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GDAL Simple job¶

Introduction¶

This simple job will demonstrate a few things about a typical sandbox usage:

installing software packages
configuration of a simple application taking geotiff files available on a remote FTP site and convert them to a chosen format (e.g. PNG)

Pre-requisites¶

To follow this simple tutorial you need:

a running sandbox
access to the sandbox
less than 30 minutes of time

Step 1: install gdal on the sandbox¶

The installation of gdal is done via yum(Yellowdog Updater Modified)

Run the command below on your sandbox:

[user@sb ~]$ sudo yum -y install gdal

Step 2: create the simplejob¶

The simple job will require a folder under /application:

[user@sb ~] cd /application
[user@sb application] mkdir simplejob
[user@sb application] cd simplejob

Create the wrapper file which handles the input parameters¶

[user@sb simplejob] vi run

Note: You can use any editor you like

Paste the code below in the run file:¶

#!/bin/bash

# Project:       ${project.name}
# Author:        $Author: stripodi $ (Terradue Srl)
# Last update:   $Date: 2011-09-08 12:01:58 +0200 (Thu, 08 Sep 2011) $
# Element:       ${project.name}
# Context:       services/${project.artifactId}
# Version:       ${project.version} (${implementation.build})
# Description:   ${project.description}
#
# This document is the property of Terradue and contains information directly
# resulting from knowledge and experience of Terradue.
# Any changes to this code is forbidden without written consent from Terradue Srl
#
# Contact: info@terradue.com
# 2012-02-10 - NEST in jobConfig upgraded to version 4B-1.1

# source the ciop functions (e.g. ciop-log)
source ${ciop_job_include}

# define the exit codes
SUCCESS=0
ERR_NOINPUT=1
ERR_NOPARAMS=2
ERR_GDAL=4

# add a trap to exit gracefully
function cleanExit ()
{
   local retval=$?
   local msg="" 
   case "$retval" in
     $SUCCESS)      msg="Processing successfully concluded";;
     $ERR_NOPARAMS) msg="Outout format not defined";;
     $ERR_GDAL)    msg="Graph processing of job ${JOBNAME} failed (exit code $res)";;
     *)             msg="Unknown error";;
   esac
   [ "$retval" != "0" ] && ciop-log "ERROR" "Error $retval - $msg, processing aborted" || ciop-log "INFO" "$msg" 
   exit $retval
}
trap cleanExit EXIT

# retrieve the parameters value from workflow or job default value
format=`ciop-getparam format`

# run a check on the format value
[ -z "$format" ] && exit $ERR_NOPARAMS

# loop through all geotiff URLs passed as stdin
while read inputfile 
do
    # report activity in log
    ciop-log "INFO" "Retrieving $inputfile from storage" 

    # retrieve the remote geotiff product to the local temporary folder
    retrieved=`ciop-copy -o $TMPDIR $inputfile`

    # check if the file was retrieved
    [ "$?" == "0" -a -e "$retrieved" ] || exit $ERR_NOINPUT

    # report activity
    ciop-log "INFO" "Retrieved $retrieved" 

    # invoke gdal to convert the geotiff into selected format
    gdal_translate -of $format $retrieved $OUTPUTDIR/`basename $retrieved`    

    # check error code
    [ "$?" != "0" ] && exit $ERR_GDAL || ciop-log "INFO" "Processed $inputfile" 
done

exit 0

Create the application descriptor¶

Go up one level to /application

[user@sb ~] cd /application
[user@sb application] vi application.xml

Paste the XML content:

<?xml version="1.0" encoding="UTF-8"?>
<application id="example"> <!-- you can type any id you want --> 
    <jobTemplates>
        <jobTemplate id="gdalformatconv"> <!-- this is the job name -->
            <streamingExecutable>/application/simplejob/run</streamingExecutable> <!-- this is the wrapper script --> 
            <defaultParameters>                            
                <parameter id="format">PNG</parameter> <!-- this sets the default value for parameter format -->
            </defaultParameters>
        </jobTemplate>
    </jobTemplates>
    <workflow id="workflow">    <!-- Sample workflow -->
        <workflowVersion>1.0</workflowVersion>
        <workflowDescription>My simple workflow</workflowDescription> <!-- provide a description to the workflow -->
        <node id="gdal">         <!-- workflow node unique id -->
            <job id="gdalformatconv"></job>        <!-- job defined above -->
            <sources>
                <source refid="file:urls" >/home/fbrito/geotiff.urls</source> <!-- the geotiff URLs are provided on an ASCII file, set your username value -->
            </sources>
            <parameters></parameters>
        </node>
    </workflow>
</application>

Create the URLs files in your home directory

[user@sb application] cd 
[user@sb ~] vi geotiff.urls

Add a few URLs:

ftp://ftp.remotesensing.org/pub/geotiff/samples/spot/chicago/SP27GTIF.TIF
ftp://ftp.remotesensing.org/pub/geotiff/samples/spot/chicago/UTM2GTIF.TIF

Step 3: execute the job¶

Execute the simple job¶

Optionally list the nodes you can execute:

[user@sb ~] ciop-simjob -n

This will return:

gdal

Process it!

 
[user@sb ~] ciop-simjob gdal

The job is executed and a tracking URL is provided to follow the progress and access the execution logs. Open the URL on a browser

TBC

Check the gdal node results¶

The generated files are published on a local filesystem:

[user@sb ~] cd /share/tmp/TBC

There should be two image files in the file format defined by default: PNG

Define another file format to test the node¶

Edit the application.xml file and add the line:

<parameter id="format">JPEG</parameter>

To obtain:

<?xml version="1.0" encoding="UTF-8"?>
<application id="example">
    <jobTemplates>
        <jobTemplate id="gdalformatconv">
            <streamingExecutable>/application/simplejob/run</streamingExecutable>
            <defaultParameters>                            
                <parameter id="format">PNG</parameter>
            </defaultParameters>
        </jobTemplate>
    </jobTemplates>
    <workflow id="workflow">                            <!-- Sample workflow -->
        <workflowVersion>1.0</workflowVersion>
        <workflowDescription>My simple workflow</workflowDescription>
        <node id="gdal">                            <!-- workflow node unique id -->
            <job id="gdalformatconv"></job>                    <!-- job defined above -->
            <sources>
                <source refid="file:urls" >/home/fbrito/geotiff.urls</source>
            </sources>
            <parameters>
                <parameter id="format">JPEG</parameter>
            </parameters>
        </node>
    </workflow>
</application>

Run the job again this time using the ciop-simjob flag to delete the previous run results:

 
[user@sb ~] ciop-simjob -f gdal

The generated files are published on a local filesystem:

[user@sb ~] cd /share/tmp/TBC

There should be two image files in the file format defined at workflow level: JPEG

Run the application as a workflow¶

Our workflow has a single job but it's still a workflow!

You can trigger the workflow with:

[user@sb ~] ciop-simwf

You can track the workflow execution on the shell. Wait for the workflow conclusion.

Use the command below to get the latest workflow run:

[user@sb ~] ciop-simwf -l
0000000-130405042430716-oozie-oozi-W

Use the value returned above to check the workflow results:

[user@sb ~] ll tmp/sandbox/run/0000000-130405042430716-oozie-oozi-W/gdal/output

You can optionally delete the generated results:

Conclusion¶

With this simple job you have learned:

how to install packages to run your application using yum
how to create a job template in your sanbox
how to write the job wrapper script
how to define the application descriptor
how to execute the job with the default parameter
how to execute the job with the parameter value definition
how to execute the workflow
how to check the generated results

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Updated by Herve Caumont over 10 years ago · 3 revisions

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