Mantle: Gluing Container Linux together

This repository is a collection of utilities for developing Container Linux. Most of the tools are for uploading, running, and interacting with Container Linux instances running locally or in a cloud.

Overview

Mantle is composed of many utilities:

• cork for handling the Container Linux SDK
• gangue for downloading from Google Storage
• kola for launching instances and running tests
• kolet an agent for kola that runs on instances
• ore for interfacing with cloud providers
• plume for releasing Container Linux

All of the utilities support the help command to get a full listing of their subcommands and options.

Tools

cork

Cork is a now-deprecated tool that was used to help in working with Container Linux images and the SDK.

Please see developer guides to see how to work with Flatcar SDK.

gangue

Gangue is a tool for downloading and verifying files from Google Storage with authenticated requests. It is primarily used by the SDK.

gangue get

Get a file from Google Storage and verify it using GPG.

kola

Kola is a framework for testing software integration in Container Linux instances across multiple platforms. It is primarily designed to operate within the Container Linux SDK for testing software that has landed in the OS image. Ideally, all software needed for a test should be included by building it into the image from the SDK.

Kola supports running tests on multiple platforms, currently QEMU, GCE, AWS, VMware VSphere, Packet, and OpenStack. In the future systemd-nspawn and other platforms may be added. Machines on cloud platforms do not have direct access to the kola so tests may depend on Internet services such as discovery.etcd.io or quay.io instead.

Kola outputs assorted logs and test data to _kola_temp for later inspection.

Kola is still under heavy development and it is expected that its interface will continue to change.

By default, kola uses the qemu platform with the image /mnt/host/source/src/build/images/BOARD/latest/flatcar_production_image.bin.

kola run

Getting started with QEMU

The easiest way to get started with kola is to run a qemu test.

requirements:

• IPv4 forwarding (to provide internet access to the instance): sudo sysctl -w net.ipv4.ip_forward=1
• Stop firewalld.service or similar frameworks: sudo systemctl stop firewalld.service (for permanent disablement use sudo systemctl disable --now firewalld.service)
• swtmp, dnsmasq, go and iptables installed and present in the $PATH
• qemu-system-x86_64 and / or qemu-system-aarch64 to respectively tests amd64 and / or arm64

From the pulled sources, kola and kolet must be compiled:

git clone https://github.com/flatcar/mantle/
cd mantle
./build kola kolet

Alternatively, there is a container image with the required dependencies and the mantle binaries for the latest commit on flatcar-master:

sudo docker run --privileged --net host -v /dev:/dev --rm -it ghcr.io/flatcar/mantle:git-$(git rev-parse HEAD)
# inside the container you can run "kola …" because it is in the PATH, and "sudo kola" is also not needed

Finally, a Flatcar image must be available on the system:

• from a locally built image
• from an official release

Run tests for AMD64

Example with the latest alpha release:

wget https://alpha.release.flatcar-linux.net/amd64-usr/current/flatcar_production_qemu_image.img
wget https://alpha.release.flatcar-linux.net/amd64-usr/current/flatcar_production_qemu_image.img.sig
gpg --verify flatcar_production_qemu_image.img.sig

wget https://alpha.release.flatcar-linux.net/amd64-usr/current/flatcar_production_qemu_uefi_efi_code.qcow2
wget https://alpha.release.flatcar-linux.net/amd64-usr/current/flatcar_production_qemu_uefi_efi_code.qcow2.sig
gpg --verify flatcar_production_qemu_uefi_efi_code.qcow2.sig

wget https://alpha.release.flatcar-linux.net/amd64-usr/current/flatcar_production_qemu_uefi_efi_vars.qcow2
wget https://alpha.release.flatcar-linux.net/amd64-usr/current/flatcar_production_qemu_uefi_efi_vars.qcow2.sig
gpg --verify flatcar_production_qemu_uefi_efi_vars.qcow2.sig

sudo ./bin/kola run --board amd64-usr --key ${HOME}/.ssh/id_rsa.pub -k -b cl -p qemu \
    --qemu-firmware flatcar_production_qemu_uefi_efi_code.qcow2 \
    --qemu-ovmf-vars flatcar_production_qemu_uefi_efi_vars.qcow2 \
    --qemu-image flatcar_production_qemu_image.img \
    cl.locksmith.cluster

