At the previous section we've learnt about the first input argument of the app.Run, here we will take a look of what the second one is.

Let's start from basics. The iris.New function returns an iris.Application. This Application value can be configured through its Configure(...iris.Configurator) and Run methods.

The second optional, varadiac argument of app.Run method accepts one or more iris.Configurator. An iris.Configurator is just a type of: func(app *iris.Application). Custom iris.Configurator can be passed to modify yours *iris.Application as well.

There are built-iniris.Configurators for each of the core Configuration's fields, such as iris.WithoutStartupLog, iris.WithCharset("UTF-8"), iris.WithOptimizations and iris.WithConfiguration(iris.Configuration{...}) functions.

Each “module” like the iris view engine, websockets, sessions and each middleware has its own configurations and options, most of them, separately from the core configuration.

Using the Configuration

The only one configuration structure is the iris.Configuration. Let's start by that one which can be passed on the iris.WithConfiguration function to make it an iris.Configurator.

All of the iris.Configuration fields are defaulted to the most common use cases. Iris doesn’t need any configuration before its app.Run but if you want to make use of a custom iris.Configurator before the server runs then you can use the app.Configure method to pass the configurator(s) there.

config := iris.WithConfiguration(iris.Configuration {
DisableStartupLog: true,
Optimizations: true,
Charset: "UTF-8",
app.Listen(":8080", config)

Load from YAML

Using the iris.YAML("path").

File: iris.yml

FireMethodNotAllowed: true
DisableBodyConsumptionOnUnmarshal: true
TimeFormat: Mon, 01 Jan 2006 15:04:05 GMT
Charset: UTF-8

File: main.go

config := iris.WithConfiguration(iris.YAML("./iris.yml"))
app.Listen(":8080", config)

Load from TOML

Using the iris.TOML("path").

File: iris.tml

FireMethodNotAllowed = true
DisableBodyConsumptionOnUnmarshal = false
TimeFormat = "Mon, 01 Jan 2006 15:04:05 GMT"
Charset = "UTF-8"
ServerName = "my fancy iris server"
ServerOwner = ""

File: main.go

config := iris.WithConfiguration(iris.TOML("./iris.tml"))
app.Listen(":8080", config)

Using the functional way

As we already mention, you can pass any number of iris.Configurator in the app.Run’s second argument. Iris provides an option for each of its iris.Configuration’s fields.

app.Listen(":8080", iris.WithoutInterruptHandler,
iris.WithTimeFormat("Mon, 01 Jan 2006 15:04:05 GMT"),

Good when you want to change some of the configuration's field. Prefix: "With" or "Without", code editors will help you navigate through all configuration options without even a glitch to the documentation.

Custom values

The iris.Configuration contains a field called Other map[string]interface{} which accepts any custom key:value option, therefore you can use that field to pass specific values that your app expects based on the custom requirements.

iris.WithOtherValue("ServerName", "my amazing iris server"),
iris.WithOtherValue("ServerOwner", ""),

You can access those fields via app.ConfigurationReadOnly.

serverName := app.ConfigurationReadOnly().Other["MyServerName"]
serverOwner := app.ConfigurationReadOnly().Other["ServerOwner"]

Access Configuration from Context

Inside a handler, retrieve those fields using the following: