Adding a Neo4j GIE

[thobalose]

The Neo4j IE described in this issue.

Thanks to @bgruening and @erasche.

[hexylena]

is this needed? That should be default.

[thobalose]

This must have been whilst debugging the issues with proxy_ipc. Having seen and noting that it's not present when galaxy launched the proxy.

[pvanheus]

For this code to work with the nginx proxy it needs this in the nginx.conf:

        #Neo4J
        location /gie_proxy/neo {
            proxy_pass http://localhost:8800/;
            proxy_redirect default;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
        }

        location /db/data {
            proxy_pass http://localhost:8800/db/data;
            proxy_redirect default;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
        }

1. Does the first block clash with other IEs? I.e. will the proxy know to direct that message to the correct IE?
2. The second block does not refer to /gie_proxy. This is because the AngularJS app that implements the Neo4j shell does calls to that URL - this is not configurable at present, but a PR should be made against the Neo4j code to make it configurable.

If this PR is being merged, we need to add this info the GIE docs.

[pvanheus]

A bit of testing suggests that (1) is causing an issue. To reproduce the problem:

1. Start a Jupyter IE
2. Start a Neo4j IE
3. The Jupyter IE goes to "Not found" and control of the IE is lost from the side of Galaxy.

In other words, this IE doesn't play nicely with other IEs on the same server.

[bgruening]

As discussed this is a general IE issue at the moment, at least with the IE proxy, afaik.