Automated deployment of applications in Service Mesh lite

Prerequisites

Ensure python version 3.7 or later.

Ensure that the pip3 is installed.

Install the required Python libraries using the following command:

pip3 install -r https://raw.githubusercontent.com/citrix/citrix-k8s-ingress-controller/master/docs/how-to/sml/requirements.txt

You need to provide some inputs which are explained in the following section while running the script for your microservice applications.

Information on required inputs

This section provides information on the inputs you need to provide.

Provide one of the following while running the script:

Provide the YAML file that contains your application deployments and services. If choose this option, you can directly go to step 2.
Provide all service names and the namespace in which they are already running in a Kubernetes cluster. Deployment YAMLs remain the same for running an application in SML architecture, so they can be used as it is. In this case, you must provide more inputs as follows:

You can run the applications from a Kubernetes cluster where the provided services are already running or from a client. Depending on the option you need, choose Yes or No.
```
Do you want to connect to a Remote Kubernetes Cluster? (Y/N):
```
If you are running the script from a Kubernetes cluster where the services, that you want the SML YAML files for, are already running then choose which Kubeconfig file to use.
- Choose Y if you want to use the default kubeconfig file of the Kubernetes cluster.
```
     Do you want to use default kubeconfig file present at "/root/.kube/config"? (Y/N):
```
- Otherwise, provide the path of the kubeconfig file that you want to use:
```
     Please provide path of kubeconfig file:
```
If you want to run the application from a client, the remote Kubernetes cluster can be accessed either using a bearer token or the Kubeconfig file.
- If the remote cluster is accessed using the bearer token, provide the following inputs:
  1. Choose Y if you are using a bearer token to access the remote Kubernetes Cluster:
    Do you want to use Bearer Token for connecting to a Remote Kubernetes Cluster? (Y/N):
  2. Provide the bearer token.
    Please provide Bearer Token key of SA having permission to access given service:
  3. Provide API server and port number of the remote Kubernetes cluster.
    Please provide API server <IP:PORT>: x.x.x.x:<port>
- If the remote cluster is accessed using the Kubeconfig File, provide the following inputs.
  1. Choose N if you are using Kubeconfig File to access the remote Kubernetes Cluster:
    Do you want to use bearer token for connecting to a Remote Kubernetes Cluster? (Y/N):
  2. Provide the path of the kubeconfig file of the remote Kubernetes Cluster:
    Please provide the path of the kubeconfig file:

Provide the name of the front-end microservice of the application.

Please provide the name of the service exposed to tier-1:

Provide the host name for the application.

Please provide hostname for exposing the "<frontend-micoservice-name>" service:

Provide information about the protocol which your microservice is using. The value can be tcp,udp,http,https, or grpc.

Please enter protocol to be used for service "<service-name>" (tcp/udp/http/https/grpc):

If the Kubernetes service YAML for your microservice is exposing more than one port, then provide the port that is working on the protocol you provided in the previous step.

Found multiple ports in the service "<service-name>". Please enter port to be used <port-list>:

If the HTTPS protocol is being used by any service, provide the secret to configure TLS certificates for NetScaler SSL-based virtual servers.

Please give secret-name for TLS certificate:

For more information on TLS certificate handling by the NetScaler Ingress Controller, see TLS certificates handling in the NetScaler Ingress Controller.

If you want to enable NetScalers to send data to the NetScaler Application Delivery Management, select ‘yes’:

NetScaler ADM required? (Y/N):

Provide NetScaler ADM agent IP address for NetScaler CPX to communicate with ADM, this is generally the service IP address of the ADM container agent:
```
Please provide IP of ADM Agent(svcIP of container agent) for NetScaler CPX:
```
Provide Kubernetes Secret created using NetScaler ADM agent credentials, default value for this is “admlogin”:
```
Please provide name of K8s Secret created using ADM Agent credentials. Press ENTER for 'admlogin':
```

If you want to use NetScaler Ingress Controller for Tier1 Citix NetScaler VPX/MPX, select ‘yes’:

NetScaler Ingress Controller for tier-1 ADC required? (Y/N):

Provide Tier-1 NetScaler VPX/MPX NSIP:
```
Please provide tier-1 ADC NSIP:
```
Provide Tier-1 NetScaler VPX/MPX VIP:
```
Please provide tier-1 ADC VIP:
```
Provide Kubernetes Secret created using NetScaler ADM agent credentials, default value for this is “nslogin”:
```
Please provide name of K8s Secret created using ADC credentials. Press ENTER for 'nslogin':
```
If have you opted to use ADM in step 7, provide NetScaler ADM agent IP address for VPX/MPX to communicate with ADM, this is generally the pod IP address of the ADM container agent:
```
Please provide IP of ADM Agent(podIP of container agent) for NetScaler VPX/MPX:
```

Provide the port on which you want to expose frontend microservice of your application:

 Please provide port used to expose "<frontend-micoservice-name>" service to Tier-1 ADC:

Provide the which protocol you want to expose frontend microservice of your application:

 Please provide protocol used to expose "<frontend-micoservice-name>" service to Tier-1 ADC (tcp/udp/http/https/grpc):

Note:

You must create the Kubernetes secret used for the certificates and access NetScaler or NetScaler ADM agent before applying the service mesh lite YAMLs.

