manager

Manager

Manager service provides a barebones gRPC API and Service interface implementation for the development of the manager service.

Configuration

The service is configured using the environment variables from the following table. Note that any unset variables will be replaced with their default values.

Setup

git clone https://github.com/ultravioletrs/cocos
cd cocos

NB: all relative paths in this document are relative to cocos repository directory.

QEMU-KVM

QEMU-KVM is a virtualization platform that allows you to run multiple operating systems on the same physical machine. It is a combination of two technologies: QEMU and KVM.

• QEMU is an emulator that can run a variety of operating systems, including Linux, Windows, and macOS.
• KVM is a Linux kernel module that allows QEMU to run virtual machines.

To install QEMU-KVM on a Debian based machine, run

sudo apt update
sudo apt install qemu-kvm

Create img directory in cmd/manager.

Virtual filesystem

9P (or Plan 9 Filesystem) in QEMU is a lightweight, network-based file-sharing protocol. In Cocos, the 9P is used to transfer environment variables and TLS certificates for cloud communication from the Manager to the Agent.

You should define the environment variables in a file called environment. For the number and meaning of the environment variables, please refer to the Agent Readme.

Prepare Cocos HAL

Cocos HAL for Linux is framework for building custom in-enclave Linux distribution. Use the instructions in Readme. Once the image is built copy the kernel and rootfs image to cmd/manager/img from buildroot/output/images/bzImage and buildroot/output/images/rootfs.cpio.gz respectively.

Another option is to use release versions of EOS that can be downloaded from the Cocos GitHub repository.

Test VM creation

cd cmd/manager

sudo find / -name OVMF_CODE.fd
# => /usr/share/OVMF/OVMF_CODE.fd
OVMF_CODE=/usr/share/OVMF/OVMF_CODE.fd

sudo find / -name OVMF_VARS.fd
# => /usr/share/OVMF/OVMF_VARS.fd

# Create a local copy of OVMF_VARS.
cp /usr/share/OVMF/OVMF_VARS.fd .

# Create a directory for the environment file and the certificates for cloud certificates.
mkdir env
mkdir certs

# Enter the env directory and create the environemnt file.
cd env
touch environment

# Define Computations endpoint URL for agent.
# Make sure the Computation endpoint is running (like Cocos Prism).
echo AGENT_CVM_GRPC_URL=localhost:7001 >> ./environment
# Define log level for the agent.
echo AGENT_LOG_LEVEL=debug >> ./environment

# Return to cmd/manager
cd ..

OVMF_VARS=./OVMF_VARS.fd
KERNEL="img/bzImage"
INITRD="img/rootfs.cpio.gz"
ENV_PATH=./env
CERTH_PATH=./certs

qemu-system-x86_64 \
    -enable-kvm \
    -cpu EPYC-v4 \
    -machine q35 \
    -smp 4 \
    -m 2048M,slots=5,maxmem=10240M \
    -no-reboot \
    -drive if=pflash,format=raw,unit=0,file=$OVMF_CODE,readonly=on \
    -drive if=pflash,format=raw,unit=1,file=$OVMF_VARS \
    -netdev user,id=vmnic,hostfwd=tcp::7020-:7002 \
    -device virtio-net-pci,disable-legacy=on,iommu_platform=true,netdev=vmnic,romfile= \
    -kernel $KERNEL \
    -append "earlyprintk=serial console=ttyS0" \
    -initrd $INITRD \
    -nographic \
    -monitor pty \
    -monitor unix:monitor,server,nowait \
    -fsdev local,id=env_fs,path=$ENV_PATH,security_model=mapped \
    -device virtio-9p-pci,fsdev=env_fs,mount_tag=env_share \
    -fsdev local,id=cert_fs,path=$CERTH_PATH,security_model=mapped \
    -device virtio-9p-pci,fsdev=cert_fs,mount_tag=certs_share

Once the VM is booted press enter and on the login use username root.

Build and run Agent

Agent is started automatically in the VM.

# List running processes and use 'grep' to filter for processes containing 'agent' in their names.
ps aux | grep cocos-agent
# This command helps verify that the 'agent' process is running.
# The output shows the process ID (PID), resource usage, and other information about the 'cocos-agent' process.
# For example: 118 root     cocos-agent

We can also check if Agent is reachable from the host machine:

# Use netcat (nc) to test the connection to localhost on port 7020.
nc -zv localhost 7020
# Output:
# nc: connect to localhost (::1) port 7020 (tcp) failed: Connection refused
# Connection to localhost (127.0.0.1) 7020 port [tcp/*] succeeded!

Conclusion

Now you are able to use Manager with Agent. Namely, Manager will create a VM with a separate OVMF variables file on manager /run request.

OVMF

We need Open Virtual Machine Firmware. OVMF is a port of Intel's tianocore firmware - an open source implementation of the Unified Extensible Firmware Interface (UEFI) - used by a qemu virtual machine. We need OVMF in order to run virtual machine with focal-server-cloudimg-amd64. When we install QEMU, we get two files that we need to start a VM: OVMF_VARS.fd and OVMF_CODE.fd. We will make a local copy of OVMF_VARS.fd since a VM will modify this file. On the other hand, OVMF_CODE.fd is only used as a reference, so we only record its path in an environment variable.

sudo find / -name OVMF_CODE.fd
# => /usr/share/OVMF/OVMF_CODE.fd
MANAGER_QEMU_OVMF_CODE_FILE=/usr/share/OVMF/OVMF_CODE.fd

sudo find / -name OVMF_VARS.fd
# => /usr/share/OVMF/OVMF_VARS.fd
MANAGER_QEMU_OVMF_VARS_FILE=/usr/share/OVMF/OVMF_VARS.fd

NB: we set environment variables that we will use in the shell process where we run manager.

