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Install and Manage Redis, Prometheus, & Grafana on Kubernetes Using Helm

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•13 min read
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Ganesh Balimidi

Scenario:

As a DevOps engineer at Solution One, you are responsible for managing various applications on clients' Kubernetes clusters. Some clients have raised concerns about the complexity of installing well-known applications, such as web servers, on Kubernetes. They struggle with tasks like application deployment, managing upgrades and rollbacks, and handling configuration management across different environments. Consequently, the installation process becomes time-consuming and cumbersome.

To address these challenges, you recognize that Helm, a Kubernetes package manager, can provide a solution. Helm simplifies the deployment process by packaging applications as Helm charts. This allows clients to easily install or remove applications on their Kubernetes clusters and customize configurations, ensuring consistent and efficient deployments. By leveraging Helm, you can streamline application management and provide clients with a seamless experience.

Objectives

  • Search for and select correct Helm charts for different applications

  • Customize Helm charts to meet specific requirements and configurations

  • Install and remove applications easily on Kubernetes using Helm

  • Verify successful Helm installation for applications and ensure they function as expected

Requirement

  • Basic knowledge of Linux commands

  • Basic knowledge of Kubernetes commands

What you'll learn

  • Helm

  • Helm charts

Your project assignment

Some of our clients are having issues when operating their Kubernetes cluster. They complain that deploying and managing applications on Kubernetes can take a long time due to complex deployments, upgrade management, and configuration handling across various environments. To overcome these obstacles, you will leverage Helm on the Kubernetes cluster. This will streamline the application management process and enhance operational efficiency.

Using Helm, DevOps Engineers can focus on delivering value rather than spending time on manual deployment tasks, ultimately improving efficiency and reducing errors in the application lifecycle.

The goal is to use Helm for managing applications on Kubernetes and simplify the installation, upgrade, and configuration processes for various applications, ensuring consistent deployments across different environments.

Key points:

  1. Understanding Helm and its role in application management on Kubernetes

  2. Searching and selecting Helm charts from Helm repositories.

  3. Installing applications using Helm, considering configuration values and parameters.

  4. Managing application upgrades/removals using Helm

Task 1: Install Helm

Your task is to install Helm, a Kubernetes package manager, on an existing Kubernetes cluster. Follow the installation steps provided on the official Helm website.

Task 2: Deploy Redis using Helm

Your objective is to deploy Redis, a popular in-memory data store, on the Kubernetes cluster using Helm. Find the Redis Helm chart on the Helm artifact hub and install it. Verify the successful installation by accessing the Redis CLI and running a few Redis commands.

Task 3: Install Prometheus, Grafana, and Alert Manager using Helm

Your goal is to install Prometheus, Grafana, and Alert Manager, a combination of applications commonly used for system monitoring and dashboarding. Find the corresponding Helm charts for these applications on the Helm artifact hub and install them. Ensure that each individual application (Prometheus, Grafana, Alert Manager) is accessible.

Task 4: Uninstall Helm Charts

Remove the installed Redis Helm chart from the Kubernetes cluster, as it is no longer needed. Additionally, uninstall the Kube-prometheus stack, which is currently installed in the default namespace, to follow a more structured work practice. Later, you will reinstall it in a different namespace.

Task 5: Deploy Redis with Custom Configuration

Install Redis using Helm with the following requirements:

  • Create a new namespace named "data-store".

  • Use the name "solution-one-redis" for the Redis installation.

  • Set the Redis password to "TheRedis123".

  • Enable the FLUSHALL command on the Redis master node.

Task 6: Deploy Kube-Prometheus Stack with Custom Configuration

Install Prometheus, Grafana, and Alert Manager with the following requirements:

  • Deploy these applications in a new namespace named "monitoring".

  • Use the name "solution-one-kube-prometheus" for the installation.

  • Expose Prometheus using an Ingress resource on the path "/prometheus".

  • Expose Grafana using an Ingress resource on the path "/grafana".

  • Expose Alert Manager using an Ingress resource on the path "/alert-manager".

Use a YAML configuration file to fulfill these requirements.

Task 1: Install Helm

  1. Go to the Helm website and find the installation instructions. Usually you can navigate to the menu like Docs, or Getting Started, and find the installation instructions

  2. Open your Kubernetes terminal, and install Helm following the installation instructions from the Helm website.

    Run the first command below to download the installation script.

     curl -fsSL -o get_helm.sh https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3

  3. Run the second command below to change the file permission, allowing the owner to read, write, and execute the file.

     chmod 700 get_helm.sh

  4. Run the script

     ./get_helm.sh

  5. Make sure the installation is successful and Helm was installed by using this terminal command:

     helm version

Task 2: Deploy Redis using Helm

  1. Go to the Helm artifact hub, and find the Redis Helm chart. There will be several charts available, but a good chart usually has more stars than the others. In this case, you can use Redis Helm chart from Bitnami provider.

