/
evolve.go
96 lines (85 loc) · 2 KB
/
evolve.go
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package main
import (
"fmt"
"io/ioutil"
"log"
"os"
"sort"
"strings"
"github.com/jmoiron/sqlx"
_ "github.com/lib/pq"
)
func main() {
db, err := sqlx.Connect("postgres", os.Args[2])
if err != nil {
log.Fatal(err)
}
defer db.Close()
appName := os.Args[1]
version := getVersion(db, appName)
log.Println("current schema version:", version)
latest := getLatest()
if version < latest {
log.Printf("updating %s database to: %s\n", appName, latest)
evolve(db, version, appName)
} else {
log.Printf("%s database up to date.\n", appName)
}
}
func evolve(db *sqlx.DB, startVersion string, appName string) {
files, _ := ioutil.ReadDir("./schema")
sort.Sort(ByName(files))
i := 0
if startVersion != "-1" {
for ; i < len(files); i++ {
if stripExt(files[i].Name()) == startVersion {
i++
break
}
}
files = files[i:]
}
for _, file := range files {
log.Println("running file:", "./schema/"+file.Name())
commands, err := ioutil.ReadFile("./schema/" + file.Name())
if err != nil {
log.Fatal(err)
}
_ = db.MustExec(string(commands))
if err != nil {
log.Fatal(err)
}
_ = db.MustExec(fmt.Sprintf("update %s_meta set version=$1", appName), stripExt(file.Name()))
if err != nil {
log.Fatal(err)
}
}
}
func stripExt(file string) string {
return strings.Replace(file, ".sql", "", 1)
}
func getLatest() string {
files, _ := ioutil.ReadDir("./schema")
sort.Sort(ByName(files))
return stripExt(files[len(files)-1].Name())
}
type ByName []os.FileInfo
func (a ByName) Len() int { return len(a) }
func (a ByName) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func (a ByName) Less(i, j int) bool { return a[i].Name() < a[j].Name() }
func getVersion(db *sqlx.DB, appName string) string {
rows, err := db.Query(fmt.Sprintf("select version from %s_meta;", appName))
if err != nil {
log.Println(err)
return "-1"
}
defer rows.Close()
rows.Next()
var version string
err = rows.Scan(&version)
if err != nil {
log.Println(err)
return "-1"
}
return version
}