[WIP] Adding mount options to functions.

[alshabib]

This allows functions to mount volumes and other
directories. It uses the same configuration as is
used by docker.

Signed-off-by: Ali Al-Shabibi [email protected]

Description

This change allows functions to mount volumes just as other containers running in a docker environment can. This pull request fixes #320.

Motivation and Context

Passing large amounts of data over the http/stdin isn't very efficient and can cause bottlenecks. Instead, functions can pick up data from known locations mounted into their running container.

How Has This Been Tested?

This has been manually tested by starting openfaas, creating a function over the REST API using the following json:

{
  "service": "nodeindo",
  "network": "functions",
  "image": "functions/nodeinfo",
  "mounts": [
    {
      "type" : "volume",
      "source" : "myvol",
      "target" : "/tmp"
    }
  ]
}

The resulting container was inspected to observe the volume was received and deployed by docker with the following output:

...
Mounts": [
            {
                "Type": "volume",
                "Name": "myvol",
                "Source": "/mnt/sda1/var/lib/docker/volumes/myvol/_data",
                "Destination": "/tmp",
                "Driver": "local",
                "Mode": "z",
                "RW": true,
                "Propagation": ""
            }
        ],
...

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
  While this does not require new documentation, it would certainly benefit from it. I am happy to document it, if someone points me to the right documentation to update.
• I've read the CONTRIBUTION guide
• I have signed-off my commits with git commit -s
• I have added tests to cover my changes.
• All new and existing tests passed.

[alexellis]

Hi, thank you for your contribution. There should be a proposal raised for PRs. Please read the contribution guide which explains that a proposal is needed before carrying out work.

[alshabib]

I added a proposal (#320). Let me know if I missed anything else.

[open-derek]

Thank you for your contribution. I've just checked and your commit doesn't appear to be signed-off.
That's something we need before your Pull Request can be merged. Please see our contributing guide.

[alexellis]

Please see comment one the linked issue.