Have your own geocoder up and running within the hour, you will require about 60GB of disk space and has no further dependencies.
Feel free to fork and improve.
The image itself is pretty small, the first time the container is executed, a 30GB searchindex will be downloaded.
The data volume is exposed as /photon/photon_data and can be mounted, this way you'll only have to download the data once.
docker run -p 2322:2322 -it thomasnordquist/photon-geocoder:latesthttp://localhost:2322/api?q=berlin
For more details on the API check the photon github repository.
https://github.com/thomasnordquist/photon-docker
docker-compose build #optional
docker-compose upNote: if you abort the download, you have to remove the volume photon_data before restarting the container
docker build --tag thomasnordquist/photon-geocoder .- 
How do I pass arguments to the photon.jar?The entrypoint accepts arguments for the photon.jar, you can invoke it by usingdocker exec
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Do I need to have nominatim ? The container downloads the latest prebuilt search index, there is no immediate need to have nominatim installed. 
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What is photon ? photon is a geocoder, check out their website and their github repository