add labels do dockerfiles, consolidate some layers (#145)

Makefile

@@ -3,7 +3,8 @@
 #
 PKG_NAME := synse
 IMG_NAME := vaporio/synse-server
-PKG_VER := $(shell python -c "import synse ; print(synse.__version__)")
+PKG_VER  := $(shell python -c "import synse ; print(synse.__version__)")
+DATE     := $(shell date -u +'%Y-%m-%dT%H:%M:%SZ')
 export GIT_VER := $(shell /bin/sh -c "git log --pretty=format:'%h' -n 1 || echo 'none'")
 
 
@@ -55,14 +56,22 @@ pycache-clean:
 docker-slim:
 	tags="" ; \
 	for tag in $(SLIM_TAGS); do tags="$${tags} -t $${tag}"; done ; \
-	docker build -f dockerfile/slim.dockerfile $${tags} .
+	docker build -f dockerfile/slim.dockerfile \
+		--build-arg BUILD_DATE=$(DATE) \
+		--build-arg BUILD_VERSION=$(PKG_VER) \
+		--build-arg VCS_REF=$(GIT_VER) \
+		$${tags} .
 
 # build the docker images of synse server with the emulator
 .PHONY: docker-default
 docker-default:
 	tags="" ; \
 	for tag in $(DEFAULT_TAGS); do tags="$${tags} -t $${tag}"; done ; \
-	docker build -f dockerfile/release.dockerfile $${tags} .
+	docker build -f dockerfile/release.dockerfile \
+		--build-arg BUILD_DATE=$(DATE) \
+		--build-arg BUILD_VERSION=$(PKG_VER) \
+		--build-arg VCS_REF=$(GIT_VER) \
+		$${tags} .
 
 
 # Targets

bin/install_emulator.sh

@@ -0,0 +1,38 @@
+#!/usr/bin/env bash
+
+# install_emulator.sh
+#
+# This script is used to install the latest release of the emulator
+# plugin into the current working directory. This is used in the
+# Synse Server Dockerfile, but can also be run locally.
+#
+# This script requires `curl` and `jq` to be installed.
+#
+# The following environment variables can be used with the script
+# to modify the default behavior:
+#   EMULATOR_BIN - the name of the emulator binary to download. see
+#      https://github.com/vapor-ware/synse-emulator-plugin/releases
+#      for the names of all available assets. (default: emulator_linux_amd64)
+#   EMULATOR_OUT - the path to output the downloaded binary
+#      (default: `./$EMULATOR_BIN`)
+#
+set -o errexit -o pipefail
+
+EMULATOR_REPO=vapor-ware/synse-emulator-plugin
+
+EMULATOR_BIN=${EMULATOR_BIN:-"emulator_linux_amd64"}
+EMULATOR_OUT=${EMULATOR_OUT:-""}
+
+# Get the GitHub release data for the Synse Emulator Plugin repo.
+data=$(curl -s https://api.github.com/repos/${EMULATOR_REPO}/releases/latest)
+
+# Get the URL for the latest release asset binary.
+bin_url=$(echo ${data} | jq --arg bin "$EMULATOR_BIN" '.assets[] | select(.name == $bin) | .url' | tr -d '"')
+
+# Download the binary
+curl -L -H "Accept: application/octet-stream" -o ${EMULATOR_BIN} ${bin_url}
+chmod +x ${EMULATOR_BIN}
+
+if [ "$EMULATOR_OUT" ]; then
+    mv ${EMULATOR_BIN} ${EMULATOR_OUT}
+fi

dockerfile/release.dockerfile

@@ -1,44 +1,49 @@
 FROM python:3.6-alpine
-
 LABEL maintainer="vapor@vapor.io"
 
-# Environment variables for downloading the emulator plugin
-ENV EMULATOR_REPO vapor-ware/synse-emulator-plugin
-ENV EMULATOR_BIN  emulator_linux_amd64
+ARG BUILD_DATE
+ARG BUILD_VERSION
+ARG VCS_REF
 
 # Environment variables for built-in emulator configuration.
-ENV PLUGIN_DEVICE_CONFIG /synse/emulator/config
-ENV PLUGIN_CONFIG /synse/emulator
+ENV PLUGIN_DEVICE_CONFIG="/synse/emulator/config" \
+    PLUGIN_CONFIG="/synse/emulator"
 
