issue_comments

Hi @wragge,

This looks great, thanks for the share! I refactored it into a self-contained function, binding on a random available TCP port (multi-user context). I am using subprocess API directly since the %run magic was leaving defunct process behind :/

```python import socket

from signal import SIGINT from subprocess import Popen, PIPE

from IPython.display import display, HTML from notebook.notebookapp import list_running_servers

def get_free_tcp_port(): """ Get a free TCP port. """ tcp = socket.socket(socket.AF_INET, socket.SOCK_STREAM) tcp.bind(('', 0)) _, port = tcp.getsockname() tcp.close() return port

def datasette(database): """ Run datasette on an SQLite database. """ # Get current running servers servers = list_running_servers()

# Get the current base url
base_url = next(servers)['base_url']

# Get a free port
port = get_free_tcp_port()

# Create a base url for Datasette suing the proxy path
proxy_url = f'{base_url}proxy/absolute/{port}/'

# Display a link to Datasette
display(HTML(f'<p><a href="{proxy_url}">View Datasette</a> (Click on the stop button to close the Datasette server)</p>'))

# Launch Datasette
with Popen(
    [
        'python', '-m', 'datasette', '--',
        database,
        '--port', str(port),
        '--config', f'base_url:{proxy_url}'
    ],
    stdout=PIPE,
    stderr=PIPE,
    bufsize=1,
    universal_newlines=True
) as p:
    print(p.stdout.readline(), end='')
    while True:
        try:
            line = p.stderr.readline()
            if not line:
                break
            print(line, end='')
            exit_code = p.poll()
        except KeyboardInterrupt:
            p.send_signal(SIGINT)

```

Ideally, I'd like some extra magic to notify users when they are leaving the closing the notebook tab and make them terminate the running datasette processes. I'll be looking for it.

Hi,

I came across this issue while looking for a way to spawn Datasette as a SQLite files viewer in JupyterLab. I found https://github.com/simonw/jupyterserverproxy-datasette-demo which seems to be the most up to date proof of concept, but it seems to be failing to list the available db (at least in the Binder demo, https://hub.gke.mybinder.org/user/simonw-jupyters--datasette-demo-uw4dmlnn/datasette/, I only have :memory).

Does anyone tried to improve on this proof of concept to have a Datasette visualization for SQLite files?

Thanks!

Great - thanks again.

Hi Simon - I'm just (trying, at least) to follow along in the above. I can't try it out now, but I will if no one else gets to it. Sorry I didn't write any tests in the original bit of code I pushed - I was just trying to see if it could work & whether you'd want to maybe head in that direction. Anyway, thank you, I will certainly use this. Comment back here if no one tried it out & I'll make time.

@simonw You're welcome - I was just trying it out back in December as I thought it should work. Now there's a pandemic to work on though.... so no time at all for more at the moment. BTW, I have datasette running on several protein and full (virus) genome databases I build, and it's great - thank you! Hi and best regards to you & Nat :-)

I just updated #652 to remove a merge conflict. I think it's an easy way to add this functionality. I don't have time to do more though, sorry!

On mybinder.org we allow access to arbitrary processes listening on a port inside the container via a reverse proxy.

This means we need support for a proxy prefix as the proxy ends up running at a URL like /something/random/proxy/datasette/...

An example that shows the problem is https://github.com/psychemedia/jupyterserverproxy-datasette-demo. Launch directly into a datasette instance on mybinder.org with https://mybinder.org/v2/gh/psychemedia/jupyterserverproxy-datasette-demo/master?urlpath=datasette then try to follow links inside the UI.

@simonw What about allowing a base url. The <base>....</base> tag has been around forever. Then just use all relative URLs, which I guess is likely what you already do. See https://www.w3schools.com/TAGs/tag_base.asp

Hmmm, wait, maybe my mindless (copy/paste) use of proxy_redirect is causing me grief...

Agreed, this would be nice to have. I'm currently working around it in nginx with additional location blocks:

```

location /datasette/ {
    proxy_pass         http://127.0.0.1:8001/;
    proxy_redirect     off;
    include proxy_params;
}

location /dna-protein-genome/ {
    proxy_pass         http://127.0.0.1:8001/dna-protein-genome/;
    proxy_redirect     off;
    include proxy_params;
}

location /rna-protein-genome/ {
    proxy_pass         http://127.0.0.1:8001/rna-protein-genome/;
    proxy_redirect     off;
    include proxy_params;
}

```

The 2nd and 3rd above are my databases. This works, but I have a small problem with URLs like /rna-protein-genome?params.... that I could fix with some more nginx munging. I seem to do this sort of thing once every 5 years and then have to look it all up again.

Thanks!