Merge pull request #480 from crazy-max/back-to-sha-7

back to commit sha length of 7

Author: crazy-max

README.md

@@ -361,11 +361,11 @@ So it can be used with our [Docker Build Push action](https://github.com/docker/
 
 ### environment variables
 
-| Name                                 | Type   | Description                                                                                                                                   |
-|--------------------------------------|--------|-----------------------------------------------------------------------------------------------------------------------------------------------|
-| `DOCKER_METADATA_PR_HEAD_SHA`        | Bool   | If `true`, set associated head SHA instead of commit SHA that triggered the workflow on pull request event                                    |
-| `DOCKER_METADATA_SHORT_SHA_LENGTH`   | Number | Specifies the length of the [short commit SHA](#typesha) to ensure uniqueness. Default is `12`, but can be increased for larger repositories. |
-| `DOCKER_METADATA_ANNOTATIONS_LEVELS` | String | Comma separated list of annotations levels to set for annotations output separated (default `manifest`)                                       |
+| Name                                 | Type   | Description                                                                                                                                  |
+|--------------------------------------|--------|----------------------------------------------------------------------------------------------------------------------------------------------|
+| `DOCKER_METADATA_PR_HEAD_SHA`        | Bool   | If `true`, set associated head SHA instead of commit SHA that triggered the workflow on pull request event                                   |
+| `DOCKER_METADATA_SHORT_SHA_LENGTH`   | Number | Specifies the length of the [short commit SHA](#typesha) to ensure uniqueness. Default is `7`, but can be increased for larger repositories. |
+| `DOCKER_METADATA_ANNOTATIONS_LEVELS` | String | Comma separated list of annotations levels to set for annotations output separated (default `manifest`)                                      |
 
 ## `context` input
 
@@ -725,9 +725,9 @@ tags: |
 ```
 
 Output Git short commit (or long if specified) as Docker tag like
-`sha-860c1904a1ce`.
+`sha-860c190`.
 
-By default, the length of the short commit SHA is `12` characters. You can
+By default, the length of the short commit SHA is `7` characters. You can
 increase this length for larger repositories by setting the
 [`DOCKER_METADATA_SHORT_SHA_LENGTH` environment variable](#environment-variables):
 
@@ -742,7 +742,7 @@ increase this length for larger repositories by setting the
           tags: |
             type=sha
         env:
-          DOCKER_METADATA_SHORT_SHA_LENGTH: 16
+          DOCKER_METADATA_SHORT_SHA_LENGTH: 12
 ```
 
 Extended attributes and default values: