Update builder.md
Single value labels do not work in 1.6 and multi-label instructions only work when separated by non-EOL whitespace.
I also added an example snip from the inspect output with the labels that are included in this guide.
@@ -373,9 +373,8 @@ blackslashes as you would in command-line parsing.
LABEL "com.example.vendor"="ACME Incorporated"
An image can have more than one label. To specify multiple labels, separate each
-key-value pair by an EOL.
+key-value pair with whitespace.
- LABEL com.example.label-without-value
LABEL com.example.label-with-value="foo"
LABEL version="1.0"
LABEL description="This text illustrates \
@@ -386,12 +385,24 @@ possible. Each `LABEL` instruction produces a new layer which can result in an
inefficient image if you use many labels. This example results in four image
layers.
+ LABEL multi.label1="value1" multi.label2="value2" other="value3"
+
Labels are additive including `LABEL`s in `FROM` images. As the system
encounters and then applies a new label, new `key`s override any previous labels
with identical keys.
To view an image's labels, use the `docker inspect` command.
+ "Labels": {
+ "com.example.vendor": "ACME Incorporated"
+ "com.example.label-with-value": "foo",
+ "version": "1.0",
+ "description": "This text illustrates that label-values can span multiple lines.",
+ "multi.label1": "value1",
+ "multi.label2": "value2",
+ "other": "value3"
+ },
+
## EXPOSE
EXPOSE <port> [<port>...]
