Day-14 | Configuration Management With Ansible |Puppet vs Ansible |Live Projects | #ansible #devops

Introduction to Configuration Management in DevOps

Welcome and Course Overview

• Abhishek introduces himself and celebrates reaching 10,000 subscribers, expressing gratitude for the support and feedback from viewers.

• The video is part of a 45-day DevOps course covering various aspects including interview questions, scenarios, and real-time projects.

• Previous projects included AWS and shell scripting; future projects will involve Ansible, Terraform, Kubernetes, and Docker.

Understanding Configuration Management

• Configuration management is presented as one of the simpler topics in DevOps compared to others that may have more complexities.

• The focus of today's video is on theoretical understanding of configuration management and the widespread use of Ansible in this field.

What is Configuration Management?

Definition and Importance

• Configuration management involves managing server configurations or infrastructure setups by DevOps engineers.

• It addresses challenges faced by system administrators before the evolution of DevOps practices.

Real-world Scenario

• A scenario illustrates a system administrator managing on-premises servers within a company’s data center.

• The example includes managing multiple servers with different operating systems (Linux distributions like CentOS and Ubuntu).

Key Responsibilities in Configuration Management

Tasks Performed by System Administrators

• System administrators are responsible for maintaining server upgrades to ensure security patches are applied timely.

• They must also handle installations of necessary software packages across multiple servers efficiently.

Challenges Faced

• Managing updates across numerous servers can be cumbersome; logging into each server individually becomes impractical for teams.

Configuration Management in the Age of Cloud

The Evolution of Server Management

• Previously, system administrators relied on scripts for server management, using shell scripts for Linux and PowerShell for Windows.

• Different Linux distributions (e.g., CentOS vs. Ubuntu) required different commands, complicating the scripting process.

• As server counts increased from hundreds to thousands or tens of thousands, managing installations via scripts became increasingly challenging.

Transition to Cloud Computing

• The shift to cloud computing led to a tenfold increase in the number of servers being created.

• Simultaneously, the size and resources allocated per server decreased due to microservice architecture.

• This exponential growth in server numbers exacerbated existing management challenges.

The Need for Configuration Management Tools

• There was a clear need for tools that could simplify configuration management across diverse operating systems and distributions.

• System administrators faced difficulties writing effective scripts due to varying commands across different environments (e.g., Ubuntu vs. Alpine).

Introduction to Configuration Management Concepts

• Configuration management emerged as a solution to manage multiple servers efficiently within organizations.

• Every organization today typically manages hundreds or thousands of servers due to advancements in cloud technology.

Popular Tools in Configuration Management

• Notable configuration management tools include Puppet, Chef, Ansible, and SaltStack.

• Among these tools, Ansible has gained significant popularity among DevOps engineers due to its user-friendliness and effectiveness.

Personal Experiences with Configuration Management Tools

• Many DevOps professionals began their journey with Puppet or Chef before transitioning to Ansible around 2016–2017 when it gained traction.

Ansible: The Go-To Tool for Configuration Management

Introduction to Ansible

• Ansible became part of Red Hat around 2018 or 2019 and is continuously updated by Red Hat, making it a leading tool for configuration management.

• For those starting in configuration management, the recommendation is to begin with Ansible due to its widespread use in organizations (90% likelihood).

• While other tools like Puppet, Chef, and Salt exist, Ansible's popularity makes it a practical choice for beginners.

Why Choose Ansible Over Other Tools?

• A common interview question is why one would choose Ansible over Puppet or Chef; understanding the architecture of these tools is crucial.

• The primary distinction lies in their operational models: Puppet uses a pull mechanism while Ansible employs a push mechanism.

Push vs. Pull Mechanism

• In a scenario where a DevOps engineer manages AWS configurations, using Ansible allows them to push updates from their laptop directly to multiple EC2 instances.

• With Puppet's pull model, the engineer would need each instance to request updates from a central server instead of pushing changes directly.

Advantages of Using Ansible

• One significant advantage of Ansible is its agentless model; there’s no need for additional software on target machines.

• Unlike Puppet's Master-Slave architecture requiring configuration on each slave node, with Ansible you only need an inventory file listing server names or IP addresses.

Inventory File and Authentication

• The inventory file can include either DNS names or IP addresses of servers that will be managed by Ansible.

• Passwordless authentication must be enabled so that the machine running the playbook can connect without needing passwords for each instance.

Ansible vs Puppet: Understanding Configuration Management

Agentless Architecture of Ansible

• Ansible operates on an agentless model, requiring only the IP address for configuration management, unlike Puppet which relies on certificates and a master-slave architecture.

