Hosting Static Sites
Static sites are made up of individual pages and files (HTML, JS, graphics, fonts) that are hosted on a server and delivered exactly as they're stored. It doesn’t take many system resources to maintain them, and they can be easily backed up. Static pages can be created and edited in any text editor.
Selectel Cloud Storage is an easy-to-use platform for hosting static sites and offers the following features:
- index files
- error pages
- stylized directory listings (CSS)
- traffic statistics
- caching headers
- upload links
- second level domain binding
- low cost - starting at 1 ruble a month
Cloud Storage is also a convenient platform for hosting single-page applications (SPA). SPAs are hosted the same as static sites.
Step 1: Create a Public Container
Log into the control panel and select Cloud Storage.
Create a public container by clicking New container.
Step 2: Configure Special Pages
Now we need to configure special pages: an index and error page.
Open the Container settings tab and choose Special pages:
This opens the Special pages block:
In the Index file field, specify the path to index.html, which will load when a user accesses the directory.
The path to the index file can be absolute or relative (without a / slash at the beginning):
- An absolute path indicates the strictly defined file location, regardless of the current folder or other circumstances. It always starts from the root container.
- Relative paths start in the current directory and then move backwards. The system will first look for index.html in the folder nearest the end of the path; if the file isn't found, then the the system will check the root.
To illustrate, we’ll create a file in our text editor and add the following text:
<html> <body> <h1>Hello, world!</h1> </body> </html>
We then save it as index.html.
We upload it to the container, and then assign it as the index file.
If we type http://xxxxx.selcdn.ru/site/ in our browser, we’ll be returned the index page with the text “Hello, world!”.
Under 404 error, enter the path of the file the user will be sent to if he requests a non-existent file.
In our case, we'll open our text editor, make a file with the text “Page not found” and save it as error.html.
We then assign it as the error file. If we enter a path to a non-existant page in our browser (for example, http://xxxxx.selcdn.ru/site/1), then we’ll be redirected to the error page we set, and the text “Page not found” will be displayed in our browser. Error pages can be assigned for different codes, including 404, 307, and 200.
We can also enter the address of an external resource (if we link to the site http://example.com, then that is where the user will be redirected to in the event of a 404 error).
By checking the box next to Web listing, you can determine how the contents of our catalog are organized:
- by name
- by size
- newest first
- oldest first
You can also apply a CSS file to our listing page.
Under Listing style file, enter the path to the CSS file you'd like to apply to your directory listing.
Step 3: Map a Domain
To map or bind a domain to the container, open the the Domain management block:
All of the files saved in the container will be available via the mapped domain. If, for example, we assign the domain images.example.com to the container my_images, then all of the files from this container will be available at http://images.example.com.
Before we can assign a domain, we need to add the necessary records to the DNS.
Second level domains can be mapped to containers by adding the A record (or AAAA record for IPv6 addresses) that links the address entered in the control panel to the DNS.
Step 4: Upload Files
All of the basic configurations have been set for your site. Now upload your website's content to the container.
Managing HTTP Headers
Cloud Storage lets you manage HTTP headers for caching.
Under Container settings, select the HTTP headers block. Using the Expires header, you can set the amount of time a browser will cache data for. In the Expires field, you can enter the date when a site’s data will become irrelevant (expire) in the following format: day of the week, date month year hour: minute: second GMT (for example: Tue, 31 Jan 2012 15:02:53 GMT). After the given date, data in the cache will no longer be read, and updated data will be downloaded from the server.
Using the cache-control header, you can manage how a page is cached. The following values can be assigned to the header:
- no cache — completely prohibits caching (used on frequently updated pages)
- public — allows caching by both a local client and proxy server
- private — allows caching only by local clients
- max-age — uses a cached document for a specific period (in seconds)
- no-store — prohibits a page that contains private data from being cached
Accelerating Static Sites
From the user’s point of view, one of the most important criteria for a site is its load time. Below are some tips for optimizing static sites in Cloud Storage.
Tip 1. Use the CDN
CDNs save all static content (images, text files, JS, CSS, etc.) to caching servers located all over the world.
When a website or its resources are accessed, the request is processed by the caching server closest to the user. With a CDN, sites load faster on both mobile and desktop devices.
The CDN caches data for 24 hours by default.
You can clear the CDN at any time. Under Storage settings, open the CDN block. In the field, enter the addresses of the pages you want to clear the cache for and click Purge cache.
The cache will be purged approximately 15 minutes after the form is submitted.
Tip 2. Pay Attention to the Cache-Control Header
To set the amount of time a file should be saved in a browser’s cache, the original file in our storage should contain a Cache-Control header with a max-age directive.
This header can significantly reduce load times. If the file is cached, then the browser will instantly display content from the cache without sending a request to the site.
A file’s caching period is shown in seconds:
In the given example, it’s set to 7200 seconds (2 hours). This is how CSS, JS, and image files are usually cached. These files can be cached indefinitely; if the content changes, just update the links in the HTML. RFC 2616 recommends not caching these files for longer than 1 year:
If a file should never be cached and always be sent fresh, the following value should be set for the Cache-Control header:
This means the element should never be cached and the client must request it every time they access the cloud (in this case, the file’s load time will increase since the body must be downloaded each time).
For HTML pages, the preferred Cache-Control header value is no-cache. If you need to make an urgent change to a page, and the client has cached said page (modern browsers do this by default), the client may not see the changes at all.
In some cases, it’s better to base the cache time of an HTML page on the frequency changes are made. For example, if a page contains news that updates every hour, then the max-age value should be set to 3600 (1 hour).
Cache-Control header values (just like other HTTP headers) in our cloud can be set from our web interface: