Purge all domains on Fastly (#6835)

When invalidating the cache on Fastly using the "single URL" endpoint,
the content is only purged for that specific URL. This can cause
inconsistencies, since we have two domains associated with each Fastly
service (namely `static.*` and `fastly-static.*`). The invalidation
logix has been refactor to purge a path for both domains.

Author: jdno

src/worker/fastly.rs

@@ -23,7 +23,8 @@ impl Fastly {
     /// Invalidate a path on Fastly
     ///
     /// This method takes a path and invalidates the cached content on Fastly. The path must not
-    /// contain a wildcard, since the Fastly API does not support wildcard invalidations.
+    /// contain a wildcard, since the Fastly API does not support wildcard invalidations. Paths are
+    /// invalidated for both domains that are associated with the Fastly service.
     ///
     /// Requests are authenticated using a token that is sent in a header. The token is passed to
     /// the application as an environment variable.
@@ -38,11 +39,21 @@ impl Fastly {
             ));
         }
 
+        let domains = [
+            &self.static_domain_name,
+            &format!("fastly-{}", self.static_domain_name),
+        ];
         let path = path.trim_start_matches('/');
-        let url = format!(
-            "https://api.fastly.com/purge/{}/{}",
-            self.static_domain_name, path
-        );
+
+        for domain in domains.iter() {
+            let url = format!("https://api.fastly.com/purge/{}/{}", domain, path);
+            self.purge_url(client, &url)?;
+        }
+
+        Ok(())
+    }
+
+    fn purge_url(&self, client: &Client, url: &str) -> anyhow::Result<()> {
         trace!(?url);
 
         let api_token = self.api_token.expose_secret();
@@ -54,7 +65,7 @@ impl Fastly {
 
         debug!("sending invalidation request to Fastly");
         let response = client
-            .post(&url)
+            .post(url)
             .headers(headers)
             .send()
             .context("failed to send invalidation request to Fastly")?;
@@ -76,7 +87,7 @@ impl Fastly {
                     "invalidation request to Fastly failed"
                 );
 
-                Err(error).with_context(|| format!("failed to invalidate {path} on Fastly"))
+                Err(error).with_context(|| format!("failed to purge {url}"))
             }
         }
     }