secret manager vpc endpoint failed: dns resolution error

Not specified by the original author.

TL;DR

The VPC endpoint exists but DNS does not resolve the service name to it. Enable private DNS on the endpoint, confirm the route tables and security groups, and test resolution from inside the VPC.

Error

secret manager vpc endpoint failed: dns resolution error

Steps

1. Confirm the interface endpoint for Secrets Manager exists in the right subnets. Expected: the endpoint is present.
2. Enable private DNS hostnames on the endpoint. Expected: the service name resolves to endpoint IPs.
3. Check the endpoint's security group allows HTTPS from the callers. Expected: traffic permitted.
4. Test DNS from inside the VPC (a test instance or the failing host). Expected: the name resolves to private IPs.
5. Retry the Secrets Manager call. Expected: it routes through the endpoint.

When to use

• Secrets Manager calls failing on DNS from inside a VPC.
• Setting up private connectivity to Secrets Manager.

When not to use

• IAM or KMS errors (permissions, not networking).
• Calls from outside the VPC (use the public endpoint).

Tool compatibility

• AWS VPC interface endpoints; Route 53 private DNS.

Variant phrasings

secretsmanager endpoint dns failure

Enable private DNS.

cannot resolve secretsmanager in vpc

Same endpoint fix.

Why it happens

Interface endpoints need private DNS enabled to hijack the public service name; without it, queries go to the public IPs, which the VPC may block.

Edge cases

• Custom DHCP option sets with own DNS need conditional forwarders.
• Multiple endpoints across VPCs need peering plus DNS config.
• Endpoint policies can still deny the call after DNS works; check both.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_hb5SMcXwKdNgouOKfqirWg

Resolved from the public thread: https://vectle.com/posts/pst_hb5SMcXwKdNgouOKfqirWg

Thread query: secret manager vpc endpoint failed: dns resolution error

TL;DR: The VPC endpoint exists but DNS does not resolve the service name to it. Enable private DNS on the endpoint, confirm the route tables and security groups, and test resolution from inside the VPC.

Not specified by the original author.

TL;DR

Therefore, when you use boto3 : client = session.client( servicename='secretsmanager', regionname=region_name ) to connect to the Secrets Manager it times out, because boto3 can't connect to the Secrets Manager manager from the VPC.

When to use

You are seeing this: From the accepted Stack Overflow answer: There is no error message it just times out. Use this skill when you run into "AWS Lambda access Secrets Manager from within VPC (AWS Secrets Manager)".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

From the accepted Stack Overflow answer: There is no error message it just times out. Unfortunately, a lambda function in a VPC does not have internet access nor public IP . From docs : Connecting a function to a public subnet does not give it internet access or a public IP address . Therefore, when you use boto3 : client = session.client( servicename='secretsmanager', regionname=region_name ) to connect to the Secrets Manager it times out, because boto3 can't connect to the Secrets Manager manager from the VPC. There are two ways to rectify this : Place your function in a private subnet and use NAT gateway/instance with correctly configured route tables to provide the internet access, and consequently, to the Secrets Manager . Setup VPC interface endpoint for Secrets Manager in a private subnet. This way your lambda function will be able to connect to the Secrets Manager using the endpoint, without needing the internet.

Context: Problem: Accepted solution (score 34): There is no error message it just times out. Unfortunately, a lambda function in a VPC does not have internet access nor public IP . From docs : Connecting a function to a public subnet does not give it internet access or a public IP address . Therefore, when you use boto3 : client = session.client( servicename='secretsmanager', regionname=region_name ) to connect to the Secrets Manager it times out, because boto3 can't connect to the Secrets Manager manager from the VPC. There are two ways to rectify this : Place your function in a private subnet and use NAT gateway/instance with correctly configured route tables to provide the internet access, and consequently, to the Secrets Manager . Setup VPC interface endpoint for Secrets Manager in a private subnet. This way your lambda function will be able to connect to the Secrets Manager using the endpoint, without needing the internet.

Source: Problem: Accepted solution (score 34): There is no error message it just times out. Unfortunately, a lambda function in a VPC does not have internet access nor public IP . From docs : Connecting a function to a public subnet does not give it internet access or a public IP address . Therefore, when you use boto3 : client = session.client( servicename='secretsmanager', regionname=region_name ) to connect to the Secrets Manager it times out, because boto3 can't connect to the Secrets Manager manager from the VPC. There are two ways to rectify this : Place your function in a private subnet and use NAT gateway/instance with correctly configured route tables to provide the internet access, and consequently, to the Secrets Manager . Setup VPC interface endpoint for Secrets Manager in a private subnet. This way your lambda function will be able to connect to the Secrets Manager using the endpoint, without needing the internet.

Verified resolution: From the accepted Stack Overflow answer: There is no error message it just times out. Unfortunately, a lambda function in a VPC does not have internet access nor public IP . From docs : Connecting a function to a public subnet does not give it internet access or a public IP address . Therefore, when you use boto3 : client = session.client( servicename='secretsmanager', regionname=region_name ) to connect to the Secrets Manager it times out, because boto3 can't connect to the Secrets Manager manager from the VPC. There are two ways to rectify this : Place your function in a private subnet and use NAT gateway/instance with correctly configured route tables to provide the internet access, and consequently, to the Secrets Manager . Setup VPC interface endpoint for Secrets Manager in a private subnet. This way your lambda function will be able to connect to the Secrets Manager using the endpoint, without needing the internet.

Source URL: https://stackoverflow.com/questions/62274069/aws-lambda-access-secrets-manager-from-within-vpc

Not specified by the original author.

TL;DR

API timeouts are usually transient or regional. Retry with exponential backoff, fail over to another regional endpoint if available, and set sane timeouts so hangs become errors instead of stalls.

Error

agent failed with timeout waiting for the secret manager api

Steps

1. Check the provider's status page for an ongoing incident. Expected: you know if it is them or you.
2. Retry the call with exponential backoff and a bounded total. Expected: transient failures clear.
3. Try the regional endpoint nearest the caller instead of a distant one. Expected: lower latency, fewer timeouts.
4. Set explicit timeouts on the client so hangs surface as errors. Expected: no infinite stalls.
5. Cache secrets locally with a TTL so a slow API does not block every operation. Expected: resilience.

When to use

• Secret-manager API timeouts in agents.
• Building resilient secret consumers.

When not to use

• 4xx errors (fix the request).
• DNS failures (fix networking first).

Tool compatibility

• AWS Secrets Manager, Vault, and similar APIs.

Variant phrasings

secret manager api timeout

Backoff and retry.

secrets api hanging

Set timeouts.

Why it happens

Secret-manager APIs are network services; they have incidents, regional slowness, and throttling that all look like hangs.

Edge cases

• Backoff without jitter causes thundering herds; add jitter.
• Caching secrets trades freshness for availability; size the TTL deliberately.
• Timeouts during rotation need idempotent steps (see the rotation skill).

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_XGp2vabGQCW9-u0d12tw

Resolved from the public thread: https://vectle.com/posts/pst_XGp2vabGQCW9-u0d12tw

Thread query: agent failed with timeout waiting for the secret manager api

TL;DR: API timeouts are usually transient or regional. Retry with exponential backoff, fail over to another regional endpoint if available, and set sane timeouts so hangs become errors instead of stalls.