Deploying MercuryDPM using Ansible

This is useful if you want to automate deployment and running of MDPM on remote environments. In this example, I'll be controlling a remote machine called 'albatross', a Raspberry Pi with username 'pi'. I'll be building a driver and running it doing all the parameterisations through Ansible.

Preparation

Setting up inventory

Create a file called hosts and put in it the IP address of the remote machine:

hosts

[albatross]
192.168.1.108  # the IP address of the remote machine

When you have created a playbook, you have to specify using this hosts file by running ansible-playbook -i hosts playbook.yaml.

Setting up connection credentials

On the remote system, add your SSH public key to ~/.ssh/authorized_keys.

Playbook

In your base directory, create the file playbook.yml:

playbook.yaml

--- 
- name: Mount S3 storage
  hosts: albatross
  remote_user: pi
  become: no
  gather_facts: no

  vars_files:
    - vars.yml

  roles:
    - role: mountstorage


- name: Build and run MercuryDPM
  hosts: albatross
  remote_user: pi
  become: no # FIXME Do we have to run everything as root?
  gather_facts: no

  vars_files:
    - vars.yml

  roles: 
    - role: workhorse

In this example, we shall give albatross two roles. First, it should mount storage, e.g. an S3 bucket. Next, it should download MercuryDPM, build our driver, and run it.

Mounting storage

If you're storing on a local disc, nothing needs to be done here. If you want to store on a Google Drive, an S3 bucket or a remote filer, then you will need to have a role for mountstorage.

Create a file at mountstorage/tasks/main.yml and put the following in it:

(TODO)

Tasks for the `workhorse` role

Create a file at workhorse/tasks/main.yml (relative to your base directory) and put the following in it.:

workhorse/tasks/main.yml

---
# tasks file for workhorse
- name: update apt cache and install prerequisite packages
  apt:
    update_cache: yes
    name:
      - python3
  become: yes

- name: Download and build MercuryDPM 
  block:
    - name: Install MercuryDPM dependencies
      apt:
        update_cache: yes
        name:
          - build-essential
          - g++
          - gfortran
          - subversion
          - cmake
          - graphviz
        state: present
      become: yes

    - name: Copy MercuryDPM build script
      copy: src=build_mdpm.sh dest=/opt mode=0755

    - name: Download and build MDPM
      command: bash /opt/build_mdpm.sh
      register: build_output

    - name: Print info
      debug: msg="{{build_output.stdout}}"
    - name: Print errors
      debug: msg="{{build_output.stderr}}"

- name: Prepare script that builds and runs driver
  template:
    src: build_and_run_driver.sh.j2
    dest: /opt/MercuryDPM/build_and_run_driver.sh
    mode: 0755

- name: Run that script
  # TODO https://stackoverflow.com/questions/39347379/ansible-run-command-on-remote-host-in-background
  shell: (nohup /opt/MercuryDPM/build_and_run_driver.sh </dev/null >/dev/null 2>&1 &)
  # command: bash /opt/MercuryDPM/build_and_run_driver.sh
  async: 10
  poll: 0

`workhorse/files/build_mdpm.sh`: Download MercuryDPM and build MercuryBase

This script downloads MercuryDPM and builds MercuryBase.

workhorse/files/build_mdpm.sh

#!/bin/bash
set -eux

DPMDIR=/opt/MercuryDPM

declare -a SVN_FLAGS="--non-interactive --trust-server-cert --trust-server-cert-failures=unknown-ca,cn-mismatch,expired,not-yet-valid,other"
declare -a CMAKE_FLAGS="-DCMAKE_BUILD_TYPE=Release -DMercury_BUILD_DOCUMENTATION=OFF -DMercury_BUILD_USER_DIR=OFF -DMercury_Include_Xballs_Support=OFF -DMercury_USE_MPI=OFF"

mkdir -p $DPMDIR && cd $DPMDIR
# CHANGEME if you want to log in as a user so that you can build the USER/ directory
svn checkout https://svn.MercuryDPM.org/SourceCode/Trunk MercurySource --username guest --password '' ${SVN_FLAGS}
cd $DPMDIR/MercurySource

# CHANGEME If you want to use a particular version of MercuryDPM
# SVN_VERSION=5000
# svn update -r $SVN_VERSION --username guest --password '' ${SVN_FLAGS}

mkdir -p $DPMDIR/MercuryBuild && cd $DPMDIR/MercuryBuild
rm -f CMakeCache.txt

# Call cmake twice so that the CMakeDefinitions files are generated
# properly.
cmake ${CMAKE_FLAGS} ../MercurySource
cmake ${CMAKE_FLAGS} ../MercurySource
make clean
make mercury

`workhorse/templates/build_and_run_driver.sh.j2`: Build and run your driver

workhorse/templates/build_and_run_driver.sh.j2

#!/bin/bash
set -eux
DPMDIR=/opt/MercuryDPM
SIMDIR=/mnt/s3gf/{{series}}/{{simulation}}
DRIVER_DIR=$DPMDIR/MercuryBuild/Drivers/{{driver_dir}}
DRIVER_PATH=$DRIVER_DIR/{{driver}}
cd $DRIVER_DIR
make {{driver}}
mkdir -p $SIMDIR
cd $SIMDIR
$DRIVER_PATH {{flags}}