adding as examples, in case they are wanted or needed

Author: vsoch

examples/docker2singularity/docker2singularity.py

@@ -0,0 +1,88 @@
+#!/usr/bin/env python
+
+'''
+docker.py: an example of converting a docker to a singularity image using
+singularity-python. This is now dated and not the recommended standard. The recommended way
+is to use singularity natively, see:
+
+http://singularity.lbl.gov/docs-docker
+
+'''
+
+from singularity.utils import check_install, getsudo, run_command
+from singularity.package import get_image_hash
+from singularity.cli import Singularity
+import tempfile
+import tarfile
+import requests
+import shutil
+import os
+
+dockerhub = ""
+
+def docker2singularity(docker_image,output_folder=None):
+    '''docker2singulrity is a wrapper for the Singularity.docker2singularity
+    client function. Does not currently include runscript (/singularity) in image,
+    but does export full docker image spec under /singularity.json
+    :param docker_image: the full docker repo/image,eg "ubuntu:latest"
+    :param output_folder: the output folder to create the image in. If not 
+    specified, will use pwd.
+    '''
+
+    S = Singularity()
+    docker_image = S.docker2singularity(docker_image=docker_image,
+                                        output_dir=output_folder)
+    return docker_image
+
+
+def get_docker_guts(docker_image,sudopw=None):
+    '''get_docker_guts will get the files and folders within a docker image by converting to tar first.
+    :param docker_image: the name of the docker image, doesn't have to be on local machine (eg, ubuntu:latest) 
+    :param sudopw: sudopw to use in function.
+    '''
+    if check_install('docker') == True:
+
+        # get sudopwd once to send to all following commands
+        if sudopw == None:
+            print("\nYOU MUST ENTER PASSWORD TO CONTINUE AND USE DOCKER:")
+            sudopw = getsudo() 
+
+        cmd = ['docker','run','-d',docker_image,'tail','-f','/dev/null']
+        runningid = run_command(cmd=cmd,sudopw=sudopw)
+        # sha256:d59bdb51bb5c4fb7b2c8d90ae445e0720c169c553bcf553f67cb9dd208a4ec15
+        
+        # Take the first 12 characters to get id of container
+        container_id=runningid[0:12]
+ 
+        # Get image name
+        cmd = ['docker','inspect','--format="{{.Config.Image}}"',container_id]
+        image_name = run_command(cmd=cmd,sudopw=sudopw)
+
+        # Export tar to get files and folders
+        print("Extracting filesystem from %s, please wait..." %(docker_image))
+        tmpdir = tempfile.mkdtemp()
+        tmptar = "%s/%s.tar" %(tmpdir,container_id)
+        cmd = ['docker','export',container_id,'>',tmptar]
+        run_command(cmd=cmd,sudopw=sudopw,suppress=True)
+
+        # Give the list a VERSION based on the tarfile
+        version = get_image_hash(tmptar)
+        dockerstuffs = {"VERSION": version,
+                        "image":image_name}
+
+        # Read in files and folders from the tar!
+        tar = tarfile.open(tmptar)
+        members = tar.getmembers()
+        files = [x.path for x in members if x.isfile()]
+        folders = [x.path for x in members if x.isdir()]
+        dockerstuffs["files.txt"] = files
+        dockerstuffs["folders.txt"] = folders
+
+        # Finally,stop the container
+        print("Stopping container... please wait!")
+        run_command(cmd=['docker','stop',container_id],sudopw=sudopw)
+
+        # clean up the temporary directory
+        shutil.rmtree(tmpdir)
+ 
+        return dockerstuffs