apt/keyring: download 3 keyrings for sid

src/distro_info.rs

@@ -134,6 +134,18 @@ pub async fn get_ordered_series_name(dist: &str) -> Result<Vec<String>, Box<dyn
 
 /// Get the latest released series for a dist (excluding future releases and special cases like sid)
 pub async fn get_latest_released_series(dist: &str) -> Result<String, Box<dyn Error>> {
+    let latest = get_n_latest_released_series(dist, 1).await?;
+    latest
+        .first()
+        .cloned()
+        .ok_or("No released series found".into())
+}
+
+/// Get the N latest released series for a dist (excluding future releases and special cases like sid)
+pub async fn get_n_latest_released_series(
+    dist: &str,
+    n: usize,
+) -> Result<Vec<String>, Box<dyn Error>> {
     let series_info_list = get_ordered_series(dist).await?;
 
     let today = chrono::Local::now().date_naive();
@@ -153,11 +165,11 @@ pub async fn get_latest_released_series(dist: &str) -> Result<String, Box<dyn Er
     // Sort by release date descending (newest first)
     released_series.sort_by(|a, b| b.release.cmp(&a.release));
 
-    if let Some(latest) = released_series.first() {
-        Ok(latest.series.clone())
-    } else {
-        Err("No released series found".into())
-    }
+    Ok(released_series
+        .iter()
+        .take(n)
+        .map(|s| s.series.clone())
+        .collect())
 }
 
 /// Obtain the distribution (eg. debian, ubuntu) from a distribution series (eg. noble, bookworm)
@@ -202,8 +214,11 @@ pub fn get_base_url(dist: &str) -> String {
     DATA.dist.get(dist).unwrap().base_url.clone()
 }
 
-/// Obtain the URL for the archive keyring of a distribution series
-pub async fn get_keyring_url(series: &str) -> Result<String, Box<dyn Error>> {
+/// Obtain the URLs for the archive keyrings of a distribution series
+///
+/// For 'sid' and 'experimental', returns keyrings from the 3 latest releases
+/// since sid needs keys from all recent releases.
+pub async fn get_keyring_urls(series: &str) -> Result<Vec<String>, Box<dyn Error>> {
     let dist = get_dist_from_series(series).await?;
     let dist_data = DATA
         .dist
@@ -212,24 +227,36 @@ pub async fn get_keyring_url(series: &str) -> Result<String, Box<dyn Error>> {
 
     // For Debian, we need the series number to form the keyring URL
     if dist == "debian" {
-        // Special case for 'sid' - use the latest released version
+        // Special case for 'sid' - use keyrings from the 3 latest released versions
         if series == "sid" || series == "experimental" {
-            let latest_released = get_latest_released_series("debian").await?;
-            let series_num = get_debian_series_number(&latest_released).await?.unwrap();
-            // Replace {series_num} placeholder with the latest released series number
-            Ok(dist_data
-                .archive_keyring
-                .replace("{series_num}", &series_num))
+            let latest_released = get_n_latest_released_series("debian", 3).await?;
+            let mut urls = Vec::new();
+            for released_series in latest_released {
+                if let Some(series_num) = get_debian_series_number(&released_series).await? {
+                    urls.push(
+                        dist_data
+                            .archive_keyring
+                            .replace("{series_num}", &series_num),
+                    );
+                }
+            }
+            if urls.is_empty() {
+                Err("No keyring URLs found for sid/experimental".into())
+            } else {
+                Ok(urls)
+            }
         } else {
             let series_num = get_debian_series_number(series).await?.unwrap();
             // Replace {series_num} placeholder with the actual series number
-            Ok(dist_data
-                .archive_keyring
-                .replace("{series_num}", &series_num))
+            Ok(vec![
+                dist_data
+                    .archive_keyring
+                    .replace("{series_num}", &series_num),
+            ])
         }
     } else {
         // For other distributions like Ubuntu, use the keyring directly
-        Ok(dist_data.archive_keyring.clone())
+        Ok(vec![dist_data.archive_keyring.clone()])
     }
 }
 
@@ -347,14 +374,47 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_get_keyring_url_sid() {
-        // Test that 'sid' uses the latest released version for keyring URL
-        let sid_keyring = get_keyring_url("sid").await.unwrap();
-        let latest_released = get_latest_released_series("debian").await.unwrap();
-        let latest_keyring = get_keyring_url(&latest_released).await.unwrap();
+    async fn test_get_keyring_urls_sid() {
+        // Test that 'sid' returns keyrings from the 3 latest released versions
+        let sid_keyrings = get_keyring_urls("sid").await.unwrap();
 
-        // The keyring URL for 'sid' should be the same as the latest released version
-        assert_eq!(sid_keyring, latest_keyring);
+        // Should have keyring URLs for sid
+        assert!(!sid_keyrings.is_empty());
+        assert!(sid_keyrings.len() <= 3);
+
+        // Each URL should be a valid Debian keyring URL
+        for url in &sid_keyrings {
+            assert!(
+                url.contains("ftp-master.debian.org/keys"),
+                "URL '{}' does not contain expected pattern",
+                url
+            );
+        }
+    }
+
+    #[tokio::test]
+    async fn test_get_keyring_url_regular_series() {
+        // Test that regular series (like bookworm) returns a single keyring URL
+        let bookworm_keyring = &get_keyring_urls("bookworm").await.unwrap()[0];
+        assert!(
+            bookworm_keyring.contains("ftp-master.debian.org/keys"),
+            "URL '{}' does not contain expected pattern",
+            bookworm_keyring
+        );
+    }
+
+    #[tokio::test]
+    async fn test_get_n_latest_released_series() {
+        // Test getting 3 latest released series
+        let latest_3 = get_n_latest_released_series("debian", 3).await.unwrap();
+
+        // Should have at most 3 series
+        assert!(!latest_3.is_empty());
+        assert!(latest_3.len() <= 3);
+
+        // Should not contain 'sid' or 'experimental'
+        assert!(!latest_3.contains(&"sid".to_string()));
+        assert!(!latest_3.contains(&"experimental".to_string()));
     }
 
     #[tokio::test]