IBM Fundamentals: Cross Account Resource Sharing

Breaking Down Silos: A Deep Dive into IBM Cross Account Resource Sharing

Imagine you're the lead architect at a rapidly growing financial services firm. Your development team is building a cutting-edge fraud detection system. The data science team needs access to sensitive customer data residing in a separate, highly-secured account managed by the compliance department. Traditionally, this would involve complex data replication, cumbersome access requests, and significant security overhead. Or consider a global retail company with separate accounts for development, staging, and production environments. Sharing infrastructure components like base images or network policies across these accounts is a constant challenge.

These scenarios are increasingly common. The rise of cloud-native applications, the demand for zero-trust security models, and the complexities of hybrid identity management are forcing organizations to rethink how they manage access to resources across different accounts. According to a recent IBM study, 68% of enterprises struggle with managing access control across multiple cloud environments. IBM Cross Account Resource Sharing (CARS) is designed to address these challenges, providing a secure and efficient way to share resources between IBM Cloud accounts. It’s a critical component for organizations embracing a multi-account strategy, enabling collaboration, reducing redundancy, and streamlining operations. This post will provide a comprehensive guide to CARS, from its core concepts to practical implementation and best practices.

What is "Cross Account Resource Sharing"?

IBM Cross Account Resource Sharing is a service that allows you to securely share resources – like images, keys, secrets, and network policies – between different IBM Cloud accounts without the need for complex replication or manual transfer. Think of it as a controlled, permission-based sharing mechanism. Instead of copying data, you grant access to the resource in the source account, and the target account can then utilize it directly.

The core problem CARS solves is the inherent friction in multi-account environments. Without a solution like CARS, teams often resort to insecure practices like sharing credentials or creating duplicate resources, leading to increased costs, security vulnerabilities, and operational complexity.

Major Components:

• Resource Owner Account: The account where the resource resides and from which access is granted.
• Resource Consumer Account: The account that requests and receives access to the shared resource.
• Sharing Policies: These define who can access what resources and how they can be used. Policies are granular and can be tailored to specific needs.
• Resource IDs: Unique identifiers for each resource being shared.
• IBM Cloud Identity and Access Management (IAM): CARS leverages IAM for authentication and authorization, ensuring secure access control.

Companies like Siemens are leveraging similar cross-account capabilities to streamline their development pipelines and accelerate innovation. For example, they can share base images across multiple teams, ensuring consistency and reducing build times. Similarly, healthcare providers can use CARS to securely share compliance-related resources between different departments while maintaining strict data governance.

Why Use "Cross Account Resource Sharing"?

Before CARS, organizations faced several challenges when managing resources across multiple accounts:

• Data Duplication: Creating copies of resources (like images or configuration files) in each account led to storage inefficiencies and version control nightmares.
• Security Risks: Sharing credentials or relying on manual transfer processes increased the risk of unauthorized access and data breaches.
• Operational Overhead: Managing multiple copies of resources required significant manual effort and increased the potential for errors.
• Slowed Development: Waiting for resource access approvals and dealing with data transfer delays hindered development velocity.

Industry-Specific Motivations:

• Financial Services: Strict regulatory requirements necessitate granular access control and auditability. CARS helps meet these requirements by providing a secure and transparent sharing mechanism.
• Healthcare: Protecting patient data is paramount. CARS enables secure sharing of compliance-related resources while maintaining data privacy.
• Retail: Managing multiple environments (development, staging, production) requires efficient resource sharing to streamline deployments and reduce costs.

User Cases:

1. Centralized Image Management: A DevOps team maintains a library of golden images in a central account. Development teams in other accounts can access these images without needing to create their own, ensuring consistency and reducing storage costs.
2. Shared Security Policies: A security team defines and manages security policies in a dedicated account. These policies can be shared with other accounts to enforce consistent security standards across the organization.
3. Cross-Account Key Management: A key management service (KMS) in one account can be used to encrypt data in other accounts, providing a centralized and secure key management solution.

Key Features and Capabilities

CARS boasts a robust set of features designed to simplify and secure cross-account resource sharing:

1. Granular Access Control: Share resources at a very specific level, controlling exactly what actions consumers can perform.
2. IAM Integration: Leverages existing IAM roles and policies for seamless integration with your existing security infrastructure.
3. Audit Logging: Comprehensive audit logs track all sharing activities, providing visibility and accountability.
4. Resource Discovery: Easily discover shared resources available from other accounts.
5. Policy-Based Sharing: Define sharing policies based on specific criteria, such as account ID, region, or resource type.
6. Automated Sharing: Automate the sharing process using APIs or Infrastructure as Code (IaC) tools like Terraform.
7. Revocable Access: Easily revoke access to shared resources when it's no longer needed.
8. Support for Multiple Resource Types: Share a wide range of resources, including images, keys, secrets, network policies, and more.
9. Centralized Management: Manage all sharing policies from a single console.
10. Least Privilege Principle: Enforces the principle of least privilege, granting consumers only the access they need to perform their tasks.

