.. This work is licensed under a Creative Commons Attribution 4.0 International License. .. http://creativecommons.org/licenses/by/4.0 .. Copyright 2018 Amdocs, Bell Canada .. Links .. _Curated applications for Kubernetes: https://github.com/kubernetes/charts .. _Services: https://kubernetes.io/docs/concepts/services-networking/service/ .. _ReplicaSet: https://kubernetes.io/docs/concepts/workloads/controllers/replicaset/ .. _StatefulSet: https://kubernetes.io/docs/concepts/workloads/controllers/statefulset/ .. _Helm Documentation: https://docs.helm.sh/helm/ .. _Helm: https://docs.helm.sh/ .. _Kubernetes: https://Kubernetes.io/ .. _user-guide-label: OOM User Guide ############## The ONAP Operations Manager (OOM) provide the ability to manage the entire life-cycle of an ONAP installation, from the initial deployment to final decommissioning. This guide provides instructions for users of ONAP to use the Kubernetes_/Helm_ system as a complete ONAP management system. This guide provides many examples of Helm command line operations. For a complete description of these commands please refer to the `Helm Documentation`_. .. figure:: oomLogoV2-medium.png :align: right The following sections describe the life-cycle operations: - Deploy_ - with built-in component dependency management - Configure_ - unified configuration across all ONAP components - Monitor_ - real-time health monitoring feeding to a Consul UI and Kubernetes - Heal_- failed ONAP containers are recreated automatically - Scale_ - cluster ONAP services to enable seamless scaling - Upgrade_ - change-out containers or configuration with little or no service impact - Delete_ - cleanup individual containers or entire deployments .. figure:: oomLogoV2-Deploy.png :align: right Deploy ====== The OOM team with assistance from the ONAP project teams, have built a comprehensive set of Helm charts, yaml files very similar to TOSCA files, that describe the composition of each of the ONAP components and the relationship within and between components. Using this model Helm is able to deploy all of ONAP with a few simple commands. Pre-requisites -------------- Your environment must have both the Kubernetes `kubectl` and Helm setup as a one time activity. Install Kubectl ~~~~~~~~~~~~~~~ Enter the following to install kubectl (on Ubuntu, there are slight differences on other O/Ss), the Kubernetes command line interface used to manage a Kubernetes cluster:: > curl -LO https://storage.googleapis.com/kubernetes-release/release/v1.8.6/bin/linux/amd64/kubectl > chmod +x ./kubectl > sudo mv ./kubectl /usr/local/bin/kubectl > mkdir ~/.kube Paste kubectl config from Rancher (see the :ref:`cloud-setup-guide-label` for alternative Kubenetes environment setups) into the `~/.kube/config` file. Verify that the Kubernetes config is correct:: > kubectl get pods --all-namespaces At this point you should see six Kubernetes pods running. Install Helm ~~~~~~~~~~~~ Helm is used by OOM for package and configuration management. To install Helm, enter the following:: > wget http://storage.googleapis.com/kubernetes-helm/helm-v2.6.1-linux-amd64.tar.gz > tar -zxvf helm-v2.6.1-linux-amd64.tar.gz > sudo mv linux-amd64/helm /usr/local/bin/helm Verify the Helm version with:: > helm version Install the Helm Tiller application and initialize with:: > helm init Install the Helm Repo --------------------- Once kubectl and Helm are setup, one needs to setup a local Helm server to server up the ONAP charts:: > helm install osn/onap .. note:: The osn repo is not currently available so creation of a local repository is required. Helm is able to use charts served up from a repository and comes setup with a default CNCF provided `Curated applications for Kubernetes`_ repository called stable which should be removed to avoid confusion:: > helm repo remove stable .. To setup the Open Source Networking Nexus repository for helm enter:: .. > helm repo add osn 'https://nexus3.onap.org:10001/helm/helm-repo-in-nexus/master/' To prepare your system for an installation of ONAP, you'll need to:: > git clone http://gerrit.onap.org/r/oom > cd oom/kubernetes To setup a local Helm server to server up the ONAP charts:: > helm init > helm serve & Note the port number that is listed and use it in the Helm repo add as follows:: > helm repo add local http://127.0.0.1:8879 To get a list of all of the available Helm chart repositories:: > helm repo list NAME URL local http://127.0.0.1:8879 Then build your local Helm repository:: > make all The Helm search command reads through all of the repositories configured on the system, and looks for matches:: > helm search -l NAME VERSION DESCRIPTION local/appc 2.0.0 Application