Fixes #11: Error attempting to ecs-cli compose up

[tiffanyfay]

Fixes #11

-Cherry-picked PR #23 (thanks @mcanevet)
-The above PR made it so it wouldn't fail, but the same volume was shared amongst all container paths without a host path, so I added this
-Updated test
-Tested it with ecs-cli compose up on random compose file I mushed together:

data-container:
  image: redis:latest
  volumes:
    - /tmp/stuff 
    - /tmp/bar:/foo/baz
    - /tmp/ponies
    - /tmp/foo:/tmp/bar
    - /tmp/foo:/tmp/baz
  mem_limit: 100M

data-container2:
  image: redis:latest
  volumes:
    - /tmp/hi:/tmp/hello
    - /tmp/foo:/tmp/foo
    - /tmp/unicorns
  mem_limit: 100M

[aaithal]

volumeHasHost seems like something that you'd use for naming a bool. Can you use a better name here?

[tiffanyfay]

Yeah

[aaithal]

This doesn't need to be a global variable I think.

[tiffanyfay]

Will try again. Wherever I had put it before resulted in it overwriting itself every time it was called.

[tiffanyfay]

Basically I think I would just have to add another parameter to the function being called otherwise. Should I do that instead?

[aaithal]

Have you tried using testify/assert package for these kinds of things? Makes it less verbose and more elegant.

[tiffanyfay]

I didn't because that would require rewriting the entire test file or just changing the section I was dealing with.

[tiffanyfay]

Adding testify/assert will be a separate PR since it's not specific to this issue and isn't currently used in the file.

[aaithal]

I think that hard-coding this index might be better than incrementing using a pointer. We already hardcode the index for the mountPointsOut slice when this is invoked. What do you think about not incrementing this variable, but passing in a hard-coded value from where it's invoked? So it'd be verifyMountPoint(t *testing.T, output *ecs.MountPoint, volumes *volumes, hostPath, containerPath string, readonly bool, emptyHostIndex int). And then you'll invoke it with the appropriate index from TestConvertToMountPoints(). Does that make sense?