README
¶
README
This codebase has been generated by Autostrada.
Getting started
Before running the application you will need a working PostgreSQL installation and a valid DSN (data source name) for connecting to the database.
Please open the cmd/web/main.go file and edit the db-dsn command-line flag to include your valid DSN as the default value.
flag.StringVar(&cfg.db.dsn, "db-dsn", "YOUR DSN GOES HERE", "postgreSQL DSN")
Note that this DSN must be in the format user:pass@localhost:port/db and not be prefixed with postgres://.
Make sure that you're in the root of the project directory and run the cmd/web application using go run:
go run ./cmd/web
Then visit https://localhost:4444 in your browser. The first time you do this you will probably get a security warning because the application is using a self-signed certificate. Please go ahead and accept this.
Project structure
Everything in the codebase is designed to be editable. Feel free to change and adapt it to meet your needs.
assets
Contains the non-code assets for the application.
↳ assets/emails/
Contains email templates.
↳ assets/migrations/
Contains SQL migrations.
↳ assets/static/
Contains static UI files (images, CSS etc).
↳ assets/templates/
Contains HTML templates.
↳ assets/efs.go
Declares an embedded filesystem containing all the assets.
cmd/web
Your application-specific code (handlers, routing, middleware, helpers) for dealing with HTTP requests and responses.
↳ cmd/web/context.go
Contains helpers for working with request context.
↳ cmd/web/errors.go
Contains helpers for managing and responding to error conditions.
↳ cmd/web/handlers.go
Contains your application HTTP handlers.
↳ cmd/web/main.go
The entry point for the application. Responsible for parsing configuration settings initializing dependencies and running the server. Start here when you're looking through the code.
↳ cmd/web/middleware.go
Contains your application middleware.
↳ cmd/web/routes.go
Contains your application route mappings.
↳ cmd/web/templates.go
Contains helpers for working with HTML templates.
internal
Contains various helper packages used by the application.
↳ internal/cookies
Contains helper functions for reading/writing signed and encrypted cookies.
↳ internal/database/
Contains your database-related code (setup, connection and queries).
↳ internal/funcs/
Contains custom template functions.
↳ internal/password/
Contains helper functions for hashing and verifying passwords.
↳ internal/leveledlog/
Contains a leveled logger implementation.
↳ internal/request/
Contains helper functions for decoding HTML forms and URL query strings.
↳ internal/response/
Contains helper functions for rendering HTML templates.
↳ internal/server/
Contains a helper function for starting and gracefully shutting down the server.
↳ internal/smtp/
Contains a SMTP sender implementation.
↳ internal/token/
Contains functions for generating and hashing cryptographically secure random tokens.
↳ internal/validator/
Contains validation helpers.
↳ internal/version/
Contains the application version number definition.
tls
Contains TLS certificates.
This folder is excluded from git. You need a suitable certificate (cert.pem and key.pem) in order to proceed.
Configuration settings
Configuration settings are managed via command-line flags in main.go.
You can try this out by using the -addr flag to configure the network address that the server is listening:
go run ./cmd/web --addr=:9999
Feel free to adapt the main() function to parse additional command-line flags and store their values in the config struct. For example, to add a configuration setting to enable a 'debug mode' in your application you could do this:
type config struct {
addr string
debug bool
}
...
func main() {
var cfg config
flag.StringVar(&cfg.addr, "addr", ":4444", "server address")
flag.BoolVar(&cfg.debug, "debug", false, "enable debug mode")
flag.Parse()
...
}
If you don't want to use command-line flags for configuration that's fine. Feel free to adapt the code so that the config struct is populated from environment variables or a settings file instead.
Creating new handlers
Handlers are defined as http.HandlerFunc methods on the application struct. They take the pattern:
func (app *application) yourHandler(w http.ResponseWriter, r *http.Request) {
// Your handler logic...
}
Handlers are defined in the cmd/web/handlers.go file. For small applications, it's fine for all handlers to live in this file. For larger applications (10+ handlers) you may wish to break them out into separate files.
Handler dependencies
Any dependencies that your handlers have should be initialized in the main() function cmd/web/main.go and added to the application struct. All of your handlers, helpers and middleware that are defined as methods on application will then have access to them.
You can see an example of this in the cmd/web/main.go file where we initialize a new logger instance and add it to the application struct.
