Error: Build 'amazon-ebs' errored: Error creating AMI: InvalidAMIName.Malformed

Error: Build 'amazon-ebs' errored: Error creating AMI: InvalidAMIName.Malformed

TL;DR

Your ami_name contains characters AWS rejects (like + or spaces). Restrict it to letters, numbers, ( ) . - / _, 3-128 chars, and rebuild.

The error

==> amazon-ebs: Error creating AMI: InvalidAMIName.Malformed: AMI names must be between 3 and 128 characters long, and may contain letters, numbers, '(', ')', '.', '-', '/' and '_'
	status code: 400, request id: OMITTED
Build 'amazon-ebs' errored: Error creating AMI: InvalidAMIName.Malformed

Fix it

1. Inspect your ami_name: look for spaces, +, or other characters outside the allowed set.

• Success check: you spot the offending characters (in the issue, Centos 7 + Stuff).

1. Sanitize it: replace spaces with - or _, drop + and other symbols. E.g. centos-7-stuff-{{timestamp}}.

• Success check: the name matches [A-Za-z0-9()./_-]{3,128}.

1. Note the prevalidation gap: packer validate may not catch this; it fails late, after provisioning. Consider it a known rough edge.

• Success check: you validate names yourself before long builds.

1. Re-run packer build.

• Success check: Creating the AMI succeeds.

When to use this

You hit this at the very end of an amazon-ebs build, after provisioning succeeded, when AWS rejects the AMI name.

When NOT to use this

Do not use this for InvalidAMIName.Duplicate (name taken; make it unique) or for build failures earlier in provisioning.

Compatibility

Packer 1.x, amazon-ebs. The character rules come from the EC2 API.

Variants

• InvalidAMIName.Malformed from timestamps or variables injecting spaces
• Names over 128 chars from long prefixes plus timestamps

Root cause

EC2 AMI names allow only a restricted charset. Packer's prevalidation did not reject the bad name, so the build burned full provisioning time before AWS refused it at CreateImage.

Edge cases

• {{timestamp}} is safe (digits only). The risk is in your static prefix and variable values.
• Slashes are allowed but can confuse console filtering; prefer -.