add settings and environment

This commit adds the environment to the stack so that the db connection
can be used by easily without using a global. It also prepares for using
the template system.

boot.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+  "github.com/gibheer/zero-blog/lib"
+)
+
+func boot_system() (*lib.Environment, error) {
+  env := &lib.Environment{}
+  settings, err := lib.LoadConfiguration()
+  if err != nil {
+    return env, err
+  }
+  env.Config = settings
+
+  env.DB, err = lib.NewDatabase(settings.Connection)
+  if err != nil {
+    return env, err
+  }
+  return env, nil
+}

lib/database.go

@@ -0,0 +1,31 @@
+package lib
+
+import (
+  "errors"
+  "database/sql"
+  pq "github.com/lib/pq"
+)
+
+type Database struct {
+  Conn *sql.DB
+}
+
+func (d *Database) Query(query string) (*sql.Rows, error) {
+  res, err := d.Conn.Query(query)
+  if err != nil {
+    err := err.(*pq.Error)
+    return nil, errors.New(err.Code.Name())
+  }
+  return res, nil
+}
+
+func NewDatabase(connection string) (*Database, error) {
+  if connection == "" {
+    return nil, errors.New("No connection string given! Check the config.yml file!")
+  }
+  DB, err := sql.Open("postgres", connection)
+  if err != nil {
+    return nil, err
+  }
+  return &Database{DB}, nil
+}

lib/environment.go

@@ -0,0 +1,30 @@
+package lib
+
+import (
+  "io/ioutil"
+  "gopkg.in/yaml.v1"
+)
+
+type Settings struct {
+  Connection string
+}
+
+type Environment struct {
+  // settings from the config file
+  Config *Settings
+  // the database connection pool
+  DB *Database
+}
+
+func LoadConfiguration() (*Settings, error) {
+  configfile, err := ioutil.ReadFile("config.yml")
+  if err != nil {
+    return nil, err
+  }
+  settings := Settings{}
+  err = yaml.Unmarshal(configfile, &settings)
+  if err != nil {
+    return nil, err
+  }
+  return &settings, nil
+}

lib/router.go

@@ -10,6 +10,8 @@ import (
 
 // this router defines each action to take for an URI including the middlewares
 type Router struct {
+  // the environment of the application with settings and database connection
+  env *Environment
   // path that this engine takes care of relative to the parent
   path string
   // the list of functions to run on a request
@@ -20,6 +22,11 @@ type Router struct {
   parent *Router
 }
 
+// create a new router with the specific environment
+func NewRouter(env *Environment) *Router {
+  return &Router{env, "", make([]ContextFunc, 0), httprouter.New(), nil}
+}
+
 // Bundle all parameters into the context to make it easier to push important
 // data into functions.
 type Context struct {
@@ -34,15 +41,13 @@ type Context struct {
   funcList []ContextFunc
   // the current position in the function list
   current int
+  // a direct link to the environment
+  Env *Environment
 }
 
 // the func type for internal routes
 type ContextFunc func(*Context) error
 
-func NewRouter() *Router {
-  return &Router{"", make([]ContextFunc, 0), httprouter.New(), nil}
-}
-
 func (r *Router) fullpath(path string) string {
   if r.parent != nil {
     return r.parent.fullpath(r.path + path)
@@ -88,7 +93,7 @@ func (r *Router) createHandleFunction(target ContextFunc) httprouter.Handle {
     params   httprouter.Params) {
 
     ctx := &Context{
-      request, response, params, append(r.fullFuncList(), target), 0,
+      request, response, params, append(r.fullFuncList(), target), 0, r.env,
     }
     for i := 0; i < len(ctx.funcList); i++ {
       ctx.funcList[i](ctx)
@@ -101,7 +106,7 @@ func (r *Router) Use(middleware ContextFunc) {
 }
 
 func (r *Router) NewGroup(path string) *Router {
-  return &Router{path, make([]ContextFunc, 0), r.router, r}
+  return &Router{r.env, path, make([]ContextFunc, 0), r.router, r}
 }
 
 func (r *Router) Start() {

main.go

@@ -1,14 +1,20 @@
 package main
 
 import (
-  "fmt"
+  "log"
+  "os"
   "github.com/gibheer/zero-blog/lib"
   "github.com/gibheer/zero-blog/controller"
 )
 
 func main() {
-  router := lib.NewRouter()
-  authentication := router.NewGroup("/admin")
+  environment, err := boot_system()
+  if err != nil {
+    log.Fatal("Boot crashed with message: ", err)
+    os.Exit(1)
+  }
+
+  router := lib.NewRouter(environment)
   controller.DefineRoutes(router)
   router.Start()
 }