Centralize encrypted bot profiles

isolation.ts

@@ -0,0 +1,60 @@
+import type { RuntimeProfile } from "./runtime.ts";
+
+export function agentCommand(
+  profile: RuntimeProfile,
+  command: string,
+  args: string[],
+  options: Omit<Deno.CommandOptions, "args" | "uid" | "gid"> = {},
+): Deno.Command {
+  return new Deno.Command(command, {
+    ...options,
+    args,
+    uid: profile.uid,
+    gid: profile.gid,
+  });
+}
+
+async function profileProcessIds(uid: number): Promise<number[]> {
+  const ids: number[] = [];
+  for await (const entry of Deno.readDir("/proc")) {
+    if (!entry.isDirectory || !/^\d+$/.test(entry.name)) continue;
+    const status = await Deno.readTextFile(`/proc/${entry.name}/status`).catch(
+      () => null,
+    );
+    const owner = status?.match(/^Uid:\s+(\d+)/m)?.[1];
+    if (owner !== undefined && Number(owner) === uid) {
+      ids.push(Number(entry.name));
+    }
+  }
+  return ids;
+}
+
+export async function killProfileProcesses(uid: number): Promise<void> {
+  for (let attempt = 0; attempt < 100; attempt++) {
+    const ids = await profileProcessIds(uid);
+    if (ids.length === 0) return;
+    for (const pid of ids) {
+      try {
+        Deno.kill(pid, "SIGKILL");
+      } catch (error) {
+        if (!(error instanceof Deno.errors.NotFound)) throw error;
+      }
+    }
+    await new Promise((resolve) => setTimeout(resolve, 10));
+  }
+  throw new Error(`profile UID ${uid} still owns processes after cleanup`);
+}
+
+export async function readProfileFile(
+  profile: RuntimeProfile,
+  path: string,
+): Promise<string> {
+  const stat = await Deno.lstat(path);
+  if (
+    !stat.isFile || stat.isSymlink || stat.uid !== profile.uid ||
+    (stat.mode! & 0o077) !== 0
+  ) {
+    throw new Error(`${path}: expected a profile-owned regular private file`);
+  }
+  return await Deno.readTextFile(path);
+}