👨‍💻 😮 🚂 Launching Camunda BPM on Kubernetes 🥖 🐩 👨🏽‍🤝‍👨🏻

Using Kubernetes? Ready to move your Camunda BPM instances from VMs, or just try running them on Kubernetes? Let's take a look at some common configurations and individual elements that can be tailored to your specific needs.

This assumes you have used Kubernetes before. If not, why not take a look at the manual and start your first cluster?

Authors

Alastair Firth - Senior Site Reliability Engineer on Camunda Cloud Team;
Lars Lange is a DevOps Engineer at Camunda.

In short:

 git clone https://github.com/camunda-cloud/camunda-examples.git
      

        
        
        
      

    
 cd camunda-examples/camunda-bpm-demo
      

        
        
        
      

    
 make skaffold

Ok, it probably didn't work, since you don't have skaffold and kustomize installed. Well then read on!

What is Camunda BPM

Camunda BPM is an open source business process management and decision automation platform that connects business users and software developers. It's perfect for coordinating and connecting people, (micro) services or even bots! You can read more about the different use cases here .

Why use Kubernetes

Kubernetes - Linux. , . API-, Kubernetes , : , . 2020 6 , , , ( Linux). , .

Camunda BPM Engine , , Kubernetes , , ( ).

, Prometheus, Grafana, Loki, Fluentd Elasticsearch, . , Prometheus Java (JVM).

, Docker- Camunda BPM (github), Kubernetes.

;
;
;
.

: Enterprise? .

Skaffold Docker Google Cloud Build. ( Kustomize Helm), CI , . skaffold.yaml.tmpl Google Cloud Build GKE, .

make skaffold Dockerfile Cloud Build, GCR, . , make skaffold, Skaffold .

yaml Kubernetes kustomize yaml , git pull --rebase . kubectl .

envsubst GCP * .yaml.tmpl. , makefile .

Kubernetes
Kustomize
Skaffold — docker GKE
Envsubst

kustomize skaffold, generated-manifest.yaml .

Prometheus Kubernetes. , AWS Cloudwatch Metrics, Cloudwatch Alerts, Stackdriver Metrics, StatsD, Datadog, Nagios, vSphere Metrics . . Grafana — , . prometheus-operator.

Prometheus <service>/metrics, sidecar- . , JMX JVM, sidecar- . jmx_exporter Prometheus JVM, , /metrics .

Prometheus jmx_exporter

 -- images/camunda-bpm/Dockerfile
      

        
        
        
      

    
 FROM camunda/camunda-bpm-platform:tomcat-7.11.0
      

        
        
        
      

    
 
      

        
        
        
      

    
 ## Add prometheus exporter
      

        
        
        
      

    
 RUN wget https://repo1.maven.org/maven2/io/prometheus/jmx/
      

        
        
        
      

    
 jmx_prometheus_javaagent/0.11.0/jmx_prometheus_javaagent-0.11.0.jar -P lib/
      

        
        
        
      

    
 #9404 is the reserved prometheus-jmx port
      

        
        
        
      

    
 ENV CATALINA_OPTS -javaagent:lib/
      

        
        
        
      

    
 jmx_prometheus_javaagent-0.11.0.jar=9404:/etc/config/prometheus-jmx.yaml

, . tomcat Prometheus <svc>:9404/metrics

, prometheus-jmx.yaml? , JVM, tomcat — , . tomcat, wildfly, kafka . tomcat ConfigMap Kubernetes, .

-, platform/config/

 platform/config
      

        
        
        
      

    
 └── prometheus-jmx.yaml

ConfigMapGenerator kustomization.yaml.tmpl:

 -- platform/kustomization.yaml.tmpl
      

        
        
        
      

    
 apiVersion: kustomize.config.k8s.io/v1beta1
      

        
        
        
      

    
 kind: Kustomization
      

        
        
        
      

    
 [...]
      

