#Understanding IAM Policy Documents in Vidos

IAM policy documents in Vidos define the permissions that determine who can access what resources and perform which actions. These documents provide a structured, declarative way to express access control rules that enforce the principle of least privilege across your Vidos environment.

#What are IAM Policy Documents?

An IAM policy document is a structured JSON object that specifies permissions through a collection of statements. Each policy document:

• Declares who can access specific Vidos resources
• Defines what actions can be performed on those resources
• Operates within specific IAM scopes (management or service)
• Follows a consistent, declarative structure
• Uses explicit allow or deny statements

Policy documents are attached to identities (such as API keys or service roles) and establish the boundaries of what those identities can do within the Vidos system.

#Policy Evaluation

When evaluating access requests, Vidos processes all applicable policies according to these principles:

#Evaluation Order

1. By default, all requests are denied (implicit deny)
2. Explicit deny statements are evaluated first
3. Explicit allow statements are evaluated next
4. If no statements match, the request is denied

#Effect Precedence

• Explicit deny takes highest precedence
• Explicit allow takes precedence over implicit deny
• Implicit deny applies when no matching statement exists

#Scope Separation

• Policies are evaluated within their defined scope (management or service)
• A policy with management scope permissions cannot grant access to service scope operations
• Each scope maintains its own evaluation context

This evaluation model ensures secure-by-default access control with clear, predictable behavior.

#Design Rationale

Vidos IAM policy documents follow established industry practices while addressing specific needs of the platform:

#Declarative Control

Policy documents provide a declarative approach to access control that:

• Makes permissions explicit and reviewable
• Enables programmatic policy generation and analysis
• Facilitates automation of security governance
• Creates self-documenting access patterns

#Granular Permissions

The structured format allows for precise permission boundaries:

• Resource-level controls for fine-grained access
• Action-specific permissions to limit operational scope
• Effect-based rules for explicit allows and denies
• Scope-based separation for distinct operational contexts

#Security Best Practices

The policy model implements security principles:

• Deny-by-default for secure baseline
• Explicit statement of allowed actions
• Separation of management and service operations
• Precedence rules that prioritize security

#Best Practices

When working with IAM policy documents in Vidos:

#Start with Least Privilege

• Grant only the permissions required for the specific task
• Avoid using wildcards (*) when specific resources or actions can be listed
• Review and refine policies regularly to remove unnecessary permissions

#Organize for Clarity

• Group related permissions within policy documents
• Use clear, consistent resource naming patterns
• Document the purpose of each policy
• Structure policies around functional roles or specific use cases

#Leverage Scope Separation

• Keep management and service permissions in separate statements
• Align policies with the scope boundaries of your architecture
• Use the appropriate scope for each permission statement
• Avoid mixing concerns across management and service boundaries

#Follow Security Principles

• Explicitly deny sensitive actions where needed
• Regularly audit policy documents for overly permissive settings
• Implement time-bound or conditional access for sensitive operations
• Test policies in non-production environments before deployment

#Integration with Other Concepts

IAM policy documents work in concert with other key Vidos concepts:

#Relation to IAM Scopes

• Policy permissions operate within the defined IAM scopes
• Each scope provides a distinct security context for policy evaluation
• Policy statements must specify the appropriate scope for their intended operation

#Relation to Instances

• Policies can grant access to specific service instances
• Resource definitions in policies reference instance identifiers
• Instance creation and management requires appropriate management-scoped policies
• Instance usage requires appropriate service-scoped policies

#Relation to Regions

• Policies can be region-specific through the region field in resource definitions
• Cross-region access requires explicit permissions for resources in each region
• Regional isolation can be enforced through policy restrictions

By understanding and effectively using IAM policy documents, you can implement precise, secure access control across your Vidos environment while maintaining operational flexibility and clarity.