Basic Terminologies

OCS: VM instance created on private cloud based on Openstack (self-managed)
VCS: VM instance created on private cloud based on VMWare (Global Tech Service team managed)
- IMAGE: OS template (e.g. CentOS, Red Hat OS)
- FLAVOR: Size of Ram, CPU and Disk storage
- KEYPAIR: SSH key-pair
- SECURITY GROUPS: referring to firewall rules
- NETWORK (zone): the zone the instance is in (e.g. hk-hongkong-1, hk-hongkong-2)
Cloud Platform XaaS: Anything as a Service (An Unitary infra.) - including OCS and VCS
IaC: Infra as Code - referring to ansible and terraform
- Ansible: Config management, software installation… = deployment automation = managing application and env at scale
  - Pros:
    - Agentless: works via ssh, no need to install agent on target VM
    - Declarative language: using yaml to write structured playbooks to describe auto tasks
    - Config management: via playbook
    - easy to use
    - uniformity: consistent config across uat, dev and prod env
    - centralization: centralizing config management and simplifying node syncs
    - process automation: coordinating complex tasks between servers (i.e. cronjobs)
    - consistent execution:
- Terraform: Provisioning infra from data center (i.e. VM) = an open source tool by HashiCorp

Setting up VCS terraform & ansible