#!/bin/bash
echo "ip container: $(/sbin/ip -o -4 addr list eth0 | awk '{print $4}' | cut -d/ -f1)"
echo "ip host: $(curl -s "http://169.254.169.254/latest/meta-data/local-ipv4")"

cat << 'EOF' >> /tmp/mpi_hello_world.c
// Copyright 2011 www.mpitutorial.com
//
// An intro MPI hello world program that uses MPI_Init, MPI_Comm_size,
// MPI_Comm_rank, MPI_Finalize, and MPI_Get_processor_name.
//
#include <mpi.h>
#include <stdio.h>
#include <stddef.h>

int main(int argc, char** argv) {
  // Initialize the MPI environment. The two arguments to MPI Init are not
  // currently used by MPI implementations, but are there in case future
  // implementations might need the arguments.
  MPI_Init(NULL, NULL);

  // Get the number of processes
  int world_size;
  MPI_Comm_size(MPI_COMM_WORLD, &world_size);

  // Get the rank of the process
  int world_rank;
  MPI_Comm_rank(MPI_COMM_WORLD, &world_rank);

  // Get the name of the processor
  char processor_name[MPI_MAX_PROCESSOR_NAME];
  int name_len;
  MPI_Get_processor_name(processor_name, &name_len);

  // Print off a hello world message
  printf("Hello world from processor %s, rank %d out of %d processors\n",
         processor_name, world_rank, world_size);

  // Finalize the MPI environment. No more MPI calls can be made after this
  MPI_Finalize();
}
EOF


# get shared dir
IFS=',' _shared_dirs=(${PCLUSTER_SHARED_DIRS})
_shared_dir=${_shared_dirs[0]}
_job_dir="${_shared_dir}/${AWS_BATCH_JOB_ID%#*}-${AWS_BATCH_JOB_ATTEMPT}"
_exit_code_file="${_job_dir}/batch-exit-code"

if [[ "${AWS_BATCH_JOB_NODE_INDEX}" -eq  "${AWS_BATCH_JOB_MAIN_NODE_INDEX}" ]]; then
    echo "Hello I'm the main node ${HOSTNAME}! I run the mpi job!"

    mkdir -p "${_job_dir}"

    echo "Compiling..."
    /usr/lib64/openmpi/bin/mpicc -o "${_job_dir}/mpi_hello_world" "/tmp/mpi_hello_world.c"

    echo "Running..."
    /usr/lib64/openmpi/bin/mpirun --mca btl_tcp_if_include eth0 --allow-run-as-root --machinefile "${HOME}/hostfile" "${_job_dir}/mpi_hello_world"

    # Write exit status code
    echo "0" > "${_exit_code_file}"
    # Waiting for compute nodes to terminate
    sleep 30
else
    echo "Hello I'm the compute node ${HOSTNAME}! I let the main node orchestrate the mpi execution!"
    # Since mpi orchestration happens on the main node, we need to make sure the containers representing the compute
    # nodes are not terminated. A simple trick is to wait for a file containing the status code to be created.
    # All compute nodes are terminated by Batch if the main node exits abruptly.
    while [ ! -f "${_exit_code_file}" ]; do
        sleep 2
    done
    exit $(cat "${_exit_code_file}")
fi