* fix(bedrock): prevent duplicate role assumption in EKS/IRSA environments
Fixes issue where AWS role assumption would fail in EKS/IRSA environments
when trying to assume the same role that's already being used.
The problem occurred when:
1. EKS/IRSA automatically assumes a role (e.g., LitellmRole)
2. LiteLLM tries to assume the same role again, causing AccessDenied errors
3. Different models with different roles would fail due to incorrect role context
Changes:
- Added check in _auth_with_aws_role() to detect if already using target role
- Skip role assumption if current identity matches target role
- Return current credentials instead of attempting duplicate assumption
- Added comprehensive test coverage for the fix
This ensures proper role chaining works in EKS/IRSA environments where:
- Service Account can assume Role A
- Role A can assume Role B for different models/accounts
Resolves the AccessDenied errors reported in bedrock usage scenarios.
* fix(bedrock): simplify role assumption for EKS/IRSA environments
Fixes AWS Bedrock role assumption in EKS/IRSA environments by properly
handling ambient credentials when no explicit credentials are provided.
The issue occurred because commit 197e7efa8f
introduced changes that broke role assumption in EKS/IRSA environments.
Changes:
- Simplified _auth_with_aws_role() to use ambient credentials when no
explicit AWS credentials are provided (aws_access_key_id and
aws_secret_access_key are both None)
- This allows web identity tokens in EKS/IRSA to work automatically
through boto3's credential chain
- Maintains backward compatibility for explicit credential scenarios
Added comprehensive test coverage:
- test_eks_irsa_ambient_credentials_used: Verifies ambient credentials work
- test_explicit_credentials_used_when_provided: Ensures explicit creds still work
- test_partial_credentials_still_use_ambient: Edge case handling
- test_cross_account_role_assumption: Multi-account scenarios
- test_role_assumption_with_custom_session_name: Custom session names
- test_role_assumption_ttl_calculation: TTL calculation verification
- test_role_assumption_error_handling: Error propagation
- test_multiple_role_assumptions_in_sequence: Sequential role assumptions
This fix ensures that in EKS/IRSA environments:
1. Service accounts can assume their initial role via web identity
2. That role can then assume other roles across accounts as configured
3. Different models can use different roles without conflicts
* fix(bedrock): add automatic IRSA detection for EKS environments
- Detect AWS_WEB_IDENTITY_TOKEN_FILE and AWS_ROLE_ARN environment variables
- Automatically use web identity token flow when IRSA is detected
- Read web identity token from file and pass to existing auth method
- Add test coverage for IRSA environment detection
- Fixes authentication errors in EKS with IRSA when no explicit credentials provided
* fix(bedrock): skip role assumption when IRSA role matches requested role
- Detect when AWS_ROLE_ARN environment variable matches the requested role
- Skip unnecessary role assumption when already running as the target role
- Use existing env vars authentication method for IRSA credentials
- Add test coverage for same-role IRSA scenario
- Fixes 'not authorized to perform: sts:AssumeRole' errors when trying to assume the same role
* fix(bedrock): use boto3's native IRSA support for cross-account role assumption
- Replace custom web identity token handling with boto3's built-in IRSA support
- boto3 automatically reads AWS_WEB_IDENTITY_TOKEN_FILE and assumes initial role
- Then use standard assume_role for cross-account access
- Update test to mock boto3 STS client instead of internal methods
- Fixes 'OIDC token could not be retrieved from secret manager' error
* fix(bedrock): improve IRSA error handling and add debug logging
- Add debug logging to show current identity and role assumption attempts
- Provide clearer error messages for trust policy issues
- Fix region handling in IRSA flow
- Re-raise exceptions instead of silently falling through
- This helps diagnose cross-account role assumption permission issues
* fix(bedrock): manually assume IRSA role with correct session name for cross-account scenarios
- When doing cross-account role assumption, manually assume the IRSA role first with the desired session name
- This ensures the session name in the assumed role ARN matches what's expected in trust policies
- For same-account scenarios, continue using boto3's automatic IRSA support
- Updated tests to handle the new flow
- This fixes the issue where cross-account trust policies require specific session names
* fix: Fix linting issues in base_aws_llm.py
- Fix f-string without placeholders (F541)
- Refactor _auth_with_aws_role to reduce statements count (PLR0915)
- Extract _handle_irsa_cross_account helper method
- Extract _handle_irsa_same_account helper method
- Extract _extract_credentials_and_ttl helper method
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Co-authored-by: openhands <openhands@all-hands.dev>
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