====== Orchestration ======

===== Overview =====

  * Docker swarm / compose
  * Kubernetes (k8s)
  * OpenShift (productized k8s) / OKD
  * Nomad
  * Mesos
  * Rancher


===== Docker swarm =====

Setup: Simple setup, when Docker engine is installed

Scaling: Scale up or down commands (no auto-scaling?)


Blue green deployments:
  * Swarm (nginx) https://www.goetas.com/blog/traps-on-the-way-of-blue-green-deployments/
  * Swarm https://github.com/cecchisandrone/docker-swarm-blue-green
  *  (nginx, consul): https://botleg.com/stories/blue-green-deployment-with-docker/
  * Compose and Traefik https://coderbook.com/@marcus/how-to-do-zero-downtime-deployments-of-docker-containers/

===== Kubernetes =====
  * Installer:  kubespray, kops, kubeadm
  * Mini-dev-dist:
    * minikube (uses vms, needs hypervisor)
    * microk8s (snap)

===== Mesos =====
Resource manager: Pool resources of data center, expose API for Frameworks with scheduling and job management logic.

Architecture: Zookeeper dependency

Frameworks on top: Aurora, Marathon
===== Nomad =====

General purpose: virtualized, containerized and standalone apps

Simpler architecture: Client and server binaries

Composing with Consul (service discovery) and Vault (secret management)

Scale: > 10.000 nodes (stated by HashiCorp)

Locations: multi-datacenter, multi-region

===== OpenShift =====

Requirements:
RHEL, CoreOS, CentOS

Enhanced security: No root containers, RBAC, integration with AD

Additional components: Internal container registry, EFK logging stack, Prometheus Monitoring, Jenkins

Templates: No Helm

Ingress: Router instead of Ingress

===== Rancher =====

K8s distribution

Simplification of Kubernetes deployment / management

===== Related =====

Service meshs
  * Istio
  * Consul (also Service discovery)