Subdomains

Iris has the simplest known form for subdomains registration to a single application. Of course you can always use nginx or caddy for management in production.

Subdomains are separated into two categories: static and dynamic/wildcard.

  • Static : when you know the subdomain, i.e : analytics.mydomain.com

  • Wildcard : when you don't know the subdomain but you know that it's before a particular subdomain or root domain, i.e : user_created.mydomain.com, otheruser.mydomain.com like the username.github.io

We use the Subdomain and WildcardSubdomain methods of an iris.Party or iris.Application to register subdomains.

The Subdomain method returns a new Party which is responsible to register routes to this specific "subdomain".

The only difference from a regular Party is that if called from a child party then the subdomain will be prepended to the path instead of appended. So if app.Subdomain("admin").Subdomain("panel") then the result is: "panel.admin.".

Subdomain(subdomain string, middleware ...Handler) Party

The WildcardSubdomain method returns a new Party which is responsible to register routes to a dynamic, wildcard(ed) subdomain. A dynamic subdomain is a subdomain which can handle any subdomain requests. Server will accept any subdomain (if not static subdomain found) and it will search and execute the handlers of this Party.

WildcardSubdomain(middleware ...Handler) Party

Example Code:

// [app := iris.New...]
admin := app.Subdomain("admin")
// admin.mydomain.com
admin.Get("/", func(ctx iris.Context) {
ctx.Writef("INDEX FROM admin.mydomain.com")
})
// admin.mydomain.com/hey
admin.Get("/hey", func(ctx iris.Context) {
ctx.Writef("HEY FROM admin.mydomain.com/hey")
})
// [other routes here...]
app.Run(iris.Addr("mydomain.com:80"))

For local development you'll have to edit your hosts, for example in windows operating system open the C:\Windows\System32\Drivers\etc\hosts file and append:

127.0.0.1 mydomain.com
127.0.0.1 admin.mydomain.com

To prove that subdomains works like any other regular Party you can also register a subdomain using the alternative method below:

adminSubdomain:= app.Party("admin.")
// or
adminAnalayticsSubdomain := app.Party("admin.analytics.")
// or for a dynamic one:
anySubdomain := app.Party("*.")

There is also an iris.Application method which allows to register a global redirection rule for subdomains as well.

The SubdomainRedirect sets (or adds if used more than one time) a router wrapper which redirects(StatusMovedPermanently) a (sub)domain to another subdomain or to the root domain as fast as possible, before the execution of the route's handler(s).

It receives two arguments, they are the from and to/target locations, 'from' can be a wildcard subdomain as well (app.WildcardSubdomain()) 'to' is not allowed to be a wildcard for obvious reasons, 'from' can be the root domain(app) when the 'to' is not the root domain and visa-versa.

SubdomainRedirect(from, to Party) Party

Usage

www := app.Subdomain("www")
app.SubdomainRedirect(app, www)

The above will redirect all http(s)://mydomain.com/%anypath% to http(s)://www.mydomain.com/%anypath%.

The Context offers four main methods when working with subdomains that may be helpful for you.

// Host returns the host part of the current url.
Host() string
// Subdomain returns the subdomain of this request, if any.
// Note that this is a fast method which does not cover all cases.
Subdomain() (subdomain string)
// IsWWW returns true if the current subdomain (if any) is www.
IsWWW() bool
// FullRqeuestURI returns the full URI,
// including the scheme, the host and the relative requested path/resource.
FullRequestURI() string

Usage

func info(ctx iris.Context) {
method := ctx.Method()
subdomain := ctx.Subdomain()
path := ctx.Path()
ctx.Writef("\nInfo\n\n")
ctx.Writef("Method: %s\nSubdomain: %s\nPath: %s", method, subdomain, path)
}