DevOps CodeLabs Consul and Docker Swarm Cluster http://eueung.github.io/docker-stuff/consul

1. Container Cluster
Consul & Swarm
Eueung Mulyana
http://eueung.github.io/docker-stuff/consul
CodeLabs | Attribution-ShareAlike CC BY-SA
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2. Outline
Consul - Introduction
RPI Swarm Cluster + Consul
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3. Consul
Introduction
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Consul
Consul is s a tool for discovering and con guring services in
our infrastructure.
Key Features
Service Discovery | Health Checking | Key/Value Store |
Multi Datacenter

5. Service Discovery
Clients of Consul can provide a service, such as api or mysql,
and other clients can use Consul to discover providers of a
given service. Using either DNS or HTTP, applications can
easily nd the services they depend upon.
Health Checking
Consul clients can provide any number of health checks,
either associated with a given service ("is the webserver
returning 200 OK"), or with the local node ("is memory
utilization below 90%"). This information can be used by an
operator to monitor cluster health, and it is used by the
service discovery components to route tra c away from
unhealthy hosts.
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Key/Value Store
Applications can make use of Consul's hierarchical key/value
store for any number of purposes, including dynamic
con guration, feature agging, coordination, leader election,
and more. The simple HTTP API makes it easy to use.
Multi Datacenter
Consul supports multiple datacenters out of the box. This means
users of Consul do not have to worry about building additional
layers of abstraction to grow to multiple regions.
Ref: Introduction - Consul by HashiCorp

6. Architecture
Consul is a distributed, highly available
system.
Every node that provides services to Consul
runs a Consul agent. Running an agent is
not required for discovering other services
or getting/setting key/value data. The agent
is responsible for health checking the
services on the node as well as the node
itself.
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The agents talk to one or more Consul servers. The Consul
servers are where data is stored and replicated. The servers
themselves elect a leader. While Consul can function with one
server, 3 to 5 is recommended to avoid failure scenarios leading
to data loss. A cluster of Consul servers is recommended for
each datacenter.
Components of your infrastructure that need to discover other
services or nodes can query any of the Consul servers or any of
the Consul agents. The agents forward queries to the servers
automatically.
Each datacenter runs a cluster of Consul servers. When a cross-
datacenter service discovery or con guration request is made,
the local Consul servers forward the request to the remote
datacenter and return the result.
Ref: Introduction - Consul by HashiCorp

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8. RPI Swarm Cluster + Consul
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9. Let's rebuild our previous container cluster
with Consul..
Check it again if necessary: Docker Swarm Cluster
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A 3-Node RPI
Cluster
node1
192.168.1.102
node2
192.168.1.101
node3
192.168.1.100

11. $ssh-keygen-Rnode1.local
$ssh-copy-id-oStrictHostKeyChecking=no-oCheckHostIP=noroot@$node1.local
#ifnecessary
$ssh-oStrictHostKeyChecking=no-oCheckHostIP=noroot@$node1.local
$ssh-keygen-R192.168.1.102
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A Note
SSH Setting

12. #etc/default/docker
DOCKER_OPTS="--storage-driver=overlay-D-Htcp://0.0.0.0:2375--cluster-st
#ifnecessary
$systemctlrestartdocker
$dockerinfo
$psaux|grepdocker
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Engine Config
DOCKER_OPTS

13. $./start.shnode1.local
#start.sh
functiongetip(){(traceroute$12>&1|head-n1|cut-d(-f2|cut
IP_ADDRESS=$(getip$1)
echo$IP_ADDRESS
docker-H$IP_ADDRESS:2375run
-d--net=host--name=consul
-v/data-p8500:8500
hypriot/rpi-consul:0.6.4agent-server-data-dir/data-bootstrap-expect
-ui-dir=/ui
-advertise=$IP_ADDRESS-bind=$IP_ADDRESS-client=$IP_ADDRESS
docker-H$IP_ADDRESS:2375run
-d-p10000:6000--name=swarm-master
hypriot/rpi-swarm:1.2.1manage-H0.0.0.0:6000
--discovery-opt="kv.path=docker/nodes"
consul://$IP_ADDRESS:8500
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Start Consul &
Swarm Master

14. $exportDOCKER_HOST=tcp://192.168.1.102:10000
$dockerrun-d-p8080:80hypriot/rpi-nano-httpd
571d31928b3db90fc6baffa088c25c645f8d55d5e144dc03816ef5f6af62ae21
$dockerps
CONTAINERID IMAGE COMMAND CRE
571d31928b3d hypriot/rpi-nano-httpd "/httpd80" 8
d897b5aeab29 hypriot/rpi-swarm:1.2.1 "/swarmmanage-H0.0"
dc1bb0bd5188 hypriot/rpi-consul:0.6.4 "/consulagent-serve"
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Check & Test

15. $dockerinfo
Containers:3
Running:3-Paused:0-Stopped:0
Images:11
ServerVersion:swarm/1.2.1
Role:primary
Strategy:spread
Filters:health,port,containerslots,dependency,affinity,constraint
Nodes:3
node1:192.168.1.102:2375
-ID:ASSH:N743:XQ4D:2B3A:LQA6:ESIO:PHBI:RPN7:NWMP:5WK2:4X4F:WNY5-Statu
-Containers:2
-ReservedCPUs:0/4
-ReservedMemory:0B/971.8MiB
-Labels:executiondriver=native-0.2,kernelversion=4.1.17-hypriotos-v7+,
-Error:(none)-UpdatedAt:2016-05-15T08:34:02Z
-ServerVersion:1.10.2
node2:192.168.1.101:2375
-Containers:1
-ReservedCPUs:0/4
-ReservedMemory:0B/971.8MiB
node3:192.168.1.100:2375
-Containers:0
-ReservedCPUs:0/4
-ReservedMemory:0B/971.8MiB
...
KernelVersion:4.1.17-hypriotos-v7+-OperatingSystem:linux-Architectu
CPUs:12
TotalMemory:2.847GiB
Name:d897b5aeab29
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Check & Test

16. Consul UI
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17. Consul UI
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18. Consul UI
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19. $dockerrun-d-p9000:9000hypriot/rpi-dockerui:v0.9.0-ehttp://192.168
a08588d3e7888952875e9f14496ccf5e943af954a8e70a4c51439025ff31a943
$dockerps
CONTAINERID IMAGE COMMAND CRE
a08588d3e788 hypriot/rpi-dockerui "/dockerui-ehttp://" 6
571d31928b3d hypriot/rpi-nano-httpd "/httpd80" Abo
d897b5aeab29 hypriot/rpi-swarm:1.2.1 "/swarmmanage-H0.0" Abo
dc1bb0bd5188 hypriot/rpi-consul:0.6.4 "/consulagent-serve" Abo
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Now: UI for Docker
Try DockerUI

20. DockerUI
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21. DockerUI
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22. DockerUI
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23. DockerUI
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24. Refs
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25. Refs
1. Introduction - Consul by HashiCorp
2. Consul Architecture - Consul by HashiCorp
3. kevana/ui-for-docker: An uno cial web interface for Docker, formerly known
as DockerUI
4. consul @ docker hub
5. progrium/consul @ docker hub
6. gliderlabs/consul @ docker hub | consul-agent | consul-server
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26. END
Eueung Mulyana
http://eueung.github.io/docker-stuff/consul
CodeLabs | Attribution-ShareAlike CC BY-SA
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