joint openstack kubernetes environment (march 17 update)
TRANSCRIPT
March 2017 Update:Will it blend? Joint OpenStack Kubernetes Environment
A pragmatic operational assessment of if and when Kubernetes can become an underlay for OpenStack.
TL;DR: Yesand then Kubernetes wins as the platform.
Rob Hirschfeld (aka Zehicle online)
In Community: OpenStack Board Member (4 years)
Co-Chair of Kubernetes Cluster Ops SIG
Founder of Digital Rebar & Crowbar Projects
Professional: CEO of RackN - hybrid automation software
Executive at Dell - scale data center ops
Cloud Data Center Ops going back to 1999
Addressing Operators Needs
Operational Success is Essential to Project Success
Operators are not developers!
Simple, Transparent and Stable are key concerns
Becoming a super-user of the platform should not be required to run it
Scale & Upgradability has both internal and external drivers
Generally, Kubernetes has good operational fundamentals
We’re Talking Underlay, not Overlay
We’re talking about installing Kubernetes first (aka underlay) and using it to manage the OpenStack control plane.
Objectives for Kubernetes Underlay:
● Must Work with Kubernetes Primatives● Not a Dedicated Kubernetes● Limited Outside Management
Physical Infrastructure
KubernetesUnderlay
OpenStack
KubernetesOverlay
This Talk
Simplest conception of the K8s OpenStack Sandwich
What is Kubernetes?
Container Scheduler (no, it’s not really Orchestration)
API driven to provide restart, placement, network routing and life-cycle
For Applications designed for Kubernetes
Key Design Elements: Immutable Infrastructure (stateless ops)
12 Factor Configuration
Service Oriented
What is Kubernetes: A Three Tier Application
Client
0Ready
1Prereq
2Control
3Nodes
etcd(cluster)etcd
(cluster)etcd
(cluster)
API(cluster)
API(cluster)
API(cluster)
Kubelet
KubeCtl
Container Manager
5Apps
Network CNI
HostNetwork
HostStorage
HostInit
Pod Pod Pod Pod
4Add-Ons
CertificateAuthority
Scheduler(leader)
Heapster
InfrastructureAPIs
Routers,Storage,
LBs...
Proxy
...
Controller(leader)
DNS Watcher ...
Together 4ever: API server + Kubelet
Client
0Ready
1Prereq
2Control
3Nodes
etcd(cluster)etcd
(cluster)etcd
(cluster)
API(cluster)
API(cluster)
API(cluster)
Kubelet
KubeCtl
Container Manager
5Apps
Network CNI
HostNetwork
HostStorage
HostInit
Pod Pod Pod Pod
4Add-Ons
CertificateAuthority
Scheduler(leader)
Heapster
InfrastructureAPIs
Routers,Storage,
LBs...
Proxy
...
Controller(leader)
DNS Watcher ...
Kubernetes = Rainbows?!
Why do we want Kubernetes as Underlay?
Community Perception Accuracy
1 OpenStack Operations is still not “solved” True (no change)
2 We already do most new deploys in containers True (was partially)
3 Kubernetes is awesome at containers True (was partially)
4 Kubernetes is simple, stable and secure (for operators) Partially (was false)
5 Kubernetes means easy Upgrades and High Availability Partially (was false)
There are REAL Potential Benefits
● Leverage Docker packaging efforts and reduce Python & O/S dependencies● Upgrades would benefit from Kubernetes built-in processes● Use of the Kubernetes job scheduler for maintenance● “Free” fault tolerance of key components● Easier install if Kubernetes already running on-site● More constrained options for configuration and operation
BUT REALLY, IT’S ABOUT COMMUNITY SIZE...
I expect more people will understand Kubernetes operations than OpenStack operations because Kubernetes is cloud and physical.
Kubernetes Underlay is coming,So let’s get pragmatic about it.
Leadership Kudos toSAP, ATT Comummity Dev, & Port Direct
Issue 1: Marketing Message is Confusing
Marketing around Kubernetes under OpenStack is a “hot mess”
● People hear “Kubernetes is stable, OpenStack is not”● Further confuses “OpenStack one platform message”● Encourages Kubernetes as target instead of OpenStack
Confusion with the Plain Old Container Install (“POCI”) message
● Canonical (Ubuntu Cloud Install), ● Rackspace (OpenStack Ansible)● Cisco (Kolla)● Triple O
Key Principle: Containerization vs Kubernetes
Containers can be treated as a) lightweight vms or 2) packaged daemon sets.
● Canonical builds their containers like persistent vms and configures with Juju● Kolla & OSA treats containers as packaging and configures with Ansible
Kubernetes accepts neither approach – they expect containers to be immutable and 12 factor configured
● Kubernetes manages the full container life-cycle● Containers need to be able to handle being added, removed ● Services need to be able to handle IP address changes (or use DNS names)
This work is progressing quickly!
Using Kubernetes v1.5+ Primatives
● Using Kubernetes Helm Charts● Services are tagged to nodes● Agents become Daemon sets● Databases using Stateful sets● Multiple container sources
Hard work remains….
● Networking, Configuraton & Storage● OpenStack Projects must handle immutable
container requirements
Physical Infrastructure
Kubernetes + HelmUnderlay
OpenStackMgmt
OpenStackNodes
OtherApps
KubernetesWorkers
More Detail: Kubernetes Underlay of OpenStack
Physical Infrastructure
Kub
erne
tes
Con
trolle
rs
OpenStackMgmt
OpenStackNodesD
ata
base
If you to really want to build this, give me a call - RackN has all the components
Msg
B
usSoftware Defined NetworkingCeph Distributed Storage
OtherWorkloads
Hel
m
Issue 2: Technical Challenges Remain
This discussion keep kicking the operations & install problems down the field
Kubernetes is much newer than OpenStack, so even less understood
Yet more complexity and some very basic questions:
● Now we have a both a Kubernetes and OpenStack upgrade problem● We still need tooling to manage OpenStack in Kubernetes● We still need someone to package the containers● Relies on Docker to keep systems running● Storage and Networking are still being worked out
In summary,
OpenStack operability is not solved via the underlay platform alone.
Technical Leadership motivation required for OpenStack adopting Kubernetes architecture requirements.
Serious messaging confusion in effort has to be resolved.
However, this collaboration is required for OpenStack
Because Kubernetes will have a larger footprint in Operations