Whether you are in the process of deciding to host a new containerized application or refactoring an existing application to use containers, Kubernetes is a great choice as the most scalable and feature-rich container orchestration platform in the market today.
While Kubernetes is the best choice, it doesn’t have built-in tools to meet every application’s needs. It’s also not without its own challenges. It is common for enterprises to use additional tools for use cases such as
- Application definition and management
- Continuous integration and continuous delivery
- Secret management
- Networking and service mesh
Fortunately, there are several open-source tools to help fill these gaps. To help you find the right solution for your applications, in this article, we review some of the most popular Kubernetes tools that can help you solve common problems.
Kubernetes tools: An overview
Before we dive into each category, here’s a high-level overview of the Kubernetes tools in this article.
|App Definition & Management||HelmOperator Framework||Define Kubernetes applications Manage and automate the application lifecycle|
|CI/CD||ArgoCDFluxCD||Implement GitOps Create consistent, repeatable deployments|
|Secret Management||Vault||Manage secrets in a clusterGrant and revoke access to different servicesAvoid copying secrets and tokens in|
|Security||Open Policy Agent Gatekeeper|
Syft & Grype (Anchore)
|Enforce cluster-wide security policiesContainer vulnerability scanning|
|Networking & Service Mesh||LinkerdIstio||Provide service discovery, observability, and securityRemove complexity from the application layer|
|Monitoring||Prometheus (basic monitoring)Grafana (basic monitoring)OpsRamp (advanced monitoring and AIOps)||Gather metrics from containers and servicesMonitor Kubernetes cluster in a hybrid infrastructureAlerts and automation|
Kubernetes tools for app definition & management
The Kubernetes tools in this category can help you better manage and automate application lifecycles.
Helm is a package manager for Kubernetes. A Kubernetes package consists of multiple manifest files that define resources such as pods and deployments for an application. These resources tell Kubernetes how to run the application.
For smaller projects, a developer can create and configure these files manually. However, manually maintaining files for larger and more involved projects is cumbersome. Helm significantly simplifies the process.
With Helm, developers create a Helm Chart that includes the same set of manifest files with Helm. Helm then takes care of packaging, deployment, versioning, upgrades, rollbacks, and deletion of these resources in the cluster. It also provides a templating engine for additional configurations.
The ArtifactHub chart repository is one of the most important aspects of Helm. With ArtifactHub, developers can create and share charts for different tools like Kafka. As a result, you can quickly deploy any of these tools to your Kubernetes cluster with an already published chart.
The idea is to codify the knowledge of operating a complex system into the operator. Tasks that usually require a human to perform such as upgrading, backup, and recovery can then be automated using the operator. The operator runs in the Kubernetes cluster and continuously performs these tasks without human intervention.
Operator Framework is a handy tool for creating a custom operator for your application. It provides the building blocks to get started and easy-to-use APIs.
OperatorHub.io is the main repository of open-source and published operators. There is an operator for Elasticsearch, Kafka, and many more cloud-native products. Deploying software using an OperatorHub.io verified operator is fast and follows best security practices.
Kubernetes tools for CI\CD
The Kubernetes tools in this category can help you optimize your CI\CD pipelines.
ArgoCD is an open-source continuous delivery tool built for Kubernetes and implements GitOps workflows. The ArgoCD operator is deployed to the Kubernetes cluster. It monitors a version control repository, often Git, that defines the Kubernetes manifest files. It also supports Kustomize, Helm, or YAML files.
With ArgoCD, the state defined in the version control (i.e. the “desired state”), is frequently compared against the state of the cluster. If there is any variation between the two, ArgoCD updates the cluster state. As a result, teams only need to update the code to change the state of a cluster. Additionally, they can collaborate and review changes to the infrastructure.
FluxCD is another popular open-source continuous delivery tool. Similar to ArgoCD, FluxCD is used to set up CI/CD pipelines. It deploys applications and resources to Kubernetes from the source repository. Flux is also compatible with Kustomize, Helm, Ansible, and even has support for manifest files stored in an S3 bucket.
If you use another CI/CD tool such as Jenkins or Github Action, you might think you don’t need another tool. However, the main advantage of both FluxCD and ArgoCD over others is that they remove the need to store credentials outside the cluster.
Put simply, ArgoCD and FluxCD are deployed to the cluster. They run as a native processes and pull the content from the outside cluster. In other words, they are more secure and involve less secret management.
Kubernetes tools for secret management
The Kubernetes tool in this category can help you secure sensitive secrets and tokens and improve access controls.
Vault is a secret management tool often used alongside Kubernetes. It is open-source and mainly developed by Hashicorp. Its main features are:
- Secret management
- Encryption as a service
- Identity & access management.
Vault integrates natively with Kubernetes to simplify secret management. It replaces the secrets stored in code, a version control system, or a random developer's computer. It also runs in any cloud or on-premise hardware -- so there’s no vendor lock-in.
Let’s consider a typical scenario where the back-end application must communicate with a database. The back-end application uses Vault to retrieve unique temporary credentials, then uses the credentials to authenticate with the database. Unique and time-limited credentials enable many new capabilities and security protections. For instance, the administrators can quickly audit access patterns and revoke credentials if compromised.
