TIL
AWS SSO credentials don't work when mounted into Docker containers
Mounting ~/.aws into a Docker container fails to resolve SSO tokens. Extract temporary credentials from boto3 and pass them as environment variables instead.
TIL
Today I Learned — Daily learnings
TIL
Strands agent() hangs inside FastAPI async def endpoints
Strands Agents SDK's agent() is a blocking call. Calling it inside an async def FastAPI endpoint blocks the event loop and hangs the request. Switching to def fixes it.
1 min read
TIL
Cyclic Graph requires explicit set_entry_point
Strands Agents SDK Graph with cycles (feedback loops) fails build() auto-detection with ValueError. Use set_entry_point to specify the starting node explicitly.
1 min read
TIL
Graph's result.execution_time returns 0ms — use node sum instead
Strands Agents SDK Graph's result.execution_time returns 0ms. Per-node execution_time is correct, so calculate the total yourself.
1 min read
TIL
Swarm agents that hand off produce no text output
In Strands Agents SDK Swarm, agents that hand off via handoff_to_agent have no text block in their result. The final text output comes from the last agent that didn't hand off.
1 min read
TIL
Agent Registry AGENT_SKILLS record has different parameter names in CLI vs REST API
AWS Agent Registry CLI uses skillMd (dict with inlineContent) while REST API uses skillMarkdown (string). descriptorType is AGENT_SKILLS, not SKILL.
1 min read
TIL
Agent Registry MCP record creation fails silently on server.json schema constraints
AWS Agent Registry MCP records require reverse-DNS name format, 100-char description limit, and explicit schemaVersion. The error message doesn't tell you which field is wrong.
1 min read
TIL
RDS Proxy Blue/Green Switchover produces SSL disconnect, not AdminShutdown
During Aurora PostgreSQL Blue/Green Switchover, the docs mention AdminShutdown as the expected error. Through RDS Proxy, you get SSL connection has been closed unexpectedly instead. Important for error handling design.
1 min read
TIL
EKS Auto Mode clusters need vpc-cni addon before adding managed node groups
Adding a managed node group to an EKS Auto Mode cluster fails with NodeCreationFailure (cni plugin not initialized). Installing vpc-cni, kube-proxy, and coredns addons resolves the issue.
1 min read
TIL
amazon-efs-utils v2.x blocks the official installer from upgrading to v3.0.0
The official efs-utils installer script doesn't upgrade to v3.0.0 when v2.x is already installed from the Amazon Linux 2023 repo. Run the installer on a fresh instance without efs-utils pre-installed.