Revision as of 01:42, 25 October 2020

Architecture Istio v1.7

Namespace: <app namespace>
  | app1  |                | app2  |  # main container
  | proxy |  <---------->  | proxy |  # Data Plane (all Envoy sidecar proxies)
  |  pod  |                |  pod  |

Namespace: istio-system
| |citadel|        |mixer|       |pilot| |
| |  pod  |        | pod |       | pod | | 
|      C o n t r o l  P l a n e  A P I   |
 ----------------------------------------

Note: All proxies are collectively named Data Plane and everything else that Istio deployed is called Control Plane

Note: Proxy term meaning is when someone has authority to represent someone. In software proxy components are invisible to clients. proxies

Istio components

Istio-telemetry
Istio-pilot
Istio-tracing

Istio components
Envoy L7 proxy	Pilot	Citadel	Mixer[deprecate]	Galley
Dynamic service discovery Load balancing TLS termination Health checks Staged rollouts Fault injection	Converts Istio configuration into a format that Envoy can understand. Aware about pods health, what pods are available and sends to the proxy pods that are alive with any other configuration updates. Propagates the configuration to the Proxies Service discovery Intelligent routing Resiliency	Manages certificates, allows to enable TLS/SSL across entire cluster. User authentication Credential management Certificate management Traffic encryption Pods istio-citadel-* It's certificate store.	handles Access control Usage policies, rate limiting Telemetry data (data scraping) It has a lot of modules/plugins. Pods: istio-policy-* istio-telemetry-*	Interface for underlying Istio API gateway(aka server). It reads in k8s yaml and transforms it into internal structure Istio understand.

Istio UI components:

grafana:3000 - dashboards
kiali:31000 - visualisation, tells what services are part of istio, how are they connected and performing
jaeger:31001 - tracing

Noticeable changes

In Istio 1.6, completed transition and fully moved functionality into Istiod. This has allow to remove the separate deployments for Citadel, the sidecar injector, and Galley.

Istio on minikube

# Minimum requirements are 8G and 4 CPUs
PROFILE=minikube-v1.17.6-istio
minikube start --memory=8192 --cpus=4 --kubernetes-version=v1.17.6 --profile $PROFILE
minikube start --memory=8192 --cpus=4 --kubernetes-version=v1.17.6 --driver kvm --profile $PROFILE-kvm2

minikube tunnel --profile $PROFILE
minikube addons enable istio --profile $PROFILE # [1] error

Troubleshooting

[1] - no matches for kind "IstioOperator"

💣  enable failed: run callbacks: running callbacks: [sudo KUBECONFIG=/var/lib/minikube/kubeconfig /var/lib/minikube/binaries/v1.17.6/kubectl apply -f /etc/kubernetes/addons/istio-default-profile.yaml: Process exited with status 1
stdout:
namespace/istio-system unchanged

stderr:
error: unable to recognize "/etc/kubernetes/addons/istio-default-profile.yaml": no matches for kind "IstioOperator" in version "install.istio.io/v1alpha1"

Install istioctl tool

# Istio 1.6.x - option-1
curl -L https://istio.io/downloadIstio | ISTIO_VERSION=1.6.8 sh -
cd istio-1.6.8/  # istio package directory
export PATH=$PWD/bin:$PATH
export PATH=$PATH:/git3rd/istio-1.6.8/bin

# Istio 1.7.x - option-2
export ISTIO_VERSION=1.7.3
curl -L https://istio.io/downloadIstio | sh -
export PATH=$PWD/istio-$ISTIO_VERSION/bin:$PATH
export ISTIO_INSTALL_DIR=$PWD/istio-$ISTIO_VERSION

# Check version
istioctl version --remote
client version: 1.7.3
control plane version: 1.7.3
data plane version: 1.7.3 (7 proxies)

# make sure you can connect to k8s cluster, then verify the install
istioctl verify-install
...
CustomResourceDefinition: templates.config.istio.io.default checked successfully
CustomResourceDefinition: istiooperators.install.istio.io.default checked successfully
Checked 25 custom resource definitions
Checked 1 Istio Deployments
Istio is installed successfully