Controller local/clamp 2.0.0 ONAP Clamp local/common 2.0.0 Common templates for inclusion in other charts local/onap 2.0.0 Open Network Automation Platform (ONAP) local/robot 2.0.0 A helm Chart for kubernetes-ONAP Robot local/so 2.0.0 ONAP Service Orchestrator In any case, setup of the Helm repository is a one time activity. Once the repo is setup, installation of ONAP can be done with a single command:: > helm install local/onap -name development This will install ONAP from a local repository in a 'development' Helm release. As described below, to override the default configuration values provided by OOM, an environment file can be provided on the command line as follows:: > helm install local/onap -name development -f onap-development.yaml To get a summary of the status of all of the pods (containers) running in your deployment:: > kubectl get pods --all-namespaces -o=wide .. note:: The Kubernetes namespace concept allows for multiple instances of a component (such as all of ONAP) to co-exist with other components in the same Kubernetes cluster by isolating them entirely. Namespaces share only the hosts that form the cluster thus providing isolation between production and development systems as an example. The OOM deployment of ONAP in Beijing is now done within a single Kubernetes namespace where in Amsterdam a namespace was created for each of the ONAP components. .. note:: The Helm `-name` option refers to a release name and not a Kubernetes namespace. To install a specific version of a single ONAP component (`so` in this example) with the given name enter:: > helm install onap/so --version 2.0.1 -n so To display details of a specific resource or group of resources type:: > kubectl describe pod so-1071802958-6twbl where the pod identifier refers to the auto-generated pod identifier. .. figure:: oomLogoV2-Configure.png :align: right Configure ========= Each project within ONAP has its own configuration data generally consisting of: environment variables, configuration files, and database initial values. Many technologies are used across the projects resulting in significant operational complexity and an inability to apply global parameters across the entire ONAP deployment. OOM solves this problem by introducing a common configuration technology, Helm charts, that provide a hierarchical configuration configuration with the ability to override values with higher level charts or command line options. The structure of the configuration of ONAP is shown in the following diagram. Note that key/value pairs of a parent will always take precedence over those of a child. Also note that values set on the command line have the highest precedence of all. .. graphviz:: digraph config { { node [shape=folder] oValues [label="values.yaml"] demo [label="onap-demo.yaml"] prod [label="onap-production.yaml"] oReq [label="requirements.yaml"] soValues [label="values.yaml"] soReq [label="requirements.yaml"] mdValues [label="values.yaml"] } { oResources [label="resources"] } onap -> oResources onap -> oValues oResources -> environments oResources -> oReq oReq -> so environments -> demo environments -> prod so -> soValues so -> soReq so -> charts charts -> mariadb mariadb -> mdValues } The top level onap/values.yaml file contains the values required to be set before deploying ONAP. Here is the contents of this file: .. include:: onap_values.yaml :code: yaml One may wish to create a value file that is specific to a given deployment such that it can be differentiated from other deployments. For example, a onap-development.yaml file may create a minimal environment for development while onap-production.yaml might describe a production deployment that operates independently of the developer version. For example, if the production OpenStack instance was different from a developer's instance, the onap-production.yaml file may contain a different value for the vnfDeployment/openstack/oam_network_cidr key as shown below. .. code-block:: yaml nsPrefix: onap nodePortPrefix: 302 apps: consul msb mso message-router sdnc vid robot portal policy appc aai sdc dcaegen2 log cli multicloud clamp vnfsdk aaf kube2msb dataRootDir: /dockerdata-nfs # docker repositories repository: onap: nexus3.onap.org:10001 oom: oomk8s aai: aaionap filebeat: docker.elastic.co image: pullPolicy: Never # vnf deployment environment vnfDeployment: openstack: ubuntu_14_image: "Ubuntu_14.04.5_LTS" public_net_id: "e8f51956-00dd-4425-af36-045716781ffc" oam_network_id: "d4769dfb-c9e4-4f72-b3d6-1d18f4ac4ee6" oam_subnet_id: "191f7580-acf6-4c2b-8ec0-ba7d99b3bc4e" oam_network_cidr: "192.168.30.0/24" <...