With the growth of the internet of things (IoT), expected to connect more than 50 billion devices (things) in next three years, building intelligent systems in a more connected world is presenting many challenges. Especially in building software for IoT, beyond hardware and network connectivity challenges there are numerous challenges in development, test, release, managing the infrastructure, monitoring the infrastructure and devices (things) and security.
This article focuses on key components in IoT platform, how to select right set of DevOps tools for building those components, and creating a DevOps pipeline for the IoT platform.
Building Your Own Services and IoT Platform with DevOps
The main components in IoT solution comprises of device registration and identity, data ingestion, command and control, rules and actions for hot data analytics and cold data analytics, data storage, alerts and reporting.
Device Registration and Identity: The devices/edge need to connect to each other and to a cloud gateway to send/receive the data, for which the devices have to be uniquely identified and registered at the gateway so that only authenticated and authorized devices/users can communicate to the cloud. Every IoT platform vendors has its own way of device registration and identity methods for storing device metadata such as AWS Things Shadow and AWS Gateway Rules Engine, Device twin and Azure IOT hub in Azure, GE Predix, etc.
Data Ingestion: The devices communicate to the cloud/field gateway, which further ingests the data (device info and telemetry info, such as temperature data from sensors) into the cloud. You can use multiple options of PAAS services from Azure/AWS/GE predix, etc. for this component.
Command and Control: These components cause the device to take an action and send messages to a device from the cloud, which can be built with PaaS services such as AWS Kinesis, Lambda functions, Azure functions, Azure Logic Apps, etc. or open-source technologies.
Rules and Actions: These components act on specific device-to-cloud data, using the rules defined for processing hot data (where the data needs to be queried and analyzed within specified time interval) and cold data (where the data can be stored for delayed querying and further analysis). These components can also be built with existing PaaS services or using open-source tools such as Apache Storm, Map Reduce, Hive, Data Lake, etc. for data streaming and analytics.
Data Storage: You need to store multiple types of data ranging from device metadata, telemetry data from specified set of devices, hot data and cold raw data, which needs to be stored and scaled up based on demand.
Alerts/Notifications: The analyzed data needs to be visualized to derive more useful business metrics and outcomes, which can be integrated to external systems or other business applications to take preventive and predictive actions. Customized dashboards and data monitoring tools needs to be integrated to the solution to enable monitoring, alerts and notifications.
With increased complexity in IoT development, the large number of devices to be monitored and large volumes of data to be analyzed and to manage complex infrastructure, DevOps becomes essential to the IoT development life cycle.
Selecting the Right DevOps Tools for an IoT Platform
Selecting the right DevOps tools for an IoT platform can help overcome challenges in creating/pushing applications and firmware updates to large scale of devices, as well as monitoring and infrastructure provisioning on-demand.
With PaaS services used for IoT development, there is less code development but more configurations and rules-based development for developing key IoT components.
Also, the teams developing device software and application development may be distributed, but the releases need to be streamlined with complete traceability and auditability. You need to manage a scalable infrastructure to support an IoT platform.
Given below are some of the DevOps Tools used in most of IoT developments to help DevOps teams develop, build and release an IoT platform seamlessly.
- Version Control: Git, for distributed teams and maintaining repositories for device development, application development and infrastructure automation development. Other tools are Clear case, SVN or TFVC.
- Continuous Integration: Jenkins, VSTS (Visual Studio Team Services) and Bamboo to create jobs to do build, unit test and code quality analysis for the application, device software and infrastructure scripts, with the support of large collection of tools plugins and usage of different build tools such as gradle, maven, msbuild, etc., as well as supporting multiple technology stacks.
- Infrastructure Provisioning and Automation: Ansible, ARM (Azure Resource Manager) and AWS cloud formation templates to automate the infrastructure in multiple cloud vendors and use tools such as Terraform or Spinnaker to automate the provisioning of infrastructure across hybrid clouds and maintain a common infrastructure blueprint, which enables the porting/migration of infrastructure workloads across clouds.
- Infrastructure Testing: When PaaS services are used for developing certain components in an IoT platform, testing those PaaS components is a bit different—PaaS services have less code but more configurations and endpoints from dev/test team perspectives. Testing these components will involve endpoint testing, whether rules are created properly, how data flows between the different components and robust infrastructure verification. These infrastructure testing scripts can be written using Python/groovy or Vagrant to simulate the environment and test, or by using testing frameworks such as Pester for PowerShell scripts. You can extend your test solutions to leverage the REST APIs/CLI commands, exposed by different PaaS services, and these test scripts can test the PaaS services too, with simulated test data and generate the test result reports.
- Continuous Deployment: VSTS Release manager, Jenkins, Capistrano, CA Nolio, etc. can be used to create the deployment workflows for deploying device firmware updates, application updates separately with control to release on multiple environments, gated checks and streamlined deployment process, with feedback enabled.
- Test Automation: Selenium, Jmeter, security testing tools such as Veracode, EMMA, CA Lisa, Inspec, Robot framework and performance test tools are used for test automation. Testing in IiT is complex, as it needs an end-to-end testing of multiple devices interconnected. Most of the other device development may not be in your control, except your own device development, so to test an end-to-end functionality you need to have robust test cases and simulated test devices and test environments. This is where containers can help in test automation—a simulated device as a Docker container can run in one test environment and testers can use service virtualization tools such as IBM Rational Test Virtualization Server, CA Service Virtualization, Parasoft Virtualize or HP Service Virtualization to test their end-to end functionality when other dependent components/devices are being developed or not available.
