'docker run -d -p 8080:8080 parking_api' starts it, but it stops after 2 secs

doing this:

docker run -d -p 8080:8080 parking_api

leads to this:

$ docker ps
CONTAINER ID        IMAGE               COMMAND                CREATED             STATUS              PORTS                    NAMES
e58256819ad3        parking_api         "clockwork clock.rb"   1 seconds ago       Up 1 seconds        0.0.0.0:8080->8080/tcp   infallible_lovelace

but then it stops:

$ docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES

These are the logs:

$ docker logs e58256819ad3
D, [2016-09-28T20:34:46.932793 #1] DEBUG -- : HTTPI GET request to overpass-api.de (net_http)
/usr/src/app/lib/parking_scraper.rb:14:in `overpass_to_geojson': undefined method `[]' for nil:NilClass (NoMethodError)
    from /usr/src/app/lib/parking_scraper.rb:27:in `block in <module:ParkingScraper>'
    from /usr/local/lib/ruby/2.3.0/csv.rb:1748:in `each'
    from /usr/local/lib/ruby/2.3.0/csv.rb:1131:in `block in foreach'
    from /usr/local/lib/ruby/2.3.0/csv.rb:1282:in `open'
    from /usr/local/lib/ruby/2.3.0/csv.rb:1130:in `foreach'
    from /usr/src/app/lib/parking_scraper.rb:24:in `<module:ParkingScraper>'
    from /usr/src/app/lib/parking_scraper.rb:7:in `<top (required)>'
    from /usr/src/app/clock.rb:2:in `require'
    from /usr/src/app/clock.rb:2:in `<top (required)>'
    from /usr/local/bundle/gems/clockwork-1.2.0/bin/clockwork:12:in `require'
    from /usr/local/bundle/gems/clockwork-1.2.0/bin/clockwork:12:in `<top (required)>'
    from /usr/local/bundle/bin/clockwork:17:in `load'
    from /usr/local/bundle/bin/clockwork:17:in `<main>'

codeformuenster / parkleitsystem-api

'docker run -d -p 8080:8080 parking_api' starts it, but it stops after 2 secs #13