Creating new routes
Flow is used for routing, but it's fine to swap to a different router if you want.
Routes are defined in the routes() method in the cmd/web/routes.go file. For example:
func (app *application) routes() http.Handler {
mux := flow.New()
mux.HandleFunc("/your/path", app.yourHandler, "GET")
return mux
}
For more information on using flow and example usage, please see the official documentation.
Adding middleware
Middleware is defined as methods on the application struct in the cmd/web/middleware.go file. Feel free to add your own. They take the pattern:
func (app *application) yourMiddleware(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
// Your middleware logic...
next.ServeHTTP(w, r)
})
}
You can then register this middleware with the router using the Use() method:
func (app *application) routes() http.Handler {
mux := flow.New()
mux.Use(app.yourMiddleware)
mux.HandleFunc("/your/path", app.yourHandler, "GET")
return mux
}
It's possible to use middleware on specific routes only by creating route 'groups':
func (app *application) routes() http.Handler {
mux := flow.New()
mux.Use(app.yourMiddleware)
mux.HandleFunc("/your/path", app.yourHandler, "GET")
mux.Group(func(mux *flow.Mux) {
mux.Use(app.yourOtherMiddleware)
mux.HandleFunc("/your/other/path", app.yourOtherHandler, "GET")
})
return mux
}
Note: Route 'groups' can also be nested.
Rendering HTML templates
HTML templates are stored in the assets/templates directory and use the standard library html/template package. The structure looks like this:
assets/templates/base.tmpl
The 'base' template containing the shared HTML markup for all your web pages.
assets/templates/pages/
Directory containing files with the page-specific content for your web pages. See assets/templates/pages/home.tmpl for an example.
assets/templates/partials/
Directory containing files with 'partials' to embed in your web pages or base template. See assets/templates/partials/footer.tmpl for an example.
The HTML for web pages can be sent using the response.Page() function. For convenience, an app.newTemplateData() method is provided which returns a map[string]any map. You can add data to this map and pass it on to your templates.
For example, to render the HTML in the assets/templates/pages/example.tmpl file:
func (app *application) yourHandler(w http.ResponseWriter, r *http.Request) {
data := app.newTemplateData()
data["hello"] = "world"
err := response.Page(w, http.StatusOK, data, "pages/example.tmpl")
if err != nil {
app.serverError(w, r, err)
}
}
Specific HTTP headers can optionally be sent with the response too:
func (app *application) yourHandler(w http.ResponseWriter, r *http.Request) {
data := app.newTemplateData()
data["hello"] = "world"
headers := make(http.Header)
headers.Set("X-Server", "Go")
err := response.PageWithHeaders(w, http.StatusOK, data, headers, "pages/example.tmpl")
if err != nil {
app.serverError(w, r, err)
}
}
Note: All the files in the assets/templates directory are embedded into your application binary and can be accessed via the EmbeddedFiles variable in assets/efs.go.
Adding default template data
If you have data that you want to display or use on multiple web pages, you can adapt the newTemplateData() helper in the templates.go file to include this by default. For example, if you wanted to include the current year value you could adapt it like this:
func (app *application) newTemplateData() map[string]any {
data := map[string]any{
"CurrentYear": time.Now().Year(),
}
return data
}
Custom template functions
Custom template functions are defined in internal/funcs/funcs.go and are automatically made available to your HTML templates when you use response.Page() and email templates when you use app.mailer.Send() .
The following custom template functions are already included by default:
now
Returns the current time.
timeSince arg1
Returns the time elapsed since arg1.
timeUntil arg2
Returns the time until arg1.
formatTime arg1 arg2
Returns the time arg2 as formatted using the pattern arg1.
approxDuration arg1
Returns the approximate duration of arg1 in a 'human-friendly' format ("3 seconds", "2 months", "5 years") etc.
uppercase arg1
Returns arg1 converted to uppercase.
lowercase arg1
Returns arg1 converted to lowercase.
pluralize arg1 arg2 arg3
If arg1 equals 1 then return arg2, otherwise return arg3.
slugify arg1
Returns the lowercase of arg1 with all non-ASCII characters and punctuation removed (expect underscores and hyphens). Whitespaces are also replaced with a hyphen.
safeHTML arg1
Output the verbatim value of arg1 without escaping the content. This should only be used when arg1 is from a trusted source.
