check-web | Web client for Meedan Check, a collaborative media annotation platform | Frontend Framework library

You need to escape the $ in the makefile. Turn ${nginx_https_port} into \${nginx_https_port}.

The string in your makefile is:

"command='curl -k -s https://localhost:${nginx_https_port}/healthcheck'"

Since it's a string encased by double quotes, variable substitution/expansion happens. So ${nginx_https_port} is expanded in the makefile, on the host the makefile runs on. To prevent that, you need the escape the $, so the string is loaded into ansible as-is.

In single quote strings (e.g. 'echo $hello') no variable substitution/expansion happens, which is also why the docker exec (executed on the shell) works for you:

docker exec webproxy sh -c 'curl -k -s https://localhost:${nginx_https_port}/healthcheck'

Here the string curl -k -s https://localhost:${nginx_https_port}/healthcheck' is given as-is to the sh inside the docker container, where then it is executed without any quotes and the variable can be expanded.