> To deploy ONAP with this environment file, enter:: > helm install local/onap -n beijing -f environments/onap-production.yaml .. include:: environments_onap_demo.yaml :code: yaml When deploying all of ONAP a requirements.yaml file control which and what version of the ONAP components are included. Here is an excerpt of this file: .. code-block:: yaml # Referencing a named repo called 'local'. # Can add this repo by running commands like: # > helm serve # > helm repo add local http://127.0.0.1:8879 dependencies: <...> - name: so version: ~2.0.0 repository: '@local' condition: so.enabled <...> The ~ operator in the `so` version value indicates that the latest "2.X.X" version of `so` shall be used thus allowing the chart to allow for minor upgrades that don't impact the so API; hence, version 2.0.1 will be installed in this case. The onap/resources/environment/onap-dev.yaml (see the excerpt below) enables for fine grained control on what components are included as part of this deployment. By changing this `so` line to `enabled: false` the `so` component will not be deployed. If this change is part of an upgrade the existing `so` component will be shut down. Other `so` parameters and even `so` child values can be modified, for example the `so`'s `liveness` probe could be disabled (which is not recommended as this change would disable auto-healing of `so`). .. code-block:: yaml ################################################################# # Global configuration overrides. # # These overrides will affect all helm charts (ie. applications) # that are listed below and are 'enabled'. ################################################################# global: <...> ################################################################# # Enable/disable and configure helm charts (ie. applications) # to customize the ONAP deployment. ################################################################# aaf: enabled: false <...> so: # Service Orchestrator enabled: true replicaCount: 1 liveness: # necessary to disable liveness probe when setting breakpoints # in debugger so K8s doesn't restart unresponsive container enabled: true <...> .. figure:: oomLogoV2-Monitor.png :align: right Monitor ======= All highly available systems include at least one facility to monitor the health of components within the system. Such health monitors are often used as inputs to distributed coordination systems (such as etcd, zookeeper, or consul) and monitoring systems (such as nagios or zabbix). OOM provides two mechanims to monitor the real-time health of an ONAP deployment: - a Consul GUI for a human operator or downstream monitoring systems and Kubernetes liveness probes that enable automatic healing of failed containers, and - a set of liveness probes which feed into the Kubernetes manager which are described in the Heal section. Within ONAP Consul is the monitoring system of choice and deployed by OOM in two parts: - a three-way, centralized Consul server cluster is deployed as a highly available monitor of all of the ONAP components,and - a number of Consul agents. The Consul server provides a user interface that allows a user to graphically view the current health status of all of the ONAP components for which agents have been created - a sample from the ONAP Integration labs follows: .. figure:: consulHealth.png :align: center To see the real-time health of a deployment go to: http://:30270/ui/ where a GUI much like the following will be found: .. figure:: oomLogoV2-Heal.png :align: right Heal ==== The ONAP deployment is defined by Helm charts as mentioned earlier. These Helm charts are also used to implement automatic recoverability of ONAP components when individual components fail. Once ONAP is deployed, a "liveness" probe starts checking the health of the components after a specified startup time. Should a liveness probe indicate a failed container it will be terminated and a replacement will be started in its place - containers are ephemeral. Should the deployment specification indicate that there are one or more dependencies to this container or component (for example a dependency on a database) the dependency will be satisfied before the replacement container/component is started. This mechanism ensures that, after a failure, all of the ONAP components restart successfully. To test healing, the following command can be used to delete a pod:: > kubectl delete pod [pod name] -n [pod namespace] One could then use the following command to monitor the pods and observe the pod being terminated and the service being automatically healed with the creation of a replacement pod:: > kubectl get pods --all-namespaces -o=wide .. figure:: oomLogoV2-Scale.png :align: right Scale ===== Many