join arg1 arg2
Returns the values in arg1 joined using the separator arg2.
containsString arg1 arg2
Returns true if arg1 contains the string value arg2.
incr arg1
Increments arg1 by 1.
decr arg1
Decrements arg1 by 1.
formatInt arg1
Returns arg1 formatted with commas as the thousands separator.
formatFloat arg1 arg2
Returns arg1 rounded to arg2 decimal places and formatted with commas as the thousands separator.
yesno arg1
Returns "Yes" if arg1 is true, or "No" if arg1 is false.
urlSetParam arg1 arg2 arg3
Returns the URL arg1 with the key arg2 and value arg3 added to the query string parameters.
urlDelParam arg1 arg2
Returns the URL arg1 with the key arg2 (and corresponding value) removed from the query string parameters.
To add another custom template function, define the function in internal/funcs/funcs.go and add it to the TemplateFuncs map. For example:
var TemplateFuncs = template.FuncMap{
...
"yourFunction": yourFunction,
}
func yourFunction(s string) (string, error) {
// Do something...
}
Static files
By default, the files in the assets/static directory are served using Go's http.Fileserver whenever the application receives a GET request with a path beginning /static/. So, for example, if the application receives a GET /static/css/main.css request it will respond with the contents of the assets/static/css/main.css file.
If you want to change or remove this behavior you can by editing the routes.go file.
Note: The files in assets/static directory are embedded into your application binary and can be accessed via the EmbeddedFiles variable in assets/efs.go.
Working with forms
The codebase includes a request.DecodePostForm() function for automatically decoding HTML form data into a struct, and request.DecodeQueryString() for decoding URL query strings into a struct. Behind the scenes this decoding is managed using the go-playground/form package.
As an example, let's say you have a page with the following HTML form for creating a 'person' record and routing rule:
<form action="/person/create" method="POST">
<div>
<label>Your name:</label>
<input type="text" name="Name" value="{{.Form.Name}}">
</div>
<div>
<label>Your age:</label>
<input type="number" name="Age" value="{{.Form.Age}}">
</div>
<button>Submit</button>
</form>
func (app *application) routes() http.Handler {
mux := flow.New()
mux.HandleFunc("/person/create", app.createPerson, "GET", "POST")
return mux
}
Then you can display and parse this form with a createPerson handler like this:
package main
import (
"net/http"
"github.com/nstoker/go-autobuild/internal/request"
"github.com/nstoker/go-autobuild/internal/response"
)
func (app *application) createPerson(w http.ResponseWriter, r *http.Request) {
type createPersonForm struct {
Name string `form:"Name"`
Age int `form:"Age"`
}
switch r.Method {
case http.MethodGet:
data := app.newTemplateData()
// Add any default values to the form.
data["Form"] = createPersonForm{
Age: 21,
}
err := response.Page(w, http.StatusOK, data, "/path/to/page.tmpl")
if err != nil {
app.serverError(w, r, err)
}
case http.MethodPost:
var form createPersonForm
err := request.DecodePostForm(r, &form)
if err != nil {
app.badRequest(w, r, err)
return
}
// Do something with the data in the form variable...
}
}
Validating forms
The internal/validator package includes a simple (but powerful) validator.Validator type that you can use to carry out validation checks.
Extending the example above:
package main
import (
"net/http"
"github.com/nstoker/go-autobuild/internal/request"
"github.com/nstoker/go-autobuild/internal/response"
"github.com/nstoker/go-autobuild/internal/validator"
)
func (app *application) createPerson(w http.ResponseWriter, r *http.Request) {
type createPersonForm struct {
Name string `form:"Name"`
Age int `form:"Age"`
Validator validator.Validator `form:"-"`
}
switch r.Method {
case http.MethodGet:
data := app.newTemplateData()
// Add any default values to the form.
data["Form"] = createPersonForm{
Age: 21,
}
err := response.Page(w, http.StatusOK, data, "/path/to/page.tmpl")
if err != nil {
app.serverError(w, r, err)
}
case http.MethodPost:
var form createPersonForm
err := request.DecodePostForm(r, &form)
if err != nil {
app.badRequest(w, r, err)
return
}
form.Validator.CheckField(form.Name != "", "Name", "Name is required")
form.Validator.CheckField(form.Age != 0, "Age", "Age is required")
form.Validator.CheckField(form.Age >= 21, "Age", "Age must be 21 or over")
if form.Validator.HasErrors() {
data := app.newTemplateData()
data["Form"] = form
err := response.Page(w, http.StatusUnprocessableEntity, data, "/path/to/page.tmpl")
if err != nil {
app.serverError(w, r, err)
}
return
}
// Do something with the form information, like adding it to a database...
