First, open Code Ocean's custom package management system.
Next, use apt-get to install build-essential .
Then, in a postInstall script, write:
#!/bin/bash
curl -fsS https://dlang.org/install.sh | bash -s install ldc-1.6.0
See the following two examples for more specific usage demonstrations:
https://codeocean.com/2018/01/04/d-lpar-dlang-rpar-hello-world/code
https://codeocean.com/2018/01/04/vectorflow-mnist-example-lpar-dlang-dub-rpar/code
Note that the second example also installs supplementary D libraries via the postInstall script.