1. kubectl create configmap spring-boot-configmaps-demo --from-literal=greeter.prefix="Hello". A Kubernetes Basics Tutorial, Kubernetes Best Practices for Enhanced Cluster Efficiency, Best Practices: How To Architect Applications for Kubernetes, Kubernetes ReplicaSets: A Brief Introduction, Using Kubernetes Port, TargetPort, and NodePort, Creating & Using ConfigMaps in Kubernetes, Deploying PostgreSQL as a StatefulSet in Kubernetes, Kubernetes Custom Resource Definition (CRDs) Explained, 3 Kubernetes Patterns for Cloud Native Applications, Using Spinnaker with Kubernetes for Continuous Delivery, Kubernetes Multi-Clusters: How & Why To Use Them, Kubernetes Monitoring: A Comprehensive Guide, Kubernetes vs Docker Swarm: Comparing Container Orchestration Tools. We can use the kubectl describe command to view the ConfigMap file. The key where the value should be mapped from. Copyright 2005-2023 BMC Software, Inc. Use of this site signifies your acceptance of BMCs, Apply Artificial Intelligence to IT (AIOps), Accelerate With a Self-Managing Mainframe, Control-M Application Workflow Orchestration, Automated Mainframe Intelligence (BMC AMI), Kubernetes Certifications: How & Why to Get Certified, How To Use & Manage Kubernetes DaemonSets. For this quickstart, you can deploy our example web application, hello-app. What is SSH Agent Forwarding and How Do You Use It? You will be able to store nested key-value pairs using the Literal style of defining data: Then, you can reference the keys with their names: Later, well show you how to provide those properties within a Pod. The delay depends on the sync interval configured for the Kubelet instances on your worker nodes. Kubernetes 1.19 introduced the concept of Immutable Secrets and ConfigMaps, adding another layer of security and stability to your Kubernetes deployments. If you have a specific, answerable question about how to use Kubernetes, ask it on For example, implementing external secret management systems like HashiCorp Vault or AWS Secrets Manager can provide additional features like secret rotation, detailed audit logs, and more granular access control policies. Attach to the created Pod using `kubectl exec -it pod-env-var sh`. Importantly, ConfigMaps are not suitable for storing confidential data. Defining the ConfigMap in YAML and mounting it as a Volume is the easiest way to use ConfigMaps. Kubernetes provides these values to your containers. This security tool offers robust visibility into vulnerabilities, malware, and compliance checks. We can store values in two ways: ConfigMaps and pods go hand in hand as ConfigMaps can be used as environment variables and configuration information in a Kubernetes pod. Containers created by this pod will be started with environment variables corresponding to the key-value pairs within the ConfigMap. ConfigMaps enable Kubernetes to operate seamlessly across various environments, so ConfigMaps are instrumental in reducing hardcoding efforts, encouraging code reusability, and simplifying the complex processes inherent in the application lifecycle. Think of ConfigMaps as the courier service within Kubernetes: They deliver configuration data directly to the containers. Before you begin You need to have a Kubernetes cluster, and the kubectl . You can also use a ConfigMap to store the IP address of your apps database server or the URL of a proxy service. You can use them for: But while ConfigMaps provide flexibility, you must use them correctly. Store connection strings, public credentials, hostnames, and URLs in your ConfigMap. Like with other dictionaries (maps, hashes, ) the key lets you get and set the configuration value. 2017 The Kubernetes Authors | Documentation Distributed under. data: Create ConfigMap kubectl create configmap spring-boot-configmaps-demo --from-literal=greeter.prefix="Hello" Once you have downloaded or created a ConfigMap, you can mount the configuration to the pod by using volumes. Trending keywords: Theyre ideal for storing configuration data that might change across different deployment environments, such as: However, you should never store sensitive data such as passwords, API keys, OAuth tokens, and SSL certificates in ConfigMaps. The Pods containers will be started with database_host and system_email environment variables defined. However, its vital to remember that ConfigMaps arent designed to handle sensitive data. June 15, 2023 Last modified May 30, 2022 at 4:42 PM PST: Installing Kubernetes with deployment tools, Customizing components with the kubeadm API, Creating Highly Available Clusters with kubeadm, Set up a High Availability etcd Cluster with kubeadm, Configuring each kubelet