  2. See the installation instruction

  3. Copy paste command A (shown on step 2, red rectangle) to your Kubernetes cluster to add Helm repository which owns the Helm chart

     helm repo add bitnami https://charts.bitnami.com/bitnami

  4. Copy paste command B (shown on step 2, red rectangle) to your Kubernetes cluster to install the Helm chart. Wait for a moment for Helm to download and install. Notice here that the command uses specific version, which is usually the latest version. If need, you can specify a different version.

     helm install my-redis bitnami/redis --version 17.11.3

    Some applications provide post-installation guide for further processing. In this case, you can test the Redis installation using the guidance.

    From the post-installation guide, run the commands to get Redis password, and run a Redis client. Follow these sequences:

  5. Export Redis password to Kubernetes cluster

     export REDIS_PASSWORD=$(kubectl get secret --namespace default my-redis -o jsonpath="{.data.redis-password}" | base64 -d)

    Run a Redis client

     kubectl run --namespace default redis-client --restart='Never'  --env REDIS_PASSWORD=$REDIS_PASSWORD  --image docker.io/bitnami/redis:7.0.11-debian-11-r12 --command -- sleep infinity

    Connect to running Redis client terminal

     kubectl exec --tty -i redis-client --namespace default -- bash

    1.  I have no name!@redis-client:/$

  6. Connect to Redis server using the command from post-installation guide.

    REDISCLI_AUTH="$REDIS_PASSWORD" redis-cli -h my-redis-master

  7. Try to run several Redis commands to check that the installed Redis can be used

    1. Set one data with key: my-key and value: my-dummy-value which will expire in 5 minutes

       SET my-key my-dummy-value EX 300

    2. Make sure that the key exists

       KEYS my-key

    3. Retrieve the value

       GET my-key

  1. Try to flush all keys using the following Redis command

     FLUSHALL

    This is a valid Redis command, but we can't use it. We will fix this issue later

  2. Exit the Redis client and go back to Kubernetes CLI. Keep typing exit until going back to the main Kubernetes terminal

Task 3: Install Prometheus, Grafana, and Alert Manager using Helm

  1. The three application combination that is specific for Kubernetes is commonly known as Kube-Prometheus Stack. Go to Helm artifact hub, and find the kube-prometheus Helm chart. There will be several charts available, but a good chart usually has more stars than the others. In this case, you can use the Helm chart from prometheus-community provider.

  2. See the installation instructions

  3. Copy paste command A (shown on step 2, red rectangle) to your Kubernetes cluster to add Helm repository which owns the Helm chart

     helm repo add prometheus-community https://prometheus-community.github.io/helm-charts

  4. Copy paste command B to your Kubernetes cluster to install the Helm chart. Wait for a moment for Helm to download and install.

    helm install my-kube-prometheus-stack prometheus-community/kube-prometheus-stack --version 46.6.0
  1. Make sure the pods are created. Check the status by running the command from post-installation guide (yellow rectangle on step #4)
    kubectl --namespace default get pods -l "release=my-kube-prometheus-stack"

  1. The Helm chart for the Kube-prometheus stack will also create Kubernetes services, which you can check using the command below:

     kubectl get services -n default | grep kube-prometheus

    Notice they are ClusterIP, which means you can access them using the port-forward

  2. Create services port-forward as below. Run all the port forwarding on background, by adding & at the end of port-forward command:

    1. Prometheus (ClusterIP port 9090) to host port 9090

       kubectl port-forward service/my-kube-prometheus-stack-prometheus 9090:9090 &

    2. Grafana (ClusterIP port 80) to host port 8080 (port 80 on host is already occupied by Traefik Ingress Controller)

       kubectl port-forward service/my-kube-prometheus-stack-grafana 8080:80 &

      Then CTRL-C (Windows) or Command-C (Mac)

    3. Alert Manager (ClusterIP port 9093) to host port 9093

       kubectl port-forward service/my-kube-prometheus-stack-alertmanager 9093:9093 &

      Then CTRL-C (Windows) or Command-C (Mac)

  3. Check that all three services are available. You can use curl command to each port-forwarded port to check that the servers are accessible.