Kubernetes tools for security
The Kubernetes tools in this category can help you better enforce security policies across clusters and improve your security scanning.
|Platform||Dashboards||Alerts||On Premises||Multi Cloud||Machine Learning||Workflow Automation|
|Native Cloud Tools||✔||✔|
|Open Source Tools||✔||✔||✔|
Open Policy Agent GateKeeper
A common pain point for system administrators is enforcing cluster-wide policies that all teams adhere to. With Gatekeeper, administrators define policies that enforce a set of rules. Using the Admission Controller, the OPA Gatekeeper enforces policies for every team in the organization.
For instance, a rule could be that no container should run as the root user. Another rule could be that all the referenced container images reside in a single private repository. These policies are declarative and can be defined as Kubernetes YAML files. In the hands of administrators, this is a powerful utility to keep clusters secure. Using the Gatekeeper, organizations can ensure their infrastructures comply with rules or restrictions.
Grype & Syft
Developed by Anchore, Syft and Grype are two open-source tools that work together to detect container vulnerabilities. Syft scans containers and creates reports of all the OS binaries and language-specific packages. After Syft produces a report, Grype checks those entries against a database of known vulnerabilities and outputs all the vulnerable resources in the container.
By integrating these two CLI tools in your CI/CD pipelines, you can detect vulnerabilities early in the process. Therefore, you can have higher confidence that your containers are free of any known vulnerabilities.
Kubernetes tools for networking & service mesh
The Kubernetes tools in this category can help you simplify discovery, observability, and security and remove application layer complexity.
Linkerd is an open-source service-mesh solution designed for Kubernetes. Its main advantage over the competition is that it's fast and lightweight. Consequently, it has very low overhead.
Linkerd, similar to other service meshes, solves the main challenge of a microservice architecture: communication and networking. Primarily, it takes care of communication between microservices. This allows developers and teams to focus on their mission instead of writing a lot of boilerplate and repeated logic. How? The Linkerd team says it best:
“... [Linkerd] makes running services easier and safer by giving you runtime debugging, observability, reliability, and security—all without requiring any changes to your code.“
Istio is a widely trusted service-mesh software. While Istio and Linkerd solve the same set of problems, their approach is quite different. Specifically, Istio is a general-purpose tool that tries to solve many problems. Hence, it is a heavier application that requires more configurations and tuning.
Kubernetes tools for monitoring
The Kubernetes tools in this category can help you monitor key DevOps metrics and improve infrastructure observability.
Prometheus (basic monitoring)
Developed by SoundCloud, Prometheus is a free and open-source monitoring system for microservices. It is no surprise that monitoring hundreds or even thousands of services at scale is a challenging task. Prometheus is a basic, easy-to-configure, and reliable solution for this use case.
To use Prometheus, individual services expose important metrics as an HTTP API. Prometheus servers can query, store and expose these metrics by using the PromQL query language. While Prometheus has a built-in UI for viewing the metrics from different services, in most cases tools like Grafana or OpsRamp are used to visualize metrics and alert service owners.
One of the main challenges with Prometheus is scaling it to meet the requirements of enterprises and larger applications. Organizations often use additional solutions such as Prometheus Cortex or Thanos to address these challenges. .
Grafana (basic monitoring)
Grafana is a popular open-source dashboarding tool that supports different data sources, including Prometheus. Due to Grafana’s better visualization capabilities, it is often used as the default Prometheus dashboard. It provides features to create a variety of charts such as time series, gauges and bar charts. Additionally, basic alerts can be set up in Grafana to notify service owners if any issue arises.
OpsRamp (advanced monitoring)
OpsRamp provides configurable and powerful dashboards to monitor Kubernetes clusters. If you want to monitor cluster metrics, it’s simple to install an OpsRamp agent in your Kubernetes cluster. The agent understands Kubernetes and gathers detailed information such as namespaces, services, and running pods in the cluster.
OpsRamp’s hybrid cloud support enables monitoring Kubernetes clusters from different cloud providers and users’ own on-premises deployments. OpsRamp dashboards and visualization tools allow a closer examination of services’ resource usages. With OpsRamp, the DevOps team and administrators can have a single-pane view of hybrid or multi-cloud infrastructure.
Based on these metrics, OpsRamp provides extensive alerting and automation solutions. For instance, alerts can be generated based on pre-configured thresholds or machine learning detected anomalies. Event correlation pinpoints the root cause of a performance problem and triggers the appropriate automated action to remedy the issue.
OpsRamp is built as a Prometheus Cortex which means that it supports PromQL and offers a native integration with Prometheus. After integration with OpsRamp, Prometheus metrics can be used for dashboarding, alerting, and automation.
In this article, we listed some of the most popular Kubernetes tools. Using these tools, teams can develop applications faster, deploy easier, instill security best practices, and monitor Kubernetes infrastructure.
Kubernetes is great for container orchestration but doesn’t address every use case. Other tools can help fill gaps in areas like package management and continuous delivery. Additionally, in many cases, Kubernetes is only one component of a broader hybrid cloud environment. For enterprises that host their applications on a hybrid cloud, advanced tools that provide centralized monitoring for all infrastructure in a single pane of glass are a must.