I have a docker-compose file containing 2 images to a security tool I am using. My challenge is to convert it into helm chart consisting of deployment.yaml and service.yaml. The docker-compose looks like this -

  version: '3'

  services:

  nginx:
    ports:
      - "80:80"
      - "443:443"
    environment:
      - NG_SERVER_NAME=192.168.1.228
    links:
      - tomcat8
    image: continuumsecurity/iriusrisk-prod:nginx-prod-ssl
    container_name: iriusrisk-nginx
    volumes:
      - "./cert.pem:/etc/nginx/ssl/star_iriusrisk_com.crt"
      - "./key.pem:/etc/nginx/ssl/star_iriusrisk_com.key"

  tomcat8:
    environment:
      - IRIUS_DB_URL=jdbc\:postgresql\://192.168.1.228\:5432/iriusprod?user\=iriusprod&password\=alongandcomplexpassword2523
      - IRIUS_EDITION=saas
      - IRIUS_EXT_URL=http\://192.168.1.228
      - grails_env=production
    image: continuumsecurity/iriusrisk-prod:tomcat8-2
    container_name: iriusrisk-tomcat8

There is a postgres server running too which I am able to convert into a helm chart and expose it to my ip (192.168.1.228) on port 5432. But for the iriusrisk and tomcat image which are linked to each other, I am not able to it figure out. This has been my solution for the deployment file for both.

deployment-tomcat.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: tomcat
  labels:
    app: {{ .Values.tomcat.app.name }}
spec:
  replicas: {{ .Values.tomcat.replicas }}
  selector:
    matchLabels:
      app: {{ .Values.tomcat.app.name }}
  template:
    metadata:
      labels:
        app: {{ .Values.tomcat.app.name }}
    spec:
      {{- if .Values.tomcat.imagePullSecretsName }}
      imagePullSecrets:
      - name: {{ .Values.tomcat.imagePullSecretsName }}
      {{- end}}
      restartPolicy: Always
      serviceAccountName: {{ .Values.tomcat.serviceAccountName }}

      containers:
      - name: {{ .Values.tomcat.app.name }}
        image: "{{ .Values.tomcat.ImageName }}:{{ .Values.tomcat.ImageTag }}"
        container_name: iriusrisk-tomcat8
        imagePullPolicy: {{ .Values.tomcat.ImagePullPolicy }}
        ports:
        - containerPort: {{ .Values.tomcat.port }}
        env:
          - name: IRIUS_DB_URL
            value: jdbc\:postgresql\://192.168.1.228\:5432/iriusprod?user\=iriusprod&password\=alongandcomplexpassword2523
          - name: IRIUS_EDITION
            value: saas
          - name: IRIUS_EXT_URL
            value: http\://192.168.1.228
          - name: grails_env
            value: production

deployment-iriusrisk.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: iriusrisk
  labels:
    app: {{ .Values.iriusrisk.app.name }}
spec:
  replicas: {{ .Values.iriusrisk.replicas }}
  selector:
    matchLabels:
      app: {{ .Values.iriusrisk.app.name }}
  template:
    metadata:
      labels:
        app: {{ .Values.iriusrisk.app.name }}
    spec:
      {{- if .Values.iriusrisk.imagePullSecretsName }}
      imagePullSecrets:
      - name: {{ .Values.iriusrisk.imagePullSecretsName }}
      {{- end}}
      restartPolicy: Always
      serviceAccountName: {{ .Values.iriusrisk.serviceAccountName }}

      containers:
      - name: {{ .Values.iriusrisk.app.name }}
        image: "{{ .Values.iriusrisk.ImageName }}:{{ .Values.iriusrisk.ImageTag }}"
        container_name: iriusrisk-nginx
        imagePullPolicy: {{ .Values.iriusrisk.ImagePullPolicy }}
        ports:
        - containerPort: {{ .Values.iriusrisk.port }}
        env:
          - name: NG_SERVER_NAME
            value: "192.168.1.228"
        volumes: 
          - "./cert.pem:/etc/nginx/ssl/star_iriusrisk_com.crt"
          - "./key.pem:/etc/nginx/ssl/star_iriusrisk_com.key"

How should I go around solving this issue? I have looked at "linking" pods with each other but none of the solutions I tried worked. I am bit new to this hence I am still a bit confused about how to expose pods and connect to each other.