Using jsonschema within a Rocket endpoint

[mvahowe]

I'm building a webserver using Rocket. As part of that I'd like to validate JSON. I had validation working with this module about a year ago. A lot has changed since, I've updated my code, but I'm getting

thread 'tokio-runtime-worker' panicked at [...]:
Cannot drop a runtime in a context where blocking is not allowed. This happens when a runtime is dropped from within an asynchronous context.

I've tried jsonschema::validate and also making a validator. Both give me this error.

I think the issue is that Rocket itself is running in a runtime:

Rocket is executing inside of a custom runtime

Does this mean that the blocking version of jsonschema is also using a runtime? Any ideas on how to mitigate this issue?

[mvahowe]

I reworked my server code to use the standard rocket launcher, but it's still a runtime. Here's some of the backtrace (to where I immediately call jsonschema:

GET /burrito/audit/_local_/_quarantine_/fr_tn:
   >> Matched: (audit) GET /burrito/audit/<repo_path..>
thread 'rocket-worker-thread' panicked at /home/mark/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.43.0/src/runtime/blocking/shutdown.rs:51:21:
Cannot drop a runtime in a context where blocking is not allowed. This happens when a runtime is dropped from within an asynchronous context.
stack backtrace:
   0: rust_begin_unwind
             at /rustc/90b35a6239c3d8bdabc530a6a0816f7ff89a0aaf/library/std/src/panicking.rs:665:5
   1: core::panicking::panic_fmt
             at /rustc/90b35a6239c3d8bdabc530a6a0816f7ff89a0aaf/library/core/src/panicking.rs:74:14
   2: tokio::runtime::blocking::shutdown::Receiver::wait
             at /home/mark/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.43.0/src/runtime/blocking/shutdown.rs:51:21
   3: tokio::runtime::blocking::pool::BlockingPool::shutdown
             at /home/mark/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.43.0/src/runtime/blocking/pool.rs:263:12
   4: <tokio::runtime::blocking::pool::BlockingPool as core::ops::drop::Drop>::drop
             at /home/mark/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.43.0/src/runtime/blocking/pool.rs:284:9
   5: core::ptr::drop_in_place<tokio::runtime::blocking::pool::BlockingPool>
             at /home/mark/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:574:1
   6: core::ptr::drop_in_place<tokio::runtime::runtime::Runtime>
             at /home/mark/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:574:1
   7: reqwest::blocking::wait::enter
             at /home/mark/.cargo/registry/src/index.crates.io-6f17d22bba15001f/reqwest-0.12.15/src/blocking/wait.rs:80:21
   8: reqwest::blocking::wait::timeout
             at /home/mark/.cargo/registry/src/index.crates.io-6f17d22bba15001f/reqwest-0.12.15/src/blocking/wait.rs:13:5
   9: reqwest::blocking::client::ClientHandle::new
             at /home/mark/.cargo/registry/src/index.crates.io-6f17d22bba15001f/reqwest-0.12.15/src/blocking/client.rs:1246:15
  10: reqwest::blocking::client::ClientBuilder::build
             at /home/mark/.cargo/registry/src/index.crates.io-6f17d22bba15001f/reqwest-0.12.15/src/blocking/client.rs:114:9
  11: reqwest::blocking::get
             at /home/mark/.cargo/registry/src/index.crates.io-6f17d22bba15001f/reqwest-0.12.15/src/blocking/mod.rs:107:5
  12: <jsonschema::retriever::DefaultRetriever as referencing::retriever::Retrieve>::retrieve
             at /home/mark/.cargo/registry/src/index.crates.io-6f17d22bba15001f/jsonschema-0.32.1/src/retriever.rs:22:24
  13: referencing::registry::process_resources
             at /home/mark/.cargo/registry/src/index.crates.io-6f17d22bba15001f/referencing-0.32.1/src/registry.rs:775:39
  14: referencing::registry::Registry::try_from_resources_impl
             at /home/mark/.cargo/registry/src/index.crates.io-6f17d22bba15001f/referencing-0.32.1/src/registry.rs:329:9
  15: referencing::registry::RegistryOptions<alloc::sync::Arc<dyn referencing::retriever::Retrieve>>::build
             at /home/mark/.cargo/registry/src/index.crates.io-6f17d22bba15001f/referencing-0.32.1/src/registry.rs:217:9
  16: jsonschema::compiler::build_validator
             at /home/mark/.cargo/registry/src/index.crates.io-6f17d22bba15001f/jsonschema-0.32.1/src/compiler.rs:265:13
  17: jsonschema::options::ValidationOptions::build
             at /home/mark/.cargo/registry/src/index.crates.io-6f17d22bba15001f/jsonschema-0.32.1/src/options.rs:521:9
  18: jsonschema::validator::Validator::new
             at /home/mark/.cargo/registry/src/index.crates.io-6f17d22bba15001f/jsonschema-0.32.1/src/validator.rs:223:9
  19: jsonschema::validator_for
             at /home/mark/.cargo/registry/src/index.crates.io-6f17d22bba15001f/jsonschema-0.32.1/src/lib.rs:751:5
  20: jsonschema::validate
             at /home/mark/.cargo/registry/src/index.crates.io-6f17d22bba15001f/jsonschema-0.32.1/src/lib.rs:729:5
  21: pankosmia_web::utils::validate_json::validate_json_value
             at /home/mark/repos/pankosmia/pankosmia-web/src/utils/validate_json.rs:5:15

validate.json is a thin wrapper around jsonschema:

pub fn validate_json_value(schema_spec: Value, json_value: &Value) -> Vec<String> {
        match jsonschema::validate(&schema_spec, json_value) {
            Ok(()) => vec![],
            Err(e) => vec![e.to_string()],
    }
}