If mkcert is not available, create certificates using openssl

haproxy/prepare-cert.sh

@@ -9,7 +9,19 @@ combined="src/combined.pem"
 if [[ ! -f $combined ]]; then
     echo "Creating certificates..."
     cd src
-    mkcert -cert-file localhost.pem -key-file localhost-key.pem localhost 127.0.0.1
+    if type 2>1 >/dev/null mkcert ; then
+      mkcert -cert-file localhost.pem -key-file localhost-key.pem localhost 127.0.0.1
+    elif type 2>1 >/dev/null openssl ; then
+      echo "Command 'mkcert' not found, using openssl fallback."
+      echo "You will need to accept an security exception for the"
+      echo "generated certificate in your browser manually."
+      openssl req -x509 -newkey rsa:4096 -nodes -days 3650 \
+              -subj "/C=DE/O=Selfsigned Test/CN=localhost" \
+              -keyout localhost-key.pem -out localhost.pem
+    else
+      echo >&2 "FATAL: No valid certificate generation tool found!"
+      exit -1
+    fi
     cat localhost.pem localhost-key.pem > combined.pem
     echo "done"
 else