feat: add human-friendly entry point

* Added /start as entry point, for humans and iPXE

The '/poll/1/${netX/mac:hexhyp}' is fairly iPXE internal, not something
that invites curious people to look better at shoelaces. Neither it is
looking nice in DHCP server configuration.

This change adds a HTTP handler for '/start'. And '/start' points
to '/poll/1/${netX/mac:hexhyp}'. The benefit of it is that human visible
documentation can replace the "voodoo" '/poll/1/${netX/mac:hexhyp}'
with "friendly" '/start'.

Because it is an addition are the existing HTTP handlers not effected,
neither the installed deployments effected.

Signed-off-by: Geert Stappers <stappers@stappers.it>

1 files changed, 30 insertions, 0 deletions

diff --git a/internal/polling/polling.go b/internal/polling/polling.go
index 853a751..cfd489f 100644
--- a/internal/polling/polling.go
+++ b/internal/polling/polling.go
@@ -34,6 +34,16 @@ import (
 type ManualAction int
 
 const (
+	startScript = "#!ipxe\n" +
+		"echo Shoelaces starts polling\n" +
+		"chain --autofree --replace \\\n" +
+		"    http://{{.baseURL}}/poll/1/${netX/mac:hexhyp}\n" +
+		"#\n" +
+		"#\n" +
+		"# Do\n" +
+		"#    curl http://{{.baseURL}}/poll/1/06-66-de-ad-be-ef\n" +
+		"# to get an idea about what iPXE will receive.\n"
+
 	maxRetry = 10
 
 	retryScript = "#!ipxe\n" +
@@ -226,6 +236,26 @@ func setHostName(params map[string]interface{}, mac string) {
 	}
 }
 
+func GenStartScript(logger log.Logger, baseURL string) string {
+	variablesMap := map[string]interface{}{}
+	parsedTemplate := &bytes.Buffer{}
+
+	tmpl, err := template.New("retry").Parse(startScript)
+	if err != nil {
+		logger.Info("component", "polling", "msg", "Error parsing start template")
+		panic(err)
+	}
+
+	variablesMap["baseURL"] = baseURL
+	err = tmpl.Execute(parsedTemplate, variablesMap)
+	if err != nil {
+		logger.Info("component", "polling", "msg", "Error executing start template")
+		panic(err)
+	}
+
+	return parsedTemplate.String()
+}
+
 func genBootScript(logger log.Logger, templateRenderer *templates.ShoelacesTemplates, baseURL string, script *mappings.Script) string {
 	script.Params["baseURL"] = utils.BaseURLforEnvName(baseURL, script.Environment)
 	text, err := templateRenderer.RenderTemplate(logger, script.Name, script.Params, script.Environment)