Merge pull request #5126 from dvdksn/docs-improve-LegacyKeyValueFormat

docs: add a multi-line ENV example
moby · Jul 9, 2024 · 7950fa4 · 7950fa4
2 parents 0b1a789 + 465c933
commit 7950fa4
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diff --git a/frontend/dockerfile/docs/rules/legacy-key-value-format.md b/frontend/dockerfile/docs/rules/legacy-key-value-format.md
@@ -36,3 +36,21 @@ FROM alpine
 ARG foo=bar
 ```
 
+❌ Bad: multi-line variable declaration with a space separator.
+
+```dockerfile
+ENV DEPS \
+    curl \
+    git \
+    make
+```
+
+✅ Good: use an equals sign and wrap the value in quotes.
+
+```dockerfile
+ENV DEPS="\
+    curl \
+    git \
+    make"
+```
+
diff --git a/frontend/dockerfile/linter/docs/LegacyKeyValueFormat.md b/frontend/dockerfile/linter/docs/LegacyKeyValueFormat.md
@@ -28,3 +28,21 @@ ARG foo bar
 FROM alpine
 ARG foo=bar
 ```
+
+❌ Bad: multi-line variable declaration with a space separator.
+
+```dockerfile
+ENV DEPS \
+    curl \
+    git \
+    make
+```
+
+✅ Good: use an equals sign and wrap the value in quotes.
+
+```dockerfile
+ENV DEPS="\
+    curl \
+    git \
+    make"
+```