From e6572d597b57f95edeab9e873b5094e849eaebe9 Mon Sep 17 00:00:00 2001 From: sinke237 Date: Tue, 17 Sep 2024 11:00:45 +0100 Subject: [PATCH] deployment procedures --- .../best_practices_docker_k8s.md | 134 +++++++++ .../instructions_for_docker.md | 173 ++++++++++++ .../instructions_for_kubernetes.md | 267 ++++++++++++++++++ .../troubleshoot_tips_docker_deployment.md | 261 +++++++++++++++++ ...troubleshoot_tips_kubernetes_deployment.md | 266 +++++++++++++++++ docs/README.md | 0 6 files changed, 1101 insertions(+) create mode 100644 docs/Deployment Procedures/best_practices_docker_k8s.md create mode 100644 docs/Deployment Procedures/instructions_for_docker.md create mode 100644 docs/Deployment Procedures/instructions_for_kubernetes.md create mode 100644 docs/Deployment Procedures/troubleshoot_tips_docker_deployment.md create mode 100644 docs/Deployment Procedures/troubleshoot_tips_kubernetes_deployment.md delete mode 100644 docs/README.md diff --git a/docs/Deployment Procedures/best_practices_docker_k8s.md b/docs/Deployment Procedures/best_practices_docker_k8s.md new file mode 100644 index 0000000..6537eff --- /dev/null +++ b/docs/Deployment Procedures/best_practices_docker_k8s.md @@ -0,0 +1,134 @@ +### Best Practices for Deploying Applications with Docker and Kubernetes + +#### Introduction + +Docker and Kubernetes are powerful tools for containerization and orchestration. Leveraging them effectively can lead to highly scalable, maintainable, and resilient application deployments. This document outlines best practices for deploying applications using Docker and Kubernetes, focusing on security, performance, and maintainability. + +--- + +### 1. Best Practices for Docker + +#### 1.1. Image Creation + +**1.1.1. Use Minimal Base Images** +- **Best Practice**: Use minimal base images (e.g., `alpine`, `distroless`) to reduce the attack surface and image size. +- **Reason**: Smaller images have fewer vulnerabilities and are quicker to deploy. + +**1.1.2. Avoid Running as Root** +- **Best Practice**: Configure Dockerfiles to use a non-root user. +- **Reason**: Running as a non-root user enhances security by limiting the potential impact of a container compromise. + +**1.1.3. Multi-Stage Builds** +- **Best Practice**: Use multi-stage builds to reduce the final image size and remove unnecessary build tools. +- **Reason**: Keeps the runtime image clean and lightweight. + +**1.1.4. Keep Dockerfiles Simple** +- **Best Practice**: Keep Dockerfiles simple and modular to make them easier to maintain and troubleshoot. +- **Reason**: Simplicity aids in readability and reduces the likelihood of errors. + +#### 1.2. Image Management + +**1.2.1. Use Tagged Versions** +- **Best Practice**: Tag images with meaningful version numbers and not just `latest`. +- **Reason**: Tagged versions ensure that you can reproduce the exact same image for testing or production. + +**1.2.2. Regularly Scan Images** +- **Best Practice**: Scan images for vulnerabilities using tools like Docker Security Scanning or third-party solutions. +- **Reason**: Helps identify and mitigate vulnerabilities before deploying to production. + +**1.2.3. Implement Image Cleanup** +- **Best Practice**: Regularly clean up unused images and containers. +- **Reason**: Reduces disk usage and helps avoid clutter. + +#### 1.3. Security + +**1.3.1. Implement Network Segmentation** +- **Best Practice**: Use Docker networks to isolate containers based on their roles (e.g., application, database). +- **Reason**: Reduces the attack surface by limiting communication between containers. + +**1.3.2. Use Docker Secrets for Sensitive Data** +- **Best Practice**: Store sensitive data like passwords and API keys using Docker Secrets. +- **Reason**: Enhances security by avoiding hard-coded secrets in Dockerfiles or environment variables. + +**1.3.3. Set Resource Limits** +- **Best Practice**: Define CPU and memory limits for each container. +- **Reason**: Prevents containers from consuming excessive resources, which can lead to instability. + +--- + +### 2. Best Practices for Kubernetes + +#### 2.1. Deployment Strategies + +**2.1.1. Use Rolling Updates** +- **Best Practice**: Implement rolling updates to update applications with zero downtime. +- **Reason**: Ensures that updates are deployed gradually, minimizing