}
}
And you can display the error messages in your HTML form like this:
<form action="/person/create" method="POST">
{{if .Form.Validator.HasErrors}}
<p>Something was wrong. Please correct the errors below and try again.</p>
{{end}}
<div>
<label>Your name:</label>
{{with .Form.Validator.FieldErrors.Name}}
<span class='error'>{{.}}</span>
{{end}}
<input type="text" name="Name" value="{{.Form.Name}}">
</div>
<div>
<label>Your age:</label>
{{with .Form.Validator.FieldErrors.Age}}
<span class='error'>{{.}}</span>
{{end}}
<input type="number" name="Age" value="{{.Form.Age}}">
</div>
<button>Submit</button>
</form>
In the example above we use the CheckField() method to carry out validation checks for specific fields. You can also use the Check() method to carry out a validation check that is not related to a specific field. For example:
input.Validator.Check(input.Password == input.ConfirmPassword, "Passwords do not match")
The validator.AddError() and validator.AddFieldError() methods also let you add validation errors directly:
input.Validator.AddFieldError("Email", "This email address is already taken")
input.Validator.AddError("Passwords do not match")
The internal/validator/helpers.go file also contains some helper functions to simplify validations that are not simple comparison operations.
NotBlank(value string)
Check that the value contains at least one non-whitespace character.
MinRunes(value string, n int)
Check that the value contains at least n runes.
MaxRunes(value string, n int)
Check that the value contains no more than n runes.
Between(value, min, max T)
Check that the value is between the min and max values inclusive.
Matches(value string, rx *regexp.Regexp)
Check that the value matches a specific regular expression.
In(value T, safelist ...T)
Check that a value is in a 'safelist' of specific values.
AllIn(values []T, safelist ...T)
Check that all values in a slice are in a 'safelist' of specific values.
NotIn(value T, blocklist ...T)
Check that the value is not in a 'blocklist' of specific values.
NoDuplicates(values []T)
Check that a slice does not contain any duplicate (repeated) values.
IsEmail(value string)
Check that the value has the formatting of a valid email address.
IsURL(value string)
Check that the value has the formatting of a valid URL.
For example, to use the Between check your code would look similar to this:
input.Validator.CheckField(validator.Between(input.Age, 18, 30), "Age", "Age must between 18 and 30")
Feel free to add your own helper functions to the internal/validator/helpers.go file as necessary for your application.
Working with the database
This codebase is set up to use PostgreSQL with the lib/pq driver. You can control which database you connect to using the -db-dsn command-line flag when starting the application to pass in a DSN, or by adapting the default value in main().
The codebase is also configured to use jmoiron/sqlx, so you have access to the whole range of sqlx extensions as well as the standard library Exec(), Query() and QueryRow() methods .
The database is available to your handlers, middleware and helpers via the application struct. If you want, you can access the database and carry out queries directly. For example:
func (app *application) yourHandler(w http.ResponseWriter, r *http.Request) {
...
_, err := app.db.Exec("INSERT INTO people (name, age) VALUES ($1, $2)", "Alice", 28)
if err != nil {
app.serverError(w, r, err)
return
}
...
}
Generally though, it's recommended to isolate your database logic in the internal/database package and extend the DB type to include your own methods. For example, you could create a internal/database/people.go file containing code like:
type Person struct {
ID int `db:"id"`
Name string `db:"name"`
Age int `db:"age"`
}
func (db *DB) NewPerson(name string, age int) error {
_, err := db.Exec("INSERT INTO people (name, age) VALUES ($1, $2)", name, age)
return err
}
func (db *DB) GetPerson(id int) (Person, error) {
var person Person
err := db.Get(&person, "SELECT * FROM people WHERE id = $1", id)
return person, err
}
And then call this from your handlers:
func (app *application) yourHandler(w http.ResponseWriter, r *http.Request) {
...
