Don't hardcode container interface in Docker vmms

Instead of putting all the file copying and su-ing in the docker run
command constructed by the vmm, include an interface script in the
container and use it as the container entrypoint. The only thing
passed from the vmm to the container are the resource limit parameters.

In addition, rewrite the dockerfile so it (1) includes fewer RUN lines, and
(2) does not need to fetch Tango from github in order to build autodriver;
Instead, the autodriver source is copied to the container using the ADD
instruction

autodriver/Dockerfile

@@ -0,0 +1,32 @@
+# Autolab - autograding docker image
+
+FROM ubuntu:14.04
+MAINTAINER Mihir Pandya <mihir.m.pandya@gmail.com>
+
+RUN apt-get update && apt-get install -y build-essential wget
+
+# Install autodriver
+WORKDIR /home
+RUN useradd autolab && useradd autograde
+RUN mkdir autolab autograde output && chown autolab:autolab autolab output && chown autograde:autograde autograde
+ADD . /home/autodriver
+WORKDIR /home/autodriver
+RUN make clean && make && install -c -o root -g root -m 4755 autodriver /usr/bin/autodriver && install -c -m 755 autograde_wrapper.py /usr/bin/autograde_wrapper
+ENTRYPOINT ["/usr/bin/autograde_wrapper"]
+
+# Install C0
+WORKDIR /home
+RUN wget http://c0.typesafety.net/dist/cc0-v0440-linux3.18.1-64bit-bin.tgz
+RUN tar -xvzf cc0-*
+WORKDIR /home/cc0
+RUN bin/cc0 -d doc/src/exp.c0 doc/src/exp-test.c0
+#RUN ./a.out
+RUN cp bin/cc0 /usr/bin/cc0
+
+# Clean up
+WORKDIR /home
+RUN apt-get remove -y wget && apt-get -y autoremove
+RUN rm -rf autodriver cc0*
+
+# Check installation
+RUN ls -l /home && which autodriver && which cc0

autodriver/autograde_wrapper.py

@@ -0,0 +1,33 @@
+#!/usr/bin/python3
+import sys
+import os
+import pwd
+import shutil
+import subprocess
+print("Running "+ str(sys.argv))
+
+for f in os.listdir("mount"):
+  src=os.path.join("mount", f)
+  dst=os.path.join("autolab", f)
+  shutil.copy(src, dst)
+
+autolabuser=pwd.getpwnam("autolab")
+pid=os.fork()
+if pid == 0:
+   os.setgroups([])
+   os.setgid(autolabuser.pw_gid)
+   os.setuid(autolabuser.pw_uid)
+   outfile=open("output/feedback", "w")
+   args=["autodriver"]
+   args.extend(sys.argv[1:])
+   args.append("autolab")
+   print("Executing "+str(args), file=outfile)
+   sys.exit(subprocess.call(args, stdout=outfile, stderr=outfile, close_fds=True))
+(np, status)=os.waitpid(pid, 0)
+# if core, exit -1, else pass through code.
+if status & 0xff:
+   status=-1
+else:
+   status>>=8;
+shutil.copy("output/feedback", "mount/feedback")
+sys.exit(status)

vmms/localDocker.py

@@ -133,16 +133,8 @@ def runJob(self, vm, runTimeout, maxOutputFileSize):
         args = ['docker', 'run', '--name', instanceName, '-v']
         args = args + ['%s:%s' % (volumePath, '/home/mount')]
         args = args + [vm.image]
-        args = args + ['sh', '-c']
 
-        autodriverCmd = 'autodriver -u %d -f %d -t %d -o %d autolab &> output/feedback' % \
-                        (config.Config.VM_ULIMIT_USER_PROC, 
-                        config.Config.VM_ULIMIT_FILE_SIZE,
-                        runTimeout, config.Config.MAX_OUTPUT_FILE_SIZE)
-
-        args = args + ['cp -r mount/* autolab/; su autolab -c "%s"; \
-                        cp output/feedback mount/feedback' % 
-                        autodriverCmd]
+        args = args + [ "-u", str(config.Config.VM_ULIMIT_USER_PROC), "-f", str(config.Config.VM_ULIMIT_FILE_SIZE), "-t", str(runTimeout), "-o", str(config.Config.MAX_OUTPUT_FILE_SIZE)]
 
         self.log.debug('Running job: %s' % str(args))
         ret = timeout(args, runTimeout)