• By adding the EC2 instance's IP address to the inventory file, users can easily update configurations with a simple command or by running an Ansible playbook.

Dynamic Environments and Scalability

• In dynamic environments, such as during peak load times (e.g., holidays), organizations can scale their servers up or down quickly.

• Ansible simplifies this process; users just need to add public IP addresses to the inventory file for scaling instances without additional complexity.

Introduction of Dynamic Inventory

• The concept of dynamic inventory allows Ansible to automatically detect new servers created in AWS without manual updates to the inventory file.

• Users can configure Ansible to recognize new EC2 instances in specific regions or availability zones automatically.

Comparison with Puppet and Chef

• Key differences between Ansible and other tools like Puppet include:

• Pull vs Push Model: Puppet uses a pull model while Ansible employs a push model.

• Architecture: Puppet follows a master-slave architecture compared to Ansible’s agentless approach.

Support for Windows and Linux

• Ansible provides robust support for both Windows and Linux systems, making it easier for DevOps engineers who manage diverse environments.

• After Red Hat's acquisition of Ansible, many modules were introduced that improved its functionality with Windows servers.

Simplicity of Language in Configuration Files

• Unlike Puppet which requires learning its specific language, Ansible utilizes YAML manifests that are more accessible since many DevOps professionals are already familiar with YAML syntax.

• This ease of use is crucial when adopting new tools; familiarity with YAML helps reduce the learning curve associated with using Ansible.

Summary of Key Differences

• Model Type: Pull (Puppet) vs Push (Ansible).

• Architecture: Master-Slave (Puppet) vs Agentless (Ansible).

• OS Support: Strong support for both Windows and Linux in Ansible.

Ansible: Advantages and Disadvantages

Overview of Ansible's Capabilities

• The speaker acknowledges that while Ansible is a leading tool for configuration management, it does have disadvantages.

• Users of Windows servers may face challenges with Ansible due to differences in configuration management between Windows and Linux systems.

Key Issues with Ansible

• Debugging is highlighted as a significant concern; users need effective mechanisms to identify issues during playbook execution.

• The current debugging logs are not user-friendly, making it difficult for DevOps engineers to troubleshoot problems effectively.

• Performance issues arise when managing large numbers of servers (e.g., 10,000+), particularly during parallel executions.

Advantages of Custom Modules

• One notable advantage of Ansible is the ability to write custom modules tailored to specific applications or organizational needs.

• Organizations can create modules for their unique applications (e.g., load balancers), which can then be shared across different teams using Ansible Galaxy.

Community Contribution and Collaboration

• Sharing custom modules through Ansible Galaxy fosters collaboration among organizations, allowing them to leverage each other's work.

• This open-source approach encourages contributions from various organizations, enhancing the overall functionality and capabilities of Ansible.

Upcoming Practical Session on Ansible

Live Project Demonstration

• The speaker plans to conduct a live project demonstrating how to write an Ansible Playbook, including its structure and content updates.

• Participants will learn how to create instances on AWS and push configurations via GitHub for broader accessibility.

Ansible Interview Questions

Preparation Resources

Interview Questions on Ansible

Common Interview Questions

• One common interview question is about the programming language used by Ansible. The answer is Python, which allows users to write custom modules.

• If asked whether you have contributed to Ansible or written custom modules, you can mention your comfort with Python and readiness to create modules if needed.

Support for Operating Systems

• Ansible supports both Linux and Windows operating systems. For Linux, it uses SSH protocol, while for Windows, it utilizes WinRM protocol.

• This distinction between protocols is often a key question in interviews regarding Ansible's compatibility with different operating systems.

Configuration Management Tools Comparison

• Interviewers frequently ask about the differences between configuration management tools like Puppet and Chef compared to Ansible. It's important to articulate why one might choose Ansible over others.

• A thorough understanding of these differences can be found in earlier parts of the video.

Mechanism of Operation

• Another typical question pertains to whether Ansible operates on a push or pull mechanism. The answer is that it uses a push mechanism, which has its advantages over pull mechanisms.

Cloud Provider Compatibility

• Candidates may be questioned about whether Ansible supports all cloud providers such as AWS, Azure, and GCP. The key point is that what matters is not the cloud provider but rather if the machine has a public IP address and SSH access enabled.

• Clarify that as long as SSH access from the Ansible host is allowed, automation can proceed regardless of the cloud provider being used.

Final Thoughts and Upcoming Content

• The session concludes with an overview of six interview questions discussed so far. Future videos will cover more interview questions along with practical projects related to Ansible.