From b586b1eac866f1feca87cab92284a5c3d35a2eae Mon Sep 17 00:00:00 2001
From: Patrice Ferlet <metal3d@gmail.com>
Date: Tue, 30 Nov 2021 15:45:36 +0100
Subject: [PATCH] More documentation

---
 compose/parser.go  |  2 ++
 compose/types.go   | 29 ++++++++++++++++-------------
 generator/main.go  | 13 ++++++++++---
 helm/deployment.go |  1 +
 main.go            |  2 ++
 5 files changed, 31 insertions(+), 16 deletions(-)

diff --git a/compose/parser.go b/compose/parser.go
index 0a34aa5..7ae32d6 100644
--- a/compose/parser.go
+++ b/compose/parser.go
@@ -7,12 +7,14 @@ import (
 	"gopkg.in/yaml.v3"
 )
 
+// Parser is a docker-compose parser.
 type Parser struct {
 	Data *Compose
 }
 
 var Appname = ""
 
+// NewParser create a Parser and parse the file given in filename.
 func NewParser(filename string) *Parser {
 
 	f, err := os.Open(filename)
diff --git a/compose/types.go b/compose/types.go
index 9cca9d6..b84fc17 100644
--- a/compose/types.go
+++ b/compose/types.go
@@ -1,5 +1,21 @@
 package compose
 
+// Compose is a complete docker-compse representation.
+type Compose struct {
+	Version  string                 `yaml:"version"`
+	Services map[string]Service     `yaml:"services"`
+	Volumes  map[string]interface{} `yaml:"volumes"`
+}
+
+// NewCompose resturs a Compose object.
+func NewCompose() *Compose {
+	c := &Compose{}
+	c.Services = make(map[string]Service)
+	c.Volumes = make(map[string]interface{})
+	return c
+}
+
+// Service represent a "service" in a docker-compose file.
 type Service struct {
 	Image       string            `yaml:"image"`
 	Ports       []string          `yaml:"ports"`
@@ -9,16 +25,3 @@ type Service struct {
 	Volumes     []string          `yaml:"volumes"`
 	Expose      []int             `yaml:"expose"`
 }
-
-type Compose struct {
-	Version  string                 `yaml:"version"`
-	Services map[string]Service     `yaml:"services"`
-	Volumes  map[string]interface{} `yaml:"volumes"`
-}
-
-func NewCompose() *Compose {
-	c := &Compose{}
-	c.Services = make(map[string]Service)
-	c.Volumes = make(map[string]interface{})
-	return c
-}
diff --git a/generator/main.go b/generator/main.go
index f859957..54229be 100644
--- a/generator/main.go
+++ b/generator/main.go
@@ -17,10 +17,13 @@ var serviceWaiters = make(map[string][]chan int)
 var locker = &sync.Mutex{}
 var serviceTick = make(chan int, 0)
 
+// Ingresses is kept in memory to create ingresses.
 var Ingresses = make(map[string]*helm.Ingress, 0)
+
+// Values is kept in memory to create a values.yaml file.
 var Values = make(map[string]map[string]interface{})
 
-var DependScript = `
+var dependScript = `
 OK=0
 echo "Checking __service__ port"
 while [ $OK != 1 ]; do
@@ -32,6 +35,7 @@ echo
 echo "Done"
 `
 
+// Create a Deployment for a given compose.Service. It returns a list of objects: a Deployment and a possible Service (kubernetes represnetation as maps).
 func CreateReplicaObject(name string, s compose.Service) (ret []interface{}) {
 
 	Magenta("Generating deployment for ", name)
@@ -86,7 +90,7 @@ func CreateReplicaObject(name string, s compose.Service) (ret []interface{}) {
 			os.Exit(1)
 		}
 		c := helm.NewContainer("check-"+dp, "busybox", nil, s.Labels)
-		command := strings.ReplaceAll(strings.TrimSpace(DependScript), "__service__", dp)
+		command := strings.ReplaceAll(strings.TrimSpace(dependScript), "__service__", dp)
 
 		wait.Add(1)
 		go func(dp string) {
@@ -120,6 +124,7 @@ func CreateReplicaObject(name string, s compose.Service) (ret []interface{}) {
 	return
 }
 
+// Create a service (k8s).
 func createService(name string, s compose.Service) *helm.Service {
 
 	Magenta("Generating service for ", name)
@@ -163,6 +168,7 @@ func createService(name string, s compose.Service) *helm.Service {
 	return ks
 }
 
+// Create an ingress.
 func createIngress(name string, port int, s compose.Service) {
 	ingress := helm.NewIngress(name)
 	Values[name]["ingress"] = map[string]interface{}{
@@ -196,6 +202,7 @@ func createIngress(name string, port int, s compose.Service) {
 	locker.Unlock()
 }
 
+// This function is called when a possible service is detected, it append the port in a map to make others to be able to get the service name. It also try to send the data to any "waiter" for this service.
 func detected(name string, port int) {
 	locker.Lock()
 	servicesMap[name] = port
@@ -217,6 +224,7 @@ func getPort(name string) (int, error) {
 	return -1, errors.New("Not found")
 }
 
+// Waits for a service to be discovered. Sometimes, a deployment depends on another one. See the detected() function.
 func waitPort(name string) chan int {
 	locker.Lock()
 	c := make(chan int, 0)
@@ -231,7 +239,6 @@ func waitPort(name string) chan int {
 }
 
 func buildSelector(name string, s compose.Service) map[string]string {
-
 	return map[string]string{
 		"katenary.io/component": name,
 		"katenary.io/release":   "{{ .Release.Name }}",
diff --git a/helm/deployment.go b/helm/deployment.go
index cb892f4..57cef9c 100644
--- a/helm/deployment.go
+++ b/helm/deployment.go
@@ -2,6 +2,7 @@ package helm
 
 import "strings"
 
+// Deployment is a k8s deployment.
 type Deployment struct {
 	*K8sBase `yaml:",inline"`
 	Spec     *DepSpec `yaml:"spec"`
diff --git a/main.go b/main.go
index b257cf1..0014fac 100644
--- a/main.go
+++ b/main.go
@@ -32,6 +32,8 @@ func main() {
 
 	for name, s := range p.Data.Services {
 		wait.Add(1)
+		// it's mandatory to make the build in goroutines because some dependencies can
+		// wait for a port number. So the entire services are built in parallel.
 		go func(name string, s compose.Service) {
 			o := generator.CreateReplicaObject(name, s)
 			files[name] = o