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What are Tagging Strategies in Kubernetes?


Tagging Strategy in Kubernetes

For every Kubernetes expert, it is common knowledge that understanding tagging techniques, labelling use cases, recommended practices, and things you absolutely want to avoid is necessary for using Kubernetes labels efficiently when dealing with cluster organization.

For instance, you may automatically assign Identity and Access Management roles to users who are contractors using access restrictions and Tags to enable them to access particular clusters that are typically only accessible to full-time workers. Whichever is the case, to properly organize cluster resources, you must fully understand what “tagging strategy” involves.

In this well-detailed article, we'll see how cluster resources are organized using the two Kubernetes tagging strategies: labels and annotations. Let’s get straight into it!

Why are tags very important in managing your K8s projects?

The cloud resources used by the Kubernetes clusters you build with Container Engine for Kubernetes may be organized, controlled, managed, and reported on using tags. With tags, you can collect different resources into different compartments and annotate them with your metadata. In other words, they will facilitate your daily life by optimizing your ability to understand your projects in very heterogeneous ecosystems, as we know

Specifically, tagging is helpful for the following:

  • Authorization Grouping: Giving authorization to a group and simply adding each individual resources to the group reduces the chance of security leaks by human error. For instance, granting worker nodes access to a specific object storage bucket.

  • Resources Tracking: Accurately tagging the cluster's resources (e.g block volumes, compute instances, and load balancers) helps keep track of their status and more easily identify which resources have issues in the case of downtime.

  • Cost Management: Getting a thorough cost analyses of the operation of the Kubernetes clusters by sector labels (e.g business, application), helps your organization understand and more efficiently predict the needs of different sectors.

Concepts & definitions

Labels

Labels in Kubernetes are key-value combinations that link distinguishing metadata to objects in the container-management system. They are affixed to various things, such as pods. Labels indicate distinguishing characteristics of significant and valuable objects to users but do not automatically entail semantics to the primary system.

"metadata": {
  "labels": {
    "key1" : "value1",
    "key2" : "value2",
    "key3" : "value3"
  }
}

Labels can be assigned to objects at the creation time. One or more key/value labels can be defined for each item. For a specific object, each Key must be distinct.

Users can also outline their preferred organizational structures to system objects using loosely linked labels without users needing to maintain these mappings.

In addition, batch processing pipelines and service deployments are frequently multi-dimensional objects. And cross-cutting actions are commonly required in management, which undermines the encapsulation of tightly hierarchical representations, particularly inflexible hierarchies set by the architecture rather than by users.

Annotations

Annotations are key-value combinations that are used to add anonymous metadata to objects. Unlike labels, annotations are not typically intended for querying or implementing actions to a subset of Kubernetes. Adding annotations to the deployment configuration will allow you to apply labels to any currently unassigned labels.

If a label assigned through the container Task Profile and the annotations in the deployment configuration file disagree, the label from the Container Task Profile will take precedence. Using a distinct scope to obtain a preferential security policy, this security mechanism would prevent a bad actor.

"metadata": {
   "annotations": {
     "key1" : "value1",
     "key2" : "value2",
     "key3" : "value3"
      }
 }

Characters and Syntax for Setting Up A Valid Label

When organizing the cluster resources, you must ensure that a valid label is used. Now, a name and an optional prefix, distinguished by a slash (/), make up a valid label key. The name segment is necessary and must be 63 characters or less, with dashes (-), underscores (_), dots (. ), and alphanumerics in between.

The name segment must start and end with an alphanumeric character (a-z, 0-9, A-Z). The prefix is not required. If a prefix is supplied, it should be a DNS subdomain consisting of a string of DNS labels divided by dots (.), not exceeding 253 characters overall, and then a slash (/).

The label Key is assumed to be exclusive to the user if the beginning is left out. Automated system components that add labels to end-user objects, such as "Kube-scheduler", "Kube-controller-manager", "Kube-APIserver", or other third-party automation, must specify a prefix.

Now that we understand the importance of labels in organizing cluster resources let’s briefly discuss what annotations are before we look at the Kubernetes Recommended Best Label Practices.

Best practices for Applying Efficient Tagging Strategy

Understand the Various Methods Used in Label Selection

Kubernetes offers equality and set-based selections as its two methods for choosing items with labels. In Equality, you can choose objects that match one or more label values equally or not at all. The conditions must be satisfied for a resource to check this selector, and you can have more than one selector. While in Set-based selection: sets enable selection based on a range of values. A set is comparable to the SQL IN keyword. For instance, "environment in [dev,uat] will choose resources with the labels "dev" and "uat." The operators are accepted: "in" and "exists."

Kubernetes provides a list of suggested labels for resource object grouping. The custom labels that you can individually add using a "company.com" prefix are distinguished from the labels that Kubernetes recommends using the "app.kubernetes.io" prefix.

Establish Organizational-Wide Label Naming Conventions

Labeling conventions must be adequately adhered to throughout the organization. The same, well-defined naming standards should be followed by all teams using Kubernetes resources. The config files in your build pipeline must also be checked to ensure all required labels are applied.

Monitoring programs frequently use labels to filter out the components needed to sustain a production environment. This method prevents monitoring alarms from Kubernetes components connected to the testing environment from being raised, which would divert the operations teams' attention.

In the Pod Templates, Add the Necessary Labels.

Add a subset of labels to your pod templates that you believe necessary. Kubernetes controllers use pod templates as manifests to build a pod with the parameters for the state it should be in. Workload resources like Deployments and DaemonSets contain pod templates.

Label Everything

Label things as much as possible to retain visibility across your whole architecture. Let's say you need to identify the process consuming most of your infrastructure resources or swiftly debug an issue. In this situation, thorough labeling will make it simpler for you to precisely dig deeper into your Kubernetes resources.

Since labels are designed to hold cross-cutting metadata, you should utilize them effectively to tag cross-cutting problems. At your organization, you can set up rules that suit your requirements.

Additionally, you may use your CI/CD (continuous integration and continuous delivery) tools to automate some of the labels for cross-cutting issues. You can automatically connect release stage labels and semantic version labels using your CD tooling.

For instance, if you have different release CD pipelines for development, staging, and production. This strategy can also make sure that less dependence is placed on the developers to label everything accurately.

Institutionalize Tagging Throughout your Organization

Its importance is crucial. Tags ensure optimal project management by making them readable by all of your business units. For example, a developer will be able to configure their environment and deploy applications without having in-depth knowledge of each cloud provider or Kubernetes platform.

To meet this technical requirement while removing its natural complexity, we wanted with CNO to propose an organizational and project approach to tags.

Organizational Tagging Strategy

At the organizational level, you can add tags with values (multiple choices) or tags with a free field and choose if they are mandatory or not at the project level. In this sense, you can institutionalize the use of tags by creating strategies specific to your use cases while facilitating their use (it only takes a few clicks to achieve this).

Project Tagging Strategy

When the project owner creates his project, the tags previously set up are automatically included in the creation form. But that's not all. The project owner also has the freedom to add specific tags to his project.

Our Advice for a Great Start

To complete a tagging strategy, you need to track your connected workloads running in your clusters if you want to perform deployment activities, report on them, monitor them, bill them or keep track of them for security. We recommend the application of the following tags:

  • Tags for each type of environment, such as development, bench or production
  • Tags for deployment choices with restrictions (such as priority and policy settings);

  • The criticality of the applications, especially if a database, an application or a presentation is critical.

  • The availability of areas or regions for micro- or nano-segmentation purposes. For example, network tags of areas and locations.

  • Tags to indicate the computer language used.


Last update: 2022-11-24