support migration script override

Author: bom-d-van

README.md

@@ -226,7 +226,7 @@ Add `BuildCmd` option in `App` as bellow:
 ```
 "App": {
 	"Name":       "app",
-	"BuildCmd":   "docker run -t -v $GOPATH:/home/app golang  /bin/sh -c 'GOPATH=/home/app /usr/local/go/bin/go build -o /home/app/src/github.com/bom-d-van/harp/%s %s'"
+	"BuildCmd":   "docker run -t -v $GOPATH:/home/app golang  /bin/sh -c 'cd /home/app/src/github.com/bom-d-van/harp; GOPATH=/home/app /usr/local/go/bin/go build -o /home/app/src/github.com/bom-d-van/harp/%s %s'"
 }
 ```
 
@@ -253,10 +253,14 @@ harp supports you to override its default deploy script. Add configuration like
 ```
 "App": {
 	"Name":         "app",
-	"DeployScript": "path-to-your-script-template"
+	"DeployScript": "path-to-your-script-template",
+	"RestartScript": "path-to-your-script-template",
+	"MigrationScript": "path-to-your-script-template",
 },
 ```
 
+#### Deploy and Restart Script
+
 The script could be a `text/template.Template`, into which harp pass a data as bellow:
 
 ```
@@ -270,33 +274,43 @@ map[string]interface{}{
 type App struct {
 	Name       string
 	ImportPath string
-	Files      []string
+
+	NoRelMatch       bool
+	DefaultExcludeds []string
+	Files            []File
 
 	Args []string
 	Envs map[string]string
 
-	BuildCmd string
+	BuildCmd  string
+	BuildArgs string
 
 	KillSig string
 
-	// TODO: could override default deploy script for out-of-band deploy
+	// Default: 1MB
+	FileWarningSize int64
+
 	DeployScript  string
 	RestartScript string
 }
 
 type Server struct {
+	ID string
+
 	Envs   map[string]string
+	Home   string
 	GoPath string
 	LogDir string
-	PIDDir string
 
 	User string
 	Host string
 	Port string
 
-	Set string
+	Set string // aka, Type
 
 	client *ssh.Client
+
+	Config *Config
 }
 ```
 
@@ -318,6 +332,18 @@ set -e
 
 You can inspect your script by evoking command: `harp -s prod inspect deploy` or `harp -s prod inspect restart`.
 
+#### Migration Script
+
+Migration script template data is:
+
+```
+map[string]interface{}{
+	"Server":        harp.Server,
+	"App":           harp.App,
+	"DefaultScript": string,
+}
+```
+
 ### Server Informations
 
 You can use `harp info` to retrieve build and deploy information about the current running server. For example:

harp.go

@@ -105,8 +105,9 @@ type App struct {
 	// Default: 1MB
 	FileWarningSize int64
 
-	DeployScript  string
-	RestartScript string
+	DeployScript    string
+	RestartScript   string
+	MigrationScript string
 }
 
 type Tasks []string

harp_test.sh

@@ -63,6 +63,8 @@ tmp/harp -c test/harp.json -s prod run github.com/bom-d-van/harp/test/migration3
 echo ====================
 echo tmp/harp -c test/harp2.json -s prod run github.com/bom-d-van/harp/test/migration3
 tmp/harp -c test/harp2.json -s prod run github.com/bom-d-van/harp/test/migration3
+ssh app@$dmip -p 49153 -- tail migration.log
+ssh app@$dmip -p 49153 -- tail /home/app/src/github.com/bom-d-van/harp/test/migration.log
 
 echo ====================
 echo tmp/harp -c test/harp.json -s prod rollback ls

migration.go

@@ -181,6 +181,19 @@ func (s *Server) runMigration(migrations []Migration) {
 		exitf("failed to generate migration script: %s", err)
 	}
 
+	if s.Config.App.MigrationScript != "" {
+		var customScript bytes.Buffer
+		err := template.Must(template.New("migration.sh").ParseFiles(s.Config.App.MigrationScript)).Execute(&customScript, map[string]interface{}{
+			"Server":        s,
+			"App":           s.Config.App,
+			"DefaultScript": script.String(),
+		})
+		if err != nil {
+			exitf("failed to generate custom script (%s): %s", s.Config.App.MigrationScript, err)
+		}
+		script = customScript
+	}
+
 	if option.debug || option.hand {
 		log.Printf("===============\n%s\n%s", s, trimEmptyLines(script.String()))
 		if option.hand {

test/harp2.json

@@ -6,7 +6,8 @@
 		"ImportPath": "github.com/bom-d-van/harp/test",
 		"DeployScript": "test/deploy.sh",
 		"RestartScript": "test/restart.sh",
-		"BuildCmd": "docker run -t -v $GOPATH:/home/app golang  /bin/sh -c 'GOPATH=/home/app /usr/local/go/bin/go build -o /home/app/src/github.com/bom-d-van/harp/%s %s'",
+		"MigrationScript": "test/migration.sh",
+		"BuildCmd": "docker run -t -v $GOPATH:/home/app golang  /bin/sh -c 'cd /home/app/src/github.com/bom-d-van/harp; GOPATH=/home/app /usr/local/go/bin/go build -o /home/app/src/github.com/bom-d-van/harp/%s %s'",
 		"Files":      [
 			"github.com/bom-d-van/harp/test/files",
 			"github.com/bom-d-van/harp/test/file"

test/migration.sh

@@ -0,0 +1,7 @@
+set -e
+
+echo $(date) start >> migration.log
+
+{{.DefaultScript}}
+
+echo $(date) done >> migration.log

version.go

@@ -1,3 +1,3 @@
 package main
 
-const version = 2
+const version = 3