concurrent git syncs sharing an SSH credential no longer fail on a missing temp key

src/lib/server/git-ssh-key.ts

@@ -0,0 +1,46 @@
+/**
+ * Per-operation temporary SSH key path handling for Git operations (#1413).
+ *
+ * Concurrent syncs of the SAME credential must NOT share one key file: a
+ * per-credential path (`/tmp/.ssh-key-<id>`) lets one operation's cleanup delete
+ * the key while another operation is still cloning with it, which fails as
+ * "Identity file /tmp/.ssh-key-<id> not accessible". Each operation gets a unique
+ * path (credential id + pid + uuid); the exact path is remembered so cleanup
+ * removes only the file this operation created.
+ *
+ * Pure + dependency-free so it can be unit-tested without importing the whole
+ * git.ts module (which pulls db/stacks/notifications).
+ */
+import { existsSync, rmSync } from 'node:fs';
+import { randomUUID } from 'node:crypto';
+
+// Env key under which git.ts stashes the operation's key path (so cleanup can
+// find the exact file even though the caller only has the credential + env).
+export const GIT_SSH_KEY_PATH_ENV = 'DOCKHAND_GIT_SSH_KEY_PATH';
+
+/** A unique /tmp path for this operation's SSH key. */
+export function makeSshKeyPath(credentialId: number): string {
+	return `/tmp/.ssh-key-${credentialId}-${process.pid}-${randomUUID()}`;
+}
+
+/**
+ * Resolve which key file to delete for cleanup: the exact per-operation path
+ * stashed in env, falling back to the legacy deterministic path only when no env
+ * is available (legacy callers).
+ */
+export function resolveSshKeyPathForCleanup(
+	credentialId: number,
+	env?: Record<string, string>
+): string {
+	return env?.[GIT_SSH_KEY_PATH_ENV] || `/tmp/.ssh-key-${credentialId}`;
+}
+
+/** Remove the SSH key file for an operation, ignoring errors. */
+export function removeSshKey(credentialId: number, env?: Record<string, string>): void {
+	const path = resolveSshKeyPathForCleanup(credentialId, env);
+	try {
+		if (existsSync(path)) rmSync(path);
+	} catch {
+		// Ignore cleanup errors - a leftover /tmp key is harmless.
+	}
+}