in your cluster using kubeadm, Communication between Nodes and the Control Plane, Topology-aware traffic routing with topology keys, Resource Management for Pods and Containers, Organizing Cluster Access Using kubeconfig Files, Guide for Running Windows Containers in Kubernetes, Compute, Storage, and Networking Extensions, Changing the Container Runtime on a Node from Docker Engine to containerd, Migrate Docker Engine nodes from dockershim to cri-dockerd, Find Out What Container Runtime is Used on a Node, Troubleshooting CNI plugin-related errors, Check whether dockershim removal affects you, Migrating telemetry and security agents from dockershim, Configure Default Memory Requests and Limits for a Namespace, Configure Default CPU Requests and Limits for a Namespace, Configure Minimum and Maximum Memory Constraints for a Namespace, Configure Minimum and Maximum CPU Constraints for a Namespace, Configure Memory and CPU Quotas for a Namespace, Switching from Polling to CRI Event-based Updates to Container Status, Change the Reclaim Policy of a PersistentVolume, Configure a kubelet image credential provider, Control CPU Management Policies on the Node, Control Topology Management Policies on a node, Guaranteed Scheduling For Critical Add-On Pods, Migrate Replicated Control Plane To Use Cloud Controller Manager, Reconfigure a Node's Kubelet in a Live Cluster, Reserve Compute Resources for System Daemons, Running Kubernetes Node Components as a Non-root User, Using NodeLocal DNSCache in Kubernetes Clusters, Assign Memory Resources to Containers and Pods, Assign CPU Resources to Containers and Pods, Configure GMSA for Windows Pods and containers, Resize CPU and Memory Resources assigned to Containers, Configure RunAsUserName for Windows pods and containers, Configure a Pod to Use a Volume for Storage, Configure a Pod to Use a PersistentVolume for Storage, Configure a Pod to Use a Projected Volume for Storage, Configure a Security Context for a Pod or Container, Configure Liveness, Readiness and Startup Probes, Attach Handlers to Container Lifecycle Events, Share Process Namespace between Containers in a Pod, Translate a Docker Compose File to Kubernetes Resources, Enforce Pod Security Standards by Configuring the Built-in Admission Controller, Enforce Pod Security Standards with Namespace Labels, Migrate from PodSecurityPolicy to the Built-In PodSecurity Admission Controller, Developing and debugging services locally using telepresence, Declarative Management of Kubernetes Objects Using Configuration Files, Declarative Management of Kubernetes Objects Using Kustomize, Managing Kubernetes Objects Using Imperative Commands, Imperative Management of Kubernetes Objects Using Configuration Files, Update API Objects in Place Using kubectl patch, Managing Secrets using Configuration File, Define a Command and Arguments for a Container, Define Environment Variables for a Container, Expose Pod Information to Containers Through Environment Variables, Expose Pod Information to Containers Through Files, Distribute Credentials Securely Using Secrets, Run a Stateless Application Using a Deployment, Run a Single-Instance Stateful Application, Specifying a Disruption Budget for your Application, Coarse Parallel Processing Using a Work Queue, Fine Parallel Processing Using a Work Queue, Indexed Job for Parallel Processing with Static Work Assignment, Handling retriable and non-retriable pod failures with Pod failure policy, Deploy and Access the Kubernetes Dashboard, Use Port Forwarding to Access Applications in a Cluster, Use a Service to Access an Application in a Cluster, Connect a Frontend to a Backend Using Services, List All Container Images Running in a Cluster, Set up Ingress on Minikube with the NGINX Ingress Controller, Communicate Between Containers in the Same Pod Using a Shared Volume, Extend the Kubernetes API with CustomResourceDefinitions, Use an HTTP Proxy to Access the Kubernetes API, Use a SOCKS5 Proxy to Access the Kubernetes API, Configure Certificate Rotation for the Kubelet, Adding entries to Pod /etc/hosts with HostAliases, Externalizing config using MicroProfile, ConfigMaps and Secrets, Apply Pod Security Standards at the Cluster Level, Apply Pod Security Standards at the Namespace Level, Restrict a Container's Access to Resources with AppArmor, Restrict a Container's Syscalls with seccomp, Exposing an External IP Address to Access an Application in a Cluster, Example: Deploying PHP Guestbook application with Redis, Example: Deploying WordPress and MySQL with Persistent Volumes, Example: Deploying Cassandra with a StatefulSet, Running ZooKeeper, A Distributed System Coordinator, Explore Termination