_, err := app.db.NewPerson("Alice", 28)
if err != nil {
app.serverError(w, r, err)
return
}
...
}
Managing SQL migrations
The Makefile in the project root contains commands to easily create and work with database migrations:
$ make migrations/new name=add_example_table
Create a new database migration in the assets/migrations folder.
$ make migrations/up
Apply all up migrations.
$ make migrations/down
Apply all down migrations.
$ make migrations/goto version=N
Migrate up or down to a specific migration (where N is the migration version number).
$ make migrations/force version=N
Force the database to be specific version without running any migrations.
$ make migrations/version
Display the currently in-use migration version.
Hint: You can run $ make help at any time for a reminder of these commands.
These Makefile tasks are simply wrappers around calls to the github.com/golang-migrate/migrate/v4/cmd/migrate tool. For more information, please see the official documentation.
By default all 'up' migrations are automatically run on application startup using embeded files from the assets/migrations directory. You can disable this by using the command-line flag -db-automigrate=false when running the application.
Logging
The internal/leveledlog package provides a leveled-logger implementation. It outputs color-coded log lines in the following format:
level="INFO" time="2022-08-15T08:51:09+02:00" message="starting server on localhost:4444 (version 0.0.1)"
By default, a logger is initialized in the main() function which writes all log messages to os.Stdout. You can call the logger's Info(), Warn(), Error() and Fatal() methods to log messages at different levels with fmt.Printf style formatting. For example:
logger.Info("starting server on port %d", 1234)
Note: Stack traces are automatically appended to Error() and Fatal() messages, and calling Fatal() will cause your application to terminate.
If you want to disable the color-coding, then pass false as the final parameter when initializing the logger in main().
logger := leveledlog.NewLogger(os.Stdout, leveledlog.LevelAll, false)
You can also write JSON-formated log entries instead by using the NewJSONLogger() function to initialize the logger:
logger := leveledlog.NewJSONLogger(os.Stdout, leveledlog.LevelAll)
Note: JSON-formatted log entries are not color-coded.
Feel free to adapt the internal/leveledlog package to change this behavior or include additional fields if you want.
Cookies
The internal/cookies package provides helper functions for reading and writing cookies.
The Write() function base64-encodes the cookie value and checks the cookie length is no more than 4096 bytes before writing the cookie. You can use it like this:
func (app *application) yourHandler(w http.ResponseWriter, r *http.Request) {
// Initialize a Go cookie as normal.
cookie := http.Cookie{
Name: "exampleCookie",
Value: "Hello Zoë!",
Path: "/",
MaxAge: 3600,
HttpOnly: true,
Secure: true,
SameSite: http.SameSiteLaxMode,
}
// Write the cookie.
err := cookies.Write(w, cookie)
if err != nil {
app.serverError(w, r, err)
return
}
...
}
The Read() function reads a named cookie and base64-decodes the value before returning it.
func (app *application) yourHandler(w http.ResponseWriter, r *http.Request) {
// Read the cookie value and handle any errors as necessary for your application.
value, err := cookies.Read(r, "exampleCookie")
if err != nil {
switch {
case errors.Is(err, http.ErrNoCookie):
app.badRequest(w, r, err)
case errors.Is(err, cookies.ErrInvalidValue):
app.badRequest(w, r, err)
default:
app.serverError(w, r, err)
}
return
}
...
}
The internal/cookies package also provides WriteSigned() and ReadSigned() functions for writing/reading signed cookies, and WriteEncrypted() and ReadEncrypted() functions encrypted cookies. Signed cookies are authenticated using HMAC-256, meaning that you can trust that the contents of the cookie has not been tampered with. Encrypted cookies are encrpyted using AES-GCM, which both authenticates and encrypts the cookie data, meaning that you can trust that the contents of the cookie has not been tampered with and the contents of the cookie cannot be read by the client.
When using these helper functions, you must set your own (secret) key for signing and encryption. This key should be a random 32-character string generated using a CSRNG which you pass to the application using the -cookie-key command-line flag. For example:
go run ./cmd/web --cookie-secret-key=heoCDWSgJ430OvzyoLNE9mVV9UJFpOWx
To write a new signed or encrypted cookie:
func (app *application) yourHandler(w http.ResponseWriter, r *http.Request) {
// Initialize a Go cookie as normal.
cookie := http.Cookie{
Name: "exampleCookie",
Value: "Hello Zoë!",
Path: "/",
MaxAge: 3600,
HttpOnly: true,
Secure: true,
SameSite: http.SameSiteLaxMode,
}
// Write a signed cookie using WriteSigned() and passing in the secret key
// as the final argument. Use WriteEncrypted() if you want an encrpyted
// cookie instead.
err := cookies.WriteSigned(w, cookie, app.config.cookie.secretKey)
if err != nil {
app.serverError(w, r, err)
return
}
...