        
        
        
      

    
 configMapGenerator:
      

        
        
        
      

    
 - name: config
      

        
        
        
      

    
 files:
      

        
        
        
      

    
 - config/prometheus-jmx.yaml

files[] ConfigMap. ConfigMapGenerators , , . Deployment, «» VolumeMount.

, ConfigMap :

 -- platform/deployment.yaml
      

        
        
        
      

    
 apiVersion: apps/v1
      

        
        
        
      

    
 kind: Deployment
      

        
        
        
      

    
 [...]
      

        
        
        
      

    
 spec:
      

        
        
        
      

    
 template:
      

        
        
        
      

    
 spec:
      

        
        
        
      

    
 [...]
      

        
        
        
      

    
 volumes:
      

        
        
        
      

    
 - name: config
      

        
        
        
      

    
 configMap:
      

        
        
        
      

    
 name: config
      

        
        
        
      

    
 defaultMode: 0744
      

        
        
        
      

    
 containers:
      

        
        
        
      

    
 - name: camunda-bpm
      

        
        
        
      

    
 volumeMounts:
      

        
        
        
      

    
 - mountPath: /etc/config/
      

        
        
        
      

    
 name: config
      

        
        
        
      

    
 [...]

. Prometheus , , , , . Prometheus Operator service-monitor.yaml . Service-monitor.yaml, operator design ServiceMonitorSpec .

, ConfigMapGenerator, /etc/config. . . subPath . xml- xmlstarlet sed. .

! stdout, , kubectl logs. Fluentd ( GKE) Elasticsearch, Loki . jsonify , logback.

H2. , Google Cloud SQL Cloud SQL Proxy — . , . AWS RDS .

, H2, platform/deploy.yaml. :

 -- platform/deployment.yaml
      

        
        
        
      

    
 apiVersion: apps/v1
      

        
        
        
      

    
 kind: Deployment
      

        
        
        
      

    
 [...]
      

        
        
        
      

    
 spec:
      

        
        
        
      

    
 template:
      

        
        
        
      

    
 spec:
      

        
        
        
      

    
 [...]
      

        
        
        
      

    
 containers:
      

        
        
        
      

    
 - name: camunda-bpm
      

        
        
        
      

    
 env:
      

        
        
        
      

    
 - name: DB_DRIVER
      

        
        
        
      

    
 value: org.postgresql.Driver
      

        
        
        
      

    
 - name: DB_URL
      

        
        
        
      

    
 value: jdbc:postgresql://postgres-proxy.db:5432/process-engine
      

        
        
        
      

    
 - name: DB_USERNAME
      

        
        
        
      

    
 valueFrom:
      

        
        
        
      

    
 secretKeyRef:
      

        
        
        
      

    
 name: cambpm-db-credentials
      

        
        
        
      

    
 key: db_username
      

        
        
        
      

    
 - name: DB_PASSWORD
      

        
        
        
      

    
 valueFrom:
      

        
        
        
      

    
 secretKeyRef:
      

        
        
        
      

    
 name: cambpm-db-credentials
      

        
        
        
      

    
 key: db_password
      

        
        
        
      

    
 [...]

: Kustomize : .

: valueFrom: secretKeyRef. , Kubernetes , .

, Kubernetes. , : KMS , K8S CD- — MozillaSOPS — Kustomize. , dotGPG — : HashiCorp Vault, Kustomize Secret Value Plugins.

Ingress

, Ingress Controller. ingress-nginx (Helm chart) , , , ingress-patch.yaml.tmpl platform/ingress.yaml. ingress-nginx nginx ingress class , DNS DNS, — . Ingress Controller DNS .

TLS

cert-manager kube-lego letsencrypt — . , ingress-patch.yaml.tmpl .

!

