HttpClientRecommendations.md

Recommendations:

• Use IHttpClientFactory for obtaining HttpClient instances (this is important to ensure that DNS is not cached eternally)
  • See: https://docs.microsoft.com/en-us/aspnet/core/fundamentals/http-requests
• Use a request middleware to set any headers or other options that vary over the course of the application's lifetime (eg, auth headers)
  • Eg, see: https://blog.joaograssi.com/typed-httpclient-with-messagehandler-getting-accesstokens-from-identityserver/
  • Also see docs section: https://docs.microsoft.com/en-us/aspnet/core/fundamentals/http-requests?view=aspnetcore-3.1#outgoing-request-middleware
• Avoid modifying any properties on HttpClient after it has been initialized
• Do not cache HttpClient instances in long-lived objects. (eg in class members or DI containers), either use the IHttpClientFactory every time a client is needed, or create short-lived typed clients: https://docs.microsoft.com/en-us/aspnet/core/fundamentals/http-requests?view=aspnetcore-3.1#typed-clients