Use archive.debian.org for apt sources on debian 7 (#16)

The debian 7 (wheezy) mirrors were archived since it's EOL.
I don't think we statically link with anything from wheezy we just use it because it
has an early version of glibc so we get decent OS compatibility. But we should
still consider moving to a new version.

https://lists.debian.org/debian-devel-announce/2019/03/msg00006.html

I added templating so I could make the inclusion of the sources.list file conditional.

.gitignore

@@ -4,3 +4,4 @@
 .idea
 .vagrant
 _obj
+Dockerfile

fpm/Makefile

@@ -5,6 +5,7 @@ VERSION := 1.11.0
 
 build:
 	@echo ">> Building $(REPOSITORY)/$(NAME):$(VERSION)$(SUFFIX)"
+	@go run ../template.go -t Dockerfile.tmpl -o Dockerfile
 	@docker build -t "$(REPOSITORY)/$(NAME):$(VERSION)$(SUFFIX)" \
 	--build-arg FPM_VERSION=$(VERSION) \
 	--build-arg IMAGE="$(REPOSITORY)/$(NAME):$(VERSION)$(SUFFIX)$(TAG_EXTENSION)" \

go1.10/Makefile.common

@@ -7,8 +7,11 @@ DEBIAN_VERSION ?= 9
 SUFFIX         := -$(shell basename $(CURDIR))
 TAG_EXTENSION  ?=
 
+export DEBIAN_VERSION TAG_EXTENSION
+
 build:
 	@echo ">> Building $(REPOSITORY)/$(NAME):$(VERSION)$(SUFFIX)$(TAG_EXTENSION)"
+	@go run $(SELF_DIR)/../template.go -t Dockerfile.tmpl -o Dockerfile
 	@docker build -t "$(REPOSITORY)/$(NAME):$(VERSION)$(SUFFIX)$(TAG_EXTENSION)" \
   --build-arg REPOSITORY=$(REPOSITORY) \
   --build-arg VERSION=$(VERSION) \

go1.10/base/Dockerfile → go1.10/base/Dockerfile.tmpl

@@ -1,6 +1,11 @@
 ARG DEBIAN_VERSION
 FROM debian:${DEBIAN_VERSION}
 
+{{if eq .DEBIAN_VERSION "7" -}}
+# Replace sources.list in order to use archive.debian.org.
+COPY sources-debian{{.DEBIAN_VERSION}}.list /etc/apt/sources.list
+{{end -}}
+
 RUN \
     apt-get update \
         && apt-get dist-upgrade -y \

go1.10/base/sources-debian7.list

@@ -0,0 +1,2 @@
+deb http://archive.debian.org/debian wheezy main
+deb http://security.debian.org/debian-security wheezy/updates main

go1.11/Makefile.common

@@ -7,8 +7,11 @@ DEBIAN_VERSION ?= 9
 SUFFIX         := -$(shell basename $(CURDIR))
 TAG_EXTENSION  ?=
 
+export DEBIAN_VERSION TAG_EXTENSION
+
 build:
 	@echo ">> Building $(REPOSITORY)/$(NAME):$(VERSION)$(SUFFIX)$(TAG_EXTENSION)"
+	@go run $(SELF_DIR)/../template.go -t Dockerfile.tmpl -o Dockerfile
 	@docker build -t "$(REPOSITORY)/$(NAME):$(VERSION)$(SUFFIX)$(TAG_EXTENSION)" \
   --build-arg REPOSITORY=$(REPOSITORY) \
   --build-arg VERSION=$(VERSION) \

go1.11/base/Dockerfile → go1.11/base/Dockerfile.tmpl

@@ -1,6 +1,11 @@
 ARG DEBIAN_VERSION
 FROM debian:${DEBIAN_VERSION}
 
+{{if eq .DEBIAN_VERSION "7" -}}
+# Replace sources.list in order to use archive.debian.org.
+COPY sources-debian{{.DEBIAN_VERSION}}.list /etc/apt/sources.list
+{{end -}}
+
 RUN \
     apt-get update \
         && apt-get dist-upgrade -y \

go1.11/base/sources-debian7.list

@@ -0,0 +1,2 @@
+deb http://archive.debian.org/debian wheezy main
+deb http://security.debian.org/debian-security wheezy/updates main

template.go

@@ -0,0 +1,87 @@
+// Licensed to Elasticsearch B.V. under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Elasticsearch B.V. licenses this file to you 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.
+
+package main
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+	"text/template"
+)
+
+var usageText = `
+Usage: template -t <tmpl file> [-o output]
+  This command renders the specified template file using the Go text/template
+  package. It makes the current environment available as variables.
+Options:
+`[1:]
+
+var (
+	templateFile string
+	outputFile   string
+)
+
+func init() {
+	flag.StringVar(&templateFile, "t", "", "template file")
+	flag.StringVar(&outputFile, "o", "", "output file")
+	flag.Usage = func() {
+		fmt.Fprintf(os.Stderr, usageText)
+		flag.PrintDefaults()
+	}
+}
+
+func main() {
+	flag.Parse()
+	log.SetFlags(0)
+
+	if templateFile == "" {
+		log.Fatal("Template file (-t) is required.")
+	}
+
+	t := template.Must(template.
+		New(filepath.Base(templateFile)).
+		ParseFiles(templateFile))
+
+	data := envVars()
+	buf := new(bytes.Buffer)
+	if err := t.Execute(buf, data); err != nil {
+		log.Fatal(err)
+	}
+
+	if outputFile == "-" || outputFile == "" {
+		fmt.Println(buf.String())
+	} else {
+		if err := ioutil.WriteFile(outputFile, buf.Bytes(), 0644); err != nil {
+			log.Fatal(err)
+		}
+	}
+}
+
+func envVars() map[string]string {
+	env := map[string]string{}
+	for _, e := range os.Environ() {
+		parts := strings.SplitN(e, "=", 2)
+		env[parts[0]] = parts[1]
+	}
+	return env
+}