fix(e2e): repair the credential driver test (#3565)

The credential driver e2e has not passed end to end, and the disabled
kubernetes-credential-drivers CI lane hid three problems.

The test broke when the JSON format of provider list changed.
Continuation-token pagination (#3249) changed
provider list --output json from a bare array of providers to an object
with next_page_token and a providers array. The test still parsed the
output as an array, so it failed before checking either storage
backend. Read the providers array from the new object instead.

Its sandbox name was about 58 characters, but sandbox names are
DNS-routable and limited to 19, so sandbox creation was rejected. Build
a short unique name instead.

The sandbox guard deletes its sandbox from a detached thread on drop, so
the test deleted the provider while the sandbox still existed. The
gateway rejects deleting a provider that is attached to a sandbox, the
test ignored that error, and the credential Secret remained. Delete the
sandbox explicitly before returning from the sandbox check.

Signed-off-by: Kris Hicks <khicks@nvidia.com>

Author: krishicks

e2e/rust/tests/credential_drivers.rs

@@ -182,9 +182,11 @@ async fn provider_identity(provider_name: &str) -> Result<ProviderIdentity, Stri
     if code != 0 {
         return Err(format!("provider list failed (exit {code}):\n{clean}"));
     }
-    let providers: Vec<serde_json::Value> = serde_json::from_str(&clean)
+    let listing: serde_json::Value = serde_json::from_str(&clean)
         .map_err(|err| format!("failed to parse provider list JSON: {err}\n{clean}"))?;
-    let provider = providers
+    let provider = listing["providers"]
+        .as_array()
+        .ok_or_else(|| format!("provider list JSON has no providers array:\n{clean}"))?
         .iter()
         .find(|provider| provider["name"].as_str() == Some(provider_name))
         .ok_or_else(|| format!("provider '{provider_name}' was not returned by provider list"))?;
@@ -225,7 +227,7 @@ async fn assert_provider_placeholder_available_in_sandbox(
     sandbox_name: &str,
     secret_value: &str,
 ) -> Result<(), String> {
-    let guard = SandboxGuard::create(&[
+    let mut guard = SandboxGuard::create(&[
         "--name",
         sandbox_name,
         "--provider",
@@ -239,6 +241,9 @@ async fn assert_provider_placeholder_available_in_sandbox(
     ])
     .await?;
     let clean = strip_ansi(&guard.create_output);
+    // Delete the sandbox before returning: the gateway refuses to delete a
+    // provider that is still attached to a sandbox.
+    guard.cleanup().await;
     if !contains_placeholder_for_env_key(&clean, CREDENTIAL_KEY) {
         return Err(format!(
             "sandbox {sandbox_name} did not receive provider credential placeholder:\n{clean}"
@@ -374,7 +379,12 @@ async fn provider_credentials_are_stored_in_configured_backend() {
     let suffix = unique_suffix();
     let driver_slug = driver.replace('-', "");
     let provider_name = format!("cred-storage-{driver_slug}-{suffix}");
-    let sandbox_name = format!("cred-storage-sandbox-{driver_slug}-{suffix}");
+    // Sandbox names are DNS-routable and limited to 19 characters.
+    let sandbox_name = format!(
+        "cred-{}-{}",
+        &driver_slug[..1],
+        &suffix[suffix.len() - 10..]
+    );
     let secret_value = format!("example-e2e-{driver_slug}-{suffix}");
 
     delete_provider(&provider_name).await;