

Use IU GitHub to submit assignments on a private repository. IU GitHub Guidelines

  1. Clone your private repository from the course organization. You IU Username is the name of your repository.
  2. Create a hw5 branch
git branch hw5
git checkout hw5

  1. Run pull command to fetch and merge with the template repository:

    git pull git@github.iu.edu:bdossp-sp16/assignments.git hw5

  2. Sync with remote:

    git push -u origin hw5

  3. Add files and directories to your repository:

    git add inventory git add mongodb git add site.yml git add hw5-cmd.script

  4. commit

    git commit -am "submission hw5"

  5. Sync your changes:

    git push -u origin hw5

Challenging Tasks (Optional)

The following tasks are optional but strongly recommended to try. These are to write mongodb roles for RedHat-based operating system as well using Ansible conditionals and different modules, if necessary.

MongoDB Roles for RedHat

You have completed writing mongodb roles for Ubuntu 15.10 which is Debian-based operating system only. In this challenge task, you are required to extend your mongodb roles for RedHat-based operating system as well. Ansible conditionals is recommended to select correct tasks/files in different operating systems.

Find mongodb-redhat directory in challange sub-directory. Add your extended mongodb role in the directory.

Possible Project idea (Running Ansible on Windows)

Develop Ansible Playbooks and Roles for Windows machines using PowerShell and winrm Python package instead of SSH. You may find multiple ways like:

  • develop a PowereShell script that starts a VirtualBox and runs the Debian ansible in it, have a local key be used see the instalation instructions of Cloudmesh that let you set up ssh on a windows machine also.
  • develop a Docker based ansible container. However this is not as straight forward as the key management need to be done right.

You can find more information here Windows Support