- Security and Code Quality Analysis and Security Testing is key in IoT development. As more and more devices are interconnected, the risk of data breach/data privacy is high; hence, a shift left of security testing during the development phase as part of the CI pipeline is inevitable. Tools such as Veracode, EMMA and Inspec can be used to run security analysis and identify security vulnerabilities and compliance issues. Unit testing tools such as junit, xunit, nunit or mstest can be used based on the technology stack. Code quality analysis tools such as SonarQube, coverity, cobertura and Fxcop are widely used for code quality analysis in IoT application components development.
- Containerization and Container Orchestration: You can deploy your application as Docker containers, which have less footprint in the physical/hosted infrastructure and runs only with required application framework, libraries and dependencies. These containers/cluster of containers are managed with container orchestration tools such as Kubernetes, Docker Swarm, AWS Container Services, Azure Container Services, etc. As mentioned above, simulated test devices can run in docker containers, which enables shipping/moving the containers across any cloud and making the test environments ready within minutes.
- Monitoring: Monitoring in IoT involves monitoring the devices; infrastructure VMs/clusters; telemetry data; the build, test and releases; and billing, among others. Metrics such as cluster usage, CPU usage, network availability, response time, number of devices connected and devices updated/not updated can be configured and viewed in monitoring tools including AWS Cloudwatch, Azure Application Insights & LogAnalytics, Stream Analytics, New Relic, Prometheus (open source), Nagios, Coscale, SysDig, Dynatrace and GE Predix Monitoring. The tools can be selected depending on the target platform on different clouds or on-premises, technology stack and other factors.
- Cloud and Cloud Management: Cloud providers including AWS, GE Predix, Azure and GCP provide out-of-the-box features and support for IoT platforms with starter kits, IoT device SDKs, protocols, gateways customization and more. Cloud management tools such as Right Scale cloud management platform, OneOps, etc., can be used for managing the infrastructure workloads; bringing in central governance, access control and security; monitoring billing and optimization; managing security and standards; and streamlining and orchestration of IoT platform development.
Depending on the technology stack, the DevOps requirements and business needs, the right tool needs to be selected to streamline IoT platform development with feedback flowing between the different stream of teams involved in IoT development, and to bring in standardization in security, governance and tools, metrics to measure and to better manage IoT platform.
Release, Rollout Firmware/Application Updates
Rollout of firmware updates for an IoT platform is more challenging compared to application releases; with device updates, we have to deal with network latency, issues with connectivity of devices, security issues, different sets of devices, different deployment channels, deployments done over the air and different sets of protocols used by different manufacturers.
There is additional complexity involved when there are new additions to devices or when supporting legacy devices, and this needs incorporating integrated end-to-end testing as part of deployment pipeline, to test the devices and applications from a user-centric approach.
In IoT development, there are multiple development and deployment pipelines for firmware updates, server-side code, mobile apps and multiple devices delivering to multiple endpoints. Hence, the release cadence of IoT components varies, as application code updates can be released monthly, whereas firmware updates to devices can happen every three to six months—hence, a well-defined process must be followed for regularly integrating the code.
Continuous testing involves infrastructure testing, performance testing, end user testing and functional testing, all of which must be integrated with the release pipeline, where deployments can happen to simulated test environments, provisioned as environments as code (environment with all runtime dependencies needed to run the application like Docker containers), rather than simply infrastructure as code.
DevOps teams need to keep track of releases and monitor all these deployments, ensure environments are stable, trace back the releases with the device firmware updates and track the defects. The DevOps teams should pull the release packages of different components from multiple pipelines and prepare main and customized builds to integrate and deploy the components together.
The following are the main steps in CI/CD pipeline for IoT platform development.
- Code checked into version control: Check in the code for application development, device/firmware development, PaaS services configurations, infra automation scripts and templates to the version control, pointing to the defined repositories.
- Continuous Integration: Build jobs created in a CI server such as Jenkins/VSTS/Bamboo executes build compilation, unit testing, code quality analysis, automated reviews, environment configuration preparation, running security testing analysis, creating deployment packages or baked-in container images, for deployment.
- Triggers Deployment: The build agents generate the packages for firmware updates application updates and notifies release agent to trigger deployment.
- The deployment workflow can call a service/worker job, which in turn can connect to the cloud gateway services, to notify firmware updates.
- The cloud gateway picks up the firmware updates and notifies devices for devices updates. The devices will the pull the updates and installs the updates and further send telemetry data.
- Multiple testing environments in cloud can be integrated to the release pipeline to simulate the firmware updates.
- In case of application rollouts, there will be canary releases to gradually roll out to different environments in different regions after functional testing/regression testing.
- Testing: Security testing, firmware updates targeting to specific devices, performance of the device during the updates, device identity and memory usage, etc., needs to be addressed during deployments in IoT. Once the application is deployed to the test environment, functional/regression testing occurs and generates the test reports.
- Monitoring metrics such as memory usage, performance of the device, network traffic, latency, devices connected, reliability, etc., needs to be monitored, as these are of prime importance to decide on how to implement remote updates and monitoring without affecting the performance of the devices and these metrics has to be notified to the Dev/QA/DevOps teams as part of release pipeline execution.
- On-demand environment provisioning scripts/templates must be integrated with deployment pipeline to provision the test environments, add more devices as per the scaling metrics.
Establishing a CI CD pipeline well ahead at the start of development and following mature DevOps practices such as security testing, infrastructure testing, containerization, monitoring, cloud and DevOps governance and feedback-driven development are the keys to help address the challenges in building your own services and IoT solutions.
About the Author / Lavanya Subbarayalu
Lavanya Subbarayalu is Senior Architect working with Technology Office in HCL Technologies. She has expertise in IOT, Azure, DevOps consulting & Microsoft technologies. She is associated with DevOps COE, working on design and Development of DevOps solutions and consulting tools. Connect with her on LinkedIn.