# Verify mesh coverage and config status 
istioctl proxy-status
NAME                                                  CDS        LDS        EDS        RDS        ISTIOD                      VERSION
details-v1-5974b67c8-xbp8l.default                    SYNCED     SYNCED     SYNCED     SYNCED     istiod-5c6b7b5b8f-9npdz     1.7.3
istio-ingressgateway-5689f7c67-gvrh8.istio-system     SYNCED     SYNCED     SYNCED     SYNCED     istiod-5c6b7b5b8f-9npdz     1.7.3
...

Install the control plane

Istio maintainers with increasing complexity of the project that goes against the user friendliness still support helm manifest based configuration although there is fair movement towards the operator pattern. See below for differences, v1.6 and v1.7 still support both methods.

# Tested with 1.7.3
istioctl          install --skip-confirmation --set profile=default --dry-run # via operator
istioctl manifest install --skip-confirmation --set profile=default --dry-run # via helm chart

# Uses istio operator, the install can be replaced with 'upgrade'
istioctl install --skip-confirmation --set profile=default \
  --set        kiali.enabled=true      \
  --set        prometheus.enabled=true \
  --dry-run

# Using helm templates, notice the prefix 'values.'
istioctl manifest install --skip-confirmation --set profile=default \
  --set values.kiali.enabled=true      \
  --set values.prometheus.enabled=true \
  --dry-run

Uninstall Istio

Uninstall v1.6.8, it's safe to ignore RBAC not existing resources.

istioctl manifest generate --set profile=default | kubectl delete --ignore-not-found=true -f -
kubectl delete namespace istio-system

Uninstall v1.7.x

istioctl x uninstall --purge

Get info

Profiles are istiooperators.install.istio.io CRD manifests located in istio-1.7.3/manifests/profiles

# List profiles
istioctl profile list
ls istio-1.7.3/manifests/profiles
default.yaml  demo.yaml  empty.yaml  minimal.yaml  preview.yaml  remote.yaml

# profile configuration
istioctl profile dump demo
istioctl profile dump --config-path components.pilot demo

# Differences in the profiles
istioctl profile diff default demo

Istio operator (v1.7.3), this is not super clear to me

find . -iname *operator*
./samples/operator
./samples/addons/extras/prometheus-operator.yaml
./manifests/charts/istio-operator # it's a chart to deploy operator
./manifests/charts/istio-operator/crds/crd-operator.yaml
./manifests/charts/base/crds/crd-operator.yaml
./manifests/charts/istio-telemetry/prometheusOperator
./manifests/deploy/crds/istio_v1alpha1_istiooperator_crd.yaml
./manifests/deploy/crds/istio_v1alpha1_istiooperator_cr.yaml
./manifests/deploy/operator.yaml # this [1]
./manifests/examples/customresource/istio_v1alpha1_istiooperator_cr.yaml

# [1] manifests/deploy/operator.yaml
---
apiVersion: apps/v1
kind: Deployment
metadata:
  namespace: istio-operator
  name: istio-operator
spec:
  replicas: 1
  selector:
    matchLabels:
      name: istio-operator
...

# This API get always installed
k -n istio-system get istiooperators.install.istio.io # kind: IstioOperator

# List all Istio CRDs
k get crd -A | grep istio | cut -f1 -d" "
adapters.config.istio.io
attributemanifests.config.istio.io
authorizationpolicies.security.istio.io
destinationrules.networking.istio.io
envoyfilters.networking.istio.io
gateways.networking.istio.io
handlers.config.istio.io
httpapispecbindings.config.istio.io
httpapispecs.config.istio.io
instances.config.istio.io
istiooperators.install.istio.io
peerauthentications.security.istio.io
quotaspecbindings.config.istio.io
quotaspecs.config.istio.io
requestauthentications.security.istio.io
rules.config.istio.io
serviceentries.networking.istio.io
sidecars.networking.istio.io
templates.config.istio.io
virtualservices.networking.istio.io
workloadentries.networking.istio.io

