On Wed, Nov 7, 2018 at 3:11 PM Erwan Velu <evelu@xxxxxxxxxx> wrote: > > Hi list, > > I'm working on a tool that reads the json output of several ceph commands. > > To ease the parsing, I've been choosing the JSON format which guarantee > a parseable output. > > I'm using the Unmarshall feature of golang to map this output in an > internal data structure so every member of this JSON output is easily > reachable from the code. > > That works pretty well except that I have to "anticipate" what will the > be members and their types. > > To do that, I've been transforming the sample output of my Ceph cluster > (luminous) into a data struct with https://mholt.github.io/json-to-go/ > > That works fine unless that I would be a complete output to get every > possible combination of the json output. > > > So instead of reversing the json output, and that per version of Ceph as > versions can change the format, how can I extract the complete JSON > schema from each command ? The short answer is that you can't, because there aren't defined schemas. It's not straightforward to define them, because the output of commands is coming from so many different places in the code (pretty much anything with a ::dump method might show up in a CLI at some point). However, Noah has looked at this (see thread "exported data schema validation") with a view to defining schemas for a subset of key data structures. Note that even when some schemas exist, that won't necessarily make it safe to rely on them across versions -- introducing versioning to the output of our CLIs would be a whole other question (and the answer would probably be to create an API rather than bolting that onto the CLI). John > > > Erwan, >
