Provide an image that can be used without customizing

[trajano]

Is it possible to have a version of the image built so that it can be configured using environment variables rather than building a custom image?

[rnburn]

What options do you want to configure from environmental variables?

Keep in mind that by default nginx drops all the environmental variables when it forks a worker.
http://nginx.org/en/docs/ngx_core_module.html#env

[trajano]

OPENTRACING_ENDPOINT is basically the only one I can think of. That will allow the traces to go to a specific server. So the :zipkin image will go use the zipkin library vs :datadog or :jaeger

The reason for specific images is so that not all libraries will be loaded to support some IF-THEN-ELSE condition in the configuration file

  # Load a vendor tracer
  opentracing_load_tracer /usr/local/lib/libjaegertracing_plugin.so /etc/jaeger-nginx-config.json;

  # or 
  #   opentracing_load_tracer /usr/local/lib/liblightstep_tracer_plugin.so /path/to/config;
  # or 
  #   opentracing_load_tracer /usr/local/lib/libzipkin_opentracing_plugin.so /path/to/config;
  # or
  #   opentracing_load_tracer /usr/local/lib/libdd_opentracing_plugin.so /path/to/config;

A testcontainers integration test can be created to start up zipkin (or whatever backend server) and the nginx-with-opentracing:zipkin and make a http call for the home page to and then followed by a REST API query to zipkin server to see if the entry was added successfully.