Developer Quick-Start¶
This is a quick walkthrough to get you started developing code for magnum. This assumes you are already familiar with submitting code reviews to an OpenStack project.
Setup Dev Environment¶
Install OS-specific prerequisites:
# Ubuntu Xenial:
sudo apt update
sudo apt install python-dev libssl-dev libxml2-dev curl \
libmysqlclient-dev libxslt-dev libpq-dev git \
libffi-dev gettext build-essential python3-dev
# CentOS 7:
sudo yum install -y python-devel openssl-devel mariadb-devel curl \
libxml2-devel libxslt-devel postgresql-devel git \
libffi-devel gettext gcc
# Fedora/RHEL:
sudo yum install python-devel openssl-devel mysql-devel curl \
libxml2-devel libxslt-devel postgresql-devel git \
libffi-devel gettext gcc
# openSUSE/SLE 12:
sudo zypper install git libffi-devel curl \
libmysqlclient-devel libopenssl-devel libxml2-devel \
libxslt-devel postgresql-devel python-devel \
gettext-runtime
Install pip:
curl -s https://bootstrap.pypa.io/get-pip.py | sudo python
Install common prerequisites:
sudo pip install virtualenv flake8 tox testrepository git-review
You may need to explicitly upgrade virtualenv if you’ve installed the one from your OS distribution and it is too old (tox will complain). You can upgrade it individually, if you need to:
sudo pip install -U virtualenv
Magnum source code should be pulled directly from git:
# from your home or source directory
cd ~
git clone https://opendev.org/openstack/magnum
cd magnum
All unit tests should be run using tox. To run magnum’s entire test suite:
# run all tests (unit and pep8)
tox
To run a specific test, use a positional argument for the unit tests:
# run a specific test for Python 3.7
tox -epy37 -- test_conductor
You may pass options to the test programs using positional arguments:
# run all the Python 3.7 unit tests (in parallel!)
tox -epy37 -- --parallel
To run only the pep8/flake8 syntax and style checks:
tox -epep8
To run unit test coverage and check percentage of code covered:
tox -e cover
Exercising the Services Using DevStack¶
DevStack can be configured to enable magnum support. It is easy to develop magnum with the DevStack environment. Magnum depends on nova, glance, heat and neutron to create and schedule virtual machines to simulate bare-metal (full bare-metal support is under active development).
Minimum System Requirements¶
Magnum running in DevStack requires at least: 10 GB RAM, 8 CPU and 100 GB disk storage.
NOTE: Running DevStack within a virtual machine with magnum enabled is not recommended at this time.
This session has only been tested on Ubuntu 16.04 (Xenial) and Fedora 20/21. We recommend users to select one of them if it is possible.
Set-up Environment and Create a Magnum Session¶
Clone devstack:
# Create a root directory for devstack if needed
sudo mkdir -p /opt/stack
sudo chown $USER /opt/stack
git clone https://opendev.org/openstack/devstack /opt/stack/devstack
We will run devstack with minimal local.conf settings required to enable magnum, heat, and neutron (neutron is enabled by default in devstack since Kilo, and heat must be enabled by yourself):
$ cat > /opt/stack/devstack/local.conf << END
[[local|localrc]]
DATABASE_PASSWORD=password
RABBIT_PASSWORD=password
SERVICE_TOKEN=password
SERVICE_PASSWORD=password
ADMIN_PASSWORD=password
# magnum requires the following to be set correctly
PUBLIC_INTERFACE=eth1
# Enable barbican service and use it to store TLS certificates
# For details https://docs.openstack.org/magnum/latest/user/index.html#transport-layer-security
enable_plugin barbican https://opendev.org/openstack/barbican
enable_plugin heat https://opendev.org/openstack/heat
# Enable magnum plugin after dependent plugins
enable_plugin magnum https://opendev.org/openstack/magnum
# Optional: uncomment to enable the Magnum UI plugin in Horizon
#enable_plugin magnum-ui https://opendev.org/openstack/magnum-ui
VOLUME_BACKING_FILE_SIZE=20G
END
NOTE: Update PUBLIC_INTERFACE as appropriate for your system.
