Revert "Propagate host DNS to workspaces"

This reverts commit 4778145.

Author: gorbak25

app/agent/agent-util.service.ts

@@ -92,24 +92,22 @@ export class AgentUtilService {
     }
   }
 
-  async writeFile(
-    ssh: NodeSSH,
-    path: string,
-    content: string,
-    useSudo: boolean = false,
-  ): Promise<void> {
-    const cmdPrefix = useSudo ? ["sudo"] : [];
+  async writeFile(ssh: NodeSSH, path: string, content: string): Promise<void> {
     // I don't use SFTP because I've found it to be unreliable, causing
     // untraceable errors.
     try {
       await execSshCmd(
         {
           ssh,
           opts: {
-            stdin: content,
+            execOptions: {
+              env: {
+                FILE_CONTENT: content,
+              } as any,
+            },
           },
         },
-        [...cmdPrefix, "bash", "-c", `cat - > ${path}`],
+        ["bash", "-c", `echo -n "$FILE_CONTENT" > ${path}`],
       );
     } catch (err) {
       throw new Error(`Failed to write file "${path}": ${(err as any)?.message}`);

app/agent/firecracker.service.ts

@@ -498,12 +498,6 @@ export class FirecrackerService {
             useSudo,
           );
         }
-        await this.agentUtilService.writeFile(
-          ssh,
-          "/etc/resolv.conf",
-          (await fsAsync.readFile(this.agentConfig.dnsConfigPath)).toString(),
-          useSudo,
-        );
         const r = await fn({
           ssh,
           sshConfig,

app/config/index.ts

@@ -39,8 +39,6 @@ export const config = makeConfig()({
       "/srv/jailer/resources/checkout-and-inspect.ext4",
     defaultWorkspaceRootFs:
       process.env.DEFAULT_WORKSPACE_ROOTFS_PATH ?? "/srv/jailer/resources/default-workspace.ext4",
-    // DNS config which will be propagated to vm's
-    dnsConfigPath: process.env.AGENT_DNS_CONFIG_PATH ?? "/host/resolv.conf",
     prebuildSshPublicKey:
       process.env.AGENT_PREBUILD_SSH_PUBLIC_KEY ?? DEFAULT_PREBUILD_SSH_KEY_PUBLIC,
     prebuildSshPrivateKey:

hocus-workspace/resources/docker/dnssetup

@@ -5,6 +5,7 @@
 # Required-Stop:
 # Default-Start:     2 3 4 5
 # Default-Stop:
-# Short-Description: Setups /etc/hosts
+# Short-Description: Setups /etc/resolv.conf
 ### END INIT INFO
+echo "nameserver 8.8.8.8" > /etc/resolv.conf
 echo "127.0.0.1       localhost" >> /etc/hosts

ops/docker/agent-dev.docker-compose.yml

@@ -30,5 +30,4 @@ services:
       - "${REPO_DIR}:/app"
       - "${HOCUS_RESOURCES_DIR}:/srv/jailer"
       - /dev/kvm:/dev/kvm
-      - /etc/resolv.conf:/host/resolv.conf:ro
     command: sleep infinity

ops/docker/agent-in-hocus.docker-compose.yml

@@ -16,7 +16,6 @@ services:
       - "${AGENT_REPO_DIR}:/app"
       - "${HOCUS_RESOURCES_DIR}:/srv/jailer"
       - /dev/kvm:/dev/kvm
-      - /etc/resolv.conf:/host/resolv.conf:ro
     environment:
       - "HOCUS_DEV_GIT_NAME=${HOCUS_DEV_GIT_NAME}"
       - "HOCUS_DEV_GIT_EMAIL=${HOCUS_DEV_GIT_EMAIL}"

ops/docker/hocus-local.yml

@@ -228,4 +228,3 @@ services:
     volumes:
       - agent_data:/srv/jailer:rw
       - /dev/kvm:/dev/kvm
-      - /etc/resolv.conf:/host/resolv.conf:ro

resources/docker/dnssetup

@@ -5,6 +5,7 @@
 # Required-Stop:
 # Default-Start:     2 3 4 5
 # Default-Stop:
-# Short-Description: Setups /etc/hosts
+# Short-Description: Setups /etc/resolv.conf
 ### END INIT INFO
+echo "nameserver 8.8.8.8" > /etc/resolv.conf
 echo "127.0.0.1       localhost" >> /etc/hosts