}
To read a signed or encrypted cookie:
func (app *application) yourHandler(w http.ResponseWriter, r *http.Request) {
// Read the cookie value using ReadSigned() and passing in the secret key
// as the final argument. Use ReadEncrypted() if you want to read an
// encrpyted cookie instead.
value, err := cookies.ReadSigned(r, "exampleCookie", app.config.cookie.secretKey)
if err != nil {
switch {
case errors.Is(err, http.ErrNoCookie):
app.badRequest(w, r, err)
case errors.Is(err, cookies.ErrInvalidValue):
app.badRequest(w, r, err)
default:
app.serverError(w, r, err)
}
return
}
...
}
Using Basic Authentication
The cmd/web/middleware.go file contains a basicAuth middleware that you can use to protect your application — or specific application routes — with HTTP basic authentication.
You can try this out by visiting the https://localhost:4444//basic-auth-protected endpoint in any web browser and entering the default user name and password:
User name: admin
Password: pa55word
You can change the user name and password by passing -auth-username and -auth-hashed-password command-line flags when starting the application. For example:
go run ./cmd/web --auth-username='alice' --auth-hashed-password='$2a$10$xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'
Note: You will probably need to wrap the username and password in ' quotes to prevent your shell interpreting dollar and slash symbols as special characters.
The value for -auth-hashed-password should be a bcrypt hash of the password, not the plaintext password itself. An easy way to generate the bcrypt hash for a password is to use the gophers.dev/cmds/bcrypt-tool package like so:
go run gophers.dev/cmds/bcrypt-tool@latest hash 'your_pa55word'
If you want to change the default values for username and password you can do so by editing the default command-line flag values in the cmd/web/main.go file.
Using sessions
The codebase is set up so that cookie-based sessions (using the gorilla/sessions package) work out-of-the-box.
You can use them in your handlers like this:
func (app *application) yourHandler(w http.ResponseWriter, r *http.Request) {
...
session, err := app.sessionStore.Get(r, "sessions")
if err != nil {
app.serverError(w, r, err)
return
}
session.Values["foo"] = "bar"
err = session.Save(r, w)
if err != nil {
app.serverError(w, r, err)
return
}
...
}
By default sessions are set to expire after 1 week. You can configure this along with other session cookie settings in the cmd/web/main.go file by changing the sessions.Options struct values:
sessionStore.Options = &sessions.Options{
HttpOnly: true,
MaxAge: 86400 * 7, // 1 week in seconds
Path: "/",
SameSite: http.SameSiteLaxMode,
}
When running the application in production you should use your own secret key for authenticating sessions. This key should be a random 32-character string generated using a CSRNG which you pass to the application using the -session-key command-line flag.
go run ./cmd/web --session-secret-key=npsqT5At8USavGtyRpr4tc8j9hWK2Yol
Key rotation is supported. If you want to switch to a new key run the application using the -session-key for the new key and the -session-old-key flag for the old key, until all sessions using the old key have expired.
go run ./cmd/web --session-secret-key=SfvzdTUOHeHkavOzRP6p1uUVpueX11mW --session-old-secret-key=npsqT5At8USavGtyRpr4tc8j9hWK2Yol
For more information please see the documentation for the gorilla/sessions package.
Sending emails
The application is configured to support sending of emails via SMTP.
Email templates should be defined as files in the assets/emails folder. Each file should contain named templates for the email subject, plaintext body and — optionally — HTML body.
{{define "subject"}}Example subject{{end}}
{{define "plainBody"}}
This is an example body
{{end}}
{{define "htmlBody"}}
<!doctype html>
<html>
<head>
<meta name="viewport" content="width=device-width" />
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
<p>This is an example body</p>
</body>
</html>
{{end}}
A further example can be found in the assets/emails/example.tmpl file. Note that your email templates automatically have access to the custom template functions defined in the internal/funcs package.
