feat: .Now template variable (#3853)

This will allow more customized templates using dates!

Signed-off-by: Carlos A Becker <caarlos0@users.noreply.github.com>

internal/tmpl/tmpl.go

@@ -52,6 +52,7 @@ const (
 	isSnapshot      = "IsSnapshot"
 	env             = "Env"
 	date            = "Date"
+	now             = "Now"
 	timestamp       = "Timestamp"
 	modulePath      = "ModulePath"
 	releaseNotes    = "ReleaseNotes"
@@ -102,6 +103,7 @@ func New(ctx *context.Context) *Template {
 			releaseURL:      ctx.ReleaseURL,
 			env:             ctx.Env,
 			date:            ctx.Date.UTC().Format(time.RFC3339),
+			now:             ctx.Date.UTC(),
 			timestamp:       ctx.Date.UTC().Unix(),
 			major:           ctx.Semver.Major,
 			minor:           ctx.Semver.Minor,

internal/tmpl/tmpl_test.go

@@ -6,6 +6,7 @@ import (
 	"runtime"
 	"testing"
 	"text/template"
+	"time"
 
 	"github.com/goreleaser/goreleaser/internal/artifact"
 	"github.com/goreleaser/goreleaser/internal/testctx"
@@ -38,6 +39,7 @@ func TestWithArtifact(t *testing.T) {
 		func(ctx *context.Context) {
 			ctx.ModulePath = "github.com/goreleaser/goreleaser"
 			ctx.ReleaseNotes = "test release notes"
+			ctx.Date = time.Unix(1678327562, 0)
 		},
 	)
 	for expect, tmpl := range map[string]string{
@@ -75,6 +77,9 @@ func TestWithArtifact(t *testing.T) {
 		"artifact path: /tmp/foo.exe":      "artifact path: {{ .ArtifactPath }}",
 		"artifact basename: foo.exe":       "artifact basename: {{ base .ArtifactPath }}",
 		"artifact dir: /tmp":               "artifact dir: {{ dir .ArtifactPath }}",
+		"2023":                             `{{ .Now.Format "2006" }}`,
+		"2023-03-09T02:06:02Z":             `{{ .Date }}`,
+		"1678327562":                       `{{ .Timestamp }}`,
 
 		"remove this": "{{ filter .Env.MULTILINE \".*remove.*\" }}",
 		"something with\nmultiple lines\nto test things": "{{ reverseFilter .Env.MULTILINE \".*remove.*\" }}",

www/docs/customization/templates.md

@@ -37,6 +37,7 @@ Key                   |Description
 `.IsNightly`          |`true` if `--nightly` is set, `false` otherwise
 `.Env`                |a map with system's environment variables
 `.Date`               |current UTC date in RFC 3339 format
+`.Now`                |current UTC date as `time.Time` struct, allows all `time.Time` functions (e.g. `{{ .Now.Format "2006" }}`) . Since v1.17.
 `.Timestamp`          |current UTC time in Unix format
 `.ModulePath`         |the go module path, as reported by `go list -m`
 `incpatch "v1.2.4"`   |increments the patch of the given version[^panic-if-not-semver]