Add healtcheck + some fixes

- better docs
- add healtcheck based on docker-compoe commands or labels
- fix some problems on secret names
- better dependency check

helm/types.go

@@ -1,11 +1,13 @@
 package helm
 
 import (
+	"bytes"
 	"crypto/sha1"
 	"fmt"
 	"io/ioutil"
 	"os"
 	"strings"
+	"text/template"
 )
 
 const K = "katenary.io"
@@ -16,8 +18,35 @@ const (
 	LABEL_INGRESS     = K + "/ingress"
 	LABEL_ENV_SERVICE = K + "/env-to-service"
 	LABEL_VOL_CM      = K + "/configmap-volumes"
+	LABEL_HEALTHCHECK = K + "/healthcheck"
 )
 
+func GetLabelsDocumentation() string {
+	t, _ := template.New("labels").Parse(`
+# Labels
+{{.LABEL_ENV_SECRET  | printf "%-33s"}}: set the given file names as a secret instead of configmap
+{{.LABEL_PORT        | printf "%-33s"}}: set the port to expose as a service
+{{.LABEL_INGRESS     | printf "%-33s"}}: set the port to expose in an ingress
+{{.LABEL_ENV_SERVICE | printf "%-33s"}}: specifies that the environment variable points on a service name
+{{.LABEL_VOL_CM      | printf "%-33s"}}: specifies that the volume points on a configmap
+{{.LABEL_HEALTHCHECK | printf "%-33s"}}: specifies that the container should be monitored by a healthcheck, **it overrides the docker-compose healthcheck**. 
+{{ printf "%-34s" ""}} You can use these form of label values:
+{{ printf "%-35s" ""}}- "http://[not used address][:port][/path]" to specify an http healthcheck
+{{ printf "%-35s" ""}}- "tcp://[not used address]:port" to specify a tcp healthcheck
+{{ printf "%-35s" ""}}- other string is condidered as a "command" healthcheck
+    `)
+	buff := bytes.NewBuffer(nil)
+	t.Execute(buff, map[string]string{
+		"LABEL_ENV_SECRET":  LABEL_ENV_SECRET,
+		"LABEL_ENV_SERVICE": LABEL_ENV_SERVICE,
+		"LABEL_PORT":        LABEL_PORT,
+		"LABEL_INGRESS":     LABEL_INGRESS,
+		"LABEL_VOL_CM":      LABEL_VOL_CM,
+		"LABEL_HEALTHCHECK": LABEL_HEALTHCHECK,
+	})
+	return buff.String()
+}
+
 var (
 	Appname = ""
 	Version = "1.0" // should be set from main.Version