Support for global Extensions, Environment

[turbo]

Is your feature request related to a problem? Please describe.

No.

Describe the solution you'd like

We define a lot of extensions, which we use in many of our stacks, an example would be for logging:

x-influxlog: &influxlog
  logging:
    driver: syslog
    options:
      syslog-address: "udp://localhost:514"
      tag: "{{.ImageName}}"

We would like to share these extensions so that like Docker Configs & Secrets, they can be referenced in newly created stacks without explicitly implementing them again.

Another thing that would benefit from such a mechanic is global environment variables. Maybe these can be shown as an immutable list when creating a new stack and edited somewhere else. But that's a lower priority.

Describe alternatives you've considered

AFAIK, there are none, at least not for extensions. Right now we just past them into each new stack.

[NigelKitcher]

@turbo On the global environment variables that sounds like something we have implemented (see issue #2411) to pull values out from a data source (currently an Excel spredsheet although we were thinking of extending it to be via ODBC). I'm planning on getting the changes up into my public repository shortly.
Is that the sort of thing you have in mind?

[olljanat]

@turbo on swarm mode Portainer currenlyt uses docker stack deploy command for deploying stacks so it have same limitations than Docker it selves have so to get feature like that it would need to be added to Docker first.

But if you have access to Docker nodes you can set default logging settings on there: https://docs.docker.com/config/containers/logging/configure/