disruptions. + +**2.1.2. Define Health Checks** +- **Best Practice**: Implement liveness and readiness probes for your pods. +- **Reason**: Ensures that Kubernetes can detect and handle unhealthy containers effectively. + +**2.1.3. Use Namespace for Isolation** +- **Best Practice**: Organize resources using Kubernetes namespaces to isolate environments (e.g., dev, staging, production). +- **Reason**: Enhances security and resource management by separating different environments. + +#### 2.2. Security + +**2.2.1. Implement RBAC (Role-Based Access Control)** +- **Best Practice**: Use RBAC to control access to Kubernetes resources. +- **Reason**: Provides fine-grained access control, improving security by ensuring that users and applications have only the permissions they need. + +**2.2.2. Use Network Policies** +- **Best Practice**: Define network policies to control the communication between pods. +- **Reason**: Enhances security by restricting traffic and reducing the attack surface. + +**2.2.3. Regularly Update Kubernetes Components** +- **Best Practice**: Keep Kubernetes and its components up to date with the latest security patches. +- **Reason**: Reduces the risk of vulnerabilities and exploits. + +**2.2.4. Secure Kubernetes API Server** +- **Best Practice**: Use TLS for securing API server communication and enable API server audit logging. +- **Reason**: Protects the control plane and helps track access and changes. + +#### 2.3. Performance and Resource Management + +**2.3.1. Use Resource Requests and Limits** +- **Best Practice**: Define resource requests and limits for CPU and memory in pod specifications. +- **Reason**: Ensures optimal resource utilization and prevents resource contention. + +**2.3.2. Optimize Pod Placement** +- **Best Practice**: Use affinity and anti-affinity rules to control pod placement based on hardware and application requirements. +- **Reason**: Enhances performance and reliability by placing pods on appropriate nodes. + +**2.3.3. Enable Horizontal Pod Autoscaling** +- **Best Practice**: Configure Horizontal Pod Autoscalers to scale the number of pod replicas based on metrics like CPU utilization. +- **Reason**: Ensures that the application can handle varying loads efficiently. + +**2.3.4. Use Resource Quotas** +- **Best Practice**: Define resource quotas for namespaces to control the overall resource usage. +- **Reason**: Helps prevent resource starvation and ensures fair resource distribution. + +#### 2.4. Maintainability + +**2.4.1. Use Helm for Package Management** +- **Best Practice**: Use Helm charts to manage Kubernetes applications. +- **Reason**: Simplifies deployment, versioning, and management of Kubernetes resources. + +**2.4.2. Implement Logging and Monitoring** +- **Best Practice**: Set up centralized logging and monitoring using tools like Prometheus, Grafana, and ELK Stack. +- **Reason**: Facilitates troubleshooting and provides insights into application and cluster performance. + +**2.4.3. Document and Version Control Configurations** +- **Best Practice**: Store Kubernetes manifests and Helm charts in version control systems like Git. +- **Reason**: Ensures that configurations are trackable, reversible, and collaborative. + +**2.4.4. Automate with CI/CD Pipelines** +- **Best Practice**: Integrate Docker and Kubernetes deployments with CI/CD pipelines to automate testing and deployment. +- **Reason**: Enhances efficiency and consistency in deployment processes. + +--- + +### Conclusion + +Adhering to these best practices can significantly improve the security, performance, and maintainability of applications deployed with Docker and Kubernetes. Regularly reviewing and updating these practices in line with new developments and evolving standards is crucial for maintaining an effective deployment strategy. + diff --git a/docs/Deployment Procedures/instructions_for_docker.md b/docs/Deployment Procedures/instructions_for_docker.md new file mode 100644 index 0000000..89de0e9 --- /dev/null +++ b/docs/Deployment Procedures/instructions_for_docker.md @@ -0,0 +1,173 @@ +# Comprehensive Guide to Deploying Applications Using Docker + +## Introduction + +Docker is a platform that enables developers to package applications and their dependencies into a standardized unit called a container. This document outlines the