Trusted Platform Module (TPM)

The Trusted Platform Module (TPM) plays a fundamental role in this process by providing a tamper-resistant foundation for cryptographic operations, securing sensitive artifacts, measuring system state, and enabling attestation mechanisms.

IGVM

An IGVM file contains all the necessary information to launch a virtual machine on different virtualization platforms. It includes setup commands for the guest system and verification data to ensure the VM is loaded securely and correctly.

Cocos uses the COCONUT-SVSM for the vTPM. The IGVM file contains the OVMF file and the vTPM.

Deployment

To start the service, execute the following shell script (note a server needs to be running see here):

The manager can be started as a systemd service or a standalone executable. To start the manager as a systemd service, look at the systemd service script here. The environment variables are defined in the cocos-manager.env file. Below are examples of how to start the manager.

# Download the latest version of the service
git clone git@github.com:ultravioletrs/cocos.git

cd cocos

# Compile the manager
make manager

# Set the environment variables and run the service
MANAGER_GRPC_URL=localhost:7001 \
MANAGER_LOG_LEVEL=debug \
MANAGER_QEMU_USE_SUDO=false \
MANAGER_QEMU_ENABLE_SEV=false \
./build/cocos-manager

To enable AMD SEV support, start manager like this

MANAGER_GRPC_URL=localhost:7001
MANAGER_LOG_LEVEL=debug \
MANAGER_QEMU_USE_SUDO=true \
MANAGER_QEMU_ENABLE_SEV=true \
MANAGER_QEMU_SEV_CBITPOS=51 \
./build/cocos-manager

To start SEV-SNP, define the IGVM file that contains the vTPM and the OVMF (combined OVMF_CODE and OVMF_VARS) of the CVM.

To enable AMD SEV-SNP support, start manager like this

MANAGER_GRPC_URL=localhost:7001 \
MANAGER_LOG_LEVEL=debug \
MANAGER_QEMU_ENABLE_SEV=false \
MANAGER_QEMU_ENABLE_SEV_SNP=true \
MANAGER_QEMU_SEV_CBITPOS=51 \
MANAGER_QEMU_BIN_PATH=<path to QEMU binary> \
MANAGER_QEMU_IGVM_FILE=<path to IGVM file> \
./build/cocos-manager

Troubleshooting

If the ps aux | grep qemu-system-x86_64 give you something like this

darko      13913  0.0  0.0      0     0 pts/2    Z+   20:17   0:00 [qemu-system-x86] <defunct>

means that the a QEMU virtual machine that is currently defunct, meaning that it is no longer running. More precisely, the defunct process in the output is also known as a "zombie" process.

You can troubleshoot the VM launch procedure by running directly qemu-system-x86_64 command. When you run manager with MANAGER_LOG_LEVEL=info env var set, it prints out the entire command used to launch a VM. The relevant part of the log might look like this

{"level":"info","message":"/usr/bin/qemu-system-x86_64 -enable-kvm -machine q35 -cpu EPYC -smp 4,maxcpus=64 -m 4096M,slots=5,maxmem=30G -drive if=pflash,format=raw,unit=0,file=/usr/share/OVMF/OVMF_CODE.fd,readonly=on -drive if=pflash,format=raw,unit=1,file=img/OVMF_VARS.fd -device virtio-scsi-pci,id=scsi,disable-legacy=on,iommu_platform=true -drive file=img/focal-server-cloudimg-amd64.img,if=none,id=disk0,format=qcow2 -device scsi-hd,drive=disk0 -netdev user,id=vmnic,hostfwd=tcp::2222-:22,hostfwd=tcp::9301-:9031,hostfwd=tcp::7020-:7002 -device virtio-net-pci,disable-legacy=on,iommu_platform=true,netdev=vmnic,romfile= -nographic -monitor pty","ts":"2023-08-14T18:29:19.2653908Z"}

You can run the command - the value of the "message" key - directly in the terminal:

/usr/bin/qemu-system-x86_64 -enable-kvm -machine q35 -cpu EPYC -smp 4,maxcpus=64 -m 4096M,slots=5,maxmem=30G -drive if=pflash,format=raw,unit=0,file=/usr/share/OVMF/OVMF_CODE.fd,readonly=on -drive if=pflash,format=raw,unit=1,file=img/OVMF_VARS.fd -device virtio-scsi-pci,id=scsi,disable-legacy=on,iommu_platform=true -drive file=img/focal-server-cloudimg-amd64.img,if=none,id=disk0,format=qcow2 -device scsi-hd,drive=disk0 -netdev user,id=vmnic,hostfwd=tcp::2222-:22,hostfwd=tcp::9301-:9031,hostfwd=tcp::7020-:7002 -device virtio-net-pci,disable-legacy=on,iommu_platform=true,netdev=vmnic,romfile= -nographic -monitor pty

and look for the possible problems. This problems can usually be solved by using the adequate env var assignments. Look in the manager/qemu/config.go file to see the recognized env vars. Don't forget to prepend MANAGER_QEMU_ to the name of the env vars.

Kill qemu-system-x86_64 processes

To kill any leftover qemu-system-x86_64 processes, use

pkill -f qemu-system-x86_64

The pkill command is used to kill processes by name or by pattern. The -f flag to specify that we want to kill processes that match the pattern qemu-system-x86_64. It sends the SIGKILL signal to all processes that are running qemu-system-x86_64.

If this does not work, i.e. if ps aux | grep qemu-system-x86_64 still outputs qemu-system-x86_64 related process(es), you can kill the unwanted process with kill -9 <PID>, which also sends a SIGKILL signal to the process.

Usage

For more information about service capabilities and its usage, please check out the README documentation.