temporalio.contrib.opentelemetry._context

module documentation
(source)

Attach OpenTelemetry contexts so that the matching detach is always safe.

Function attached_context Attach context for the block and detach it afterwards where possible.
Function _detach Detach context if it is current and token is valid here.
def attached_context(context: Context | None) -> Iterator[None]: (source)

Attach context for the block and detach it afterwards where possible.

None attaches nothing. The block's finally can run in a different contextvars.Context than the one that attached: a context manager abandoned by an evicted workflow is finalized wherever garbage collection happens to run. The token is not valid there, and opentelemetry.context.detach would log "Failed to detach context" even though there is nothing to detach. Checking that the attached context is still current does not catch every such case, because OpenTelemetry's threading instrumentation (enabled by strands, among others) propagates the same Context object into new threads. The thread is no test either: workflow activations move between pool threads while the asyncio task keeps its contextvars.Context, and those detaches must happen. Only contextvars knows which Context a token belongs to, so _detach performs the reset detach performs and ignores the ValueError raised for a token from another Context.

def _detach(context: Context, token: Token[Context]) -> bool: (source)

Detach context if it is current and token is valid here.