NOTE: Enable heat plugin is necessary.
Optionally, you can enable neutron/lbaas v2 with octavia to create load balancers for multi master clusters:
$ cat >> /opt/stack/devstack/local.conf << END
enable_plugin neutron-lbaas https://opendev.org/openstack/neutron-lbaas
enable_plugin octavia https://opendev.org/openstack/octavia
# Disable LBaaS(v1) service
disable_service q-lbaas
# Enable LBaaS(v2) services
enable_service q-lbaasv2
enable_service octavia
enable_service o-cw
enable_service o-hk
enable_service o-hm
enable_service o-api
END
Optionally, you can enable ceilometer in devstack. If ceilometer is enabled, magnum will periodically send metrics to ceilometer:
$ cat >> /opt/stack/devstack/local.conf << END
enable_plugin ceilometer https://opendev.org/openstack/ceilometer
END
If you want to deploy Docker Registry 2.0 in your cluster, you should enable swift in devstack:
$ cat >> /opt/stack/devstack/local.conf << END
enable_service s-proxy
enable_service s-object
enable_service s-container
enable_service s-account
END
More devstack configuration information can be found at https://docs.openstack.org/devstack/latest/configuration.html
More neutron configuration information can be found at https://docs.openstack.org/devstack/latest/guides/neutron.html
Run devstack:
cd /opt/stack/devstack
./stack.sh
NOTE: This will take a little extra time when the Fedora Atomic micro-OS image is downloaded for the first time.
At this point, two magnum process (magnum-api and magnum-conductor) will be running on devstack screens. If you make some code changes and want to test their effects, just stop and restart magnum-api and/or magnum-conductor.
Prepare your session to be able to use the various openstack clients including magnum, neutron, and glance. Create a new shell, and source the devstack openrc script:
. /opt/stack/devstack/openrc admin admin
Magnum has been tested with the Fedora Atomic micro-OS and CoreOS. Magnum will likely work with other micro-OS platforms, but each requires individual support in the heat template.
The Fedora Atomic micro-OS image will automatically be added to glance. You can add additional images manually through glance. To verify the image created when installing devstack use:
$ openstack image list
+--------------------------------------+------------------------------------+--------+
| ID | Name | Status |
+--------------------------------------+------------------------------------+--------+
| 0bc132b1-ee91-4bd8-b0fd-19deb57fb39f | Fedora-Atomic-27-20180419.0.x86_64 | active |
| 7537bbf2-f1c3-47da-97bb-38c09007e146 | cirros-0.3.5-x86_64-disk | active |
+--------------------------------------+------------------------------------+--------+
To list the available commands and resources for magnum, use:
openstack help coe
To list out the health of the internal services, namely conductor, of magnum, use:
$ openstack coe service list
+----+---------------------------------------+------------------+-------+----------+-----------------+---------------------------+---------------------------+
| id | host | binary | state | disabled | disabled_reason | created_at | updated_at |
+----+---------------------------------------+------------------+-------+----------+-----------------+---------------------------+---------------------------+
| 1 | oxy-dev.hq1-0a5a3c02.hq1.abcde.com | magnum-conductor | up | | - | 2016-08-31T10:03:36+00:00 | 2016-08-31T10:11:41+00:00 |
+----+---------------------------------------+------------------+-------+----------+-----------------+---------------------------+---------------------------+
Create a keypair for use with the ClusterTemplate:
test -f ~/.ssh/id_rsa.pub || ssh-keygen -t rsa -N "" -f ~/.ssh/id_rsa
openstack keypair create --public-key ~/.ssh/id_rsa.pub testkey
Check a dns server can resolve a host name properly:
dig <server name> @<dns server> +short
For example:
$ dig www.openstack.org @8.8.8.8 +short
www.openstack.org.cdn.cloudflare.net.
