Add open wrt test (#5985)

* First test

* Don't forget to run autogen.sh!

* Add tools needed by automake

* Try additional platforms

* Add in qemu for other platforms

* No real support for arm containers

* Fix indentation

* Simplify container build with a testing script

* Simpler names for actions

* No need to distribute OpenWRT test files

* Better list to put ignore files onto

* Create an 'ignore_files' list after all

* Add in some documentation of how OpenWRT tests work

* Fix up naming of OpenWrt

Co-authored-by: Andras Fekete <andras@wolfssl.com>

.github/workflows/docker-OpenWrt.yml

@@ -0,0 +1,33 @@
+# This workflow tests out new libraries with existing OpenWrt builds to check
+# there aren't any compatibility issues. Take a look at Docker/OpenWrt/README.md
+name: OpenWrt test
+concurrency:
+    group: ${{ github.ref }}
+
+on:
+    push:
+        branches: [ 'master', 'main', 'release/**' ]
+    pull_request:
+        branches: [ '*' ]
+
+jobs:
+    compile_container:
+        name: Build OpenWrt test container
+        runs-on: ubuntu-latest
+        steps:
+            - uses: actions/checkout@v3
+            - uses: docker/setup-qemu-action@v2
+            - uses: docker/setup-buildx-action@v2
+            -
+              name: Build but dont push
+              uses: docker/build-push-action@v3
+              with:
+                  context: .
+                  platforms: linux/amd64
+                  file: Docker/OpenWrt/Dockerfile
+                  push: false
+                  tags: openwrt-test:latest
+#                  cache-from: type=registry,ref=openwrt-test:latest
+#                  cache-to: type=inline
+                  cache-from: type=gha
+                  cache-to: type=gha,mode=max