of the ONAP components are horizontally scalable which allows them to adapt to expected offered load. During the Beijing release scaling is static, that is during deployment or upgrade a cluster size is defined and this cluster will be maintained even in the presence of faults. The parameter that controls the cluster size of a given component is found in the values.yaml file for that component. Here is an excerpt that shows this parameter: .. code-block:: yaml # default number of instances replicaCount: 1 In order to change the size of a cluster, an operator could use a helm upgrade (described in detail in the next section) as follows:: > helm upgrade --set replicaCount=3 onap/so/mariadb The ONAP components use Kubernetes provided facilities to build clustered, highly available systems including: Services_ with load-balancers, ReplicaSet_, and StatefulSet_. Some of the open-source projects used by the ONAP components directly support clustered configurations, for example ODL and MariaDB Galera. The Kubernetes Services_ abstraction to provide a consistent access point for each of the ONAP components, independent of the pod or container architecture of that component. For example, SDN-C uses OpenDaylight clustering with a default cluster size of three but uses a Kubernetes service to and change the number of pods in this abstract this cluster from the other ONAP components such that the cluster could change size and this change is isolated from the other ONAP components by the load-balancer implemented in the ODL service abstraction. A ReplicaSet_ is a construct that is used to describe the desired state of the cluster. For example 'replicas: 3' indicates to Kubernetes that a cluster of 3 instances is the desired state. Should one of the members of the cluster fail, a new member will be automatically started to replace it. Some of the ONAP components many need a more deterministic deployment; for example to enable intra-cluster communication. For these applications the component can be deployed as a Kubernetes StatefulSet_ which will maintain a persistent identifier for the pods and thus a stable network id for the pods. For example: the pod names might be web-0, web-1, web-{N-1} for N 'web' pods with corresponding DNS entries such that intra service communication is simple even if the pods are physically distributed across multiple nodes. An example of how these capabilities can be used is described in the Running Consul on Kubernetes tutorial. .. figure:: oomLogoV2-Upgrade.png :align: right Upgrade ======= Helm has built-in capabilities to enable the upgrade of pods without causing a loss of the service being provided by that pod or pods (if configured as a cluster). As described in the OOM Developer's Guide, ONAP components provide an abstracted 'service' end point with the pods or containers providing this service hidden from other ONAP components by a load balancer. This capability is used during upgrades to allow a pod with a new image to be added to the service before removing the pod with the old image. This 'make before break' capability ensures minimal downtime. Prior to doing an upgrade, determine of the status of the deployed charts:: > helm list NAME REVISION UPDATED STATUS CHART NAMESPACE so 1 Mon Feb 5 10:05:22 2018 DEPLOYED so-2.0.1 default When upgrading a cluster a parameter controls the minimum size of the cluster during the upgrade while another parameter controls the maximum number of nodes in the cluster. For example, SNDC configured as a 3-way ODL cluster might require that during the upgrade no fewer than 2 pods are available at all times to provide service while no more than 5 pods are ever deployed across the two versions at any one time to avoid depleting the cluster of resources. In this scenario, the SDNC cluster would start with 3 old pods then Kubernetes may add a new pod (3 old, 1 new), delete one old (2 old, 1 new), add two new pods (2 old, 3 new) and finally delete the 2 old pods (3 new). During this sequence the constraints of the minimum of two pods and maximum of five would be maintained while providing service the whole time. Initiation of an upgrade is triggered by changes in the Helm charts. For example, if the image specified for one of the pods in the SDNC deployment specification were to change (i.e. point to a new Docker image in the nexus3 repository - commonly through the change of a deployment variable), the sequence of events described in the previous paragraph would be initiated. For example, to upgrade a container by changing configuration, specifically an environment value:: > helm upgrade beijing onap/so --version 2.0.1 --set enableDebug=true