hashicorp/terraform · error

URL is not a valid S3 URL

Error message

URL is not a valid S3 URL

What it means

First S3 validity check in detectS3: the source contains '.amazonaws.com/' but splits into fewer than 2 parts, meaning there is no path after the host. The detector needs at least host + one path segment to identify a bucket/key, so it rejects the URL.

Solutions

1. Provide the full path including bucket and key: '<region>.amazonaws.com/BUCKET/KEY'.
2. Prefer the explicit s3:: form: 's3::https://<host>/<bucket>/<key>'.
3. Copy the full object path from the S3 console.

Example fix

# before (no path)
source = "s3.amazonaws.com/"

# after
source = "s3.amazonaws.com/my-bucket/modules/vpc.zip"

// Ensure an S3-ish source has a path after the host.
// func validS3HasPath(src string) error {
//     if !strings.Contains(src, ".amazonaws.com/") { return nil }
//     if len(strings.Split(src, "/")) < 2 {
//         return fmt.Errorf("S3 source needs bucket and key after the host")
//     }
//     return nil
// }

When it happens

Trigger: Source is just 'something.amazonaws.com/' with no bucket or key path; the trigger substring matched but no object path follows.

Common situations: User pastes only the S3 endpoint host; bare region endpoint with no bucket; copy-paste truncation losing the key.

Related errors

• GitHub URLs should be github.com/username/repo
• invalid source address
• URL is not a valid GCS URL
• can't delete default state
• can't use local directory

AI-assisted analysis of hashicorp/terraform@d32a084675 (2026-08-11). Data as JSON: /api/errors/0ede26d4c4fadd7d. Report an issue: GitHub.

Appendix: source

Thrown at internal/getmodules/moduleaddrs/detect_s3.go:22

package moduleaddrs

import (
	"fmt"
	"net/url"
	"strings"
)

// detectS3 detects strings that seem like schemeless references to
// Amazon S3 and translates them into URLs for the "s3" getter.
func detectS3(src string) (string, bool, error) {
	if len(src) == 0 {
		return "", false, nil
	}

	if strings.Contains(src, ".amazonaws.com/") {
		parts := strings.Split(src, "/")
		if len(parts) < 2 {
			return "", false, fmt.Errorf(
				"URL is not a valid S3 URL")
		}

		hostParts := strings.Split(parts[0], ".")
		if len(hostParts) == 3 {
			return detectS3PathStyle(hostParts[0], parts[1:])
		} else if len(hostParts) == 4 {
			return detectS3OldVhostStyle(hostParts[1], hostParts[0], parts[1:])
		} else if len(hostParts) == 5 && hostParts[1] == "s3" {
			return detectS3NewVhostStyle(hostParts[2], hostParts[0], parts[1:])
		} else {
			return "", false, fmt.Errorf(
				"URL is not a valid S3 URL")
		}
	}

	return "", false, nil
}

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