104.20.64.68
104.20.65.68
Building a Kubernetes Cluster - Based on Fedora CoreOS¶
Create a cluster template. This is similar in nature to a flavor and describes to magnum how to construct the cluster. The ClusterTemplate specifies a Fedora CoreOS image so the clusters which use this ClusterTemplate will be based on Fedora CoreOS
openstack coe cluster template create k8s-cluster-template \
--image fedora-coreos-35.20220116.3.0-openstack.x86_64 \
--keypair testkey \
--external-network public \
--dns-nameserver 8.8.8.8 \
--flavor ds1G \
--master-flavor ds2G \
--docker-volume-size 5 \
--network-driver flannel \
--docker-storage-driver overlay2 \
--coe kubernetes
Create a cluster. Use the ClusterTemplate name as a template for cluster creation. This cluster will result in one master kubernetes node and one minion node
openstack coe cluster create k8s-cluster \
--cluster-template k8s-cluster-template \
--node-count 1
Clusters will have an initial status of CREATE_IN_PROGRESS. Magnum will update the status to CREATE_COMPLETE when it is done creating the cluster. Do not create containers, pods, services, or replication controllers before magnum finishes creating the cluster. They will likely not be created, and may cause magnum to become confused.
The existing clusters can be listed as follows:
$ openstack coe cluster list
+--------------------------------------+-------------+------------+--------------+-----------------+
| uuid | name | node_count | master_count | status |
+--------------------------------------+-------------+------------+--------------------------------+
| 9dccb1e6-02dc-4e2b-b897-10656c5339ce | k8s-cluster | 1 | 1 | CREATE_COMPLETE |
+--------------------------------------+-------------+------------+--------------+-----------------+
More detailed information for a given cluster is obtained via:
openstack coe cluster show k8s-cluster
After a cluster is created, you can dynamically add/remove node(s) to/from the cluster by updating the node_count attribute. For example, to add one more node:
openstack coe cluster update k8s-cluster replace node_count=2
Clusters in the process of updating will have a status of UPDATE_IN_PROGRESS. Magnum will update the status to UPDATE_COMPLETE when it is done updating the cluster.
NOTE: Reducing node_count will remove all the existing pods on the nodes that are deleted. If you choose to reduce the node_count, magnum will first try to remove empty nodes with no pods running on them. If you reduce node_count by more than the number of empty nodes, magnum must remove nodes that have running pods on them. This action will delete those pods. We strongly recommend using a replication controller before reducing the node_count so any removed pods can be automatically recovered on your remaining nodes.
Heat can be used to see detailed information on the status of a stack or specific cluster:
To check the list of all cluster stacks:
openstack stack list
To check an individual cluster’s stack:
openstack stack show <stack-name or stack_id>
Monitoring cluster status in detail (e.g., creating, updating):
CLUSTER_HEAT_NAME=$(openstack stack list | \
awk "/\sk8s-cluster-/{print \$4}")
echo ${CLUSTER_HEAT_NAME}
openstack stack resource list ${CLUSTER_HEAT_NAME}
Building a Kubernetes Cluster - Based on Fedora Atomic [DEPRECATED]¶
Fedora Atomic Deprecation Notice:
Fedora CoreOS is the official successor to Fedora Atomic Host. The last Fedora Atomic Host release was version 29, which has now reached end-of-life.
