Make otel dependencies optional

DEVELOPERS.md

@@ -31,6 +31,21 @@ The `opensafely.jobrunner` package (and associated tests at tests/jobrunner)
 are currently maintained by the RAP team, rather than REX. Some things, like
 dependencies, affect the whole system, so may need some cross team reviews.
 
+### Tracing
+
+The opensafely run code is instrumented with opentelemetry, using the vendored
+opentelemety-api package. By default, this does nothing, but its fairly easy to
+enable it if needed for development or debugging.
+
+1. Install the extra dependencies:
+ - if in a devenv, they should already be installed
+ - if opensafely was installed via pip, then `install opensafely[tracing]`
+ - if opensafely was installed via uv, then `uv tool install opensafely[tracing]`
+2. Create an ingest key from the Development Environment in Honeycomb: https://ui.honeycomb.io/bennett-institute-for-applied-data-science/environments/development/api_keys
+3. set `export OTEL_EXPORTER_OTLP_HEADERS="x-honeycomb-team=<your-api-key>"
+4. Use `opensafely run` as normal.
+5. The traces should appear in the `opensafely-run` dataset in the Development environment in Honeycomb.
+
 
 ## Tests
 

justfile

@@ -7,7 +7,7 @@ export VIRTUAL_ENV  := `echo ${VIRTUAL_ENV:-.venv}`
 export BIN := VIRTUAL_ENV + if os_family() == "unix" { "/bin" } else { "/Scripts" }
 export PIP := BIN + if os_family() == "unix" { "/python -m pip" } else { "/python.exe -m pip" }
 # enforce our chosen pip compile flags
-export COMPILE := BIN + "/pip-compile --allow-unsafe"
+export COMPILE := BIN + "/pip-compile"
 
 
 # list available commands
@@ -46,12 +46,12 @@ _compile src dst *args: virtualenv
 
 # update *vendored* production dependencies. See DEVELOPERS.md.
 requirements-prod *args:
-    just _compile requirements.prod.in requirements.prod.txt {{ args }}
+    just _compile requirements.prod.in requirements.prod.txt --no-allow-unsafe {{ args }}
 
 
 # update requirements.dev.txt if requirements.dev.in has changed
 requirements-dev *args: virtualenv
-    just _compile requirements.dev.in requirements.dev.txt {{ args }}
+    just _compile requirements.dev.in requirements.dev.txt --allow-unsafe {{ args }}
 
 
 # ensure prod requirements installed and up to date

opensafely/__init__.py

@@ -6,14 +6,6 @@
 from datetime import datetime, timedelta
 from pathlib import Path
 
-# ensure pkg_resources can find the package metadata we have included, as the
-# opentelemetry packages need it
-import pkg_resources
-
-
-opensafely_module_dir = Path(__file__).parent
-pkg_resources.working_set.add_entry(f"{opensafely_module_dir}/_vendor")
-
 from opensafely import (  # noqa: E402
     check,
     clean,