Emails can be sent from your handlers using app.mailer.Send(). For example, to send an email to alice@github.com/nstoker/go-autobuild containing the contents of the assets/emails/example.tmpl file:
func (app *application) yourHandler(w http.ResponseWriter, r *http.Request) {
...
data := map[string]any{"Name": "Alice"}
err := app.mailer.Send("alice@github.com/nstoker/go-autobuild", data, "example.tmpl")
if err != nil {
app.serverError(w, r, err)
return
}
...
}
Note: The second parameter to Send() should be a map or struct containing any dynamic data that you want to render in the email template.
The SMTP host, port, username, password and sender details can be configured using the -smtp-host, -smtp-port, -smtp-username, -smtp-password and -smtp-from command-line flags when starting the application, or by adapting the default values in cmd/web/main.go.
You may wish to use Mailtrap or a similar tool for development purposes.
User accounts
The application is configured to support user accounts with fully-functional signup, login, logout and password-reset workflows.
A User struct describing the data for a user is defined in internal/database/users.go.
type User struct {
ID int `db:"id"`
Created time.Time `db:"created"`
Email string `db:"email"`
HashedPassword string `db:"hashed_password"`
}
Feel free to add additional fields to this struct (don't forget to also update the SQL queries, migrations, and handler code as necessary!).
By default login is done using the user's email address and password. When a login is successful the user's ID is stored in the session cookie. When this cookie is sent back with subsequent requests to the application, the authenticate middleware is used to look up the user's information from the database. The user's information is then stored in the current request context.
By default the session cookie lifetime is 1 week (meaning that a user will remain logged in for up to one week). You can change this value in cmd/web/main.go (see the using sessions section for more information).
You can control access to specific handlers based on whether a user is logged-in or not using the requireAuthenticatedUser and requireAnonymousUser middleware. An example of using these can be seen in the cmd/web/routes.go file.
Important: You should only call the requireAuthenticatedUser and requireAnonymousUser middleware after the authenticate middleware.
You can retrieve the details of the current user in your application handlers by calling the contextGetAuthenticatedUser() helper. This will return nil if the request is not being made by an authenticated (logged-in) user.
func (app *application) yourHandler(w http.ResponseWriter, r *http.Request) {
...
authenticatedUser := contextGetAuthenticatedUser(r)
...
}
For authenticated (logged-in) users, their information is also automatically available to your HTML templates via {{.AuthenticatedUser}}. Again, this will be nil if the current user is anonymous (not logged in), meaning that you can check if a user is logged in with {{if .AuthenticatedUser}}...{{end}} in your HTML templates. An example of this can be seen in assets/templates/partials/nav.tmpl.
The password reset functionality sends an email to the user. The email template for this is located at assets/emails/forgotten-password.tmpl. Please make sure that you have configured a SMTP host, port, username, password and sender details (see the sending emails section above for more information).
When using user accounts, all non-safe requests to the application require protection from CSRF attacks. Make sure to include a hidden input containing a CSRF token in any of your HTML forms that make a POST request:
<input type='hidden' name='csrf_token' value='{{.CSRFToken}}'>
Admin tasks
The Makefile in the project root contains commands to easily run common admin tasks:
$ make tidy
Format all code using go fmt and tidy the go.mod file.
$ make audit
Run go vet, staticheck, execute all tests and verify required modules.
$ make build
Build a binary for the cmd/web application and store it in the bin folder.
$ make run
Build and then run a binary for the cmd/web application.
Changing the TLS certificates
For convenience a self-signed TLS certificate (cert.pem) and private key (key.pem) are provided in the tls directory.
You can specify a different certificate and key at runtime using the tls-cert-file and tls-key-file command-line flags.
go run . --tls-cert-file=/path/to/cert.pem --tls-key-file=/path/to/key.pem
Application version
The application version number is generated automatically based on your latest version control system revision number. If you are using Git, this will be your latest Git commit hash. It can be retrieved by calling the version.Get() function from the internal/version package.
Important: The version control system revision number will only be available when the application is built using go build. If you run the application using go run then version.Get() will return the string "unavailable".
Changing the module path
The module path is currently set to github.com/nstoker/go-autobuild. Please find and replace all instances of github.com/nstoker/go-autobuild in the codebase with your own module path.
Directories