Don't expand RUN heredocs ourselves, let the shell do it

When handling RUN instructions that use heredoc syntax, don't bother
interpolating environment variables and argument values, and let the
command that's running handle it.

Signed-off-by: Nalin Dahyabhai <[email protected]>

tests/conformance/conformance_test.go

@@ -3102,6 +3102,13 @@ var internalTestCases = []testCase{
 		contextDir:        "multistage/copyback",
 		dockerUseBuildKit: true,
 	},
+
+	{
+		name:              "heredoc-quoting",
+		dockerfile:        "Dockerfile.heredoc-quoting",
+		dockerUseBuildKit: true,
+		fsSkip:            []string{"(dir):etc:(dir):hostname"}, // buildkit does not create a phantom /etc/hostname
+	},
 }
 
 func TestCommit(t *testing.T) {

tests/conformance/testdata/Dockerfile.heredoc-quoting

@@ -0,0 +1,215 @@
+FROM busybox
+ARG argA=argvA
+ENV varA=valueA
+
+# An argument, an environment variable, and one set in the heredoc
+RUN <<EOF
+varB=valueB
+touch /run-argA=$argA.unquoted1.txt
+touch /run-varA=$varA.unquoted1.txt
+touch /run-varB=$varB.unquoted1.txt
+EOF
+
+# An argument, an environment variable, and one set in the heredoc
+RUN <<EOF
+varB=valueB
+touch /run-argA="$argA".unquoted2.txt
+touch /run-varA="$varA".unquoted2.txt
+touch /run-varB="$varB".unquoted2.txt
+EOF
+
+# An argument, an environment variable overridden in the heredoc, and one set in the heredoc
+RUN <<EOF
+varA=valueA2
+varB=valueB
+touch /run-argA="$argA".unquoted3.txt
+touch /run-varA="$varA".unquoted3.txt
+touch /run-varB="$varB".unquoted3.txt
+EOF
+
+# An overridden argument, an environment variable overridden in the heredoc, and one set in the heredoc
+RUN <<EOF
+argA=argvA2
+varA=valueA2
+varB=valueB
+touch /run-argA="$argA".unquoted4.txt
+touch /run-varA="$varA".unquoted4.txt
+touch /run-varB="$varB".unquoted4.txt
+EOF
+
+# An argument, an environment variable, and one set in the heredoc
+RUN <<"EOF"
+varB=valueB
+touch /run-argA=$argA.quoted1.txt
+touch /run-varA=$varA.quoted1.txt
+touch /run-varB=$varB.quoted1.txt
+EOF
+
+# An argument, an environment variable, and one set in the heredoc
+RUN <<"EOF"
+varB=valueB
+touch /run-argA="$argA".quoted2.txt
+touch /run-varA="$varA".quoted2.txt
+touch /run-varB="$varB".quoted2.txt
+EOF
+
+# An argument, an environment variable overridden in the heredoc, and one set in the heredoc
+RUN <<"EOF"
+varA=valueA2
+varB=valueB
+touch /run-argA="$argA".quoted3.txt
+touch /run-varA="$varA".quoted3.txt
+touch /run-varB="$varB".quoted3.txt
+EOF
+
+# An overridden argument, an environment variable overridden in the heredoc, and one set in the heredoc
+RUN <<"EOF"
+argA=argvA2
+varA=valueA2
+varB=valueB
+touch /run-argA="$argA".quoted4.txt
+touch /run-varA="$varA".quoted4.txt
+touch /run-varB="$varB".quoted4.txt
+EOF
+
+# An argument, an environment variable, and one set in the heredoc
+COPY <<EOF /copy-unquoted1.txt
+varB=valueB
+touch /argA=$argA
+touch /varA=$varA
+touch /varB=$varB
+EOF
+
+# An argument, an environment variable, and one set in the heredoc
+COPY <<EOF /copy-unquoted2.txt
+varB=valueB
+argA="$argA"
+varA="$varA"
+varB="$varB"
+EOF
+
+# An argument, an environment variable overridden in the heredoc, and one set in the heredoc
+COPY <<EOF /copy-unquoted3.txt
+varA=valueA2
+varB=valueB
+argA="$argA"
+varA="$varA"
+varB="$varB"
+EOF
+
+# An overridden argument, an environment variable overridden in the heredoc, and one set in the heredoc
+COPY <<EOF /copy-unquoted4.txt
+argA=argvA2
+varA=valueA2
+varB=valueB
+argA="$argA"
+varA="$varA"
+varB="$varB"
+EOF
+
+# An argument, an environment variable, and one set in the heredoc
+COPY <<"EOF" /copy-quoted1.txt
+varB=valueB
+argA=$argA
+varA=$varA
+varB=$varB
+EOF
+
+# An argument, an environment variable, and one set in the heredoc
+COPY <<"EOF" /copy-quoted2.txt
+varB=valueB
+argA="$argA"
+varA="$varA"
+varB="$varB"
+EOF
+
+# An argument, an environment variable overridden in the heredoc, and one set in the heredoc
+COPY <<"EOF" /copy-quoted3.txt
+varA=valueA2
+varB=valueB
+argA="$argA"
+varA="$varA"
+varB="$varB"
+EOF
+
+# An overridden argument, an environment variable overridden in the heredoc, and one set in the heredoc
+COPY <<"EOF" /copy-quoted4.txt
+argA=argvA2
+varA=valueA2
+varB=valueB
+argA="$argA"
+varA="$varA"
+varB="$varB"
+EOF
+
+# An argument, an environment variable, and one set in the heredoc
+ADD <<EOF /add-unquoted1.txt
+varB=valueB
+touch /argA=$argA
+touch /varA=$varA
+touch /varB=$varB
+EOF
+
+# An argument, an environment variable, and one set in the heredoc
+ADD <<EOF /add-unquoted2.txt
+varB=valueB
+argA="$argA"
+varA="$varA"
+varB="$varB"
+EOF
+
+# An argument, an environment variable overridden in the heredoc, and one set in the heredoc
+ADD <<EOF /add-unquoted3.txt
+varA=valueA2
+varB=valueB
+argA="$argA"
+varA="$varA"
+varB="$varB"
+EOF
+
+# An overridden argument, an environment variable overridden in the heredoc, and one set in the heredoc
+ADD <<EOF /add-unquoted4.txt
+argA=argvA2
+varA=valueA2
+varB=valueB
+argA="$argA"
+varA="$varA"
+varB="$varB"
+EOF
+
+# An argument, an environment variable, and one set in the heredoc
+ADD <<"EOF" /add-quoted1.txt
+varB=valueB
+argA=$argA
+varA=$varA
+varB=$varB
+EOF
+
+# An argument, an environment variable, and one set in the heredoc
+ADD <<"EOF" /add-quoted2.txt
+varB=valueB
+argA="$argA"
+varA="$varA"
+varB="$varB"
+EOF
+
+# An argument, an environment variable overridden in the heredoc, and one set in the heredoc
+ADD <<"EOF" /add-quoted3.txt
+varA=valueA2
+varB=valueB
+argA="$argA"
+varA="$varA"
+varB="$varB"
+EOF
+
+# An overridden argument, an environment variable overridden in the heredoc, and one set in the heredoc
+ADD <<"EOF" /add-quoted4.txt
+argA=argvA2
+varA=valueA2
+varB=valueB
+argA="$argA"
+varA="$varA"
+varB="$varB"
+EOF
+
+RUN touch -r /etc/passwd /*.txt