How should I handle database failures in a web application?

I'm developing a simple RESTful API using Go's Goji framework (although this question is language-agnostic), in which parameters from the URL are queried against a PostgreSQL database. Here's how it works:

First we define a struct that holds a reference to our ORM

This struct contains an Init method that allows us to initialize a connection. This struct contains other methods to handle HTTP requests and exists primarily as a means to associate the database with the request handler.

type Context struct {
    db *gorm.DB
}

func (ctx Context) Init(user string, name string) (Context, error) {
    db, err := gorm.Open(
        "postgres",
        fmt.Sprintf("port=5432 sslmode=require host=domain.xxx"),
    )
    ctx.db = &db
    return ctx, err
}

func (ctx Context) handleGetRequest(c web.C, w http.ResponseWriter, r *http.Request) {
    // ... business logic
}

This structure is then initialized exatly once when the web application starts up

With this architecture, any database failure implies that the web app must be restarted.

func main() {   
    // "Context" is a means of including a DB object with route handlers
    ctx, err := context.Context{}.Init(dbuser, dbname)
    if err != nil {
        panic(err)
    }
    defer ctx.Close()

    // do other stuff, e.g. set up routing and whatnot ...
}

My questions are as follows:

1. From a software architecture point of view, what is a reasonable approach for gracefully handling database downtime and automatically reconnecting when the DB becomes available?


2. How can I work the recommendations in this answer into my design?

tl;dr: what's the industry standard for handing DB failures within web applications, from a software architecture perspective?