how to work around Travis CIs 4MB output limit?

Question

I have a Travis CI build that produces more than 4MB of output which exceeds Travis CIs limit.

I have tried sending output to /dev/null, but Travis also fails if no output is seen for 10 minutes

How can I workaround these constraints?

Answer 1

The following script sends some dummy output to keep the build alive but also records the build output to a file and displays a tail of the output if the build returns an error:

#!/bin/bash
# Abort on Error
set -e

export PING_SLEEP=30s
export WORKDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
export BUILD_OUTPUT=$WORKDIR/build.out

touch $BUILD_OUTPUT

dump_output() {
   echo Tailing the last 500 lines of output:
   tail -500 $BUILD_OUTPUT  
}
error_handler() {
  echo ERROR: An error was encountered with the build.
  dump_output
  exit 1
}
# If an error occurs, run our error handler to output a tail of the build
trap 'error_handler' ERR

# Set up a repeating loop to send some output to Travis.

bash -c "while true; do echo $(date) - building ...; sleep $PING_SLEEP; done" &
PING_LOOP_PID=$!

# My build is using maven, but you could build anything with this, E.g.
# your_build_command_1 >> $BUILD_OUTPUT 2>&1
# your_build_command_2 >> $BUILD_OUTPUT 2>&1
mvn clean install >> $BUILD_OUTPUT 2>&1

# The build finished without returning an error so dump a tail of the output
dump_output

# nicely terminate the ping output loop
kill $PING_LOOP_PID