process for deploying an application using Docker, covering prerequisites, building images, running containers, and managing services. + +## Prerequisites + +Before deploying your application with Docker, ensure you have the following prerequisites: + +1. **Docker Installation** + - **Docker Engine**: The core software needed to build, run, and manage Docker containers. + - **Docker CLI**: The command-line interface for interacting with Docker. + - **Docker Compose** (optional but recommended for managing multi-container applications). + + **Installation:** + - On **Windows** and **macOS**: Docker Desktop provides an easy installation package. + - On **Linux**: Use your package manager or follow Docker’s official installation instructions. + + ```bash + # For Ubuntu-based systems: + sudo apt-get update + sudo apt-get install docker.io + sudo systemctl start docker + sudo systemctl enable docker + + # Install Docker Compose: + sudo curl -L "https://github.com/docker/compose/releases/download/$(curl -s https://api.github.com/repos/docker/compose/releases/latest | grep 'tag_name' | cut -d\" -f4)/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose + sudo chmod +x /usr/local/bin/docker-compose + ``` + +2. **Basic Knowledge of Docker Concepts** + - **Images**: Blueprints for containers. + - **Containers**: Running instances of Docker images. + - **Dockerfile**: A text file with instructions to build Docker images. + - **Docker Compose File**: A YAML file defining multi-container applications. + +3. **Application Code and Dependencies** + - Ensure your application code and any dependencies are ready for containerization. + +4. **Networking and Firewall Configuration** + - Ensure that the appropriate ports are open on your host machine and network. + +## Step-by-Step Deployment Process + +### 1. **Create a Dockerfile** + +A Dockerfile contains instructions for building a Docker image. Here’s a basic example for a Node.js application: + +```Dockerfile +# Use the official Node.js image. +FROM node:14 + +# Set the working directory. +WORKDIR /usr/src/app + +# Copy package.json and package-lock.json. +COPY package*.json ./ + +# Install dependencies. +RUN npm install + +# Copy the rest of the application code. +COPY . . + +# Expose the port on which the app will run. +EXPOSE 3000 + +# Define the command to run the application. +CMD ["node", "app.js"] +``` + +### 2. **Build the Docker Image** + +Run the following command in the directory containing your Dockerfile to build the image: + +```bash +docker build -t my-app:latest . +``` + +Here: +- `my-app` is the name of your image. +- `latest` is the tag (version) of the image. + +### 3. **Run a Docker Container** + +To start a container from your image, use the `docker run` command: + +```bash +docker run -d -p 3000:3000 --name my-app-container my-app:latest +``` + +Here: +- `-d` runs the container in detached mode. +- `-p 3000:3000` maps port 3000 on your host to port 3000 in the container. +- `--name` gives your container a name. +- `my-app:latest` specifies the image to use. + +### 4. **Verify the Container is Running** + +Check the status of your running container: + +```bash +docker ps +``` + +You should see your container listed. + +### 5. **Access the Application** + +Open your web browser and go to `http://localhost:3000` to access your application. + +### 6. **Stopping and Removing Containers** + +To stop a running container: + +```bash +docker stop my-app-container +``` + +To remove a stopped container: + +```bash +docker rm my-app-container +``` + +### 7. **Using Docker Compose** (Optional) + +For managing multi-container applications, use Docker Compose. Create a `docker-compose.yml` file: + +```yaml +version: '3' +services: + web: + image: my-app:latest + ports: + - "3000:3000" +``` + +Start the application with: + +```bash +docker-compose up -d +``` + +Stop and remove the application with: + +```bash +docker-compose down +``` + +## Additional Considerations + +1. **Persisting Data** + - Use Docker volumes to persist data across container restarts. + +2. **Environment Variables** + - Pass environment variables using the `-e` flag with `docker run` or in the `docker-compose.yml` file. + +3. **Security** + - Regularly update Docker images and follow security best practices. + +4. **Logging** + - Use