Run tests for ARM64

Example with the latest alpha release:

wget https://alpha.release.flatcar-linux.net/arm64-usr/current/flatcar_production_qemu_uefi_image.img
wget https://alpha.release.flatcar-linux.net/arm64-usr/current/flatcar_production_qemu_uefi_image.img.sig
gpg --verify flatcar_production_qemu_uefi_image.img.sig

wget https://alpha.release.flatcar-linux.net/arm64-usr/current/flatcar_production_qemu_uefi_efi_code.qcow2
wget https://alpha.release.flatcar-linux.net/arm64-usr/current/flatcar_production_qemu_uefi_efi_code.qcow2.sig
gpg --verify flatcar_production_qemu_uefi_efi_code.qcow2.sig

sudo ./bin/kola run --board arm64-usr --key ${HOME}/.ssh/id_rsa.pub -k -b cl -p qemu \
    --qemu-firmware flatcar_production_qemu_uefi_efi_code.qcow2 \
    --qemu-image flatcar_production_qemu_uefi_image.img \
    cl.etcd-member.discovery

Note for both architectures:

• sudo is required because we need to create some iptables rules to provide QEMU Internet access
• using --remove=false -d, it's possible to keep the instances running (even after the test) and identify the PID of QEMU instances to SSH into (running processes must be killed once the action done)
• using --key, it's possible to SSH into the created instances - PID identification of the qemu instance is required:

ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o ProxyCommand="sudo nsenter -n -t <PID of the QEMU instance> nc %h %p" -p 22 core@<IP of the QEMU instance>

• using --qemu-vnc 0, it's possible to setup a VNC server. Similar to SSH you need to identify the PID of the qemu instance to setup a proxy:

mkfifo reply
nc -kl 12800 < reply | sudo nsenter -t "${QEMUPID}" -n nc localhost 5900 > reply
rm reply

Now, you can access the VNC session on localhost:12800 using a VNC client.

Advanced usage with Equinix Metal

The advantage of Kola is to be able to run tests for every supported provider without duplicating testing code. Running tests on Equinix Metal is a bit different from other providers as it boots from PXE.

The test is split into two phases:

• the initial PXE booting with the Flatcar installation
• the actual Flatcar booting with the userdata defined in the test

For this two phases, Kola needs to temporary store two files:

• an Ignition config
• an iPXE configuration

It's possible to use Google Cloud Storage or a regular webserver to host these two files. For the webserver, it needs two requirements:

• a webserver accessible from the Equinix Metal instance
• a remote access to this webserver

For example, the following command:

BASENAME="test-em"
BOARD="amd64-usr"
EQUINIXMETAL_KEY="1234"
CHANNEL="alpha"
RELEASE="3255.0.0"1
EQUINIXMETAL_PROJECT="5678"
./bin/kola run --basename=${BASENAME} --board=${BOARD} \
  --equinixmetal-api-key=${PACKET_KEY} \
  --equinixmetal-image-url=https://bucket.release.flatcar-linux.net/flatcar-jenkins/${CHANNEL}/boards/${BOARD}/${RELEASE}/flatcar_production_packet_image.bin.bz2 \
  --equinixmetal-installer-image-base-url=https://bucket.release.flatcar-linux.net/flatcar-jenkins/${CHANNEL}/boards/${BOARD}/${RELEASE} \
  --equinixmetal-project=${EQUINIXMETAL_PROJECT} \
  --equinixmetal-storage-url="ssh+https://my-server" \
  --equinixmetal-remote-document-root="/var/www" \
  --equinixmetal-remote-user="core" \
  --equinixmetal-remote-ssh-private-key-path="./id_rsa" \
  --platform=equinixmetal \
  ${TEST_NAME}

will upload the temporary files into "/var/www" using "ssh -i ./id_rsa core@my-server" and the iPXE, Ignition URL will be served at: "https://my-server/mantle-12345.{ipxe,ign}"

kola list

The list command lists all of the available tests.

