To edit the /containers/app.yml file from the root@digitialoceandropletname ssh workspace, navigate to the correct directory by running cd /var/discourse and then access the file using an editor like nano containers/app.ymljomaxro. If the file is not found, try running ls -la to confirm its existence and correct path jomaxro. Alternatively, use a template from the templates folder, such as standalone.yml, and copy it to the correct location /var/discourse/containers/app.ymlbobbyiliev. Note that the correct path is /var/discourse/containers/app.yml, not /containers/app.ymlcuriositry.
You can use one of the templates from the templates folder. For example if you would like to run a stand alone server just use the standalone.yml file.
AFAIK when not in the container, containers is a subdirectory of /var/discourse; there is no /containers directory. So unless I’m mistaken, the line “or edit /containers/app.yml manually” in INSTALL.md should read “or edit containers/app.yml manually” or “or edit /var/discourse/containers/app.yml manually”.