roachtest: include link to testeng grafana in issue posts

<what was there before: Previously, ...>
This adds a link, with relevant cluster and test timeframe, to the testeng
grafana instance for failed roachtests.
<why it needed to change: This was inadequate because ...>
<what you did about it: To address this, this patch ...>
Fixes: cockroachdb#105894
Release note: None

pkg/cmd/roachtest/github.go

@@ -14,6 +14,7 @@ import (
 	"context"
 	"fmt"
 	"os"
+	"time"
 
 	"github.com/cockroachdb/cockroach/pkg/cmd/internal/issues"
 	"github.com/cockroachdb/cockroach/pkg/cmd/roachtest/registry"
@@ -46,6 +47,25 @@ func roachtestPrefix(p string) string {
 	return "ROACHTEST_" + p
 }
 
+// TODO(BEFORE MERGING): the 'from' timestamp is zeroed out for now, until I find the correct
+// way to get the 'start' time of a roachtest
+func generateHelpCommand(g *githubIssues) func(renderer *issues.Renderer) {
+	return func(renderer *issues.Renderer) {
+		issues.HelpCommandAsLink(
+			"roachtest README",
+			"https://github.com/cockroachdb/cockroach/blob/master/pkg/cmd/roachtest/README.md",
+		)(renderer)
+		issues.HelpCommandAsLink(
+			"How To Investigate (internal)",
+			"https://cockroachlabs.atlassian.net/l/c/SSSBr8c7",
+		)(renderer)
+		issues.HelpCommandAsLink(
+			"Grafana",
+			fmt.Sprintf("https://go.crdb.dev/p/roachfana/%s/%d/%d", g.cluster.name, 0, time.Now().Unix()),
+		)(renderer)
+	}
+}
+
 // postIssueCondition encapsulates a condition that causes issue
 // posting to be skipped. The `reason` field contains a textual
 // description as to why issue posting was skipped.
@@ -192,16 +212,7 @@ func (g *githubIssues) createPostRequest(
 		Artifacts:       artifacts,
 		ExtraLabels:     labels,
 		ExtraParams:     clusterParams,
-		HelpCommand: func(renderer *issues.Renderer) {
-			issues.HelpCommandAsLink(
-				"roachtest README",
-				"https://github.com/cockroachdb/cockroach/blob/master/pkg/cmd/roachtest/README.md",
-			)(renderer)
-			issues.HelpCommandAsLink(
-				"How To Investigate (internal)",
-				"https://cockroachlabs.atlassian.net/l/c/SSSBr8c7",
-			)(renderer)
-		},
+		HelpCommand:     generateHelpCommand(g),
 	}
 }
 

pkg/cmd/roachtest/github_test.go

@@ -14,6 +14,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"path/filepath"
 	"strings"
 	"testing"
 
@@ -25,6 +26,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/internal/team"
 	rperrors "github.com/cockroachdb/cockroach/pkg/roachprod/errors"
 	"github.com/cockroachdb/cockroach/pkg/roachprod/vm"
+	"github.com/cockroachdb/cockroach/pkg/testutils/echotest"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -103,6 +105,27 @@ func TestShouldPost(t *testing.T) {
 	}
 }
 
+func TestGenerateHelpCommand(t *testing.T) {
+	vo := vm.DefaultCreateOpts()
+	vmOpts := &vo
+
+	reg := makeTestRegistry(spec.GCE, "", "", false, false)
+	clusterSpec := reg.MakeClusterSpec(1, spec.Arch("arm64"))
+	testClusterImpl := &clusterImpl{name: "foo-cluster", spec: clusterSpec, arch: vm.ArchAMD64}
+
+	github := &githubIssues{
+		vmCreateOpts: vmOpts,
+		cluster:      testClusterImpl,
+		teamLoader:   validTeamsFn,
+	}
+
+	r := &issues.Renderer{}
+	generateHelpCommand(github)(r)
+
+	// TODO (BEFORE MERGE): time.Now() in tests == no bueno. could do regex, but want something like utils.TimeNow() that cc has
+	echotest.Require(t, strings.Replace(r.String(), "\n", "", -1), filepath.Join("testdata", "help_command.txt"))
+}
+
 func TestCreatePostRequest(t *testing.T) {
 	createFailure := func(ref error) failure {
 		return failure{squashedErr: ref}

pkg/cmd/roachtest/testdata/help_command.txt

@@ -0,0 +1,3 @@
+echo
+----
+See: [roachtest README](https://github.com/cockroachdb/cockroach/blob/master/pkg/cmd/roachtest/README.md)See: [How To Investigate \(internal\)](https://cockroachlabs.atlassian.net/l/c/SSSBr8c7)See: [Grafana](https://go.crdb.dev/p/roachfana//0/1689971380)