kola spawn

The spawn command launches Container Linux instances.

kola mkimage

The mkimage command creates a copy of the input image with its primary console set to the serial port (/dev/ttyS0). This causes more output to be logged on the console, which is also logged in _kola_temp. This can only be used with QEMU images and must be used with the coreos_*_image.bin image, not the coreos_*_qemu_image.img.

kola bootchart

The bootchart command launches an instance then generates an svg of the boot process using systemd-analyze.

kola updatepayload

The updatepayload command launches a Container Linux instance then updates it by sending an update to its update_engine. The update is the coreos_*_update.gz in the latest build directory.

kola subtest parallelization

Subtests can be parallelized by adding c.H.Parallel() at the top of the inline function given to c.Run. It is not recommended to utilize the FailFast flag in tests that utilize this functionality as it can have unintended results.

kola test namespacing

The top-level namespace of tests should fit into one of the following categories:

1. Groups of tests targeting specific packages/binaries may use that namespace (ex: docker.*)
2. Tests that target multiple supported distributions may use the coreos namespace.
3. Tests that target singular distributions may use the distribution's namespace.

kola test registration

Registering kola tests currently requires that the tests are registered under the kola package and that the test function itself lives within the mantle codebase.

Groups of similar tests are registered in an init() function inside the kola package. Register(*Test) is called per test. A kola Test struct requires a unique name, and a single function that is the entry point into the test. Additionally, userdata (such as a Container Linux Config) can be supplied. See the Test struct in kola/register/register.go for a complete list of options.

kola test writing

A kola test is a go function that is passed a platform.TestCluster to run code against. Its signature is func(platform.TestCluster) and must be registered and built into the kola binary.

A TestCluster implements the platform.Cluster interface and will give you access to a running cluster of Container Linux machines. A test writer can interact with these machines through this interface.

To see test examples look under kola/tests in the mantle codebase.

For a quickstart see kola/README.md.

kola native code

For some tests, the Cluster interface is limited and it is desirable to run native go code directly on one of the Container Linux machines. This is currently possible by using the NativeFuncs field of a kola Test struct. This like a limited RPC interface.

NativeFuncs is used similar to the Run field of a registered kola test. It registers and names functions in nearby packages. These functions, unlike the Run entry point, must be manually invoked inside a kola test using a TestCluster's RunNative method. The function itself is then run natively on the specified running Container Linux instances.

For more examples, look at the coretest suite of tests under kola. These tests were ported into kola and make heavy use of the native code interface.

Manhole

The platform.Manhole() function creates an interactive SSH session which can be used to inspect a machine during a test.

kolet

kolet is run on kola instances to run native functions in tests. Generally kolet is not invoked manually.

ore

Ore provides a low-level interface for each cloud provider. It has commands related to launching instances on a variety of platforms (gcloud, aws, azure, esx, and packet) within the latest SDK image. Ore mimics the underlying api for each cloud provider closely, so the interface for each cloud provider is different. See each providers help command for the available actions.

Note, when uploading to some cloud providers (e.g. gce) the image may need to be packaged with a different --format (e.g. --format=gce) when running image_to_vm.sh

plume

Plume is the Container Linux release utility. Releases are done in two stages, each with their own command: pre-release and release. Both of these commands are idempotent.

plume pre-release

The pre-release command does as much of the release process as possible without making anything public. This includes uploading images to cloud providers (except those like gce which don't allow us to upload images without making them public).

plume release

Publish a new Container Linux release. This makes the images uploaded by pre-release public and uploads images that pre-release could not. It copies the release artifacts to public storage buckets and updates the directory index.

plume index

Generate and upload index.html objects to turn a Google Cloud Storage bucket into a publicly browsable file tree. Useful if you want something like Apache's directory index for your software download repository. Plume release handles this as well, so it does not need to be run as part of the release process.

