Docker From alias is not unique for multistage builds
Description
This rule detects whether each FROM instruction in a Dockerfile uses a unique alias when building multistage images. Aliases help to identify stages, making Dockerfiles more readable and maintainable. Enforcing unique aliases ensures clarity, prevents conflicts and avoids any unintentional overwriting of stages.
Code Example
dockerfile
FROM node:14 as builder
...
- FROM node:14 as builder # Duplicate alias
+ FROM node:14 as builder_2 # Unique alias
...Remediation
Docker
To mitigate this issue, ensure that each `FROM` instruction in your multistage Dockerfile uses a unique alias.
Example:
Rule Details
| Field | Value |
|---|---|
| ID | IAC-0844 |
| Severity | LOW |
| IaC Type | dockerfile |
| Frameworks | Docker |
| Checkov ID | CKV_DOCKER_11 |