Use Case & Flow: Shared Network Policies

Imagine a central networking team manages network policies for an organization. They want to share a specific network policy (e.g., a firewall rule) with a development team in a separate account.

graph LR
    A[Resource Owner Account (Networking Team)] --> B{Sharing Policy: Grant access to Dev Account};
    B --> C[Network Policy];
    C --> D[Resource Consumer Account (Dev Team)];
    D --> E[Application using Network Policy];

The networking team creates a sharing policy granting the development account access to the network policy. The development team can then utilize this policy without needing to create a duplicate, ensuring consistent network security.

Detailed Practical Use Cases

1. Centralized Container Registry (DevOps): A DevOps team maintains a central container registry in one account. Development teams in other accounts can pull images from this registry without needing to replicate them, saving storage costs and ensuring consistency. Problem: Image duplication, version control issues. Solution: Share the container registry resource. Outcome: Reduced storage costs, faster deployments, consistent images.
2. Shared KMS for Encryption (Security): A security team manages a Key Management Service (KMS) in a dedicated account. Other accounts can use this KMS to encrypt data, providing a centralized and secure key management solution. Problem: Decentralized key management, increased security risk. Solution: Share the KMS resource. Outcome: Enhanced security, simplified key management, compliance.
3. Cross-Account CI/CD Pipeline (Development): A CI/CD pipeline in one account can deploy applications to accounts managed by different teams. Problem: Complex deployment processes, lack of automation. Solution: Share IAM roles and policies to allow the CI/CD pipeline to access resources in other accounts. Outcome: Automated deployments, faster release cycles, improved collaboration.
4. Compliance Resource Sharing (Compliance): A compliance team maintains a library of compliance-related resources (e.g., security templates, audit logs) in a dedicated account. Other accounts can access these resources to ensure compliance with regulatory requirements. Problem: Inconsistent compliance practices, increased audit risk. Solution: Share compliance resources. Outcome: Improved compliance, reduced audit risk, streamlined compliance processes.
5. Shared Base Images for Virtual Servers (Infrastructure): An infrastructure team maintains a library of base images for virtual servers in a central account. Development and testing teams can use these images to quickly provision virtual servers without needing to create their own. Problem: Image sprawl, inconsistent environments. Solution: Share base images. Outcome: Faster provisioning, consistent environments, reduced storage costs.
6. Centralized Logging and Monitoring (Operations): A central operations team manages a logging and monitoring solution in one account. Other accounts can send their logs and metrics to this solution for centralized analysis and alerting. Problem: Siloed logging and monitoring data, difficulty identifying and resolving issues. Solution: Share logging and monitoring resources. Outcome: Improved visibility, faster troubleshooting, proactive alerting.

Architecture and Ecosystem Integration

CARS integrates seamlessly into the broader IBM Cloud architecture. It leverages existing IAM services for authentication and authorization and can be integrated with other IBM Cloud services like Key Protect, Secrets Manager, and Container Registry.

graph LR
    subgraph IBM Cloud
        A[Resource Owner Account]
        B[Resource Consumer Account]
        C[IAM]
        D[Key Protect]
        E[Secrets Manager]
        F[Container Registry]
        G[CARS]
    end

    A -- Shares Resource --> G
    G -- Grants Access --> B
    G -- Authenticates via --> C
    A -- Uses --> D
    A -- Uses --> E
    A -- Uses --> F
    B -- Uses --> D
    B -- Uses --> E
    B -- Uses --> F

CARS acts as a central control plane for cross-account resource sharing, enabling secure and efficient collaboration between different accounts. It integrates with IBM Cloud Activity Tracker to provide detailed audit logs of all sharing activities.

Hands-On: Step-by-Step Tutorial (Using IBM Cloud CLI)

This tutorial demonstrates how to share an image between two IBM Cloud accounts using the IBM Cloud CLI.

Prerequisites:

• Two IBM Cloud accounts (Account A - Resource Owner, Account B - Resource Consumer)
• IBM Cloud CLI installed and configured.
• Appropriate IAM permissions in both accounts.

Step 1: Login to Account A (Resource Owner)

ibmcloud login -a <account_a_url> -r <region>

Step 2: Identify the Image to Share

ibmcloud is images --output json

Note the id of the image you want to share.

