Fix #338: silence IDE noise during CI

.travis.yml

@@ -15,6 +15,7 @@
 
 language: c
 dist: trusty
+sudo: true
 
 env:
  global:
@@ -51,6 +52,16 @@ before_install:
   - if [ ! -d "$HOME/$ARDUINO_IDE" ] ; then { echo "fetch" && wget https://downloads.arduino.cc/arduino-${IDE_VERSION}-linux64.tar.xz && echo "untar" && tar xf arduino-${IDE_VERSION}-linux64.tar.xz && echo "move" && mv -f arduino-${IDE_VERSION} $HOME/${ARDUINO_IDE} ; } || { echo "IDE install failed"; exit 1; } ; else echo "IDE already installed" ; fi
   - ln -sf $PWD $HOME/${ARDUINO_IDE}/libraries/Test_Library
   - export PATH="$HOME/${ARDUINO_IDE}:$PATH"
+
+  # Arduino IDE adds a lot of noise caused by network traffic, trying to firewall it off
+  # (see https://github.com/per1234/arduino-ci-script/issues/1#issuecomment-504158113)
+  - sudo iptables -P INPUT DROP
+  - sudo iptables -P FORWARD DROP
+  - sudo iptables -P OUTPUT ACCEPT
+  - sudo iptables -A INPUT -i lo -j ACCEPT
+  - sudo iptables -A OUTPUT -o lo -j ACCEPT
+  - sudo iptables -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
+
   #
   # functions to generate the board settings for SAMD, STM32L0, ...
   # keep args for these aligned for any common options. $1 is always board name, $2 is region.