Setting Content Type based on file extension

In some situations you may want to override the content type that a backend returns. To do that you will need to create a new header object and an associated condition.

  1. Log in to the Fastly web interface.
  2. From the Home page, select the appropriate service. You can use the search box to search by ID, name, or domain. You can also go to CDN > CDN Services or Compute > Compute Services to access a list of services by type.
  3. Click Edit configuration and then select the option to clone the active version.
  4. Click Content.
  5. Click Create header.

    the Create a header page

  6. Fill out the Create a header fields as follows:

    • In the Name field, enter an appropriate name (e.g.,Add Content Type).
    • From the Type menu, select Cache, and from the Action menu, select Set.
    • In the Destination field, enter http.Content-Type.
    • In the Source field, enter the content type you want to match, such as "application/javascript; charset=utf-8".
    • From the Ignore if set menu, select No.
    • In the Priority field, enter 10.
  7. Click Create.

Once you have created the header object, apply a condition. Otherwise, that particular object is applied to all requests.

  1. Click Attach a condition to the right of the new header name.

    setting Content type

  2. Fill out the Create a new cache condition fields as follows:

    • In the Name field, enter a descriptive name, such as Files ending with .js.
    • In the Apply if field, enter the condition that matches your request, such as req.url.ext == "js" (to match the request for files ending in .js).
  3. Click Save and apply to. The new condition is created.

  4. Click Activate to deploy your configuration changes.

You may also be interested in our guide to Removing headers from backend response.

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