When building devstack from master, the Fedora atomic image is no longer created for us by default. We will need to create an image ourselves.
wget https://dl.fedoraproject.org/pub/alt/atomic/stable/Fedora-Atomic-27-20180419.0/CloudImages/x86_64/images/Fedora-Atomic-27-20180419.0.x86_64.qcow2
openstack image create Fedora-Atomic-27-20180419.0.x86_64 \
--public \
--disk-format=qcow2 \
--container-format=bare \
--property os_distro=fedora-atomic \
--file=Fedora-Atomic-27-20180419.0.x86_64.qcow2
Create a ClusterTemplate. This is similar in nature to a flavor and describes to magnum how to construct the cluster. The ClusterTemplate specifies a Fedora Atomic image so the clusters which use this ClusterTemplate will be based on Fedora Atomic
openstack coe cluster template create k8s-cluster-template \
--image Fedora-Atomic-27-20180419.0.x86_64 \
--keypair testkey \
--external-network public \
--dns-nameserver 8.8.8.8 \
--flavor m1.small \
--docker-volume-size 5 \
--network-driver flannel \
--coe kubernetes
Create a cluster. Use the ClusterTemplate name as a template for cluster creation. This cluster will result in one master kubernetes node and one minion node:
openstack coe cluster create k8s-cluster \
--cluster-template k8s-cluster-template \
--node-count 1
Building a Kubernetes Cluster - Based on CoreOS [DEPRECATED]¶
End-of-life announcement for CoreOS Container Linux:
On May 26, 2020, CoreOS Container Linux will reach its end of life and will no longer receive updates. We strongly recommend that users begin migrating their workloads to another operating system as soon as possible. […] Fedora CoreOS is the official successor to CoreOS Container Linux
You can create a Kubernetes cluster based on CoreOS as an alternative to Atomic or Fedora CoreOS. First, download the official CoreOS image:
wget http://beta.release.core-os.net/amd64-usr/current/coreos_production_openstack_image.img.bz2
bunzip2 coreos_production_openstack_image.img.bz2
Upload the image to glance:
openstack image create CoreOS \
--public \
--disk-format=qcow2 \
--container-format=bare \
--property os_distro=coreos \
--file=coreos_production_openstack_image.img
Create a CoreOS Kubernetes ClusterTemplate, which is similar to the Atomic Kubernetes ClusterTemplate, except for pointing to a different image:
openstack coe cluster template create k8s-cluster-template-coreos \
--image CoreOS \
--keypair testkey \
--external-network public \
--dns-nameserver 8.8.8.8 \
--flavor m1.small \
--network-driver flannel \
--coe kubernetes
Create a CoreOS Kubernetes cluster. Use the CoreOS ClusterTemplate as a template for cluster creation:
openstack coe cluster create k8s-cluster \
--cluster-template k8s-cluster-template-coreos \
--node-count 2
Using a Kubernetes Cluster¶
NOTE: For the following examples, only one minion node is required in the k8s cluster created previously.
Kubernetes provides a number of examples you can use to check that things are working. You may need to download kubectl binary for interacting with k8s cluster using:
curl -LO https://storage.googleapis.com/kubernetes-release/release/v1.2.0/bin/linux/amd64/kubectl
chmod +x ./kubectl
sudo mv ./kubectl /usr/local/bin/kubectl
We first need to setup the certs to allow Kubernetes to authenticate our connection. Please refer to Transport Layer Security for more info on using TLS keys/certs which are setup below.
