diff --git a/.gitignore b/.gitignore
index 53ba083f..aec6680f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -22,3 +22,4 @@ README
 README.html
 /unifi-poller_manual.html
 /homebrew-mugs
+/.metadata.make
diff --git a/.metadata.sh b/.metadata.sh
new file mode 100755
index 00000000..c18d6db6
--- /dev/null
+++ b/.metadata.sh
@@ -0,0 +1,34 @@
+# Each line must have an export clause.
+# This file is parsed and sourced by the Makefile, Docker and Homebrew builds.
+
+# github username
+GHUSER="davidnewhall"
+# docker hub username
+DHUSER="golift"
+MAINT="David Newhall II <david at sleepers dot pro>"
+VENDOR="Go Lift"
+DESC="Polls a UniFi controller and stores metrics in InfluxDB"
+GOLANGCI_LINT_ARGS="--enable-all -D gochecknoglobals"
+CONFIG_FILE="up.conf"
+LICENSE="MIT"
+
+# The rest if mostly automatic.
+
+BINARY="$(basename $(pwd))"
+GHREPO="${GHUSER}/${BINARY}"
+URL="https://github.com/${GHREPO}"
+
+# This parameter is passed in as -X to go build. Used to override the Version variable in a package.
+# This makes a path like github.com/davidnewhall/unifi-poller/unifipoller.Version=1.3.3
+# Name the Version-containing library the same as the github repo, without dashes.
+VERSION_PATH="github.com/${GHUSER}/${BINARY}/$(echo ${BINARY} | tr -d -- -).Version"
+
+# Dynamic. Recommend not changing.
+VERSION="$(git tag -l --merged | tail -n1 | tr -d v || echo development)"
+# This produces a 0 in some envirnoments (like Homebrew), but it's only used for packages.
+ITERATION=$(git rev-list --count --all || echo 0)
+DATE="$(date -u +%Y-%m-%dT%H:%M:%SZ)"
+COMMIT="$(git rev-parse --short HEAD || echo 0)"
+
+export GHUSER DHUSER MAINT DESC CONFIG_FILE LICENSE GOLANGCI_LINT_ARGS
+export BINARY GHREPO URL VERSION_PATH VERSION ITERATION DATE COMMIT
diff --git a/Makefile b/Makefile
index 77f25848..4a6ed5f6 100644
--- a/Makefile
+++ b/Makefile
@@ -1,39 +1,27 @@
 # This Makefile is written as generic as possible.
 # Setting these variables and creating the necesarry paths in your GitHub repo will make this file work.
 #
-# github username
-GHUSER=davidnewhall
-# docker hub username
-DHUSER=golift
-MAINT=David Newhall II <david at sleepers dot pro>
-DESC=Polls a UniFi controller and stores metrics in InfluxDB
-GOLANGCI_LINT_ARGS=--enable-all -D gochecknoglobals
-BINARY:=$(shell basename $(shell pwd))
-URL:=https://github.com/$(GHUSER)/$(BINARY)
-CONFIG_FILE=up.conf
 
-# This parameter is passed in as -X to go build. Used to override the Version variable in a package.
-# This makes a path like github.com/davidnewhall/unifi-poller/unifipoller.Version=1.3.3
-# Name the Version-containing library the same as the github repo, without dashes.
-VERSION_PATH:=github.com/$(GHUSER)/$(BINARY)/$(shell echo $(BINARY) | tr -d -- -).Version
+IGNORE := $(shell bash -c "source .metadata.sh ; env | sed 's/=/:=/;s/^/export /' > .metadata.make")
 
 # These don't generally need to be changed.
 
 # md2roff turns markdown into man files and html files.
 MD2ROFF_BIN=github.com/github/hub/md2roff-bin
-# This produces a 0 in some envirnoments (like Homebrew), but it's only used for packages.
-ITERATION:=$(shell git rev-list --count --all || echo 0)
 # Travis CI passes the version in. Local builds get it from the current git tag.
 ifeq ($(VERSION),)
-	VERSION:=$(shell git tag -l --merged | tail -n1 | tr -d v || echo development)
-endif
-ifeq ($(VERSION),)
-	VERSION:=development
+	include .metadata.make
+else
+	# Preserve the passed-in version & iteration (homebrew).
+  _VERSION:=$(VERSION)
+  _ITERATION:=$(ITERATION)
+	include .metadata.make
+	VERSION:=$(_VERSION)
+	ITERATION:=$(_ITERATION)
 endif
+
 # rpm is wierd and changes - to _ in versions.
 RPMVERSION:=$(shell echo $(VERSION) | tr -- - _)
-DATE:=$(shell date -u +%Y-%m-%dT%H:%M:%SZ)
-COMMIT:=$(shell git rev-parse --short HEAD || echo 0)
 
 # Makefile targets follow.
 
diff --git a/init/docker/Dockerfile b/init/docker/Dockerfile
index 7bc72b1e..dc00d8b4 100644
--- a/init/docker/Dockerfile
+++ b/init/docker/Dockerfile
@@ -38,19 +38,25 @@ ARG OS
 ARG BUILD_DATE
 ARG COMMIT
 ARG VERSION
+ARG LICENSE=MIT
+ARG TITLE=unifi-poller
+ARG URL=http://github.com/davidnewhall/unifi-poller
+ARG DESC=unifi-poller
+ARG VENDOR=golift
+ARG AUTHOR=golift
 