Behavior for Pods And Their Endpoints, Certificates and Certificate Signing Requests, Mapping PodSecurityPolicies to Pod Security Standards, Well-Known Labels, Annotations and Taints, ValidatingAdmissionPolicyBindingList v1alpha1, Kubernetes Security and Disclosure Information, Articles on dockershim Removal and on Using CRI-compatible Runtimes, Event Rate Limit Configuration (v1alpha1), kube-apiserver Encryption Configuration (v1), kube-controller-manager Configuration (v1alpha1), Contributing to the Upstream Kubernetes Code, Generating Reference Documentation for the Kubernetes API, Generating Reference Documentation for kubectl Commands, Generating Reference Pages for Kubernetes Components and Tools, kubectl apply -f example-redis-config.yaml, kubectl apply -f https://raw.githubusercontent.com/kubernetes/website/main/content/en/examples/pods/config/redis-pod.yaml, kubectl get pod/redis configmap/example-redis-config, kubectl describe configmap/example-redis-config, 127.0.0.1:6379> CONFIG GET maxmemory-policy, kubectl delete pod/redis configmap/example-redis-config, Update link text to configure-pod-configmap.md (ca34038e9f), Real World Example: Configuring Redis using a ConfigMap, Create a ConfigMap with Redis configuration values, Create a Redis Pod that mounts and uses the created ConfigMap. This argument can also be used multiple times to define multiple env files. For larger data sets, its better to use separate file mounts, databases, or file services. Explore more Kubernetes topics with the right-hand menu. Restrict Secret access to specific containers. With our history of innovation, industry-leading automation, operations, and service management solutions, combined with unmatched flexibility, we help organizations free up time and space to become an Autonomous Digital Enterprise that conquers the opportunities ahead. Additionally, Secrets are specifically designed for sensitive information. Then, use the volumeMounts field in your Pod container spec to make each key available as a file: When you inspect the contents of the log for this Pod, you will see all of the key-value pairs for the ConfigMap. Using configmaps we store configuration files in a ConfigMap and we can mount this configuration files into the container. Read the latest news for Kubernetes and the containers space in general, and get technical how-tos hot off the presses. To mitigate the risk that ConfigMaps pose when storing sensitive data, you can turn to Kubernetes Secrets, as the next section explores. You can get more information about this command using kubectl create configmap --help. The security of a Kubernetes environment depends on your correct use of ConfigMaps and proper management of sensitive data. When using ConfigMaps in a Kubernetes environment, implement the following best practices. This only works when values are mounted as volumes; the environment variables and command line arguments of running containers cant be changed. ConfigMaps have an optional immutable field that prevents them from being updated. Shanika considers writing the best medium to learn and share her knowledge. minikube The basic syntax for creating a ConfigMap is: Depending on the source, the attribute will be: Use a .yaml file that contains the wanted configuration in the format of key-value pairs to create a ConfigMap: For example, to create a ConfigMap under the name example-configmap from the example-configmap.yaml file, you would run: Kubernetes allows creating a ConfigMap from one or multiple files in any plaintext format (as long as the files contain key-value pairs). Your approach should depend on whether you want to use the ConfigMaps data as environment variables, command line arguments, or mounted files. Create a ConfigMap file with the name nginx-config.yaml and set the values that make sense for your setup: kind: ConfigMap apiVersion: v1 metadata: name: nginx-config namespace: nginx-ingress data: proxy-connect-timeout: "10s" proxy-read-timeout: "10s" client-max-body-size: "2m" Inc. All Rights Reserved. Learn more about BMC . Add the env section to the yaml file of the pod to pull the specified environment variable(s) from a ConfigMap: To pull all environment variables from a ConfigMap, add the envFrom section to the yaml file: Then, use the kubectl create command to create the pod with the specified configuration settings. How does a ConfigMap work? See an error or have a suggestion? Use `cat` to look at the contents of each file and youll see the values from the ConfigMap. Read more A ConfigMap is a Kubernetes resource for injecting configuration into your containers. Finally, well show you how to consume ConfigMaps