Add smoke tests, update releasing doc

RELEASING.md

@@ -19,21 +19,28 @@ How to release a new version of the `splunk-opentelemetry` project:
         - bump our version in `__about__.py`
         - update additional version string locations
         - update CHANGELOG.md
-7) Push the changes to the Github Splunk OTel Python repo
-8) Open a PR and merge after approval
-9) Navigate to the GitLab mirror and verify that the mirror has pulled the version you just merged by checking the
-   version number in the `__about__.py` file
-10) When ready to release, create a new tag like `v3.4.5` on main in GitLab
+7) Smoke test the local changes before releasing:
+    ```
+    SPLUNK_ACCESS_TOKEN=<token> ./tests/smoke/smoke-test-package.sh
+    ```
+8) Push the changes to the Github Splunk OTel Python repo
+9) Open a PR and merge after approval
+10) Navigate to the GitLab mirror and verify that the mirror has pulled the version you just merged by checking the
+    version number in the `__about__.py` file
+11) When ready to release, create a new tag like `v3.4.5` on main in GitLab
     - a tag of the format `vX.Y.Z` will trigger the CI pipeline to build and publish the package to PyPI and the Docker
       image to Quay
-11) Monitor the release pipeline in GitLab to ensure it completes successfully
-12) Post release, verify that the new package is available on PyPI and the Docker image is available on Quay
-13) Smoke test the release locally by installing the new package and running it with a small app
+12) Monitor the release pipeline in GitLab to ensure it completes successfully
+13) Smoke test the published PyPI package and Docker image:
+    ```
+    SPLUNK_ACCESS_TOKEN=<token> ./tests/smoke/smoke-test-package.sh --pypi
+    SPLUNK_ACCESS_TOKEN=<token> ./tests/smoke/smoke-test-docker-image.sh
+    ```
 14) Navigate to Pipelines in the GitLab repo, click the download button for the build job that just ran,
     and select the 'build-job' artifact
     - this will download a tarball of the package files
 15) Navigate to the Splunk OTel Python repo and create a New Release
-    - create a new tag on publish with the tag name you created in step 10
+    - create a new tag on publish with the tag name you created in step 11
     - set the title to that tag name (e.g. `v2.7.0`)
     - unpack the tarball from step 14 and drag its contents onto the attachments section of the New Release page
     - Leave the defaults selected and click Publish