    1. Prometheus : curl -i http://localhost:9090

    2. Grafana : curl -i http://localhost:8080

    3. Alert Manager : curl -i http://localhost:9093

Task 4: Uninstall Helm Charts

  1. List all of the installed Helm charts using the following command:

     helm list

    There are Redis and Kube-prometheus stack with the installation names shown in the green rectangle below

  2. Remove installed Redis Helm chart by using the command below:

     helm uninstall my-redis

  3. Remove installed Kube-Prometheus stack Helm chart by using the command below:

     helm uninstall my-kube-prometheus-stack

  4. Re-list all installed Helm charts using the command below:

     helm list

    It should show nothing now meaning no Helm chart is left installed in the Kubernetes cluster.

  5. Make sure you have no pods running on the namespace default, since the Helm charts were removed:

     kubectl get pods -n default

    Apparently, you still have redis-client, which is installed manually on Task 2 (not using a Helm chart). You can remove the Redis client pod by using the command below:

     kubectl delete pod -n default redis-client

    Re-check the pods, and you should have no pods now:

     kubectl get pods -n default

    Make sure you have no services on the namespace default, since the Helm charts are removed:

     kubectl get services -n default

    You only have kubernetes services itself, but no Redis nor Kube-prometheus related services, which means removal is successful.

Task 5: Deploy Redis with Custom Configuration

  1. Go to Helm artifact hub, and find Redis Helm chart from bitnami (same one we used in Task #2)

  2. On Redis Helm page, scroll down in the documentation page, and find items related to password, and disabled commands

    You will find three configurable parameters that will affect requirements:

    1. auth.password: to set Redis password (TheRedis123 on requirement)

    2. master.disableCommands: to display a list of disabled commands on the master node, the default is ["FLUSHDB","FLUSHALL"], that's why the command FLUSHALL on Task #2 couldn't be executed

  3. Go to the Kubernetes terminal and create a namespace data-store using command:

     kubectl create namespace data-store

  4. To install Redis and fullfil the requirements, you need to define an installation name (or the technical term: Helm release name). Also you need to set a value for configuration parameters auth.password and master.disableCommands

    Use this command:

     helm install solution-one-redis bitnami/redis --version 17.11.2 --namespace data-store --set auth.password=TheRedis123 --set master.disableCommands=

Make sure the installed Redis has the name solution-one-redis and is installed on the namespace data-store

List the Helm installations on the namespace data-store using the command below:

helm list -n data-store

  1. Make sure the Redis password is TheRedis123. The password is stored on the Kubernetes secret, with secret name is solution-one-redis (same with the installation name). You can check the password value by using the following command:

     kubectl get secret --namespace data-store solution-one-redis -o jsonpath="{.data.redis-password}" | base64 -d

  2. To check that the Redis FLUSHALL command is enabled, create a Redis client.

    First, export the Redis password to environment variable:

     export REDIS_PASSWORD=$(kubectl get secret --namespace data-store solution-one-redis -o jsonpath="{.data.redis-password}" | base64 -d)

    Run a Redis client on the namespace data-store

     kubectl run --namespace data-store redis-client --restart='Never'  --env REDIS_PASSWORD=$REDIS_PASSWORD  --image docker.io/bitnami/redis:7.0.11-debian-11-r7 --command -- sleep infinity

    Connect to running Redis client terminal:

     kubectl exec --tty -i redis-client --namespace data-store -- bash

  3. From Redis client, connect to Redis server (master node):

     REDISCLI_AUTH="$REDIS_PASSWORD" redis-cli -h solution-one-redis-master. Data-store

    1. Set one data with key: my-key and value: my-dummy-value which will expire in 5 minutes

       SET my-key my-other-dummy-value EX 300

    2. Make sure that the key exists

       KEYS my-key

    3. Try to flush all keys using the Redis command. This time, command FLUSHALL should work:

       FLUSHALL

    4. Make sure that the key was removed (this command should return an empty array):

       KEYS my-other-key

  4. Keep using the command exit until you go back to the main terminal

Task 6: Deploy Kube-Prometheus Stack with Custom Configuration

  1. Go to the Helm artifact hub, and find the Kube-Prometheus Helm chart from the prometheus-community (same one in task #3)

  2. On Kube-Prometheus stack Helm page, check the documentation, where you can see the possible configuration items by clicking the Default Values button

    You will also find a link which will redirect you to the external documentation site

    Where you can navigate further, to see how to expose Kube-Prometheus stack behind ingress controller.