, make skaffold HOSTNAME=<you.example.com> <hostname>/camunda

URL-, localhost: kubectl port-forward -n camunda-bpm-demo svc/camunda-bpm 8080:8080 localhost:8080/camunda

, tomcat . Cert-manager . — , , kubetail, kubectl:

 kubectl logs -n camunda-bpm-demo $(kubectl get pods -o=name -n camunda-bpm-demo) -f

Camunda BPM, Kubernetes, , REST API . , JWT. configmaps xml, xmlstarlet (. ) , wget, init .

, Camunda BPM JVM, , , sticky sessions (, ingress-nginx), , , Max-Age cookie. Session Manager Tomcat. , - :

 wget http://repo1.maven.org/maven2/de/javakaffee/msm/memcached-session-manager/
      

        
        
        
      

    
 2.3.2/memcached-session-manager-2.3.2.jar -P lib/ && \
      

        
        
        
      

    
 wget http://repo1.maven.org/maven2/de/javakaffee/msm/memcached-session-manager-tc9/
      

        
        
        
      

    
 2.3.2/memcached-session-manager-tc9-2.3.2.jar -P lib/ && \
      

        
        
        
      

    
 
      

        
        
        
      

    
sed -i '/^<\/Context>/i \
      

        
        
        
      

    
 <Manager className="de.javakaffee.web.msm.MemcachedBackupSessionManager" \
      

        
        
        
      

    
 memcachedNodes="redis://redis-proxy.db:22121" \
      

        
        
        
      

    
 sticky="false" \
      

        
        
        
      

    
 sessionBackupAsync="false" \
      

        
        
        
      

    
 storageKeyPrefix="context" \
      

        
        
        
      

    
 lockingMode="auto" \
      

        
        
        
      

    
 />' conf/context.xml

: xmlstarlet sed

twemproxy Google Cloud Memorystore, memcached-session-manager ( Redis) .

, ( ) Camunda BPM . « ». intialSize settings.xml. HorizontalPodAutoscaler (HPA) .

platform/deployment.yaml , . HPA, . kustomize. . ingress-patch.yaml.tmpl ./kustomization.yaml.tmpl

So we installed Camunda BPM on Kubernetes with Prometheus metrics, logs, H2 database, TLS and Ingress. We have added jar and config files using ConfigMaps and Dockerfile. We talked about communicating with volumes and directly into environment variables from secrets. In addition, provided an overview of Camunda setup for multiple replicas and authenticated API.

Links

 github.com/camunda-cloud/camunda-examples/camunda-bpm-kubernetes
      

        
        
        
      

    
 │
      

        
        
        
      

    
 ├── generated-manifest.yaml <- manifest for use without kustomize
      

        
        
        
      

    
 ├── images
      

        
        
        
      

    
 │ └── camunda-bpm
      

        
        
        
      

    
 │ └── Dockerfile <- overlay docker image
      

        
        
        
      

    
 ├── ingress-patch.yaml.tmpl <- site-specific ingress configuration
      

        
        
        
      

    
 ├── kustomization.yaml.tmpl <- main Kustomization
      

        
        
        
      

    
 ├── Makefile <- make targets
      

        
        
        
      

    
 ├── namespace.yaml
      

        
        
        
      

    
 ├── platform
      

        
        
        
      

    
 │ ├── config
      

        
        
        
      

    
 │ │ └── prometheus-jmx.yaml <- prometheus exporter config file
      

        
        
        
      

    
 │ ├── deployment.yaml <- main deployment
      

        
        
        
      

    
 │ ├── ingress.yaml
      

        
        
        
      

    
 │ ├── kustomization.yaml <- "base" kustomization
      

        
        
        
      

    
 │ ├── service-monitor.yaml <- example prometheus-operator config
      

        
        
        
      

    
 │ └── service.yaml
      

        
        
        
      

    
 └── skaffold.yaml.tmpl <- skaffold directives

08/05/2020, translation of the article by Alastair Firth, Lars Lange

Launching Camunda BPM on Kubernetes