-COPY ./requirements.txt requirements.txt
+COPY requirements.txt requirements.txt
+COPY bin/install_emulator.sh tmp/install_emulator.sh
 
 # The linux_amd64 emulator binary is built with libc, not muslc, it
 # will not work here. The musl and glibc so files are compatible, so
 # we can make a symlink to fix the missing dependency:
 # https://stackoverflow.com/a/35613430
-RUN mkdir /lib64 && ln -s /lib/libc.musl-x86_64.so.1 /lib64/ld-linux-x86-64.so.2
-
 RUN set -e -x \
+    && mkdir /lib64 && ln -s /lib/libc.musl-x86_64.so.1 /lib64/ld-linux-x86-64.so.2 \
     && apk --update --no-cache add \
         bash libstdc++ \
     && apk --update --no-cache --virtual .build-dep add \
         curl build-base jq \
     && pip install --upgrade pip \
     && pip install -r requirements.txt \
-    && bin_url=$(curl -s https://api.github.com/repos/${EMULATOR_REPO}/releases/latest | jq '.assets[] | select(.name == env.EMULATOR_BIN) | .url' | tr -d '"') \
-    && curl -L -H "Accept: application/octet-stream" -o $EMULATOR_BIN $bin_url \
-    && chmod +x $EMULATOR_BIN \
-    && mv $EMULATOR_BIN /usr/local/bin/emulator \
+    && EMULATOR_OUT=/usr/local/bin/emulator ./tmp/install_emulator.sh \
     && apk del .build-dep
 
+# Image Metadata -- http://label-schema.org/rc1/
+# This is set after the dependency install so we can cache that layer
+LABEL org.label-schema.schema-version="1.0" \
+      org.label-schema.build-date=$BUILD_DATE \
+      org.label-schema.name="vaporio/synse-server" \
+      org.label-schema.vcs-url="https://github.com/vapor-ware/synse-server" \
+      org.label-schema.vcs-ref=$VCS_REF \
+      org.label-schema.vendor="Vapor IO" \
+      org.label-schema.version=$BUILD_VERSION
+
 COPY . /synse
 WORKDIR /synse
 
-# Create directories for plugin sockets and configuration
+# Create directories for plugin sockets and configuration, then
+# install Synse Server as a python package
 RUN mkdir -p /tmp/synse/procs \
-    && mkdir -p /synse/config
-
-# install synse_server python package
-RUN python setup.py install
+    && mkdir -p /synse/config \
+    && python setup.py install
 
 ENTRYPOINT ["bin/synse.sh"]

dockerfile/slim.dockerfile

@@ -1,7 +1,10 @@
 FROM python:3.6-alpine
-
 LABEL maintainer="vapor@vapor.io"
 
+ARG BUILD_DATE
+ARG BUILD_VERSION
+ARG VCS_REF
+
 COPY requirements.txt requirements.txt
 
 RUN set -e -x \
@@ -13,14 +16,23 @@ RUN set -e -x \
     && pip install -r requirements.txt \
     && apk del .build-dep
 
+# Image Metadata -- http://label-schema.org/rc1/
+# This is set after the dependency install so we can cache that layer
+LABEL org.label-schema.schema-version="1.0" \
+      org.label-schema.build-date=$BUILD_DATE \
+      org.label-schema.name="vaporio/synse-server" \
+      org.label-schema.vcs-url="https://github.com/vapor-ware/synse-server" \
+      org.label-schema.vcs-ref=$VCS_REF \
+      org.label-schema.vendor="Vapor IO" \
+      org.label-schema.version=$BUILD_VERSION
+
 COPY . /synse
 WORKDIR /synse
 
-# Create directories for plugin sockets and configuration
+# Create directories for plugin sockets and configuration, then
+# install Synse Server as a python package
 RUN mkdir -p /tmp/synse/procs \
-    && mkdir -p /synse/config
-
-# install synse_server python package
-RUN python setup.py install
+    && mkdir -p /synse/config \
+    && python setup.py install
 
 ENTRYPOINT ["bin/synse.sh"]