docs: userguide: labels-custom-metadsata.md: update syntax for emtpy value labels

Signed-off-by: Antonio Murdaca <runcom@redhat.com>
This commit is contained in:
Antonio Murdaca 2015-12-16 13:43:41 +01:00 committed by Tibor Vass
parent 1b77149fd4
commit 8008a57ffb
1 changed files with 6 additions and 3 deletions

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@ -156,20 +156,23 @@ A Dockerfile is similar to a Makefile.
the image.
**LABEL**
-- `LABEL <key>[=<value>] [<key>[=<value>] ...]`or
-- `LABEL <key>=<value> [<key>=<value> ...]`or
```
LABEL <key>[ <value>]
LABEL <key>[ <value>]
...
```
The **LABEL** instruction adds metadata to an image. A **LABEL** is a
key-value pair. To include spaces within a **LABEL** value, use quotes and
key-value pair. To specify a **LABEL** without a value, simply use an empty
string. To include spaces within a **LABEL** value, use quotes and
backslashes as you would in command-line parsing.
```
LABEL com.example.vendor="ACME Incorporated"
or
LABEL com.example.vendor "ACME Incorporated"
LABEL com.example.vendor.is-beta ""
LABEL com.example.vendor.is-beta=
LABEL com.example.vendor.is-beta=""
```
An image can have more than one label. To specify multiple labels, separate