Kops used to only support Google Cloud DNS and Amazon Route53 to provision a kubernetes cluster. But since 1.6.2 gossip has been added which make it possible to provision a cluster without one of those DNS providers. Thanks to gossip, it's officially supported to provision a fully-functional kubernetes cluster in AWS China Region which doesn't have Route53 so far since 1.7. Should support both cn-north-1 and cn-northwest-1, but only cn-north-1 is tested.
Most of the following procedures to provision a cluster are the same with the guide to use kops in AWS. The differences will be highlighted and the similar parts will be omitted.
NOTE: THE FOLLOWING PROCEDURES ARE ONLY TESTED WITH KOPS 1.10.0, 1.10.1 AND KUBERNETES 1.9.11, 1.10.12
When aws configure, remember to set the default region name to the correct one, e.g. cn-north-1.
AWS Access Key ID [None]:
AWS Secret Access Key [None]:
Default region name [None]:
Default output format [None]:And export it correctly.
export AWS_REGION=$(aws configure get region)As the note kindly pointing out, a gossip-based cluster can be easily created by having the cluster name end with .k8s.local. We will adopt this trick below. Rest of this section can be skipped safely.
Thanks to gossip, this section can be skipped safely as well.
Since we are provisioning a cluster in AWS China Region, we need to create a dedicated S3 bucket in AWS China Region.
aws s3api create-bucket --bucket prefix-example-com-state-store --create-bucket-configuration LocationConstraint=$AWS_REGIONFirst of all, we have to solve the slow and unstable connection to the internet outside China, or the following processes won't work. One way to do that is to build a NAT instance which can route the traffic via some reliable connection. The details won't be discussed here.
We have to build our own AMI because there is no official kops ami in AWS China Regions. There're two ways to accomplish so.
First, launch an instance in a private subnet which accesses the internet fast and stably.
Because the instance launched in a private subnet, we need to ensure it can be connected by using the private ip via a VPN or a bastion.
SUBNET_ID=<subnet id> # a private subnet
SECURITY_GROUP_ID=<security group id>
KEY_NAME=<key pair name on aws>
AMI_ID=$(aws ec2 describe-images --filters Name=name,Values=debian-jessie-amd64-hvm-2016-02-20-ebs --query 'Images[*].ImageId' --output text)
INSTANCE_ID=$(aws ec2 run-instances --image-id $AMI_ID --instance-type m3.medium --key-name $KEY_NAME --security-group-ids $SECURITY_GROUP_ID --subnet-id $SUBNET_ID --no-associate-public-ip-address --query 'Instances[*].InstanceId' --output text)
aws ec2 create-tags --resources ${INSTANCE_ID} --tags Key=k8s.io/role/imagebuilder,Value=1Now follow the documentation of ImageBuilder in kube-deploy to build the image.
go get k8s.io/kube-deploy/imagebuilder
cd ${GOPATH}/src/k8s.io/kube-deploy/imagebuilder
sed -i '' "s|publicIP := aws.StringValue(instance.PublicIpAddress)|publicIP := aws.StringValue(instance.PrivateIpAddress)|" pkg/imagebuilder/aws.go
make
# cloud-init is failing due to urllib3 dependency. https://github.com/aws/aws-cli/issues/3678
sed -i '' "s/'awscli'/'awscli==1.16.38'/g" templates/1.9-jessie.yml
# If the keypair specified is not `$HOME/.ssh/id_rsa`, the config yaml file need to be modified to add the full path to the private key.
echo 'SSHPrivateKey: "/absolute/path/to/the/private/key"' >> aws-1.9-jessie.yaml
${GOPATH}/bin/imagebuilder --config aws-1.9-jessie.yaml --v=8 --publish=false --replicate=false --up=false --down=falseFollowing the comment to copy the kops image from another region, e.g. ap-southeast-1.
No matter how to build the AMI, we get an AMI finally, e.g. k8s-1.9-debian-jessie-amd64-hvm-ebs-2018-07-18.
Set up a few environment variables.
export NAME=example.k8s.local
export KOPS_STATE_STORE=s3://prefix-example-com-state-storeWe will need to note which availability zones are available to us. AWS China (Beijing) Region only has two availability zones. It will have the same problem, like other regions having less than three AZs, that there is no true HA support in two AZs. You can add more master nodes to improve the reliability in one AZ.
aws ec2 describe-availability-zonesBelow is a create cluster command which will create a complete internal cluster in an existing VPC. The below command will generate a cluster configuration, but not start building it. Make sure that you have generated SSH key pair before creating the cluster.
VPC_ID=<vpc id>
VPC_NETWORK_CIDR=<vpc network cidr> # e.g. 172.30.0.0/16
AMI=<owner id/ami name> # e.g. 123456890/k8s-1.9-debian-jessie-amd64-hvm-ebs-2018-07-18
kops create cluster \
--zones ${AWS_REGION}a \
--vpc ${VPC_ID} \
--network-cidr ${VPC_NETWORK_CIDR} \
--image ${AMI} \
--associate-public-ip=false \
--api-loadbalancer-type internal \
--topology private \
--networking calico \
${NAME}Now we have a cluster configuration, we adjust the subnet config to reuse shared subnets by editing the description.
kops edit cluster $NAMEThen change the corresponding subnets to specify the id and remove the cidr, e.g.
spec:
subnets:
- id: subnet-12345678
name: cn-north-1a
type: Private
zone: cn-north-1a
- id: subnet-87654321
name: utility-cn-north-1a
type: Utility
zone: cn-north-1aAnother tweak we can adopt here is to add a docker section to change the mirror to the official registry mirror for China. This will increase stability and download speed of pulling images from docker hub.
spec:
docker:
logDriver: ""
registryMirrors:
- https://registry.docker-cn.comPlease note that this mirror MIGHT BE not suitable for some cases. It's can be replaced by any other registry mirror as long as it's compatible with the docker api.
