Is this a docs issue?
Type of issue
I can't find what I'm looking for
Description
History
Back in 2018, there was an issue (#5854) requesting to document a feature of Docker Swarm (as it was at that time) where swarm could respond to internal docker DNS queries matching the pattern tasks.<service-name> with a "list of all tasks backing the service."
I've seen anecdotal evidence online that the feature is still present. I haven't had the opportunity to test the presence of the feature in modern swarm, but even as it was back then, the documentation wasn't super clear on:
- The format for the DNS response
- How to best use the feature (perhaps with an example, I'm thinking like an example with a Redis or a Postgres cluster of some sort would help?)
Today
I've tried searching for modern documentation of the tasks.<service-name> feature and could only find the issue where it was first requested to be documented: #5854. I spent a bit of time trying to track down where the issue went, and documented some notes in this comment.
The documentation on this feature was dropped in #18998 (2 years ago, in 2024). I checked all network, overlay and swarm documentation at that commit (35b77e4) and found nothing on the topic. This was a very complicated pull request, covering a wide range of topics, and I can't blame anyone for missing something, especially something niche.
Location
https://docs.docker.com/engine/swarm/networking/
Suggestion
I don't know if the feature is present in modern swarm.
If it is not present (or is "deprecated"), it would be nice to have clarification on that in the documentation. (probably on this page: https://docs.docker.com/engine/deprecated/)
If it is present (and not "deprecated"), documentation of this feature equal to or better than the last snapshot at 2745b53 should be restored.
As for where it should go:
As I mentioned, if restoring the documentation of the feature is the correct route, and improvement of the documentation is worth it, it'd be nice to have an example and be more clear about what is provided from the DNS query and how to use it.
Is this a docs issue?
Type of issue
I can't find what I'm looking for
Description
History
Back in 2018, there was an issue (#5854) requesting to document a feature of Docker Swarm (as it was at that time) where swarm could respond to internal docker DNS queries matching the pattern
tasks.<service-name>with a "list of all tasks backing the service."I've seen anecdotal evidence online that the feature is still present. I haven't had the opportunity to test the presence of the feature in modern swarm, but even as it was back then, the documentation wasn't super clear on:
Today
I've tried searching for modern documentation of the
tasks.<service-name>feature and could only find the issue where it was first requested to be documented: #5854. I spent a bit of time trying to track down where the issue went, and documented some notes in this comment.The documentation on this feature was dropped in #18998 (2 years ago, in 2024). I checked all network, overlay and swarm documentation at that commit (35b77e4) and found nothing on the topic. This was a very complicated pull request, covering a wide range of topics, and I can't blame anyone for missing something, especially something niche.
Location
https://docs.docker.com/engine/swarm/networking/
Suggestion
I don't know if the feature is present in modern swarm.
If it is not present (or is "deprecated"), it would be nice to have clarification on that in the documentation. (probably on this page: https://docs.docker.com/engine/deprecated/)
If it is present (and not "deprecated"), documentation of this feature equal to or better than the last snapshot at 2745b53 should be restored.
As for where it should go:
As I mentioned, if restoring the documentation of the feature is the correct route, and improvement of the documentation is worth it, it'd be nice to have an example and be more clear about what is provided from the DNS query and how to use it.