To generate an RSA key, you will use the ‘genrsa’ command of the ‘openssl’ tool.:
openssl genrsa -out client.key 4096
To generate a CSR for client authentication, openssl requires a config file that specifies a few values.:
$ cat > client.conf << END
[req]
distinguished_name = req_distinguished_name
req_extensions = req_ext
prompt = no
[req_distinguished_name]
CN = admin
O = system:masters
OU=OpenStack/Magnum
C=US
ST=TX
L=Austin
[req_ext]
extendedKeyUsage = clientAuth
END
Once you have client.conf, you can run the openssl ‘req’ command to generate the CSR.:
openssl req -new -days 365 \
-config client.conf \
-key client.key \
-out client.csr
Now that you have your client CSR, you can use the Magnum CLI to send it off to Magnum to get it signed and also download the signing cert.:
magnum ca-sign --cluster k8s-cluster --csr client.csr > client.crt
magnum ca-show --cluster k8s-cluster > ca.crt
Here’s how to set up the replicated redis example. Now we create a pod for the redis-master:
# Using cluster-config command for faster configuration
eval $(openstack coe cluster config k8s-cluster)
# Test the cert and connection works
kubectl version
cd kubernetes/examples/redis
kubectl create -f ./redis-master.yaml
Now create a service to provide a discoverable endpoint for the redis sentinels in the cluster:
kubectl create -f ./redis-sentinel-service.yaml
To make it a replicated redis cluster create replication controllers for the redis slaves and sentinels:
sed -i 's/\(replicas: \)1/\1 2/' redis-controller.yaml
kubectl create -f ./redis-controller.yaml
sed -i 's/\(replicas: \)1/\1 2/' redis-sentinel-controller.yaml
kubectl create -f ./redis-sentinel-controller.yaml
Full lifecycle and introspection operations for each object are supported. For example, openstack coe cluster create, openstack coe cluster template delete.
Now there are four redis instances (one master and three slaves) running across the cluster, replicating data between one another.
Run the openstack coe cluster show command to get the IP of the cluster host on which the redis-master is running:
$ openstack coe cluster show k8s-cluster
+--------------------+------------------------------------------------------------+
| Property | Value |
+--------------------+------------------------------------------------------------+
| status | CREATE_COMPLETE |
| uuid | cff82cd0-189c-4ede-a9cb-2c0af6997709 |
| stack_id | 7947844a-8e18-4c79-b591-ecf0f6067641 |
| status_reason | Stack CREATE completed successfully |
| created_at | 2016-05-26T17:45:57+00:00 |
| updated_at | 2016-05-26T17:50:02+00:00 |
| create_timeout | 60 |
| api_address | https://172.24.4.4:6443 |
| coe_version | v1.2.0 |
| cluster_template_id| e73298e7-e621-4d42-b35b-7a1952b97158 |
| master_addresses | ['172.24.4.6'] |
| node_count | 1 |
| node_addresses | ['172.24.4.5'] |
| master_count | 1 |
| container_version | 1.9.1 |
| discovery_url | https://discovery.etcd.io/4caaa65f297d4d49ef0a085a7aecf8e0 |
| name | k8s-cluster |
+--------------------+------------------------------------------------------------+
The output here indicates the redis-master is running on the cluster host with IP address 172.24.4.5. To access the redis master:
$ ssh fedora@172.24.4.5
$ REDIS_ID=$(sudo docker ps | grep redis:v1 | grep k8s_master | awk '{print $1}')
$ sudo docker exec -i -t $REDIS_ID redis-cli
127.0.0.1:6379> set replication:test true
OK
^D
$ exit # Log out of the host
Log into one of the other container hosts and access a redis slave from it. You can use nova list to enumerate the kube-minions. For this example we will use the same host as above:
$ ssh fedora@172.24.4.5
$ REDIS_ID=$(sudo docker ps | grep redis:v1 | grep k8s_redis | awk '{print $1}')
$ sudo docker exec -i -t $REDIS_ID redis-cli
127.0.0.1:6379> get replication:test
"true"
^D
$ exit # Log out of the host
Additional useful commands from a given minion:
sudo docker ps # View Docker containers on this minion
kubectl get pods # Get pods
kubectl get rc # Get replication controllers
kubectl get svc # Get services
kubectl get nodes # Get nodes
After you finish using the cluster, you want to delete it. A cluster can be deleted as follows:
openstack coe cluster delete k8s-cluster
Building Developer Documentation¶
To build the documentation locally (e.g., to test documentation changes before uploading them for review) chdir to the magnum root folder and run tox:
tox -edocs
NOTE: The first time you run this will take some extra time as it creates a virtual environment to run in.
When complete, the documentation can be accessed from:
doc/build/html/index.html