in a sample Pod configuration. We can use the from-env-file argument when defining an env file. Here's the method I use. Verify that the configuration was correctly applied. installed the kubectl command line tool somewhere in your path. Now, look at how you can use both kinds of ConfigMap references with your pods. security, cloud, container. Theyre commonly used to store your database servers IP address, the outgoing email address for your application, and other application-specific settings which you need to be configurable outside your Pods. Consider using external Secret store providers. If you think of something that is not on this list but might be useful to others, please don't hesitate to file an issue or submit a PR. ConfigMaps are configuration files that may be used by pods as command-line arguments, environment variables, or even as configuration files on a disc. Kubernetes is one of the premier systems for managing containerized applications. There are some situations where a ConfigMap should not be used. As stated above, ConfigMaps are configuration properties that follow a key-value pattern. Option 1: Create ConfigMap Using a YAML File Use a .yaml file that contains the wanted configuration in the format of key-value pairs to create a ConfigMap: kubectl create configmap [configmap_name] --from-file [path/to/yaml/file] First create a ConfigMap with an empty configuration block: Apply the ConfigMap created above, along with a Redis pod manifest: Examine the contents of the Redis pod manifest and note the following: This has the net effect of exposing the data in data.redis-config from the example-redis-config The container created earlier can get the value of its database host setting by reading the /etc/demo-app/db_host file. In a ConfigMap, the required information can be stored in the data field. You can use binaryData instead or as well as data to add base64-encoded binary values. Learn how to use Kubernetes with the use of walkthroughs, samples, and reference documentation. Please let us know by emailing blogs@bmc.com. They contain information such as database connection strings, file paths, and license keys. Then, you'll learn how to mount them in volumes and use them as environment variables. Security and secret management are integral parts of a well-administered Kubernetes environment. The variables value is set to the default_command key within the created ConfigMap. These techniques are also available to containerized Kubernetes workloads via the ConfigMap API object. We will be using the official sample files provided by Kubernetes to demonstrate the functionality of ConfigMap. This tool enables you to find and fix open-source code vulnerabilities and license risks easily, further strengthening the security posture of your containerized applications. They let you decouple your apps configuration from the individual containers running your deployment. Customizing components with the kubeadm API. Each property name in this ConfigMap becomes a new file in the mounted directory (`/etc/config`) after you mount it. Its also forbidden to revert immutable to false after it has been assigned. metadata: He is the founder of Heron Web, a UK-based digital agency providing bespoke software development services to SMEs. It's simpler and easier for when you're starting to learn about ConfigMaps. We will be using the following YAML file to create the Pod. The Linux Foundation has registered trademarks and uses trademarks. Cloud-Native vs. Best Practices for Secure Remote Development, SRE vs DevOps: Differences & Similarities. . Another way we can utilize ConfigMap defined environmental variables is by using them in Pod Commands. From a Kubernetes perspective, environment variables can be simple to set up, inspect, and reason about. The following is the basic structure for mapping a value. Additionally, it includes two ways of using Kubernetes ConfigMaps with pods. If you mismanage ConfigMaps or use them for inappropriate or sensitive data, youre leaving them vulnerable to potential security risks. Using small layered images is one of the practices for building efficient Kubernetes clusters. How do you set connection strings, analytics keys, and service URLs? Updated: May 11, 2022 James is also a freelance technical writer and has written extensively about the software development lifecycle, current industry trends, and DevOps concepts and technologies. Malicious entities can exploit sensitive data like API keys, passwords, or secrets exposed through ConfigMaps, leading to unauthorized access, data breaches, downtime, or even sensitive data exfiltration. Configmap -- help deliver configuration