  3. The configuration is quite complex, but basically you will need to create a yaml file on the server containing the items below:

     prometheus:
   ingress:
     enabled: true
     annotations: 
       ingress.kubernetes.io/rewrite-target: /
     paths:
     - /prometheus
   prometheusSpec:
     routePrefix: /prometheus

 grafana:
   adminPassword: changeme
   ingress:
     enabled: true
     annotations: 
       ingress.kubernetes.io/rewrite-target: /
     path: /grafana
   grafana.ini: 
     server:
       root_url: "%(protocol)s://%(domain)s:%(http_port)s/grafana"
       serve_from_sub_path: true

 alertmanager:
   ingress:
     enabled: true
     annotations: 
       ingress.kubernetes.io/rewrite-target: /
     paths:
     - /alertmanager
   alertmanagerSpec:
     routePrefix: /alertmanager

    These configurations define the settings for the Ingress resources, including path mappings, annotations, and specific configurations for Prometheus, Grafana, and Alertmanager within the kube-prometheus stack installation.

    Let's break down the contents:

    1. prometheus section:

      • ingress: create the Ingress resource for Prometheus.

      • annotations: Specifies annotations for the Ingress resource, including ingress.kubernetes.io/rewrite-target which rewrites the target URL path to "/".

      • paths: Defines the path(s) for the Ingress resource, in this case, "/prometheus".

      • prometheusSpec: Allows configuration of specific settings for Prometheus, such as routePrefix which sets the URL route prefix to "/prometheus".

    2. grafana section:

      • ingress: create the Ingress resource for Grafana.

      • annotations: Specifies annotations for the Ingress resource, including ingress.kubernetes.io/rewrite-target which rewrites the target URL path to "/".

      • path: Defines the path for the Ingress resource, which is set to "/grafana".

      • grafana.ini: Configures settings for Grafana, such as root_url which specifies the base URL for Grafana and serve_from_sub_path to serve Grafana from a subpath.

    3. alertmanager section:

      • ingress: create the Ingress resource for Alert manager.

      • annotations: Specifies annotations for the Ingress resource, including ingress.kubernetes.io/rewrite-target which rewrites the target URL path to "/".

      • paths: Defines the path(s) for the Ingress resource, in this case, "/alertmanager".

      • alertmanagerSpec: Allows configuration of specific settings for Alertmanager, such as routePrefix which sets the URL route prefix to "/alertmanager".

  4. Go to the terminal, and create the file values-monitoring.yml using the following command:

     nano values-monitoring.yml

  5. Copy & paste the configuration contents from Step 3:

    Press CTRL-X (Windows) or Command-X (Mac), then Y

    then Enter / Return to save the file and exit nano editor

  6. Install Kube-Prometheus stack using custom configuration. Use this command:

     helm install solution-one-kube-prometheus --repo https://prometheus-community.github.io/helm-charts kube-prometheus-stack --namespace monitoring --create-namespace --values values-monitoring.yml

    Let's break down the command :

    • helm install: installs a Helm chart

    • solution-one-kube-prometheus: specifies the name to assign to the Helm release

    • --repo https://prometheus-community.github.io/helm-charts: specifies the repository from which the chart should be installed. In this case, it points to the Prometheus Community Helm Charts repository located at the provided URL. Helm will fetch the chart from this repository.

    • kube-prometheus-stack: specifies name of the chart you want to install

    • --namespace monitoring: specifies the namespace in which the chart will be installed. In this case, it's being installed in the monitoring namespace.

    • --create-namespace: instructs Helm to create the specified namespace if it doesn't already exist.

    • --values values-monitoring.yml: specifies a values file (values-monitoring.yml) to provide custom configurations for the chart during installation

  1. Check that Kubernetes pods, services, and ingress, were created on the monitoring namespace

     kubectl get pod -n monitoring | grep kube-prometheus


     kubectl get service -n monitoring


  1.  kubectl get ingress -n monitoring

  1. Try checking that the applications are accessible through ingress. Use curl to show only the HTTP response status code, as the response body will be long (HTML). The response status code should be 200 (meaning "OK")

     curl -L -s -o /dev/null -w "%{http_code}\n" http://127.0.0.1/prometheus/metrics

     curl -L -s -o /dev/null -w "%{http_code}\n" http://127.0.0.1/grafana

     curl -L -s -o /dev/null -w "%{http_code}\n" http://127.0.0.1/alertmanager

Successfully we completed the Installed and Managed Redis, Prometheus, & Grafana on Kubernetes Using Helm

#redis#prometheus#grafana#kubernetes#helm

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Ganesh Balimidi

13 posts

I'm Proficient in a variety of DevOps technologies, including AWS, Linux, Shell Scripting, Docker, Terraform, Kubernetes, Jenkins, Git/GitHub, and Computer Networking.