Table of Contents
Description: - Connect two TXP microservices belonging to stateless applications
In this scenario, Unlike HTTP, instead of the service URL, ports are exposed.
The services hosted behind Istio service mesh has the sidecar proxy installed with each pod of the service. The communication between these is possible only when the TLS option is set to the "ISTIO_MUTUAL"
In the below diagram,
SERVER - httpbin (If TLS Mode is "SIIMPLE", it will accept both traffic for tls and plain text. TLS Mode must be ISTIO_MUTUAL for talking to other istio clients and MUTUAL (with ca) when talking to other external services)
CLIENTS - sleep (TLS Mode can be "SIMPLE" (for services with no sidecars) or ISTIO_MUTUAL(services with sidecars))
Diagram
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NOTE - For this scenario, the default mesh wide policy must be set to "PERMISSIVE" on both the clusters. It will not work if the default Mesh Policy is "STRICT"
Important Info - cert-chain.pem is Envoy’s cert that needs to be presented to the other side. key.pem is Envoy’s private key paired with Envoy’s cert in cert-chain.pem. root-cert.pem is the root cert to verify the peer’s cert. In this example, we only have one Citadel in a cluster, so all Envoys have the same root-cert.pem.
Add Inbound service
The intent for this scenario
POST - traffic intent for the inbound service (service hosted behind the cluster)
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| language | js |
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| theme | Midnight |
| title | POST |
| linenumbers | true |
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Add Clients
POST - traffic intent to add clients for accessing a specific inbound service
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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
"mTLS": "DISABLE", // will be the same as that of inbound service, if both are part of same logical cloud
}
}
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
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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/sleep": ["GET": "/status"],
"cluster.local/ns/default/sa/sleep" : ["GET": "/headers"]}
}
}
RETURN STATUS: 201
RETURN BODY:
{
"name": "<name>"
"Message": "Security Rules created"
}
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Generate Istio object resources
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- sleep
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destinationRule for simple TLS, Loadbalancing and circuit breaking
AuthorizationPolicy for Access Control
Cluster01 Resources
1. ServiceEntry - To enable sleep to access httpbin
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apiVersion: networking.istio.io/v1alpha3
kind: ServiceEntry
metadata:
name: servicename-httpbin
spec:
hosts:
- httpbin.default.global
# 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
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2. DestinationRule for TLS - sleep
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apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
name: sleep-dr
namespace: default
spec:
host: "sleep.default.svc.cluster.local"
trafficPolicy:
tls:
mode: DISABLE
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Cluster 02 Resources
1. DestinationRule for simple TLS, Loadbalancing and circuit breaking - httpbin
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apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
name: httpbin-dr
namespace: default
spec:
host: "httpbin.default.svc.cluster.local"
trafficPolicy:
tls:
mode: DISABLE
loadbalancer:
consistentHash:
httpCookie: "user1"
connectionPool:
tcp:
maxConnections: 10
http:
http2MaxRequests: 1000
maxRequestsPerConnection: 100
outlierDetection:
consecutiveErrors: 7
interval: 5m
baseEjectionTime: 15m
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2. AuthorizationPolicy
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| language | yml |
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| theme | Eclipse |
| title | AuthorizationPolicy |
| linenumbers | true |
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