Platform Credentials

Each platform reads the credentials it uses from different files. The aws, azure, do, esx and packet platforms support selecting from multiple configured credentials, call "profiles". The examples below are for the "default" profile, but other profiles can be specified in the credentials files and selected via the --<platform-name>-profile flag:

kola spawn -p aws --aws-profile other_profile

aws

aws reads the ~/.aws/credentials file used by Amazon's aws command-line tool. It can be created using the aws command:

$ aws configure

To configure a different profile, use the --profile flag

$ aws configure --profile other_profile

The ~/.aws/credentials file can also be populated manually:

[default]
aws_access_key_id = ACCESS_KEY_ID_HERE
aws_secret_access_key = SECRET_ACCESS_KEY_HERE

To install the aws command in the SDK, run:

sudo emerge --ask awscli

azure

azure uses ~/.azure/azureProfile.json. This can be created using the az command:

$ az login`

It also requires that the environment variable AZURE_AUTH_LOCATION points to a JSON file (this can also be set via the --azure-auth parameter). The JSON file will require a service provider active directory account to be created.

Service provider accounts can be created via the az command (the output will contain an appId field which is used as the clientId variable in the AZURE_AUTH_LOCATION JSON):

az ad sp create-for-rbac

The client secret can be created inside of the Azure portal when looking at the service provider account under the Azure Active Directory service on the App registrations tab.

You can find your subscriptionId & tenantId in the ~/.azure/azureProfile.json via:

cat ~/.azure/azureProfile.json | jq '{subscriptionId: .subscriptions[].id, tenantId: .subscriptions[].tenantId}'

The JSON file exported to the variable AZURE_AUTH_LOCATION should be generated by hand and have the following contents:

{
  "clientId": "<service provider id>", 
  "clientSecret": "<service provider secret>", 
  "subscriptionId": "<subscription id>", 
  "tenantId": "<tenant id>", 
  "activeDirectoryEndpointUrl": "https://login.microsoftonline.com", 
  "resourceManagerEndpointUrl": "https://management.azure.com/", 
  "activeDirectoryGraphResourceId": "https://graph.windows.net/", 
  "sqlManagementEndpointUrl": "https://management.core.windows.net:8443/", 
  "galleryEndpointUrl": "https://gallery.azure.com/", 
  "managementEndpointUrl": "https://management.core.windows.net/"
}

do

do uses ~/.config/digitalocean.json. This can be configured manually:

{
    "default": {
        "token": "token goes here"
    }
}

esx

esx uses ~/.config/esx.json. This can be configured manually:

{
    "default": {
        "server": "server.address.goes.here",
        "user": "user.goes.here",
        "password": "password.goes.here"
    }
}

gce

gce uses the ~/.boto file. When the gce platform is first used, it will print a link that can be used to log into your account with gce and get a verification code you can paste in. This will populate the .boto file.

See Google Cloud Platform's Documentation for more information about the .boto file.

openstack

openstack uses ~/.config/openstack.json. This can be configured manually:

{
    "default": {
        "auth_url": "auth url here",
        "tenant_id": "tenant id here",
        "tenant_name": "tenant name here",
        "username": "username here",
        "password": "password here",
        "user_domain": "domain id here",
        "floating_ip_pool": "floating ip pool here",
        "region_name": "region here"
    }
}

user_domain is required on some newer versions of OpenStack using Keystone V3 but is optional on older versions. floating_ip_pool and region_name can be optionally specified here to be used as a default if not specified on the command line.

packet

packet uses ~/.config/packet.json. This can be configured manually:

{
	"default": {
		"api_key": "your api key here",
		"project": "project id here"
	}
}

qemu

qemu is run locally and needs no credentials, but does need to be run as root.

qemu-unpriv

qemu-unpriv is run locally and needs no credentials. It has a restricted set of functionality compared to the qemu platform, such as:

• Single node only, no machine to machine networking
• DHCP provides no data (forces several tests to be disabled)
• No Local cluster