CRDs aka new `kind:` objects - demystified

Envoy terminiology Host, Downstream, Upstream, Listener, Cluster, Mesh, Runtime configuration
- Cluster: A cluster is a group of logically similar upstream hosts that Envoy connects to, eg. group of pods reviews service v1, v2 and v3.
- Cluster Discovery Service (CDS)
- Listener discovery service (LDS)
- Endpoint discovery service (EDS); cluster members are called endpoint.
- Route Discovery Service (RDS)

VirtualServices and DestinationRules are key resources for configuring Istio’s traffic routing functionality.
- VirtualServices - is used to configure how requests are routed to a service within an Istio service mesh, define how traffic is routed to a given destination
- DestinationRules define policies that apply to traffic intended for a service after routing has occurred. A DestinationRules is applied after VirtualServices routing rules are evaluated, so they apply to the traffic’s real destination.
  - subsets - defines a set of pods with common matching label eg. version: v1

gateways - taps on to ingressgateway; describe which controller to use eg. plugs into real network received by service/istio-ingressgateway that has label istio=ingressgateway
virtualservices - it bounds to a gateway(s), and describes how requests are routed to a service within the mesh
destinationrules - applied after vs routing rules to real traffic destination, defines available versions called subsets

adapters
attributemanifests
authorizationpolicies
envoyfilters
handlers
httpapispecbindings
httpapispecs
instances
istiooperators
peerauthentications
quotaspecbindings
quotaspecs
requestauthentications
rules
serviceentries
sidecars
templates
workloadentries

Customize istio installation

Configure ingress-gateways

Gateways are a special type of component, since multiple ingress and egress gateways can be defined. In the IstioOperator API, gateways are defined as a list type. The default profile installs one ingress gateway, called istio-ingressgateway.

# Show default values of the ingressgateway
istioctl profile dump --config-path components.ingressGateways
istioctl profile dump --config-path values.gateways.istio-ingressgateway

Install istio with ingressgateway servioce as internal AWS loadbalancer:

istioctl install \
   --set profile=default \
   --set addonComponents.prometheus.enabled=false \
   --set addonComponents.grafana.enabled=false \
   --set addonComponents.kiali.enabled=false \
   --set addonComponents.tracing.enabled=false \
   --set components.ingressGateways[0].enabled="true" \
   --set components.ingressGateways[0].k8s.serviceAnnotations."service\.beta\.kubernetes\.io/aws-load-balancer-internal"=\"true\"
✔ Istio core installed                                                                                                                                         
✔ Istiod installed                                                                                                                                             
✔ Ingress gateways installed                                                                                                                                   
✔ Installation complete

# --set gateways.istio-ingressgateway.serviceAnnotations."service\.beta\.kubernetes\.io/aws-load-balancer-internal"="0\.0\.0\.0/0"

istioctl version --remote
client version: 1.6.4
control plane version: 1.6.4
data plane version: 1.6.4 (1 proxies)

Ingress Gateways - controller

# manually inject the sidecar
kubectl -n bin apply -f <(istioctl kube-inject -f httpbin.yaml)

export INGRESS_HOST=$(       kubectl -n istio-system get service istio-ingressgateway -o jsonpath='{.status.loadBalancer.ingress[0].ip}')
# AWS, uses 'hostname'
export INGRESS_HOST=$(       kubectl -n istio-system get service istio-ingressgateway -o jsonpath='{.status.loadBalancer.ingress[0].hostname}')

export INGRESS_PORT=$(       kubectl -n istio-system get service istio-ingressgateway -o jsonpath='{.spec.ports[?(@.name=="http2")].port}')
export SECURE_INGRESS_PORT=$(kubectl -n istio-system get service istio-ingressgateway -o jsonpath='{.spec.ports[?(@.name=="https")].port}')

