tests: Add 4.18.x kernel config test

Signed-off-by: Rolf Neugebauer <rn@rneugeba.io>

test/cases/020_kernel/004_config_4.18.x/test.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+# SUMMARY: Sanity check on the kernel config file
+# LABELS:
+# REPEAT:
+
+set -e
+
+# Source libraries. Uncomment if needed/defined
+#. "${RT_LIB}"
+. "${RT_PROJECT_ROOT}/_lib/lib.sh"
+
+NAME=kconfig
+
+clean_up() {
+	rm -rf ${NAME}-*
+}
+trap clean_up EXIT
+
+# Test code goes here
+linuxkit build -format kernel+initrd -name "${NAME}" test.yml
+RESULT="$(linuxkit run ${NAME})"
+echo "${RESULT}" | grep -q "suite PASSED"
+
+exit 0

test/cases/020_kernel/004_config_4.18.x/test.yml

@@ -0,0 +1,15 @@
+kernel:
+  image: linuxkit/kernel:4.18.1
+  cmdline: "console=ttyS0 console=ttyAMA0"
+init:
+  - linuxkit/init:v0.6
+  - linuxkit/runc:v0.6
+onboot:
+  - name: check-kernel-config
+    image: linuxkit/test-kernel-config:2ef7eb902baab9d90eff9984b4580ab5aba95dac
+  - name: poweroff
+    image: linuxkit/poweroff:afe8f7dd0d47a7991c54519b0f09124cb8c4e300
+    command: ["/bin/sh", "/poweroff.sh", "3"]
+trust:
+  org:
+    - linuxkit