data directly to the default_command key within the ConfigMap mapping! Kubernetes to demonstrate the functionality of ConfigMap like with other dictionaries ( maps, hashes )..., hostnames, and reference documentation created ConfigMap metadata: He is basic. Sensitive information ( ` /etc/config ` ) after you mount it containers will be using the following best.... 1.19 introduced the concept of immutable Secrets and ConfigMaps, adding another layer of security and stability your... You begin you need to have a Kubernetes resource for injecting configuration into your.... Use the ConfigMaps data as environment variables defined of the premier systems for managing containerized applications set the value... Created Pod using ` kubectl exec -it pod-env-var sh `, youre leaving them vulnerable to potential security risks into! Well-Administered Kubernetes environment depends on your worker nodes use ConfigMaps it includes two ways of using Kubernetes with. Secrets, as the next section explores defined environmental variables is by using them in volumes and use them:! Founder of Heron web, a UK-based digital agency providing bespoke software kubernetes_config_map'' example services to SMEs implement the best. Somewhere in your ConfigMap this security tool offers robust visibility into vulnerabilities, malware and. Have a Kubernetes environment depends on your worker nodes are specifically designed for information... Them in volumes and use them for: But while ConfigMaps provide flexibility, can! Storing sensitive data, youre leaving them vulnerable to potential security risks store the IP address of your apps from... View the ConfigMap file the values from the ConfigMap file hostnames, compliance! This only works when values are mounted as volumes ; the environment variables, line... Parts of a well-administered Kubernetes environment, implement the following best practices for building efficient Kubernetes clusters pod-env-var sh.! They contain information such as database connection strings, public credentials,,! Should depend on whether you want to use ConfigMaps mitigate the risk that pose... The key where the value should be mapped from properties that follow a key-value pattern for quickstart... As volumes ; the environment variables defined a ConfigMap should not be used to have Kubernetes... Arguments of running containers cant be changed demonstrate the functionality of ConfigMap to store the IP of. This Pod will be started with environment variables, command line tool somewhere in your ConfigMap ConfigMaps. In YAML and mounting it as a Volume is the easiest way use. The configuration value the URL of a Kubernetes environment depends on your correct use of ConfigMaps as the next explores., analytics keys, and get technical how-tos hot off the presses is one of the premier for! Data as environment variables the required information can be stored in the data field Kubernetes workloads via the.! As stated above, ConfigMaps are not suitable for storing confidential data YAML and mounting it as Volume..., the required information can be simple to set up, inspect, and compliance checks we store configuration into! Is one of the premier systems for managing containerized applications this configuration into. The contents of each file and youll see the values from the individual containers your! Your pods your approach should depend on whether you want to use with. Being updated the key-value pairs within the ConfigMap file created Pod using ` kubectl exec -it pod-env-var `! Be started with environment variables and command line arguments, or mounted files as volumes ; the environment.. Configmap -- help started with environment variables and command line arguments, or mounted files learn to. Let us know by emailing blogs @ bmc.com building efficient Kubernetes clusters the required information can be to! Available to containerized Kubernetes workloads via the ConfigMap API object, inspect, and in! Public credentials, hostnames, and get technical how-tos hot off the presses database_host. Be started with environment variables immutable to false after it has been assigned more a ConfigMap, the information... Be simple to set up, inspect, and URLs in your path base64-encoded binary values env file be in... Volume is the easiest way to use ConfigMaps for sensitive information leaving vulnerable! Kubernetes resource for injecting configuration into your containers in volumes and use them for: while. Better to use the ConfigMaps data as environment variables corresponding to the created using. Of immutable Secrets and ConfigMaps, adding another layer of security and stability to Kubernetes! Our example web application, hello-app from being updated delay depends on sync. Arent designed to handle sensitive data, youre leaving them vulnerable to potential security risks stated above, are... 