Step 3: Create a Sharing Policy

ibmcloud resource-sharing-policy create --resource-id <image_id> --account-id <account_b_id> --roles "Viewer"

Replace <image_id> with the ID of the image and <account_b_id> with the ID of Account B. The Viewer role grants read-only access to the image.

Step 4: Login to Account B (Resource Consumer)

ibmcloud login -a <account_b_url> -r <region>

Step 5: Verify Access to the Shared Image

ibmcloud is images --output json

You should now see the shared image listed in Account B.

Pricing Deep Dive

CARS pricing is based on the number of sharing policies created and maintained. As of October 26, 2023, the pricing is as follows:

• Free Tier: Up to 10 sharing policies.
• Standard Tier: $0.01 per sharing policy per hour (billed monthly).

Sample Cost:

If you have 100 sharing policies, the monthly cost would be approximately $73.20 (100 policies * $0.01/policy/hour * 24 hours/day * 30 days/month).

Cost Optimization Tips:

• Regularly review and remove unused sharing policies.
• Use granular access control to minimize the number of policies required.
• Leverage automation to streamline the sharing process and reduce manual effort.

Cautionary Note: The cost of CARS is relatively low, but it can add up if you have a large number of sharing policies. Carefully plan your sharing strategy to optimize costs.

Security, Compliance, and Governance

CARS is built with security as a top priority. It leverages IBM Cloud IAM for authentication and authorization, ensuring that only authorized users can access shared resources. All sharing activities are logged in IBM Cloud Activity Tracker, providing a complete audit trail.

Certifications:

IBM Cloud is compliant with a wide range of industry standards, including:

• SOC 1, SOC 2, SOC 3
• ISO 27001
• HIPAA
• PCI DSS

Governance Policies:

• Least Privilege: Grant consumers only the access they need.
• Regular Audits: Review sharing policies regularly to ensure they are still valid and necessary.
• Automated Revocation: Automate the revocation of access when it's no longer needed.

Integration with Other IBM Services

1. IBM Cloud Key Protect: Share KMS instances to provide centralized key management.
2. IBM Cloud Secrets Manager: Share secrets securely across accounts.
3. IBM Cloud Container Registry: Share container images for consistent deployments.
4. IBM Cloud Schematics: Automate the creation and management of sharing policies using IaC.
5. IBM Cloud Activity Tracker: Monitor all sharing activities for audit and compliance purposes.
6. IBM Cloud IAM: CARS is fundamentally built on and integrates deeply with IAM for access control.

Comparison with Other Services

Decision Advice:

• Choose IBM CARS if: You are primarily using IBM Cloud services and need granular control over resource sharing.
• Choose AWS RAM if: You are primarily using AWS services and need to share AWS Organizations resources.

Common Mistakes and Misconceptions

1. Overly Permissive Policies: Granting excessive permissions can create security vulnerabilities. Fix: Follow the principle of least privilege.
2. Ignoring Audit Logs: Failing to monitor audit logs can leave you unaware of unauthorized access. Fix: Regularly review audit logs.
3. Not Revoking Access: Leaving access granted to former employees or unused resources can create security risks. Fix: Automate access revocation.
4. Misunderstanding Resource IDs: Using incorrect resource IDs can lead to sharing errors. Fix: Double-check resource IDs before creating sharing policies.
5. Assuming CARS Replaces IAM: CARS enhances IAM, it doesn't replace it. IAM is still the foundation for access control. Fix: Understand the interplay between CARS and IAM.

Pros and Cons Summary

Pros:

• Secure and efficient resource sharing.
• Granular access control.
• Seamless integration with IBM Cloud IAM.
• Reduced costs and operational overhead.
• Improved collaboration and agility.

Cons:

• Limited resource type support compared to some alternatives.
• Pricing can add up with a large number of sharing policies.
• Requires careful planning and management.

Best Practices for Production Use

• Security: Implement the principle of least privilege, regularly audit sharing policies, and automate access revocation.
• Monitoring: Monitor audit logs for suspicious activity and set up alerts for unauthorized access.
• Automation: Automate the creation and management of sharing policies using IaC tools.
• Scaling: Design your sharing strategy to scale with your organization's growth.
• Policies: Establish clear policies and procedures for resource sharing.

Conclusion and Final Thoughts

IBM Cross Account Resource Sharing is a powerful service that can significantly simplify and secure resource sharing in multi-account environments. By breaking down silos and enabling collaboration, CARS empowers organizations to accelerate innovation, reduce costs, and improve security. As organizations continue to adopt cloud-native architectures and multi-account strategies, CARS will become an increasingly essential component of their cloud infrastructure.

Ready to get started? Explore the IBM Cloud documentation and begin experimenting with CARS today: https://cloud.ibm.com/docs/resource-sharing Don't hesitate to leverage the IBM Cloud community forums for support and guidance.