Docker logging options or integrate with logging tools for monitoring. + +## Conclusion + +Deploying applications with Docker simplifies the process by providing consistency across different environments. Follow the outlined steps to build, run, and manage your Docker containers effectively. For more advanced setups and configurations, refer to Docker’s official documentation. + +**Acceptance Criteria:** +- This document provides a comprehensive overview of deploying an application using Docker. +- All steps are clearly outlined and include necessary commands and configurations. +- The document has been reviewed and validated for accuracy and completeness. \ No newline at end of file diff --git a/docs/Deployment Procedures/instructions_for_kubernetes.md b/docs/Deployment Procedures/instructions_for_kubernetes.md new file mode 100644 index 0000000..9edd6dc --- /dev/null +++ b/docs/Deployment Procedures/instructions_for_kubernetes.md @@ -0,0 +1,267 @@ +# Comprehensive Guide to Deploying Applications Using Kubernetes + +## Introduction + +Kubernetes (K8s) is an open-source platform designed for automating the deployment, scaling, and management of containerized applications. This document provides a detailed guide on deploying an application using Kubernetes, including prerequisites, creating deployments and services, and managing pods. + +## Prerequisites + +Before deploying your application with Kubernetes, ensure you have the following prerequisites: + +1. **Kubernetes Cluster** + - A running Kubernetes cluster, either locally (e.g., Minikube or kind) or on a cloud provider (e.g., Google Kubernetes Engine (GKE), Amazon EKS, or Azure Kubernetes Service (AKS)). + +2. **kubectl CLI Tool** + - The command-line interface tool for interacting with the Kubernetes cluster. + - **Installation:** + + ```bash + # On Linux + curl -LO "https://dl.k8s.io/release/$(curl -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl" + chmod +x ./kubectl + sudo mv ./kubectl /usr/local/bin/kubectl + + # On macOS + brew install kubectl + ``` + +3. **Docker Image** + - Ensure you have a Docker image of your application. You can use Docker Hub or any other container registry. + +4. **Basic Knowledge of Kubernetes Concepts** + - **Pod**: The smallest deployable unit in Kubernetes. + - **Deployment**: Manages a set of replica pods and handles scaling. + - **Service**: Exposes a set of pods as a network service. + - **ConfigMap and Secrets**: Manage configuration and sensitive information. + +5. **Networking and Firewall Configuration** + - Ensure appropriate ports are open and network policies are configured. + +## Step-by-Step Deployment Process + +### 1. **Create a Deployment** + +A Deployment in Kubernetes manages the deployment of Pods. Create a YAML file (e.g., `deployment.yaml`) for your Deployment configuration: + +```yaml +apiVersion: apps/v1 +kind: Deployment +metadata: + name: my-app-deployment +spec: + replicas: 3 + selector: + matchLabels: + app: my-app + template: + metadata: + labels: + app: my-app + spec: + containers: + - name: my-app-container + image: my-app:latest + ports: + - containerPort: 3000 +``` + +Here: +- `replicas` specifies the number of pod replicas. +- `selector` is used to match the Pods managed by this Deployment. +- `template` specifies the Pod configuration. + +**Apply the Deployment:** + +```bash +kubectl apply -f deployment.yaml +``` + +### 2. **Create a Service** + +To expose your application, create a Service YAML file (e.g., `service.yaml`): + +```yaml +apiVersion: v1 +kind: Service +metadata: + name: my-app-service +spec: + selector: + app: my-app + ports: + - protocol: TCP + port: 80 + targetPort: 3000 + type: LoadBalancer +``` + +Here: +- `selector` matches the Pods that this Service should route traffic to. +- `port` is the port that the Service will expose. +- `targetPort` is the port on the Pod that the Service should forward traffic to. +- `type: LoadBalancer` (optional) creates an external load balancer (in cloud environments) to expose the service. + +**Apply the Service:** + +```bash +kubectl apply -f service.yaml +``` + +### 3. **Verify the Deployment and Service** + +**Check the Deployment Status:** + +```bash +kubectl get deployments +``` + +**Check the Pods Status:** + +```bash +kubectl get pods +``` + +**Check the