From 23b2a0278ed54a9fc0a7f6dc9087575a33d7ce21 Mon Sep 17 00:00:00 2001
From: Andrew Wilkins <axwalk@gmail.com>
Date: Mon, 20 Aug 2018 10:07:55 +0800
Subject: [PATCH 1/2] module/apmgorm: require Go 1.9+

https://github.com/jinzhu/gorm/pull/2022 introduced use
of sync.Map, which was introduced by Go 1.9.
---
 module/apmgorm/apmgorm_test.go | 2 ++
 module/apmgorm/context.go      | 2 ++
 module/apmgorm/doc.go          | 2 ++
 module/apmgorm/open.go         | 2 ++
 4 files changed, 8 insertions(+)

diff --git a/module/apmgorm/apmgorm_test.go b/module/apmgorm/apmgorm_test.go
index 99413f5d1..5add7c5ba 100644
--- a/module/apmgorm/apmgorm_test.go
+++ b/module/apmgorm/apmgorm_test.go
@@ -1,3 +1,5 @@
+// +build go1.9
+
 package apmgorm_test
 
 import (
diff --git a/module/apmgorm/context.go b/module/apmgorm/context.go
index 8dee7af66..98a4c7f4c 100644
--- a/module/apmgorm/context.go
+++ b/module/apmgorm/context.go
@@ -1,3 +1,5 @@
+// +build go1.9
+
 package apmgorm
 
 import (
diff --git a/module/apmgorm/doc.go b/module/apmgorm/doc.go
index 9203be4ee..1968b1866 100644
--- a/module/apmgorm/doc.go
+++ b/module/apmgorm/doc.go
@@ -1,2 +1,4 @@
+// +build go1.9
+
 // Package apmgorm provides wrappers for tracing GORM operations.
 package apmgorm
diff --git a/module/apmgorm/open.go b/module/apmgorm/open.go
index 90fe7c06e..79ece3ac1 100644
--- a/module/apmgorm/open.go
+++ b/module/apmgorm/open.go
@@ -1,3 +1,5 @@
+// +build go1.9
+
 package apmgorm
 
 import (

From bccfb96426d57e37e85c5dd6659a108e4cdefbe0 Mon Sep 17 00:00:00 2001
From: Andrew Wilkins <axwalk@gmail.com>
Date: Mon, 20 Aug 2018 11:39:04 +0800
Subject: [PATCH 2/2] Only run Dockerfile precheck on Go 1.9+

---
 Makefile                |  2 ++
 scripts/mingoversion.go | 75 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 77 insertions(+)
 create mode 100644 scripts/mingoversion.go

diff --git a/Makefile b/Makefile
index f3deaffcc..7a1116114 100644
--- a/Makefile
+++ b/Makefile
@@ -10,7 +10,9 @@ check-goimports:
 
 .PHONY: check-dockerfile-testing
 check-dockerfile-testing:
+ifeq ($(shell go run ./scripts/mingoversion.go -print 1.9),true)
 	go run ./scripts/gendockerfile.go -d
+endif
 
 .PHONY: check-lint
 check-lint:
diff --git a/scripts/mingoversion.go b/scripts/mingoversion.go
new file mode 100644
index 000000000..e20102920
--- /dev/null
+++ b/scripts/mingoversion.go
@@ -0,0 +1,75 @@
+// +build ignore
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"regexp"
+	"runtime"
+	"strconv"
+)
+
+var (
+	printFlag = flag.Bool("print", false, "Print true or false, and always exit with 0 except in case of usage errors")
+)
+
+func main() {
+	flag.Parse()
+	if flag.NArg() == 0 {
+		fmt.Fprintf(os.Stderr, "Usage: %s <minimum-version>\n", os.Args)
+		os.Exit(2)
+	}
+
+	re := regexp.MustCompile(`^(?:go)?(\d+).(\d+)(?:\.(\d+))?$`)
+	arg := flag.Arg(0)
+	argSubmatch := re.FindStringSubmatch(arg)
+	if argSubmatch == nil {
+		fmt.Fprintln(os.Stderr, "Invalid minimum-version: expected x.y or x.y.z")
+		os.Exit(2)
+	}
+
+	runtimeVersion := runtime.Version()
+	goSubmatch := re.FindStringSubmatch(runtimeVersion)
+	if goSubmatch == nil {
+		fmt.Fprintln(os.Stderr, "Failed to parse runtime.Version(%s)", runtimeVersion)
+		os.Exit(3)
+	}
+
+	result := true
+	minVersion := makeInts(argSubmatch[1:])
+	goVersion := makeInts(goSubmatch[1:])
+	for i := range minVersion {
+		n := goVersion[i] - minVersion[i]
+		if n < 0 {
+			if *printFlag {
+				result = false
+			} else {
+				fmt.Fprintf(os.Stderr, "%s < %s\n", runtimeVersion, arg)
+				os.Exit(1)
+			}
+		}
+		if n > 0 {
+			break
+		}
+	}
+	if *printFlag {
+		fmt.Println(result)
+	}
+}
+
+func makeInts(s []string) []int {
+	ints := make([]int, len(s))
+	for i, s := range s {
+		if s == "" {
+			s = "0"
+		}
+		n, err := strconv.Atoi(s)
+		if err != nil {
+			panic(err)
+		}
+		ints[i] = n
+	}
+	return ints
+}