versiongen: add generator of TF versions

go.mod

@@ -4,6 +4,7 @@ go 1.14
 
 require (
 	github.com/google/go-cmp v0.5.8
+	github.com/hashicorp/go-cleanhttp v0.5.1
 	github.com/hashicorp/go-version v1.6.0
 	github.com/hashicorp/hcl-lang v0.0.0-20220801150536-118ac453e267
 	github.com/hashicorp/hcl/v2 v2.13.0

go.sum

@@ -20,6 +20,7 @@ github.com/google/go-cmp v0.5.8 h1:e6P7q2lk1O+qJJb4BtCQXlK8vWEO8V1ZeuEdJNOqZyg=
 github.com/google/go-cmp v0.5.8/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/hashicorp/errwrap v1.0.0 h1:hLrqtEDnRye3+sgx6z4qVLNuviH3MR5aQ0ykNJa/UYA=
 github.com/hashicorp/errwrap v1.0.0/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=
+github.com/hashicorp/go-cleanhttp v0.5.1 h1:dH3aiDG9Jvb5r5+bYHsikaOUIpcM0xvgMXVoDkXMzJM=
 github.com/hashicorp/go-cleanhttp v0.5.1/go.mod h1:JpRdi6/HCYpAwUzNwuwqhbovhLtngrth3wmdIIUrZ80=
 github.com/hashicorp/go-multierror v1.1.1 h1:H5DkEtf6CXdFp0N0Em5UCwQpXMWke8IA0+lD48awMYo=
 github.com/hashicorp/go-multierror v1.1.1/go.mod h1:iw975J/qwKPdAO1clOe2L8331t/9/fmwbPZ6JB6eMoM=

internal/versiongen/gen.go

@@ -0,0 +1,129 @@
+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/url"
+	"os"
+	"sort"
+	"text/template"
+	"time"
+
+	"github.com/hashicorp/go-cleanhttp"
+	"github.com/hashicorp/go-version"
+)
+
+var baseURL = "https://api.releases.hashicorp.com/v1"
+
+type release struct {
+	Version *version.Version `json:"version"`
+	Created *time.Time       `json:"timestamp_created"`
+}
+
+func main() {
+	var writePath string
+	flag.StringVar(&writePath, "w", "", "Path to write to")
+	flag.Parse()
+
+	output := os.Stdout
+	if writePath != "" {
+		f, err := os.OpenFile(writePath, os.O_RDWR|os.O_CREATE, 0o755)
+		if err != nil {
+			log.Fatal(err)
+		}
+		output = f
+	}
+
+	releases, err := GetTerraformReleases()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	sort.SliceStable(releases, func(i, j int) bool {
+		return releases[i].Version.GreaterThan(releases[j].Version)
+	})
+
+	outputTpl := `// Code generated by "versiongen"; DO NOT EDIT.
+package schema
+
+import (
+	"github.com/hashicorp/go-version"
+)
+
+var terraformVersions = version.Collection{
+{{- range . }}
+	version.Must(version.NewVersion("{{ .Version }}")),
+{{- end }}
+}
+`
+	tpl, err := template.New("output").Parse(outputTpl)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	err = tpl.Execute(output, releases)
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func GetTerraformReleases() ([]release, error) {
+	releases := make([]release, 0)
+
+	var after *time.Time
+	for {
+		r, err := getTerraformReleasesAfter(after)
+		if err != nil {
+			return releases, err
+		}
+		if len(r) == 0 {
+			break
+		}
+
+		releases = append(releases, r...)
+		after = r[len(r)-1].Created
+	}
+
+	return releases, nil
+}
+
+func getTerraformReleasesAfter(after *time.Time) ([]release, error) {
+	u, err := url.Parse(fmt.Sprintf("%s/releases/%s", baseURL, "terraform"))
+	if err != nil {
+		return nil, err
+	}
+
+	params := u.Query()
+	params.Set("limit", "20")
+	if after != nil {
+		params.Set("after", after.Format(time.RFC3339))
+	}
+	u.RawQuery = params.Encode()
+
+	client := cleanhttp.DefaultClient()
+	log.Printf("calling %q", u.String())
+	resp, err := client.Get(u.String())
+	if err != nil {
+		return nil, err
+	}
+
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("server returned %q", resp.Status)
+	}
+
+	b, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	var releases []release
+	err = json.Unmarshal(b, &releases)
+	if err != nil {
+		return nil, err
+	}
+
+	return releases, nil
+}

internal/versiongen/gen_test.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"testing"
+	"time"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/hashicorp/go-version"
+)
+
+func TestGetTerraformReleases(t *testing.T) {
+	releases, err := GetTerraformReleases()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	expectedLength := 234
+	if expectedLength < len(releases) {
+		t.Fatalf("expected >= %d releases, %d given", expectedLength, len(releases))
+	}
+
+	expectedDate := time.Date(2017, 3, 1, 17, 36, 49, 0, time.UTC)
+	expectedOldestRelease := release{
+		Version: version.Must(version.NewVersion("0.6.4")),
+		Created: &expectedDate,
+	}
+	oldestRelease := releases[len(releases)-1]
+	if diff := cmp.Diff(expectedOldestRelease, oldestRelease); diff != "" {
+		t.Fatalf("unexpected oldest release: %s", diff)
+	}
+}