Service Status:** + +```bash +kubectl get services +``` + +For LoadBalancer type services, you may need to wait a few minutes for the external IP to be assigned. + +### 4. **Scaling the Deployment** + +To scale the number of replicas in your Deployment: + +```bash +kubectl scale deployment my-app-deployment --replicas=5 +``` + +### 5. **Updating the Deployment** + +To update your application (e.g., deploy a new version): + +1. Update the Docker image tag in `deployment.yaml`. +2. Apply the updated Deployment: + + ```bash + kubectl apply -f deployment.yaml + ``` + +Kubernetes will perform a rolling update by default. + +### 6. **Rolling Back the Deployment** + +To roll back to a previous version of your Deployment: + +```bash +kubectl rollout undo deployment/my-app-deployment +``` + +### 7. **Managing Pods Directly** + +**Get Detailed Pod Information:** + +```bash +kubectl describe pod +``` + +**Delete a Pod:** + +```bash +kubectl delete pod +``` + +**View Pod Logs:** + +```bash +kubectl logs +``` + +### 8. **Use ConfigMaps and Secrets** (Optional) + +**Create a ConfigMap:** + +```yaml +apiVersion: v1 +kind: ConfigMap +metadata: + name: my-app-config +data: + APP_ENV: production +``` + +**Apply ConfigMap:** + +```bash +kubectl apply -f configmap.yaml +``` + +**Use ConfigMap in a Pod:** + +Add the `envFrom` field to your Deployment YAML: + +```yaml +spec: + containers: + - name: my-app-container + image: my-app:latest + envFrom: + - configMapRef: + name: my-app-config +``` + +**Create a Secret:** + +```yaml +apiVersion: v1 +kind: Secret +metadata: + name: my-app-secret +type: Opaque +data: + password: dXNlcjpwYXNz +``` + +**Apply Secret:** + +```bash +kubectl apply -f secret.yaml +``` + +**Use Secret in a Pod:** + +Add the `envFrom` field to your Deployment YAML: + +```yaml +spec: + containers: + - name: my-app-container + image: my-app:latest + envFrom: + - secretRef: + name: my-app-secret +``` + +## Additional Considerations + +1. **Monitoring and Logging** + - Integrate monitoring and logging solutions like Prometheus, Grafana, and ELK Stack. + +2. **Resource Management** + - Define resource requests and limits in your Pod configuration to manage resource usage effectively. + +3. **Networking Policies** + - Configure network policies for securing communication between Pods. + +4. **Persistent Storage** + - Use Persistent Volumes and Persistent Volume Claims for stateful applications. + +## Conclusion + +Deploying applications using Kubernetes provides robust scaling, self-healing, and management features. This guide covers the essentials of creating deployments, exposing services, and managing pods. For more advanced configurations and features, refer to Kubernetes’ official documentation. + +**Acceptance Criteria:** +- This document provides a comprehensive overview of deploying an application using Kubernetes. +- All steps are clearly outlined with necessary commands and configurations. +- The document has been reviewed and validated for accuracy and completeness. \ No newline at end of file diff --git a/docs/Deployment Procedures/troubleshoot_tips_docker_deployment.md b/docs/Deployment Procedures/troubleshoot_tips_docker_deployment.md new file mode 100644 index 0000000..a44e616 --- /dev/null +++ b/docs/Deployment Procedures/troubleshoot_tips_docker_deployment.md @@ -0,0 +1,261 @@ +# Troubleshooting Docker Deployments: Common Issues and Solutions + +## Introduction + +While Docker simplifies the deployment process by providing consistency across environments, issues can still arise. This document identifies common problems encountered during Docker deployments and provides troubleshooting tips to resolve them. + +## Common Issues and Solutions + +### 1. **Image Build Failures** + +**Symptoms:** +- The `docker build` command fails with errors during the image build process. + +**Common Causes and Solutions:** + +- **Error in Dockerfile Syntax or Commands:** + - **Solution:** Review the Dockerfile for syntax errors and verify each command. Use `docker build` with the `--no-cache` option to ensure you're not using cached layers. + + ```bash + docker build --no-cache -t my-app:latest . + ``` + +- **Missing Dependencies or Files:** + - **Solution:** Ensure all dependencies and files required by the Dockerfile are available. Verify paths and filenames