tests/smoke/smoke-test-docker-image.sh

@@ -0,0 +1,72 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Smoke test for the splunk-otel-instrumentation-python Docker image.
+# Run this after a release to validate the published image at quay.io.
+#
+# Simulates what the Kubernetes OTel Operator does: runs the init container to
+# populate /autoinstrumentation into a shared volume, then runs a Python container
+# with that volume on PYTHONPATH and sends sqlite3 spans to Splunk O11y.
+#
+# Usage:
+#   SPLUNK_ACCESS_TOKEN=<token> ./tests/smoke/smoke-test-docker-image.sh
+#   SPLUNK_ACCESS_TOKEN=<token> SPLUNK_REALM=eu0 ./tests/smoke/smoke-test-docker-image.sh
+#   SPLUNK_ACCESS_TOKEN=<token> ./tests/smoke/smoke-test-docker-image.sh --image <image:tag>
+
+: "${SPLUNK_ACCESS_TOKEN:?must be set}"
+
+DEFAULT_IMAGE="quay.io/signalfx/splunk-otel-instrumentation-python:latest"
+IMAGE="${DEFAULT_IMAGE}"
+
+while [[ $# -gt 0 ]]; do
+    case "$1" in
+        --image=*) IMAGE="${1#--image=}"; shift ;;
+        --image)   IMAGE="$2"; shift 2 ;;
+        *) shift ;;
+    esac
+done
+
+REALM="${SPLUNK_REALM:-us1}"
+SERVICE_NAME="sop-smoke-docker-image-$(date +%Y%m%d%H%M%S)"
+VOLUME="smoke-autoinstrumentation-$$"
+
+cleanup() {
+    docker volume rm "$VOLUME" >/dev/null 2>&1 || true
+}
+trap cleanup EXIT
+
+echo "==> Image: ${IMAGE}"
+echo "==> Pulling image..."
+docker pull --platform linux/amd64 "$IMAGE"
+
+echo ""
+echo "==> Running init container to populate /autoinstrumentation..."
+docker run --rm --platform linux/amd64 \
+    -v "${VOLUME}:/dest" \
+    --entrypoint cp \
+    "$IMAGE" \
+    -r /autoinstrumentation/. /dest/
+
+echo ""
+echo "==> Sending spans to Splunk O11y (realm=${REALM}, service=${SERVICE_NAME})..."
+docker run --rm --platform linux/amd64 \
+    -v "${VOLUME}:/autoinstrumentation:ro" \
+    -e PYTHONPATH=/autoinstrumentation \
+    -e OTEL_SERVICE_NAME="${SERVICE_NAME}" \
+    -e SPLUNK_ACCESS_TOKEN="${SPLUNK_ACCESS_TOKEN}" \
+    -e SPLUNK_REALM="${REALM}" \
+    -e OTEL_BSP_SCHEDULE_DELAY=200 \
+    python:3.11-slim \
+    /autoinstrumentation/bin/opentelemetry-instrument \
+    python -c "
+import sqlite3
+conn = sqlite3.connect(':memory:')
+cur = conn.cursor()
+for i in range(12):
+    cur.execute('SELECT ' + str(i))
+from opentelemetry import trace
+trace.get_tracer_provider().force_flush()
+"
+
+echo ""
+echo "Done. Check APM on ${REALM} for service '${SERVICE_NAME}'."

tests/smoke/smoke-test-package.sh

@@ -0,0 +1,47 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Smoke test for the splunk-opentelemetry Python package.
+# Installs the package (local checkout or PyPI) and sends spans to Splunk O11y to
+# verify end-to-end instrumentation works. Run this before a release (local) or
+# after a release (--pypi) to validate the published package.
+#
+# Usage:
+#   SPLUNK_ACCESS_TOKEN=<token> ./tests/smoke/smoke-test-package.sh          # local checkout
+#   SPLUNK_ACCESS_TOKEN=<token> ./tests/smoke/smoke-test-package.sh --pypi   # PyPI package
+
+: "${SPLUNK_ACCESS_TOKEN:?must be set}"
+
+USE_PYPI=false
+for arg in "$@"; do
+    [ "$arg" = "--pypi" ] && USE_PYPI=true
+done
+
+SMOKE_VENV=/tmp/smoke-venv
+
+if [ "$USE_PYPI" = "true" ]; then
+    echo "==> Installing from PyPI..."
+else
+    echo "==> Installing from local checkout..."
+fi
+
+rm -rf "$SMOKE_VENV"
+python -m venv "$SMOKE_VENV"
+if [ "$USE_PYPI" = "true" ]; then
+    "$SMOKE_VENV/bin/pip" install --quiet splunk-opentelemetry
+else
+    "$SMOKE_VENV/bin/pip" install --quiet .
+fi
+
+if [ "$USE_PYPI" = "true" ]; then
+    echo "splunk-opentelemetry $("$SMOKE_VENV/bin/pip" show splunk-opentelemetry | grep ^Version | cut -d' ' -f2)"
+fi
+
+export SPLUNK_ACCESS_TOKEN
+export SPLUNK_REALM="${SPLUNK_REALM:-us1}"
+export OTEL_SERVICE_NAME="sop-smoke-package-$(date +%Y%m%d%H%M%S)"
+
+"$SMOKE_VENV/bin/opentelemetry-instrument" \
+  "$SMOKE_VENV/bin/python" tests/integration/trace_loop.py
+
+echo "Done. Check APM on ${SPLUNK_REALM} for service '${OTEL_SERVICE_NAME}'."