Vendor all dependencies, add docker build to makefile.

Vendor and store all dependencies. This allows us to have a makefile which
builds to a minimized docker image.

Author: wrouesnel

Dockerfile

@@ -1,17 +1,16 @@
-# Copyright 2015 The Prometheus Authors
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-# http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
 
-VERSION  := 0.1.0
-TARGET   := postgres_exporter
+# Simple go build
+postgres_exporter: postgres_exporter.go
+	go build -o postgres_exporter .
 
-include Makefile.COMMON
+# Do a self-contained docker build - we pull the official upstream container,
+# then template out a dockerfile which builds the real image.
+docker:
+	docker run -v $(shell pwd):/go/src/github.com/wrouesnel/postgres_exporter \
+		golang:1.6-wheezy \
+		/go/src/github.com/wrouesnel/postgres_exporter/docker-build.bsh /postgres_exporter /go/src/github.com/wrouesnel/postgres_exporter | \
+		docker import --change "EXPOSE 9113" \
+			--change 'ENTRYPOINT [ "/postgres_exporter" ]' \
+			- wrouesnel/postgres_exporter
+
+.PHONY: docker

Makefile

@@ -3,11 +3,29 @@
 Prometheus exporter for PostgresSQL server metrics.
 Supported Postgres versions: 9.1 and up.
 
+## Quick Start
+This package is available for Docker:
+```
+docker run -e DATA_SOURCE_NAME="login:password@(hostname:port)/dbname" -p 9113:9113 wrouesnel/postgres_exporter
+```
+
 ## Building and running
+The default make file behavior is to build the binary:
+```
+make
+export DATA_SOURCE_NAME="login:password@(hostname:port)/dbname"
+./postgres_exporter <flags>
+```
+
+To build the dockerfile, run `make docker`. 
+
+This will build the docker image as `wrouesnel/postgres_exporter:latest`. This 
+is a minimal docker image containing *just* postgres_exporter. By default no SSL 
+certificates are included, if you need to use SSL you should either bind-mount 
+`/etc/ssl/certs/ca-certificates.crt` or derive a new image containing them.
 
-    make
-    export DATA_SOURCE_NAME="login:password@(hostname:port)/dbname"
-    ./postgres_exporter <flags>
+### Vendoring
+Package vendoring is handled with [`govendor`](https://github.com/kardianos/govendor)
 
 ### Flags
 
@@ -34,5 +52,5 @@ for l in StringIO(x):
     column, ctype, description = l.split('\t')
     print """"{0}" : {{ prometheus.CounterValue, prometheus.NewDesc("pg_stat_database_{0}", "{2}", nil, nil) }}, """.format(column.strip(), ctype, description.strip())
 ```
-Adjust the value of the resultant prometheus value type appropriately. This helps build
-rich self-documenting metrics for the exporter.
+Adjust the value of the resultant prometheus value type appropriately. This 
+helps build rich self-documenting metrics for the exporter.

Makefile.COMMON

@@ -0,0 +1,4 @@
+#!/bin/bash
+cd $2
+CGO_ENABLED=0 GOOS=linux go build -a -ldflags '-extldflags "-static"' -o $1 . 1>&2
+tar -cf - $1