Issuing this command will result in the appropriate container being stopped by Kubernetes and replaced with a new container with the new environment value. To upgrade a component to a new version with a new configuration file enter:: > helm upgrade beijing onap/so --version 2.0.2 -f environments/demo.yaml To fetch release history enter:: > helm history so REVISION UPDATED STATUS CHART DESCRIPTION 1 Mon Feb 5 10:05:22 2018 SUPERSEDED so-2.0.1 Install complete 2 Mon Feb 5 10:10:55 2018 DEPLOYED so-2.0.2 Upgrade complete Unfortunately, not all upgrades are successful. In recognition of this the lineup of pods within an ONAP deployment is tagged such that an administrator may force the ONAP deployment back to the previously tagged configuration or to a specific configuration, say to jump back two steps if an incompatibility between two ONAP components is discovered after the two individual upgrades succeeded. This rollback functionality gives the administrator confidence that in the unfortunate circumstance of a failed upgrade the system can be rapidly brought back to a known good state. This process of rolling upgrades while under service is illustrated in this short YouTube video showing a Zero Downtime Upgrade of a web application while under a 10 million transaction per second load. For example, to roll-back back to previous system revision enter:: > helm rollback so 1 > helm history so REVISION UPDATED STATUS CHART DESCRIPTION 1 Mon Feb 5 10:05:22 2018 SUPERSEDED so-2.0.1 Install complete 2 Mon Feb 5 10:10:55 2018 SUPERSEDED so-2.0.2 Upgrade complete 3 Mon Feb 5 10:14:32 2018 DEPLOYED so-2.0.1 Rollback to 1 .. note:: The description field can be overridden to document actions taken or include tracking numbers. Many of the ONAP components contain their own databases which are used to record configuration or state information. The schemas of these databases may change from version to version in such a way that data stored within the database needs to be migrated between versions. If such a migration script is available it can be invoked during the upgrade (or rollback) by Container Lifecycle Hooks. Two such hooks are available, PostStart and PreStop, which containers can access by registering a handler against one or both. Note that it is the responsibility of the ONAP component owners to implement the hook handlers - which could be a shell script or a call to a specific container HTTP endpoint - following the guidelines listed on the Kubernetes site. Lifecycle hooks are not restricted to database migration or even upgrades but can be used anywhere specific operations need to be taken during lifecycle operations. OOM uses Helm K8S package manager to deploy ONAP components. Each component is arranged in a packaging format called a chart - a collection of files that describe a set of k8s resources. Helm allows for rolling upgrades of the ONAP component deployed. To upgrade a component Helm release you will need an updated Helm chart. The chart might have modified, deleted or added values, deployment yamls, and more. To get the release name use:: > helm ls To easily upgrade the release use:: > helm upgrade [RELEASE] [CHART] To roll back to a previous release version use:: > helm rollback [flags] [RELEASE] [REVISION] For example, to upgrade the onap-so helm release to the latest SO container release v1.1.2: - Edit so values.yaml which is part of the chart - Change "so: nexus3.onap.org:10001/openecomp/so:v1.1.1" to "so: nexus3.onap.org:10001/openecomp/so:v1.1.2" - From the chart location run:: > helm upgrade onap-so The previous so pod will be terminated and a new so pod with an updated so container will be created. .. figure:: oomLogoV2-Delete.png :align: right Delete ====== Existing deployments can be partially or fully removed once they are no longer needed. To minimize errors it is recommended that before deleting components from a running deployment the operator perform a 'dry-run' to display exactly what will happen with a given command prior to actually deleting anything. For example:: > helm delete --dry-run beijing will display the outcome of deleting the 'beijing' release from the deployment. To completely delete a release and remove it from the internal store enter:: > helm delete --purge beijing One can also remove individual components from a deployment by changing the ONAP configuration values. For example, to remove `so` from a running deployment enter:: > helm upgrade beijing osn/onap --set so.enabled=false will remove `so` as the configuration indicates it's no longer part of the deployment. This might be useful if a one wanted to replace just `so` by installing a custom version.