calico
Kubernetes中的网络解析——以calico为例
概念
Calico 创建和管理一个扁平的三层网络(不需要overlay)，每个容器会分配一个可路由的ip。由于通信时不需要解包和封包，网络性能损耗小，易于排查，且易于水平扩展。
小规模部署时可以通过bgp client直接互联，大规模下可通过指定的BGP route reflector来完成，这样保证所有的数据流量都是通过IP路由的方式完成互联的。 Calico基于iptables还提供了丰富而灵活的网络Policy，保证通过各个节点上的ACLs来提供Workload的多租户隔离、安全组以及其他可达性限制等功能。
Calico架构
图片 - CRI架构-图片来自https://www.jianshu.com/p/f0177b84de66
calico主要由Felix,etcd,BGP client,BGP Route Reflector组成。
Etcd：负责存储网络信息
BGP client：负责将Felix配置的路由信息分发到其他节点
Felix：Calico Agent，每个节点都需要运行，主要负责配置路由、配置ACLs、报告状态
BGP Route Reflector：大规模部署时需要用到，作为BGP client的中心连接点，可以避免每个节点互联
部署
mkdir /etc/cni/net.d/
kubectl apply -f https://docs.projectcalico.org/v3.0/getting-started/kubernetes/installation/rbac.yaml
wget https://docs.projectcalico.org/v3.0/getting-started/kubernetes/installation/hosted/calico.yaml
修改etcd_endpoints的值和默认的192.168.0.0/16(不能和已有网段冲突)
kubectl apply -f calico.yaml
wget https://github.com/projectcalico/calicoctl/releases/download/v2.0.0/calicoctl
mv calicoctl /usr/loca/bin && chmod +x /usr/local/bin/calicoctl
calicoctl get ippool
calicoctl get nodeyaml文件
# Calico Version v3.0.3
# https://docs.projectcalico.org/v3.0/releases#v3.0.3
# This manifest includes the following component versions:
# calico/node:v3.0.3
# calico/cni:v2.0.1
# calico/kube-controllers:v2.0.1
# This ConfigMap is used to configure a self-hosted Calico installation.
kind: ConfigMap
apiVersion: v1
metadata:
name: calico-config
namespace: kube-system
data:
# Configure this with the location of your etcd cluster.
etcd_endpoints: "{{ ETCD_ENDPOINTS }}"
# Configure the Calico backend to use.
calico_backend: "bird"
# The CNI network configuration to install on each node.
cni_network_config: |-
{
"name": "k8s-pod-network",
"cniVersion": "0.3.0",
"plugins": [
{
"type": "calico",
"etcd_endpoints": "__ETCD_ENDPOINTS__",
"etcd_key_file": "__ETCD_KEY_FILE__",
"etcd_cert_file": "__ETCD_CERT_FILE__",
"etcd_ca_cert_file": "__ETCD_CA_CERT_FILE__",
"log_level": "info",
"mtu": 1500,
"ipam": {
"type": "calico-ipam"
},
"policy": {
"type": "k8s",
"k8s_api_root": "https://__KUBERNETES_SERVICE_HOST__:__KUBERNETES_SERVICE_PORT__",
"k8s_auth_token": "__SERVICEACCOUNT_TOKEN__"
},
"kubernetes": {
"kubeconfig": "__KUBECONFIG_FILEPATH__"
}
},
{
"type": "portmap",
"snat": true,
"capabilities": {"portMappings": true}
}
]
}
# If you're using TLS enabled etcd uncomment the following.
# You must also populate the Secret below with these files.
etcd_ca: "/calico-secrets/etcd-ca"
etcd_cert: "/calico-secrets/etcd-cert"
etcd_key: "/calico-secrets/etcd-key"
---
# The following contains k8s Secrets for use with a TLS enabled etcd cluster.
# For information on populating Secrets, see http://kubernetes.io/docs/user-guide/secrets/
apiVersion: v1
kind: Secret
type: Opaque
metadata:
name: calico-etcd-secrets
namespace: kube-system
data:
# Populate the following files with etcd TLS configuration if desired, but leave blank if
# not using TLS for etcd.
# This self-hosted install expects three files with the following names. The values
# should be base64 encoded strings of the entire contents of each file.
etcd-key: "{{ calico_etcd_key }}"
etcd-cert: "{{ calico_etcd_cert }}"
etcd-ca: "{{ calico_etcd_ca }}"
---
# This manifest installs the calico/node container, as well
# as the Calico CNI plugins and network config on
# each master and worker node in a Kubernetes cluster.
kind: DaemonSet
apiVersion: extensions/v1beta1
metadata:
name: calico-node
namespace: kube-system
labels:
k8s-app: calico-node
spec:
selector:
matchLabels:
k8s-app: calico-node
updateStrategy:
type: RollingUpdate
rollingUpdate:
maxUnavailable: 1
template:
metadata:
labels:
k8s-app: calico-node
annotations:
scheduler.alpha.kubernetes.io/critical-pod: ''
scheduler.alpha.kubernetes.io/tolerations: |
[{"key": "dedicated", "value": "master", "effect": "NoSchedule" },
{"key":"CriticalAddonsOnly", "operator":"Exists"}]
spec:
hostNetwork: true
serviceAccountName: calico-node
# Minimize downtime during a rolling upgrade or deletion; tell Kubernetes to do a "force
# deletion": https://kubernetes.io/docs/concepts/workloads/pods/pod/#termination-of-pods.
terminationGracePeriodSeconds: 0
containers:
# Runs calico/node container on each Kubernetes node. This
# container programs network policy and routes on each
# host.
- name: calico-node
image: "{{ CALICO_NODE_IMAGE }}"
env:
# The location of the Calico etcd cluster.
- name: ETCD_ENDPOINTS
valueFrom:
configMapKeyRef:
name: calico-config
key: etcd_endpoints
# Choose the backend to use.
- name: CALICO_NETWORKING_BACKEND
valueFrom:
configMapKeyRef:
name: calico-config
key: calico_backend
# Cluster type to identify the deployment type
- name: CLUSTER_TYPE
value: "k8s,bgp"
# Disable file logging so `kubectl logs` works.
- name: CALICO_DISABLE_FILE_LOGGING
value: "true"
# Set noderef for node controller.
- name: CALICO_K8S_NODE_REF
valueFrom:
fieldRef:
fieldPath: spec.nodeName
# Set Felix endpoint to host default action to ACCEPT.
- name: FELIX_DEFAULTENDPOINTTOHOSTACTION
value: "ACCEPT"
# The default IPv4 pool to create on startup if none exists. Pod IPs will be
# chosen from this range. Changing this value after installation will have
# no effect. This should fall within `--cluster-cidr`.
- name: CALICO_IPV4POOL_CIDR
value: "{{ CLUSTER_CIDR }}"
- name: CALICO_IPV4POOL_IPIP
value: "Always"
# Disable IPv6 on Kubernetes.
- name: FELIX_IPV6SUPPORT
value: "false"
# Set Felix logging to "info"
- name: FELIX_LOGSEVERITYSCREEN
value: "info"
# Set MTU for tunnel device used if ipip is enabled
- name: FELIX_IPINIPMTU
value: "1440"
# Location of the CA certificate for etcd.
- name: ETCD_CA_CERT_FILE
valueFrom:
configMapKeyRef:
name: calico-config
key: etcd_ca
# Location of the client key for etcd.
- name: ETCD_KEY_FILE
valueFrom:
configMapKeyRef:
name: calico-config
key: etcd_key
# Location of the client certificate for etcd.
- name: ETCD_CERT_FILE
valueFrom:
configMapKeyRef:
name: calico-config
key: etcd_cert
# Auto-detect the BGP IP address.
- name: IP
value: "autodetect"
- name: FELIX_HEALTHENABLED
value: "true"
securityContext:
privileged: true
resources:
requests:
cpu: 250m
livenessProbe:
httpGet:
path: /liveness
port: 9099
periodSeconds: 10
initialDelaySeconds: 10
failureThreshold: 6
readinessProbe:
httpGet:
path: /readiness
port: 9099
periodSeconds: 10
volumeMounts:
- mountPath: /lib/modules
name: lib-modules
readOnly: true
- mountPath: /var/run/calico
name: var-run-calico
readOnly: false
- mountPath: /calico-secrets
name: etcd-certs
# This container installs the Calico CNI binaries
# and CNI network config file on each node.
- name: install-cni
image: {{ CALICO_CNI_IMAGE }}
command: ["/install-cni.sh"]
env:
# Name of the CNI config file to create.
- name: CNI_CONF_NAME
value: "10-calico.conflist"
# The location of the Calico etcd cluster.
- name: ETCD_ENDPOINTS
valueFrom:
configMapKeyRef:
name: calico-config
key: etcd_endpoints
# The CNI network config to install on each node.
- name: CNI_NETWORK_CONFIG
valueFrom:
configMapKeyRef:
name: calico-config
key: cni_network_config
volumeMounts:
- mountPath: /host/opt/cni/bin
name: cni-bin-dir
- mountPath: /host/etc/cni/net.d
name: cni-net-dir
- mountPath: /calico-secrets
name: etcd-certs
volumes:
# Used by calico/node.
- name: lib-modules
hostPath:
path: /lib/modules
- name: var-run-calico
hostPath:
path: /var/run/calico
# Used to install CNI.
- name: cni-bin-dir
hostPath:
path: /opt/cni/bin
- name: cni-net-dir
hostPath:
path: /etc/cni/net.d
# Mount in the etcd TLS secrets.
- name: etcd-certs
secret:
secretName: calico-etcd-secrets
---
# This manifest deploys the Calico Kubernetes controllers.
# See https://github.com/projectcalico/kube-controllers
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: calico-kube-controllers
namespace: kube-system
labels:
k8s-app: calico-kube-controllers
annotations:
scheduler.alpha.kubernetes.io/critical-pod: ''
scheduler.alpha.kubernetes.io/tolerations: |
[{"key": "dedicated", "value": "master", "effect": "NoSchedule" },
{"key":"CriticalAddonsOnly", "operator":"Exists"}]
spec:
# The controllers can only have a single active instance.
replicas: 1
strategy:
type: Recreate
template:
metadata:
name: calico-kube-controllers
namespace: kube-system
labels:
k8s-app: calico-kube-controllers
spec:
# The controllers must run in the host network namespace so that
# it isn't governed by policy that would prevent it from working.
hostNetwork: true
serviceAccountName: calico-kube-controllers
containers:
- name: calico-kube-controllers
image: {{ CALICO_POLICY_IMAGE }}
env:
# The location of the Calico etcd cluster.
- name: ETCD_ENDPOINTS
valueFrom:
configMapKeyRef:
name: calico-config
key: etcd_endpoints
# Location of the CA certificate for etcd.
- name: ETCD_CA_CERT_FILE
valueFrom:
configMapKeyRef:
name: calico-config
key: etcd_ca
# Location of the client key for etcd.
- name: ETCD_KEY_FILE
valueFrom:
configMapKeyRef:
name: calico-config
key: etcd_key
# Location of the client certificate for etcd.
- name: ETCD_CERT_FILE
valueFrom:
configMapKeyRef:
name: calico-config
key: etcd_cert
# Choose which controllers to run.
- name: ENABLED_CONTROLLERS
value: policy,profile,workloadendpoint,node
volumeMounts:
# Mount in the etcd TLS secrets.
- mountPath: /calico-secrets
name: etcd-certs
volumes:
# Mount in the etcd TLS secrets.
- name: etcd-certs
secret:
secretName: calico-etcd-secrets
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: calico-kube-controllers
namespace: kube-system
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: calico-node
namespace: kube-systemLast updated