 # Build-time metadata as defined at https://github.com/opencontainers/image-spec/blob/master/annotations.md
 LABEL org.opencontainers.image.created="${BUILD_DATE}" \
-      org.opencontainers.image.title="UniFi Poller" \
-      org.opencontainers.image.documentation="https://github.com/davidnewhall/unifi-poller/wiki/Docker" \
-      org.opencontainers.image.description="Polls a UniFi controller and stores metrics in InfluxDB" \
-      org.opencontainers.image.url="https://github.com/davidnewhall/unifi-poller" \
+      org.opencontainers.image.title="${TITLE}" \
+      org.opencontainers.image.documentation="${URL}/wiki/Docker" \
+      org.opencontainers.image.description="${DESC}" \
+      org.opencontainers.image.url="${URL}" \
       org.opencontainers.image.revision="${COMMIT}" \
-      org.opencontainers.image.source="https://github.com/davidnewhall/unifi-poller" \
-      org.opencontainers.image.vendor="Go Lift" \
-      org.opencontainers.image.authors="David Newhall II <david at sleepers dot pro>" \
+      org.opencontainers.image.source="${URL}" \
+      org.opencontainers.image.vendor="${VENDOR}" \
+      org.opencontainers.image.authors="${AUTHOR}" \
       org.opencontainers.image.architecture="${OS} ${ARCH}" \
-      org.opencontainers.image.licenses="MIT" \
+      org.opencontainers.image.licenses="${LICENSE}" \
       org.opencontainers.image.version="${VERSION}"
 
 COPY --from=builder /go/src/github.com/davidnewhall/unifi-poller/unifi-poller.${ARCH}.${OS} /unifi-poller
diff --git a/init/docker/hooks/build b/init/docker/hooks/build
index 8e15743b..25d0c098 100755
--- a/init/docker/hooks/build
+++ b/init/docker/hooks/build
@@ -7,10 +7,7 @@ set -e -o pipefail
 # The Docker Cloud config must pass in the BUILDS env variable.
 # See README.md (in this dir) and the screenshot for more info.
 
-VERSION=$(git tag -l --merged | tail -n1 | tr -d v) # 1.2.3
-DATE=$(date -u +%Y-%m-%dT%H:%M:%SZ)
-COMMIT=$(git rev-parse --short HEAD)
-ITERATION=$(git rev-list --count --all)
+source ../../.metadata.sh
 
 # Build each configured image from Docker Cloud.
 for build in $BUILDS; do
@@ -23,6 +20,12 @@ for build in $BUILDS; do
     --build-arg "BUILD_DATE=${DATE}" \
     --build-arg "COMMIT=${COMMIT}" \
     --build-arg "VERSION=${VERSION}-${ITERATION}" \
+    --build-arg "LICENSE=${LICENSE}" \
+    --build-arg "TITLE=${TITLE}" \
+    --build-arg "DESC=${DESC}" \
+    --build-arg "URL=${URL}" \
+    --build-arg "VENDOR=${VENDOR}" \
+    --build-arg "AUTHOR=${AUTHOR}" \
     --tag "${IMAGE_NAME}_${os}_${name}" \
     --file Dockerfile ../..
 done
diff --git a/init/docker/hooks/push b/init/docker/hooks/push
index e030ad4d..c71e906c 100755
--- a/init/docker/hooks/push
+++ b/init/docker/hooks/push
@@ -4,8 +4,8 @@
 # It's all a bit complicated for some reason.
 set -e -o pipefail
 
-VERSION=$(git tag -l --merged | tail -n1 | tr -d v) # 1.2.3
-SHORTVER=$(echo $VERSION | cut -d. -f1,2)           # 1.2
+source ../../.metadata.sh
+
 if [ "$BUILDS" != "" ]; then
   TAGS=$DOCKER_TAG
 fi
diff --git a/scripts/formula-deploy.sh b/scripts/formula-deploy.sh
index 9bbe1c06..978b4507 100755
--- a/scripts/formula-deploy.sh
+++ b/scripts/formula-deploy.sh
@@ -3,26 +3,27 @@
 # Deploys a new homebrew formula file to golift/homebrew-tap.
 # Requires SSH credentials in ssh-agent to work.
 # Run by Travis-CI when a new release is created on GitHub.
-APP=unpacker-poller
+
+source ../.metadata.sh
 
 if [ -z "$VERSION" ]; then
   VERSION=$TRAVIS_TAG
 fi
 VERSION=$(echo $VERSION|tr -d v)
 
-make ${APP}.rb VERSION=$VERSION
+make ${BINARY}.rb VERSION=$VERSION
 
 if [ -z "$VERSION" ]; then
-  VERSION=$(grep -E '^\s+url\s+"' ${APP}.rb | cut -d/ -f7 | cut -d. -f1,2,3)
+  VERSION=$(grep -E '^\s+url\s+"' ${BINARY}.rb | cut -d/ -f7 | cut -d. -f1,2,3)
 fi
 
 rm -rf homebrew-mugs
-git config --global user.email "${APP}@auto.releaser"
-git config --global user.name "${APP}-auto-releaser"
+git config --global user.email "${BINARY}@auto.releaser"
+git config --global user.name "${BINARY}-auto-releaser"
 git clone git@github.com:golift/homebrew-mugs.git
 
-cp ${APP}.rb homebrew-mugs/Formula
+cp ${BINARY}.rb homebrew-mugs/Formula
 pushd homebrew-mugs
-git commit -m "Update ${APP} on Release: ${VERSION}" Formula/${APP}.rb
+git commit -m "Update ${BINARY} on Release: ${VERSION}" Formula/${BINARY}.rb
 git push
 popd