To achieve this, we can add more parameters to kops create cluster.
--master-zones ${AWS_REGION}a --master-count 3 \
--zones ${AWS_REGION}a --node-count 2 \ --master-zones ${AWS_REGION}a,${AWS_REGION}b --master-count 3 \
--zones ${AWS_REGION}a,${AWS_REGION}b --node-count 2 \Please note that this will still have 50% chance to break the cluster when one of the AZs are down.
Here is a naive, uncompleted attempt to provision a cluster in a way minimizing the requirements to the internet because even with some kind of proxies or VPN it's still not that fast and it's always much more expensive than downloading from S3.
## Setup vars
KUBERNETES_VERSION=$(curl -fsSL --retry 5 "https://dl.k8s.io/release/stable.txt")
KOPS_VERSION=$(curl -fsSL --retry 5 "https://api.github.com/repos/kubernetes/kops/releases/latest" | grep 'tag_name' | cut -d\" -f4)
ASSET_BUCKET="some-asset-bucket"
ASSET_PREFIX=""
# Please note that this filename of cni asset may change with kubernetes version
# Find this in https://github.com/kubernetes/kops/blob/master/upup/pkg/fi/cloudup/networking.go
CNI_FILENAME=cni-plugins-amd64-v0.6.0.tgz
export KOPS_BASE_URL=https://s3.cn-north-1.amazonaws.com.cn/$ASSET_BUCKET/kops/$KOPS_VERSION/
export CNI_VERSION_URL=https://s3.cn-north-1.amazonaws.com.cn/$ASSET_BUCKET/kubernetes/network-plugins/$CNI_FILENAME
export CNI_ASSET_HASH_STRING=d595d3ded6499a64e8dac02466e2f5f2ce257c9f
## Download assets
KUBERNETES_ASSETS=(
network-plugins/$CNI_FILENAME
release/$KUBERNETES_VERSION/bin/linux/amd64/kube-apiserver.tar
release/$KUBERNETES_VERSION/bin/linux/amd64/kube-controller-manager.tar
release/$KUBERNETES_VERSION/bin/linux/amd64/kube-proxy.tar
release/$KUBERNETES_VERSION/bin/linux/amd64/kube-scheduler.tar
release/$KUBERNETES_VERSION/bin/linux/amd64/kubectl
release/$KUBERNETES_VERSION/bin/linux/amd64/kubelet
)
for asset in "${KUBERNETES_ASSETS[@]}"; do
dir="kubernetes/$(dirname "$asset")"
mkdir -p "$dir"
url="https://storage.googleapis.com/kubernetes-release/$asset"
wget -P "$dir" "$url"
[ "${asset##*.}" != "gz" ] && wget -P "$dir" "$url.sha1"
[ "${asset##*.}" == "tar" ] && wget -P "$dir" "${url%.tar}.docker_tag"
done
KOPS_ASSETS=(
"images/protokube.tar.gz"
"linux/amd64/nodeup"
"linux/amd64/utils.tar.gz"
)
for asset in "${KOPS_ASSETS[@]}"; do
kops_path="kops/$KOPS_VERSION/$asset"
dir="$(dirname "$kops_path")"
mkdir -p "$dir"
url="https://kubeupv2.s3.amazonaws.com/kops/$KOPS_VERSION/$asset"
wget -P "$dir" "$url"
wget -P "$dir" "$url.sha1"
done
## Upload assets
## Get default S3 multipart_threshold
AWS_S3_DEFAULT_MULTIPART_THRESHOLD=$(aws configure get default.s3.multipart_threshold)
if [ ! -n "$AWS_S3_DEFAULT_MULTIPART_THRESHOLD" ]; then
AWS_S3_DEFAULT_MULTIPART_THRESHOLD=8MB
fi
## Set multipart_threshold to 1024MB to prevent Etag not returns MD5 when upload multipart
aws configure set default.s3.multipart_threshold 1024MB
aws s3api create-bucket --bucket $ASSET_BUCKET --create-bucket-configuration LocationConstraint=$AWS_REGION
for dir in "kubernetes" "kops"; do
aws s3 sync --acl public-read "$dir" "s3://$ASSET_BUCKET/$ASSET_PREFIX$dir"
done
aws configure set default.s3.multipart_threshold $AWS_S3_DEFAULT_MULTIPART_THRESHOLD
When create the cluster, add these parameters to the command line.
--kubernetes-version https://s3.cn-north-1.amazonaws.com.cn/$ASSET_BUCKET/kubernetes/release/$KUBERNETES_VERSIONNow most of the assets required to provision a cluster by kops and kubernetes will be downloaded from the specified S3 bucket except images like pause-amd64, dns related, etc. These images not mirrored by the docker hub mirror since they are hosted on gcr.io. There will be some problem if the connection is not good.
It hasn't been tested as this approach was only a PR when the author experimenting with provisioning a cluster in AWS China Region. It's the official way to achieve offline mode and should be superior to the previous naive attempt.