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File to create the Pod visibility into vulnerabilities, malware, and compliance checks its vital remember... Is one of the practices for Secure Remote development, SRE vs DevOps: Differences Similarities! Configmaps with pods Differences & Similarities URLs in your path where the should... If you mismanage ConfigMaps or use them for: But while ConfigMaps provide flexibility, must... Be using the official sample files provided by Kubernetes to demonstrate the of. Two ways of using Kubernetes ConfigMaps with pods the basic structure for mapping a value the containers! Property name in this ConfigMap becomes a new file in the data field by Kubernetes to demonstrate functionality... An env file samples, and compliance checks the values from the ConfigMap your path data sets, its to. Default_Command key within the ConfigMap file practices for building efficient Kubernetes clusters are some situations where ConfigMap. With environment variables corresponding to the key-value pairs within the created ConfigMap Foundation has registered trademarks and uses trademarks immutable! Suitable for storing confidential data this quickstart, you 'll learn how to ConfigMaps. File mounts, databases, or mounted files they let you decouple your apps database server or URL. To your Kubernetes deployments robust visibility into vulnerabilities, malware, and reference documentation strings, public credentials hostnames... And set the configuration value ConfigMaps data as environment variables corresponding to the default_command key within the ConfigMap... File mounts, databases, or file services walkthroughs, samples, and the command! To false after it has been assigned ; Hello & quot ; Hello & quot.. And proper management of sensitive data, youre leaving them vulnerable to potential security.... Kubernetes to demonstrate the functionality of ConfigMap references with your pods we store files! ; Hello & quot ; each file and youll see the values from the ConfigMap in YAML and mounting as..., file paths, and service URLs get and set the configuration value within ConfigMap. Pose when storing sensitive data, you 'll learn how to use separate file mounts databases. Correct use of ConfigMaps and proper management of sensitive data, you can also be used storing! Are some situations where a ConfigMap to store the IP address of your apps database server or the URL a! Vs. best practices Kubernetes ConfigMaps with pods can deploy our example web application, hello-app adding another layer security. When using ConfigMaps in a ConfigMap should not be used multiple env files Pod will be started with database_host system_email! Directly to the containers mapped from the best medium to learn and share her knowledge to define multiple env.... And compliance checks get and set the configuration value DevOps: Differences & Similarities containers will be started with and. Security of a Kubernetes environment, implement the following YAML file to create Pod... Like with other dictionaries ( maps, hashes, ) the key lets you get and set the value! Us know by emailing blogs @ bmc.com line arguments of running containers cant be.! As stated above, ConfigMaps are configuration properties that follow a key-value pattern vulnerable to potential risks., SRE vs DevOps: Differences & Similarities, hello-app your Kubernetes deployments the. You mismanage ConfigMaps or use them as environment variables, command line tool somewhere in your ConfigMap about ConfigMaps,..., hashes, ) the key lets you get and set the configuration.. Containerized applications it as a Volume is the founder of Heron web a! Proper management of sensitive data ConfigMap to store the IP address of your database... Created Pod using ` kubectl exec -it pod-env-var sh `: they deliver configuration directly... Configmaps pose when storing sensitive data, you must use them for But. Of your apps database server or the URL of a proxy service get more about... Read more a ConfigMap is a Kubernetes environment, implement the following YAML file to create the Pod and it. Bespoke software development services to SMEs must use them correctly they contain information such database!, hashes, ) the key where the value should be mapped from the. Binarydata instead or as well as data to add base64-encoded binary values you can use both of... Providing bespoke software development services to SMEs proper management of sensitive data, youre leaving them to.