# This is not necessary set/configured
export TCP_INGRESS_PORT=$(   kubectl -n istio-system get service istio-ingressgateway -o jsonpath='{.spec.ports[?(@.name=="tcp")].port}')

# Verify
env | grep INGRESS

Bookinfo examples - gateway, virtualservice

# istio-1.7.3/samples/bookinfo/networking/bookinfo-gateway.yaml
---
# Entry point gateway
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: bookinfo-gateway
spec:
  selector:
    istio: ingressgateway # use istio default controller
  servers:
  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts:
    - "*"
---
# Routes traffic to destination, could use subset for Traffic Shifting
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: bookinfo
spec:
  hosts:
  - "*"
  gateways:
  - bookinfo-gateway
  http:
  - match:
    - uri:
        exact: /productpage
    - uri:
        prefix: /static
    - uri:
        exact: /login
    - uri:
        exact: /logout
    - uri:
        prefix: /api/v1/products
    route:
    - destination:
        host: productpage
        port:
          number: 9080
       #subset: v1 # [1] if defined in DestinationRule for the host ('productpage'), it will route to any pods
                   # matching a label(s) defined in the subset

# samples/bookinfo/networking/destination-rule-all.yaml
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: productpage
spec:
  host: productpage
  subsets:   # pod selectors matching labels
  - name: v1 # [1] subset name for the host 'productpage'
    labels:
      version: v1
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: reviews
spec:
  host: reviews
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2
  - name: v3
    labels:
      version: v3
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: ratings
spec:
  host: ratings
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2
  - name: v2-mysql
    labels:
      version: v2-mysql
  - name: v2-mysql-vm
    labels:
      version: v2-mysql-vm
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: details
spec:
  host: details
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2
---

Kiali visualisations

You install kiali manually from scratch or pass arg to istioctl

# Create user name and password
KIALI_USERNAME=admin
KIALI_PASSPHRASE=admin
kubectl apply -f <(cat <<EOF
apiVersion: v1
kind: Secret
metadata:
  name: kiali
  namespace: istio-system
  labels:
    app: kiali
stringData:
  username: $KIALI_USERNAME
  passphrase: $KIALI_PASSPHRASE
EOF
)

istioctl manifest install \
  --set values.kiali.enabled=true \
  --set values.prometheus.enabled=true

kubectl wait --for=condition=Available deployment/kiali -n istio-system --timeout=300s

# Access the dashboard
istioctl dashboard kiali

Add custom headers

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: httpbin
spec:
  hosts:
  - "*"
  gateways:
  - httpbin-gateway
  http:
  - match:
    - uri:
        prefix: /headers
    route:
    - destination:
        port:
          number: 8000
        host: httpbin
      headers:
        response:            # add to response
          add:
           "key1": "abc"
        request:             # add to request
           add:
             "key2": "def"

Resources

gitops-istio Istio on a Kubernetes cluster and automating A/B testing and canary releases with GitOps pipelines example

Training Istio v1.5

Istio v1.7

VM <-> K8s mesh demo at 30 min

Difference between revisions of "Kubernetes/Istio"

Revision as of 01:42, 25 October 2020

Contents

Architecture Istio v1.7

Istio components

Istio on minikube

Install istioctl tool

Install the control plane

Uninstall Istio

Get info

CRDs aka new `kind:` objects - demystified

Customize istio installation

Configure ingress-gateways

Ingress Gateways - controller

Bookinfo examples - gateway, virtualservice

Kiali visualisations

Add custom headers

Resources

Navigation menu

Difference between revisions of "Kubernetes/Istio"

Revision as of 01:42, 25 October 2020

Architecture Istio v1.7

Istio components

Istio on minikube

Install istioctl tool

Install the control plane

Uninstall Istio

Get info

CRDs aka new kind: objects - demystified

Customize istio installation

Configure ingress-gateways

Ingress Gateways - controller

Bookinfo examples - gateway, virtualservice

Kiali visualisations

Add custom headers

Resources

Navigation menu

Search

CRDs aka new `kind:` objects - demystified