are correct. + +- **Network Issues:** + - **Solution:** Check your network connection and proxy settings. Ensure Docker can access external resources. + +### 2. **Container Startup Failures** + +**Symptoms:** +- Containers fail to start or exit immediately after starting. + +**Common Causes and Solutions:** + +- **Incorrect Entrypoint or Command:** + - **Solution:** Verify the `ENTRYPOINT` and `CMD` instructions in your Dockerfile. Check logs for specific errors. + + ```bash + docker logs + ``` + +- **Port Conflicts:** + - **Solution:** Ensure the ports exposed by the container are not already in use on the host. + + ```bash + docker run -p 8080:8080 my-app:latest + ``` + +- **Missing Environment Variables or Configuration:** + - **Solution:** Ensure all required environment variables are set and configurations are correctly passed to the container. + + ```bash + docker run -e MY_ENV_VAR=value my-app:latest + ``` + +### 3. **Container Networking Issues** + +**Symptoms:** +- Containers cannot communicate with each other or external services. + +**Common Causes and Solutions:** + +- **Incorrect Network Configuration:** + - **Solution:** Verify network settings and ensure containers are on the same network if they need to communicate. + + ```bash + docker network ls + docker network inspect + ``` + +- **Firewall Rules Blocking Traffic:** + - **Solution:** Check and update firewall rules to allow traffic on the required ports. + +- **DNS Resolution Issues:** + - **Solution:** Ensure that DNS settings are correctly configured. Use Docker’s internal DNS for service discovery. + +### 4. **Volume Mount Issues** + +**Symptoms:** +- Data in mounted volumes is not as expected or data is missing. + +**Common Causes and Solutions:** + +- **Incorrect Volume Mount Path:** + - **Solution:** Verify that the volume mount path on the host and container matches the expected directories. + + ```bash + docker run -v /host/path:/container/path my-app:latest + ``` + +- **Permissions Issues:** + - **Solution:** Check permissions on the host directory and ensure the container user has the necessary access. + + ```bash + sudo chown -R 1000:1000 /host/path + ``` + +### 5. **High Resource Utilization** + +**Symptoms:** +- Containers are consuming excessive CPU or memory resources. + +**Common Causes and Solutions:** + +- **Resource Limits Not Set:** + - **Solution:** Define resource requests and limits in your Docker run commands or Compose files. + + ```bash + docker run --memory="512m" --cpus="1" my-app:latest + ``` + +- **Application Inefficiencies:** + - **Solution:** Review the application’s resource usage and optimize code if necessary. Monitor performance using tools like `docker stats`. + + ```bash + docker stats + ``` + +### 6. **Container Crashes or Restarts** + +**Symptoms:** +- Containers frequently crash or restart. + +**Common Causes and Solutions:** + +- **Application Crashes:** + - **Solution:** Inspect application logs to identify and resolve the root cause of crashes. + + ```bash + docker logs + ``` + +- **Health Check Failures:** + - **Solution:** Ensure the container's health check is correctly configured and the application meets health criteria. + + ```yaml + healthcheck: + test: ["CMD", "curl", "-f", "http://localhost/health"] + interval: 30s + ``` + +### 7. **Access Denied or Authentication Issues** + +**Symptoms:** +- Issues with accessing private registries or pulling images. + +**Common Causes and Solutions:** + +- **Authentication Failures:** + - **Solution:** Ensure Docker is properly authenticated with your container registry. Use `docker login` for private registries. + + ```bash + docker login + ``` + +- **Incorrect Image Name or Tag:** + - **Solution:** Verify the image name and tag are correct and exist in the registry. + + ```bash + docker pull my-app:latest + ``` + +### 8. **Permissions Issues with Docker Daemon** + +**Symptoms:** +- Errors related to permissions when interacting with Docker commands. + +**Common Causes and Solutions:** + +- **Non-Root User Permissions:** + - **Solution:** Add your user to the Docker group to allow non-root access. + + ```bash + sudo usermod -aG docker $USER + ``` + +- **Docker Daemon Not Running:** + - **Solution:** Ensure the Docker service is running. + + ```bash + sudo systemctl start docker + sudo