kubernetes-vernemq

A kubernetes configuration yaml to construct VerneMQ Cluster.

Usage

Register password to Kubernetes Secret

1. create password file

   • create two user as inner and outer in order to access from Kubernetes and from Internet

   $ mkdir -p secrets
   $ touch secrets/vmq.passwd
   $ docker run --rm -v $(PWD)/secrets:/mnt -it erlio/docker-vernemq vmq-passwd /mnt/vmq.passwd inner
   $ docker run --rm -v $(PWD)/secrets:/mnt -it erlio/docker-vernemq vmq-passwd /mnt/vmq.passwd outer

2. register password file as Kubernetes Secret

   $ kubectl create secret generic vernemq-passwd --from-file=./secrets/vmq.passwd

Register self-signed certificate files to Kubernetes Secret

1. create self-signed CA

   $ openssl req -new -x509 -days 365 -extensions v3_ca -keyout secrets/ca.key -out secrets/ca.crt

2. create server certificate signed by self-signed CA

   • you have to spacify the FQDN of VerneMQ's MQTTS endpoint

   $ openssl genrsa -out secrets/server.key 2048
   $ openssl req -out secrets/server.csr -key secrets/server.key -new
   $ openssl x509 -req -in secrets/server.csr -CA secrets/ca.crt -CAkey secrets/ca.key -CAcreateserial -out secrets/server.crt -days 365

3. register certifcation files as Kubernetes Secret

   $ kubectl create secret generic vernemq-certifications --from-file=./secrets/ca.crt --from-file=./secrets/server.crt --from-file=./secrets/server.key

start VerneMQ Cluster on Kubernetes

1. start VerneMQ Cluster on Kubernetes like below:

   • start 3 pods using StatefulSet
   • create and join a VerneMQ cluster automatically
   • listen MQTT (1883/tcp) as ClusterIP which can be accessed from Kubernetes only
   • listen MQTT over TLS (8883/tcp) as LoadBalancer which can be accessed from Kubernetes and Internet

   $ kubectl apply -f vernemq-cluster.yaml

2. confirm cluster status

   $ kubectl exec vernemq-0 -- vmq-admin cluster show
   +---------------------------------------------------+-------+
   |                       Node                        |Running|
   +---------------------------------------------------+-------+
   |VerneMQ@vernemq-0.vernemq.default.svc.cluster.local| true  |
   |VerneMQ@vernemq-2.vernemq.default.svc.cluster.local| true  |
   |VerneMQ@vernemq-1.vernemq.default.svc.cluster.local| true  |
   +---------------------------------------------------+-------+

3. check MQTTS external IP

   $ kubectl get services -l app=mqtts

4. register the FQDN of VerneMQ's MQTTS endpoint to DNS Server in order to resolve MQTTS external IP

Connecting to VerneMQ from 'inner' and 'outer'

1. start 'inner' subscriber

   • 'inner' subscriber subscribe VerneMQ from inside Kubernetes using 1883/tcp (no encrypt)

   $ kubectl run inner-sub --rm -it --image efrecon/mqtt-client /bin/ash
   / # mosquitto_sub -h mqtt -p 1883 -t /foo/bar -d -u inner -P <password of 'inner'>
   

2. start 'outer' subscriber

   • 'outer' subscriber subscribe VerneMQ through Internet using 8883/tcp (mqtt over tls)

   $ mosquitto_sub -h <FQDN of VerneMQ's MQTTS endpoint> -p 8883 --cafile ./secrets/ca.crt -t /foo/bar -d -u outer -P <password of 'outer'>
   

3. publish message from 'inner' publisher

   • 'inner' publisher publish message to VerneMQ from inside Kubernetes using 1883/tcp (no encrypt)
   • When 'inner' publisher pulish message, its message push back to 'inner' subscriber and 'outer' suscriber

   $ kubectl run inner-pub --rm -it --image efrecon/mqtt-client /bin/ash
   / # mosquitto_pub -h mqtt -p 1883 -t /foo/bar -d -u inner -P <password of 'inner'> -m "Message from inner"
   

4. publish message from 'outer' publisher

   • 'outer' publisher publish message to VerneMQ through Internet using 8883/tcp (mqtt over tls)
   • When 'outer' publisher pulish message, its message push back to 'inner' subscriber and 'outer' suscriber

   $ mosquitto_pub -h <FQDN of VerneMQ's MQTTS endpoint> -p 8883 --cafile ./secrets/ca.crt -t /foo/bar -d -u outer -P <password of 'outer'> -m "Message from outer"
   

See also

• VerneMQ
• erlio/docker-vernemq

License

MIT License

Copyright

Copyright (c) 2018 Nobuyuki Matsui nobuyuki.matsui@gmail.com