VersionedAssets is middleware and taghelper for easier integration with CDN configured for origin pull. TagHelper creates asset urls with content version hash burned in url (for cache busting). Middleware handles requests comming from CDN and sets caching headers acordingly.
Following example assumes your CDN is configured with origin pull to base url
http://[your.site]/static.
TagHelper generated url: http://[your.cdn]/[version-hash]/bundles/app.js
Request from cdn are pulling from urls: http://[your.site]/static/[version-hash]/bundles/app.js
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
services.AddLogging();
services.AddMvc();
services.AddVersionedAssets();
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, ILoggerFactory loggerFactory)
{
loggerFactory.AddConsole(LogLevel.Debug);
// respond to cdn origin pull asset requests in the form /static/[hash]/*
app.UseVersionedAssets()
.WithUrlPrefix("//[your.cdn]")
app.UseMvcWithDefaultRoute();
}
}@addTagHelper "*, AspNetCore.VersionedAssets"
<!DOCTYPE html>
<html lang="cs">
<head>
<meta charset="UTF-8">
<title>SPA</title>
</head>
<body>
<script src="~/bundles/app.js" asset-version="FileVersion"></script>
</body>
</html>
There are two modes how to specify asset-version in tag helper:
- FileVersion - [version-hash] is based on file sha2 hash
- GlobalVersion - [version-hash] is static value for all assets configured in Startup.cs. It might be assembly build time, repository git hash... just something that changes for every deployment
Global version Startup.cs configuration example:
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
services.AddVersionedAssets(o => {
o.GlobalVersion = "xxx"
});
}
}It's also possible to use this without CDN for cache busting only.
When no explicit url (CDN) prefix is set VersionedAssets works in local mode with /static prefix. TagHelper generates url
like /static/[version-hash]/bundles/app.js that are served with registered middleware.