Create Service Mesh lite YAMLs

Get the required files the citrix-k8s-ingress-controller repository from GitHub using the following command.

 wget https://raw.githubusercontent.com/citrix/citrix-k8s-ingress-controller/master/docs/how-to/sml/manifestCreator.py
 wget https://raw.githubusercontent.com/citrix/citrix-k8s-ingress-controller/master/docs/how-to/sml/smlite.py

Run one of the following commands.

python3 smlite.py <list-of-path-of-application-yaml-seperated-by-comma>

or

python3 smlite.py <list-of-service-names-deployed-in-the-cluster-seperated-by-comma> <namespace>

For example:

python3 smlite.py example/netflix.yaml
Please provide name of the service exposed to tier-1: netflix-frontend-service
Please provide hostname for exposing "netflix-frontend-service" service: netflix.citrix
Please enter protocol to be used for service "netflix-frontend-service" (tcp/udp/http/https/grpc): http
Please enter protocol to be used for service "tv-shows-service" (tcp/udp/http/https/grpc): http
Please enter protocol to be used for service "movies-service" (tcp/udp/http/https/grpc): http
Please enter protocol to be used for service "metadata-store-service" (tcp/udp/http/https/grpc): http
Please enter protocol to be used for service "recommendation-engine-service" (tcp/udp/http/https/grpc): http
Please enter protocol to be used for service "trending-service" (tcp/udp/http/https/grpc): http
Please enter protocol to be used for service "similarity-calculator-service" (tcp/udp/http/https/grpc): http
Please enter protocol to be used for service "mutual-friends-interests-service" (tcp/udp/http/https/grpc): http
Please enter protocol to be used for service "telemetry-store-service" (tcp/udp/http/https/grpc): http
NetScaler ADM required? (Y/N): y
Please provide IP of ADM Agent(svcIP of container agent) for NetScaler CPX: 1.1.1.1
Please provide name of K8s Secret created using ADM Agent credentials. Press ENTER for 'admlogin':
NetScaler Ingress Controller for tier-1 ADC required? (Y/N): y
Please provide tier-1 ADC NSIP: 2.2.2.2
Please provide tier-1 ADC VIP: 3.3.3.3
Please provide name of K8s Secret created using ADC credentials. Press ENTER for 'nslogin': nscred
Please provide IP of ADM Agent(podIP of container agent) for NetScaler VPX/MPX: 4.4.4.4
Please provide port used to expose CPX service to Tier-1 ADC: 80
Please provide protocol used to expose CPX service to Tier-1 ADC (tcp/udp/http/https/grpc): http
2021-06-09 16:18:07,466 - SMLITE - INFO - Please note Tier-1 NetScaler VPX ingress tier1-vpx-ingress is created with basic config. Please edit it as per your requirements
2021-06-09 16:18:07,466 - SMLITE - INFO - ServiceMesh Lite YAMLs are created and is present in "smlite-all-in-one.yaml" file.

A YAML named smlite-all-in-one.yaml has been created with all the YAML files of your application for Service Mesh lite architecture.

Note:

If you have used service names which are running inside a cluster to generate the Service Mesh lite YAMLs for them, the smlite-all-in-one.yaml file will not contain the deployment YAML files of the application. In that case, you must deploy the deployment YAML files in the application along with the smlite-all-in-one.yaml file for running your application in the SML architecture.

This script creates an ingress to expose one of the NetScaler CPX (CPX handling your frontend microservice) to the tier-1 NetScaler VPX. This ingress contains basic configuration only. So update this ingress if some additonal configuration is required. For more information on features supported by Citrix ingress contoller, see NetScaler Ingress Controller.

Limitations

The following limitations apply to the automation procedure to generate YAMLs for the Service Mesh lite deployment.

Multiple namespaces are not supported while using this automation script. All YAMLs created by the script work only for the single namespace.

Only dual-tier deployment architecture is supported.

Automated deployment of applications in Service Mesh lite

Prerequisites

Information on required inputs

Create Service Mesh lite YAMLs

Limitations

In this article