FTP server for Google Cloud Storage

This application sets up an FTP server that communicates with Google Cloud Storage on the back end. It provides an easy way for you to set up an FTP interface for your Google Cloud Storage bucket so that you can upload, download, and manage your GCS files using your favorite FTP client.

It supports FTP over TLS (explicit encryption) and, if you wish to make use of that functionality, you should bring your SSL/TLS certificate formatted as PKCS #12 (.pfx).

The server is written in .NET Core 2.2 and is most easily built and hosted using Docker. It makes use of Fubar Development's fantastic FTP server written for .NET Standard 2.0. If you do not know about that project, you should really go and check it out.

Things to change before building

There are a few things you should change before building and running the server.

1. Installing the .NET Core 2.2 SDK

If you do not already have the .NET Core 2.2 SDK installed on your computer, you should download it from Microsoft's website. It's free and runs on Windows, macOS, and Linux.

2. Authentication

You should change the authentication mechanism in the CustomMembershipProvider class. By default, the server will authenticate any user that provides the username admin and the password admin. You probably will want to change this.

3. Bucket name

You should also provide the name for your Google Cloud Storage bucket in the GcsFileSystemProvider class. You can either hard code the name into the file or decide to provide it via configuration or an environment variable. That's entirely up to you.

4. Service account

In order to access your bucket, the server must have the private key of a service account with either roles/storage.objectAdmin or roles/storage.admin rights to the bucket.

You can create a service account from Google Cloud Console. Check out this guide to learn how.

Once you created the service account, you should export its private key. You will get a .json file, which should be included in the Docker image. Update the following lines in the Dockerfile to match the name of your .json file.

COPY my-service-account.json ./
ENV GOOGLE_APPLICATION_CREDENTIALS /app/my-service-account.json

Alternatively, if you do not wish to use Docker, you can simply set the environment variable GOOGLE_APPLICATION_CREDENTIALS to the full path of your .json file on the system where you want to run the server.

5. FTP over TLS

If you wish to support FTP over TLS, you must provide an SSL/TLS certificate, which should be protected with a password. By default, the certificate is expected to have the name ftp.pfx and be placed in the root of the project. The Docker build script will then include in the certificate in the Docker image.

You must provide the password of your .pfx file via the environment variable PFX_PASSWORD.

If you do not wish to make use of FTP over TLS, you should set environment variable DISABLE_TLS to True.

6. Logging

The server makes use of NLog. It can be combined with Stackdriver Logging. In the NLog.config file replace [YOUR PROJECT ID] and [YOUR_LOG_ID] with your Google Cloud project ID and the desired ID of your logs, respectively.

Building the server

Once you have completed all of the steps above, you can build the server really easily using Docker by running the following command:

docker build -t sebastianbk/google-storage-ftp .

If you do not wish to use Docker, you can use the dotnet command line tools. Try to run the following command:

dotnet build -c Release

Running the server

Finally, run the server using Docker by executing this command:

docker run -it \
    -p 20:20 \
    -p 21:21 \
    -p 989:989 \
    -p 990:990 \
    -p 10000:10000 \
    -p 10001:10001 \
    -p 10002:10002 \
    -p 10003:10003 \
    -p 10004:10004 \
    -p 10005:10005 \
    -p 10006:10006 \
    -p 10007:10007 \
    -p 10008:10008 \
    -p 10009:10009 \
    sebastianbk/google-storage-ftp \
    ftp

If you decided to make use of FTP over TLS, you should include the following argument to the command above:

    -e PFX_PASSWORD=[YOUR_PFX_PASSWORD]

If you do not wish to use FTP over TLS, include this argument instead:

    -e DISABLE_TLS=True

If you are running the server on an IP different from 127.0.0.1, you should also include this argument to the docker run command.

    -e PUBLIC_IP=[YOUR_IP]

After executing the command, your server should be running. You can test it out by using your favorite FTP client. If you don't already have one installed, a good choice is FileZilla.

Support

If you run into any issues or if you have suggestions for how to improve the server, please either submit an issue or create a pull request with your suggested changes. I welcome any feedback to the project. 😃