limit number of cpus in MultiProc test workflows

Author: oesteban

circle.yml

@@ -44,9 +44,9 @@ test:
     - docker run -v /etc/localtime:/etc/localtime:ro -v ~/examples:/root/examples:ro -v ~/scratch:/scratch -w /scratch nipype/nipype_test:py35 /usr/bin/run_examples.sh fmri_spm_dartel Linear /root/examples/ l2pipeline :
         timeout: 1600
     - docker run -v /etc/localtime:/etc/localtime:ro -v ~/examples:/root/examples:ro -v ~/scratch:/scratch -w /scratch nipype/nipype_test:py35 /usr/bin/run_examples.sh fmri_fsl_reuse Linear /root/examples/ level1_workflow
-    - docker run -v /etc/localtime:/etc/localtime:ro -v ~/examples:/root/examples:ro -v ~/scratch:/scratch -w /scratch nipype/nipype_test:py27 /usr/bin/run_examples.sh fmri_spm_nested MultiProc /root/examples/ level1
-    - docker run -v /etc/localtime:/etc/localtime:ro -v ~/examples:/root/examples:ro -v ~/scratch:/scratch -w /scratch nipype/nipype_test:py35 /usr/bin/run_examples.sh fmri_spm_nested MultiProc /root/examples/ level1
-    - docker run -v /etc/localtime:/etc/localtime:ro -v ~/examples:/root/examples:ro -v ~/scratch:/scratch -w /scratch nipype/nipype_test:py35 /usr/bin/run_examples.sh fmri_spm_nested MultiProc /root/examples/ l2pipeline
+    - docker run -v /etc/localtime:/etc/localtime:ro -e NIPYPE_NUMBER_OF_CPUS=4 -v ~/examples:/root/examples:ro -v ~/scratch:/scratch -w /scratch nipype/nipype_test:py27 /usr/bin/run_examples.sh fmri_spm_nested MultiProc /root/examples/ level1
+    - docker run -v /etc/localtime:/etc/localtime:ro -e NIPYPE_NUMBER_OF_CPUS=4 -v ~/examples:/root/examples:ro -v ~/scratch:/scratch -w /scratch nipype/nipype_test:py35 /usr/bin/run_examples.sh fmri_spm_nested MultiProc /root/examples/ level1
+    - docker run -v /etc/localtime:/etc/localtime:ro -e NIPYPE_NUMBER_OF_CPUS=4 -v ~/examples:/root/examples:ro -v ~/scratch:/scratch -w /scratch nipype/nipype_test:py35 /usr/bin/run_examples.sh fmri_spm_nested MultiProc /root/examples/ l2pipeline
 
   post:
     - bash docker/circleci/teardown.sh

tools/run_examples.py

@@ -20,7 +20,7 @@ def run_examples(example, pipelines, data_path, plugin=None, rm_base_dir=True):
 
     plugin_args = {}
     if plugin == 'MultiProc':
-        plugin_args['n_procs'] = cpu_count()
+        plugin_args['n_procs'] = os.getenv('NIPYPE_NUMBER_OF_CPUS', cpu_count())
 
     __import__(example)
     for pipeline in pipelines: