November 2022 Summaries

IAM roles are a type of identity and access management (IAM) entity that enables applications running on Amazon EC2 instances or other AWS services to obtain temporary security credentials. These roles can be assumed by authorized entities, such as users, applications, or services, allowing them to perform actions with specific permissions on resources in an AWS account without needing long-term access keys. IAM roles are useful for several scenarios, including: 1. Granting cross-account access: IAM roles can be used to delegate permissions across different AWS accounts, enabling users or services from one account to assume a role in another account and access resources with the permissions granted by that role. 2. Identity federation: IAM roles support identity federation, allowing users to log in using their existing credentials from external identity providers (such as Amazon, Facebook, Google) and obtain temporary security credentials for accessing AWS services. 3. Managing permissions for applications running on EC2 instances or other AWS services: By attaching an IAM role to an EC2 instance or service, the application can assume that role and obtain temporary security credentials with specific permissions, eliminating the need to embed long-term access keys in the code or configuration files. 4. IAM roles anywhere: This feature allows on-premises or workloads outside AWS (such as servers, containers, and applications) to access resources on AWS by obtaining temporary security credentials. The principal must have X.509 certificates issued by a certificate authority for this to work. IAM roles are more secure than using long-term access keys because they automatically expire after a specified period (default is one hour), reducing the risk of unauthorized access if the credentials are compromised. Additionally, IAM roles can be easily revoked or updated without impacting running applications, providing better control over permissions and security. In summary, IAM roles play a crucial role in AWS's identity and access management system by enabling secure delegation of permissions across different accounts, services, and applications while eliminating the need for long-term access keys.

Kubernetes liveness probes ensure that an application within a container is live and operational based on a specified test. They are used when a pod may appear to be running but the application may not function correctly, such as in a deadlock situation. Liveness probes can improve pod resilience and availability by triggering an automatic restart of a container once a failure of a specified test is detected. Other types of Kubernetes probes include readiness and startup probes. Probes are managed by the kubelet, which uses one of four handlers: ExecAction, TCPSocketAction, HTTPGetAction, or gRPC handler.

Spacelift has introduced Spaces to create logical containers for stacks and resources, allowing more fine-grained control over infrastructure as it grows. This feature enables the assignment of policies, permissions boundaries, cloud integrations, worker pools, and more. Spaces can be used to manage multiple teams and environments with different policy scopes, context access, and other settings. The migration process involves assigning existing resources to the root space before creating new spaces and moving stacks accordingly. Managing and organizing spaces allows for better control over stack resource visibility and access permissions. Policies can be applied to ensure only authorized personnel have access to specific Spaces.

Terraform Workspaces enable the management of multiple deployments of the same configuration. They allow isolation of independent deployments while using the same state file. The workspace command is used to list, show, create, and delete workspaces. When a new workspace is created, a corresponding new state file is maintained in the remote backend. Workspaces can be used for testing modifications to existing configurations before applying them to critical environments or managing resources differently across various environments. However, they should not be confused with Git branches, as both have different purposes. Terraform workspaces are best suited for temporary use and may not be ideal for managing multiple staging environments.

Kubernetes is a popular orchestrator for deploying and scaling containerized applications in production but it's not secure by default. To protect your clusters from attacks, you can follow these best practices: use Role-Based Access Control (RBAC) to control user access; protect the control plane by restricting access to etcd, enabling encryption, and setting up external API server authentication; harden your nodes by monitoring system logs, keeping them updated, and avoiding running other workloads directly on a node; add network security policies to control communication between Pods; use Pod-level security features like security contexts and Pod Security admission rules; and finally, harden your workloads by scanning for vulnerabilities in code and using Kubernetes Secrets to store sensitive data. By following these steps, you can securely run containers in production without worrying about security issues.

Spacelift has released a new feature called Spaces that allows organizations to organize their stacks and resources in a more efficient manner. Spaces create logical permission boundaries for stacks and resources, enabling features such as multi-tenancy. This compartmentalization allows administrators to provide users with admin rights only to the Space they are assigned, ensuring proper management and security while providing self-service attributes needed by developers. Spaces can be created through the console or using the Spacelift Terraform Provider.

The article discusses the use of kubectl exec command to get a shell into a running container in a Kubernetes (K8S) cluster and run individual commands on a container. It provides examples for connecting to a single-container pod, running single commands directly using kubectl exec, and connecting to a specified container when a pod has multiple containers. The article emphasizes the importance of modifying containers temporarily for troubleshooting purposes only and recommends updating images if permanent modifications are required.

This blog post explores the use of Terraform and GitHub Actions to manage infrastructure workflows. It provides an overview of both tools, their benefits, and potential caveats when combined. The author demonstrates a simple setup using a GitHub repository with a Terraform file that deploys an EC2 instance on AWS. They also discuss the challenges of scaling and managing Terraform at scale in large organizations and present Spacelift as an alternative solution for infrastructure management.

Deleting a pod from a Kubernetes (K8S) node is often required for troubleshooting or maintenance purposes. To delete all the pods from a particular node, first retrieve the names of the nodes and then the names of the pods using kubectl get commands. Use the kubectl drain command to evict the pods from the node and schedule them on another free node. The drain command will cordon the node to prevent new pods from being scheduled while you are preparing it for removal or maintenance. Once complete, verify that your pods are now running on a different node using kubectl get pods -o wide. To delete a single pod, use the kubectl delete pod command. Consider scaling the number of pods appropriately before deleting them and maintain application uptime by gracefully bringing pods up on another node before they are deleted.

This article provides a step-by-step guide on using the Spacelift Terraform Provider to manage and deploy Spacelift resources. It covers creating repositories, configuring administrative stacks, coding with Terraform, deploying stacks, adding contexts, and managing environment variables. The author emphasizes that Spacelift is a flexible orchestration solution for Infrastructure as Code (IaC) development, offering enhanced collaboration, automation, and controls to simplify and accelerate cloud-based infrastructure provisioning.

The article discusses how to view pod logs in Kubernetes using the kubectl logs command line tool. It explains what kubectl is and provides a quick reference guide for various kubectl log commands, including viewing logs for a specific pod, following new logs, printing logs for a container within a pod, and viewing logs for previously failed pods. The article also demonstrates how to set an alias for kubectl to save time when using the command line tool.

The CrashLoopBackoff error in Kubernetes (K8S) occurs when a pod has crashed and attempted to restart multiple times. This is due to the K8S kubelet waiting an increasing 'backoff' time between crashes before attempting to start the pod again, with a maximum of 5 minutes starting at 10 seconds. The error can be fixed by troubleshooting using commands like kubectl describe pod and kubectl logs. Common causes include misconfiguration, out of memory or resources, port conflicts, connection issues, and incorrect environment variables.