feat: add scarf analytics

Adds Scarf analytics tracking to the docker entrypoint
to enable (user) anonymised download tracking.

See https://docs.pact.io/telemetry for more information.

Author: mefellows

Dockerfile

@@ -21,6 +21,11 @@ FROM base-$TARGETARCH AS pb-dev
 ARG TARGETARCH
 ENV SUPERCRONIC_URL=https://github.com/aptible/supercronic/releases/download/v0.2.47/supercronic-linux-${TARGETARCH} \
     SUPERCRONIC=supercronic-linux-${TARGETARCH}
+
+# Scarf analytics - version/platform reported by the entrypoint on startup
+ARG VERSION=dev
+ENV PACT_BROKER_DOCKER_VERSION=${VERSION} \
+    PACT_BROKER_DOCKER_PLATFORM=linux-${TARGETARCH}
 RUN wget "$SUPERCRONIC_URL" \
  && echo "${SUPERCRONIC_SHA1SUM}  ${SUPERCRONIC}" | sha1sum -c - \
  && chmod +x "$SUPERCRONIC" \

README.md

@@ -323,13 +323,18 @@ See the [Troubleshooting][troubleshooting] page on the docs site.
 
 ## Anonymized analytics
 
-`pactfoundation/pact-broker` uses [Scarf](https://scarf.sh/) to collect [anonymized download analytics](https://about.scarf.sh/about). These analytics help support the maintainers of this image and ONLY run when you pull the image through the Scarf gateway (the pull commands shown throughout this README). To opt out, pull the image directly from Docker Hub:
+`pactfoundation/pact-broker` uses [Scarf](https://scarf.sh/) to collect anonymized analytics that help support the maintainers of this image. Two things are tracked, independently of one another:
+
+* A README impression pixel, served from `static.scarf.sh`.
+* A lightweight, anonymous ping (image version + platform) sent by the container's entrypoint on every startup.
+
+To opt out of the startup ping, set either `PACT_DO_NOT_TRACK` or `SCARF_NO_ANALYTICS` to any non-empty value when running the container:
 
 ```sh
-docker pull pactfoundation/pact-broker
+docker run --rm -e PACT_DO_NOT_TRACK=1 pactfoundation/pact-broker
 ```
 
-Alternatively, block `static.scarf.sh` at the network level (or disable image loading in your browser when viewing this README) to disable the README impression pixel.
+To opt out of the README impression pixel, block `static.scarf.sh` at the network level, or disable image loading in your browser when viewing this README.
 
 For more information, see [docs.pact.io/telemetry](https://docs.pact.io/telemetry).
 

pact_broker/entrypoint.sh

@@ -1,5 +1,12 @@
 #!/bin/sh
 
+# Send a lightweight, anonymous analytics ping (version + platform) to help us
+# understand adoption of this image. Opt out with PACT_DO_NOT_TRACK or
+# SCARF_NO_ANALYTICS. See https://docs.pact.io/telemetry for details.
+if [ -z "${PACT_DO_NOT_TRACK}" ] && [ -z "${SCARF_NO_ANALYTICS}" ]; then
+  wget -q -T 2 -O /dev/null "https://d.pactflow.io/pact-broker-docker/${PACT_BROKER_DOCKER_VERSION}/${PACT_BROKER_DOCKER_PLATFORM}" >/dev/null 2>&1 &
+fi
+
 if [ "${PACT_BROKER_DATABASE_CLEAN_ENABLED}" = "true" ]; then
   echo "Creating crontab with schedule ${PACT_BROKER_DATABASE_CLEAN_CRON_SCHEDULE} to clean database"
   echo "${PACT_BROKER_DATABASE_CLEAN_CRON_SCHEDULE} /usr/local/bin/clean" >> /pact_broker/crontab

script/release-workflow/docker-build.sh

@@ -9,6 +9,7 @@ DOCKER_IMAGE_ORG_AND_NAME="${DOCKER_REPOSITORY:-pactfoundation}/pact-broker"
 for arch in $ARCHES; do 
     docker buildx build \
     --platform linux/$arch \
+    --build-arg VERSION=${TAG} \
     --output type=docker \
     --tag ${DOCKER_IMAGE_ORG_AND_NAME}:latest-${arch} \
     .

script/release-workflow/docker-push.sh

@@ -7,13 +7,15 @@ set -euo >/dev/null
 push() {
   ## These will use cached builds, so wont build every time.
   docker buildx build --platform=linux/amd64,linux/arm64,linux/arm \
+    --build-arg VERSION=${TAG} \
     --annotation "org.opencontainers.image.source=$GITHUB_SERVER_URL/$GITHUB_REPOSITORY" \
     --annotation "org.opencontainers.image.revision=$GITHUB_SHA" \
     --output=type=image,push=true \
     -t ${DOCKER_IMAGE_ORG_AND_NAME}:$1 .
 }
 push_ghcr() {
   docker buildx build --platform=linux/amd64,linux/arm64,linux/arm \
+  --build-arg VERSION=${TAG} \
   --output=type=image,push=true \
   -t ghcr.io/$(echo $DOCKER_IMAGE_ORG_AND_NAME | sed 's/pactfoundation/pact-foundation/g'):$1 .
 }