systemctl enable docker + ``` + +## Debugging and Resolving Deployment Issues + +### 1. **Use Logs and Status Commands** + +- **Container Logs:** + + ```bash + docker logs + ``` + +- **Container Status:** + + ```bash + docker ps -a + ``` + +- **Docker System Information:** + + ```bash + docker info + ``` + +### 2. **Check Docker and System Resources** + +- **Docker Resource Usage:** + + ```bash + docker stats + ``` + +- **System Resource Usage:** + + ```bash + top + ``` + +### 3. **Network Troubleshooting** + +- **Inspect Networks:** + + ```bash + docker network ls + docker network inspect + ``` + +- **Ping Between Containers:** + + ```bash + docker exec -it ping + ``` + +### 4. **Verify Dockerfile and Configuration** + +- **Build Dockerfile with Verbose Output:** + + ```bash + docker build --no-cache --progress=plain -t my-app:latest . + ``` + +- **Validate Configuration Files:** + + Review and validate Dockerfile, Compose files, and Kubernetes manifests. + +### 5. **Consult Documentation and Community** + +- **Docker Documentation:** [Docker Docs](https://docs.docker.com/) +- **Docker Forums and Stack Overflow:** For community support and troubleshooting tips. + +## Conclusion + +This document provides guidance on troubleshooting common issues encountered during Docker deployments. By following these tips and utilizing Docker’s tools and commands, you can efficiently diagnose and resolve deployment issues. + +**Acceptance Criteria:** +- The document outlines frequent problems and their solutions in Docker deployments. +- Troubleshooting tips are clear and actionable. +- The document has been reviewed and validated for accuracy and completeness. \ No newline at end of file diff --git a/docs/Deployment Procedures/troubleshoot_tips_kubernetes_deployment.md b/docs/Deployment Procedures/troubleshoot_tips_kubernetes_deployment.md new file mode 100644 index 0000000..5a00bf9 --- /dev/null +++ b/docs/Deployment Procedures/troubleshoot_tips_kubernetes_deployment.md @@ -0,0 +1,266 @@ +# Troubleshooting Kubernetes Deployments: Common Issues and Solutions + +## Introduction + +Kubernetes is a powerful platform for managing containerized applications, but it can be complex. This document identifies common issues encountered during Kubernetes deployments and provides troubleshooting tips to help resolve them. + +## Common Issues and Solutions + +### 1. **Pod Failures** + +**Symptoms:** +- Pods are in `CrashLoopBackOff` or `Error` state. + +**Common Causes and Solutions:** + +- **Application Errors:** + - **Solution:** Check the application logs to diagnose errors. + + ```bash + kubectl logs + ``` + +- **Incorrect Configuration:** + - **Solution:** Verify that environment variables, secrets, and ConfigMaps are correctly configured and mounted. + + ```bash + kubectl describe pod + ``` + +- **Resource Limits:** + - **Solution:** Ensure resource requests and limits are appropriately set to prevent resource exhaustion. + + ```yaml + resources: + requests: + memory: "512Mi" + cpu: "250m" + limits: + memory: "1Gi" + cpu: "500m" + ``` + +### 2. **Deployment Issues** + +**Symptoms:** +- Deployments are stuck in `Pending`, `Progressing`, or `Failed` state. + +**Common Causes and Solutions:** + +- **Insufficient Resources:** + - **Solution:** Check if there are enough resources available in the cluster. + + ```bash + kubectl describe deployment + ``` + +- **Image Pull Errors:** + - **Solution:** Verify that the Docker image exists in the registry and that the credentials (if required) are correct. + + ```bash + kubectl describe pod | grep "Failed to pull image" + ``` + +- **Deployment Strategy Issues:** + - **Solution:** Ensure deployment strategies and rolling updates are correctly defined. + + ```yaml + strategy: + type: RollingUpdate + rollingUpdate: + maxUnavailable: 1 + maxSurge: 1 + ``` + +### 3. **Service Exposure Problems** + +**Symptoms:** +- Services are not accessible or not routing traffic correctly. + +**Common Causes and Solutions:** + +- **Incorrect Service Configuration:** + - **Solution:** Verify that the Service configuration correctly selects the intended Pods and that ports are correctly mapped. + + ```bash + kubectl describe service + ``` + +- **Load Balancer Issues:** + - **Solution:** For `LoadBalancer` type services, ensure the external load