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Description: - Connect two microservices belonging to stateless applications


TLS Details

MESH WIDE POLICY (In both the clusters ) - PERMISSIVE

Service level policy for httpbin - SIMPLE

Service level policy for sleep - SIMPLE

Diagram


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diagramNameus-to-us intent
simpleViewerfalse
width
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tbstyletop
lboxtrue
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revision3

NOTE - For communication between the cluster, ISTIO_MUTUAL mode is default

Add Inbound service

The intent for this scenario

POST - traffic intent for the inbound service (service hosted behind the cluster)

Code Block
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themeMidnight
titlePOST
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URL: /v2/projects/{project-name}/composite-apps/{composite-app-name}/{version}/traffic-intent-set/us-to-us-intents/

POST BODY:
{
	"metadata": {
	"name": "<name>" // unique name for each intent
    "description": "connectivity intent for stateless micro-service to stateless micro-service communication"
	"userdata1": <>,
	"userdata2": <>
	}

	"spec": { // update the memory allocation for each field as per OpenAPI standards
	"application": "<app1>",
	"servicename": "httpbin" //actual name of the client service
	"protocol": "HTTP",
	"headless": "false", // default is false. Option "True" will make sure all the instances of the headless service will have access to the client service
	"mutualTLS": "SIMPLE", // Support 2 modes. SIMPLE and ISTIO_MUTUAL. For external Client, it is SIMPLE and MUTUAL (caCertificate required)
	"port" : "80", // port on which service is exposed as through servicemesh, not the port it is actually running on
	"serviceMesh": "istio", // get it from cluster record
	"istio-proxy": "yes", // The features (mTLS, LB, Circuit breaking) are no avaialble to services without istio-proxy

	// Traffic configuration - Loadbalancing is applicable per service. The traffic to this service is distrbuted amongst the pods under it.
	"loadbalancingType": "ConsistenHash", // "Simple" and "consistentHash" are the two modes
	"loadBalancerMode": "httpCookie" // Modes for consistentHash - "httpHeaderName", "httpCookie", "useSourceIP", "minimumRingSize", Modes for simple - "LEAST_CONN", "ROUND_ROBIN", "RANDOM", "PASSTHROUGH" // choices of the mode must be explicit
	"httpCookie": "user1" // Name of the cookie to maitain stick sessions

	// Circuit Breaking
	"maxConnections": 10 //connection pool for tcp and http traffic
	"concurrenthttp2Requests": 1000 // concurent http2 requests which can be allowed
	"httpRequestPerConnection": 100 //number of http requests per connection. Valid only for http traffic
	"consecutiveErrors": 8 // Default is 5.  Number of consecutive error before the host is removed from load balancing pool
	"baseEjectionTime" : 15 // Default is 5, time for which the host will be removed from load balancing pool when it returns error for no of times more than "consecutiveErrors" limit
	"intervalSweep": 5m, //time limit before the removed hosts are added back to the load balancing pool.

	// credentials for mTLS. Not required in this scenario since the services are in one logical cloud with common rootCA. ISTIO_MUTUAL is enabled by default.
	"Servicecertificate" : "" // Present actual certificate here.
	"ServicePrivateKey" : "" // Present actual private key here.

	// Access Control
	namespaces: [] // Workloads from this namespaces can access the inbound service
	
	}
}

RETURN STATUS: 201
RETURN BODY: 
{ 
  "name": "servicehttpbin"
  "Message": "inbound service created"
}

Add Clients

POST - traffic intent to add clients for accessing a specific inbound service

Code Block
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titlePOST
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URL: /v2/projects/{project-name}/composite-apps/{composite-app-name}/{version}/traffic-group-intent/uservice-to-uservice-intent/clients
POST BODY:
{
	"metadata": {
	"name": "<name>" // unique name for each intent
    "description": "connectivity intent add client communication"
	"application": "<app1>",
	"userdata1": <>,
	"userdata2": <>
	}

	spec: {
		"clientServiceName": "sleep", // Name of the client service
		"headless": "false", // default is false. Option "True" will generate the required configs for all the instances of headless service
	}
}

RETURN STATUS: 201
RETURN BODY:
{ 
  "name": "sleep"
  "Message": "Client created"
}

Add Security details for clients

WARNING - This task requires mutual TLS enabled because the following examples use principal and namespace in the policies

Code Block
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titleGET
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URL: /v2/projects/{project-name}/composite-apps/{composite-app-name}/{version}/traffic-group-intent/uservice-to-uservice-intent/clients/sleep/security/security-intent
{
	"metadata": {
	"name": "<name>" // unique name for each intent
    "description": "Security intent"
	"application": "<app1>",
	"userdata1": <>,
	"userdata2": <>
	}

	spec:{
	serviceAccountAccess : {[ "cluster.local/ns/default/sa/bookinfo-ratings-v2": ["GET": "/health_check"],
							  "cluster.local/ns/default/sa/sleep" : ["GET": "/status"]} // template [sa: portNum] for TCP traffic
	}
}

RETURN STATUS: 201
RETURN BODY:
{ 
  "name": "<name>"
  "Message": "Security Rules created"
}

Generate Istio object resources

...

  1. echo
  2. sleep 

...

destinationRule for simple TLS, Loadbalancing and circuit breaking

AuthorizationPolicy for Access Control

Cluster01 Resources

  1. ServiceEntry - To enable sleep to access httpbin  
Code Block
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titleServiceEntry
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apiVersion: networking.istio.io/v1alpha3
kind: ServiceEntry
metadata:
  name: servicename-httpbin
spec:
  hosts:
  # template for the remote service name - <servicename.namespace.global>
  # Treat remote cluster services as part of the service mesh
  # as all clusters in the service mesh share the same root of trust.
  location: MESH_INTERNAL
  ports:
  - name: http1
    number: 8000
    protocol: http
  resolution: DNS
  addresses:
  # the IP address to which httpbin.<namespace>.<logicalcloudname> will resolve to
  # must be unique for each remote service, within a given cluster.
  # This address need not be routable. Traffic for this IP will be captured
  # by the sidecar and routed appropriately.
  - 240.0.0.2
  endpoints:
  # This is the routable address of the istio ingress gateway in cluster02
  # routed to this address.
  - address: 172.25.55.50
    ports:
      http1: 15443 //Sni. Do not change this

Cluster 02 Resources

  1. DestinationRule for simple TLS, Loadbalancing and circuit breaking 

...

languageyml
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titleDestinationRule
linenumberstrue

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