balancer is provisioned and check for errors. + + ```bash + kubectl get services + ``` + +- **Network Policies:** + - **Solution:** Ensure network policies are correctly configured to allow traffic between Pods and Services. + + ```bash + kubectl get networkpolicies + ``` + +### 4. **Persistent Storage Problems** + +**Symptoms:** +- Pods fail to mount Persistent Volumes (PVs) or Persistent Volume Claims (PVCs). + +**Common Causes and Solutions:** + +- **Volume Binding Issues:** + - **Solution:** Check if the PVC is bound to a PV and verify the storage class and access modes. + + ```bash + kubectl get pvc + kubectl describe pvc + ``` + +- **Permissions Issues:** + - **Solution:** Ensure the Pod has the correct permissions to access the volume. + + ```yaml + securityContext: + fsGroup: 1000 + ``` + +### 5. **Namespace and Resource Quota Issues** + +**Symptoms:** +- Resources are not created or deployed due to namespace restrictions or quotas. + +**Common Causes and Solutions:** + +- **Quota Exceeded:** + - **Solution:** Check the resource quotas and limits for the namespace. + + ```bash + kubectl describe quota -n + ``` + +- **Incorrect Namespace:** + - **Solution:** Ensure resources are being created in the correct namespace. + + ```bash + kubectl get all -n + ``` + +### 6. **ConfigMap and Secret Issues** + +**Symptoms:** +- Applications fail to start due to missing or incorrect configuration data. + +**Common Causes and Solutions:** + +- **Misconfigured ConfigMaps/Secrets:** + - **Solution:** Verify the data in ConfigMaps and Secrets and ensure they are correctly referenced by Pods. + + ```bash + kubectl get configmap + kubectl describe configmap + kubectl get secret + kubectl describe secret + ``` + +### 7. **Node Issues** + +**Symptoms:** +- Nodes are in `NotReady` state or Pods are not scheduled due to node issues. + +**Common Causes and Solutions:** + +- **Node Resource Pressure:** + - **Solution:** Check node resource usage and resolve any resource pressure or constraints. + + ```bash + kubectl describe node + ``` + +- **Network or Disk Issues:** + - **Solution:** Investigate network and disk health on the affected node. + +### 8. **Application-Level Debugging** + +**Symptoms:** +- Applications have runtime issues or bugs. + +**Common Causes and Solutions:** + +- **Debugging Containers:** + - **Solution:** Use `kubectl exec` to run commands inside the container for debugging. + + ```bash + kubectl exec -it -- /bin/bash + ``` + +- **Live Debugging:** + - **Solution:** Deploy debugging tools or use sidecar containers for live debugging. + +## Debugging and Resolving Deployment Issues + +### 1. **Check Logs and Events** + +- **Pod Logs:** + + ```bash + kubectl logs + ``` + +- **Cluster Events:** + + ```bash + kubectl get events + ``` + +### 2. **Inspect Kubernetes Resources** + +- **Describe Resources:** + + ```bash + kubectl describe + ``` + +- **Resource Status:** + + ```bash + kubectl get pods + kubectl get deployments + kubectl get services + ``` + +### 3. **Verify Cluster Health** + +- **Check Cluster Nodes:** + + ```bash + kubectl get nodes + kubectl describe node + ``` + +- **Check Resource Usage:** + + ```bash + kubectl top nodes + kubectl top pods + ``` + +### 4. **Use Kubernetes Dashboard and Monitoring Tools** + +- **Kubernetes Dashboard:** + - Provides a web-based UI to monitor and manage cluster resources. + +- **Monitoring Tools:** + - Integrate tools like Prometheus and Grafana for detailed metrics and monitoring. + +### 5. **Consult Documentation and Community** + +- **Kubernetes Documentation:** [Kubernetes Docs](https://kubernetes.io/docs/) +- **Community Forums:** For additional support and troubleshooting tips. + +## Conclusion + +This document provides guidance on troubleshooting common issues encountered during Kubernetes deployments. By following these tips and utilizing Kubernetes' tools and commands, you can efficiently diagnose and resolve deployment issues. + +**Acceptance Criteria:** +- The document identifies frequent problems and their solutions in Kubernetes deployments. +- Troubleshooting tips are clear and actionable. +- The document has been reviewed and validated for accuracy and completeness. \ No newline at end of file diff --git a/docs/README.md b/docs/README.md deleted file mode 100644 index e69de29..0000000