kubernetes-ingress nginx-reverse-proxy sentry nginx-ingress amazon-eks

How to resolve paths conflict in nginx ingress?

I'm running sentry on my EKS cluster and according to the official documentation it can only be exposed on rootPath "/" i'm also exposing keycloak on "/auth" which is the default web-context So i deployed nginx ingress controller and ingress resources to match these paths, but the problem i encountered was that sentry path ("/") is always redirected to "/auth" which is the default path of keycloak which would cause a conflict. in my case i'm not allowed to change the web-context of keycloak so i tried to deploy another nginx ingress controller for sentry with the same class but i did not know how to do it since all examples are using ingress controllers with different classes. so i would like to know if this possible how to deploy a seconf nginx ingress which is pretty much the same as the first one or if there is another solution please help me know it.

Here is nginx ingress controller i use :

apiVersion: v1
kind: Namespace
metadata:
  name: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx

---
# Source: ingress-nginx/templates/controller-serviceaccount.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.31.1
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx
  namespace: ingress-nginx
---
# Source: ingress-nginx/templates/controller-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.31.1
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx-controller
  namespace: ingress-nginx
data:
---
# Source: ingress-nginx/templates/clusterrole.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.31.1
    app.kubernetes.io/managed-by: Helm
  name: ingress-nginx
  namespace: ingress-nginx
rules:
  - apiGroups:
      - ''
    resources:
      - configmaps
      - endpoints
      - nodes
      - pods
      - secrets
    verbs:
      - list
      - watch
  - apiGroups:
      - ''
    resources:
      - nodes
    verbs:
      - get
  - apiGroups:
      - ''
    resources:
      - services
    verbs:
      - get
      - list
      - update
      - watch
  - apiGroups:
      - extensions
      - networking.k8s.io   # k8s 1.14+
    resources:
      - ingresses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - ''
    resources:
      - events
    verbs:
      - create
      - patch
  - apiGroups:
      - extensions
      - networking.k8s.io   # k8s 1.14+
    resources:
      - ingresses/status
    verbs:
      - update
  - apiGroups:
      - networking.k8s.io   # k8s 1.14+
    resources:
      - ingressclasses
    verbs:
      - get
      - list
      - watch
---
# Source: ingress-nginx/templates/clusterrolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.31.1
    app.kubernetes.io/managed-by: Helm
  name: ingress-nginx
  namespace: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: ingress-nginx
subjects:
  - kind: ServiceAccount
    name: ingress-nginx
    namespace: ingress-nginx
---
# Source: ingress-nginx/templates/controller-role.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.31.1
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx
  namespace: ingress-nginx
rules:
  - apiGroups:
      - ''
    resources:
      - namespaces
    verbs:
      - get
  - apiGroups:
      - ''
    resources:
      - configmaps
      - pods
      - secrets
      - endpoints
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - ''
    resources:
      - services
    verbs:
      - get
      - list
      - update
      - watch
  - apiGroups:
      - extensions
      - networking.k8s.io   # k8s 1.14+
    resources:
      - ingresses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - extensions
      - networking.k8s.io   # k8s 1.14+
    resources:
      - ingresses/status
    verbs:
      - update
  - apiGroups:
      - networking.k8s.io   # k8s 1.14+
    resources:
      - ingressclasses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - ''
    resources:
      - configmaps
    resourceNames:
      - ingress-controller-leader-nginx
    verbs:
      - get
      - update
  - apiGroups:
      - ''
    resources:
      - configmaps
    verbs:
      - create
  - apiGroups:
      - ''
    resources:
      - endpoints
    verbs:
      - create
      - get
      - update
  - apiGroups:
      - ''
    resources:
      - events
    verbs:
      - create
      - patch
---
# Source: ingress-nginx/templates/controller-rolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.31.1
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx
  namespace: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: ingress-nginx
subjects:
  - kind: ServiceAccount
    name: ingress-nginx
    namespace: ingress-nginx
---
# Source: ingress-nginx/templates/controller-service-webhook.yaml
apiVersion: v1
kind: Service
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.31.1
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx-controller-admission
  namespace: ingress-nginx
spec:
  type: ClusterIP
  ports:
    - name: https-webhook
      port: 443
      targetPort: webhook
  selector:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/component: controller
---
# Source: ingress-nginx/templates/controller-service.yaml
apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/aws-load-balancer-backend-protocol: tcp
    service.beta.kubernetes.io/aws-load-balancer-connection-idle-timeout: '60'
    service.beta.kubernetes.io/aws-load-balancer-cross-zone-load-balancing-enabled: 'true'
    service.beta.kubernetes.io/aws-load-balancer-type: nlb
    service.beta.kubernetes.io/aws-load-balancer-internal: "true"
  labels:
    helm.sh/chart: ingress-nginx-2.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.31.1
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx-controller
  namespace: ingress-nginx
spec:
  type: LoadBalancer
  externalTrafficPolicy: Local
  ports:
    - name: http
      port: 80
      protocol: TCP
      targetPort: http
    - name: https
      port: 443
      protocol: TCP
      targetPort: https
  selector:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/component: controller
---
# Source: ingress-nginx/templates/controller-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.31.1
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx-controller
  namespace: ingress-nginx
spec:
  selector:
    matchLabels:
      app.kubernetes.io/name: ingress-nginx
      app.kubernetes.io/instance: ingress-nginx
      app.kubernetes.io/component: controller
  revisionHistoryLimit: 10
  minReadySeconds: 0
  template:
    metadata:
      labels:
        app.kubernetes.io/name: ingress-nginx
        app.kubernetes.io/instance: ingress-nginx
        app.kubernetes.io/component: controller
    spec:
      dnsPolicy: ClusterFirst
      containers:
        - name: controller
          image: quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.31.1
          imagePullPolicy: IfNotPresent
          lifecycle:
            preStop:
              exec:
                command:
                  - /wait-shutdown
          args:
            - /nginx-ingress-controller
            - --publish-service=ingress-nginx/ingress-nginx-controller
            - --election-id=ingress-controller-leader
            - --ingress-class=nginx
            - --configmap=ingress-nginx/ingress-nginx-controller
            - --validating-webhook=:8443
            - --validating-webhook-certificate=/usr/local/certificates/cert
            - --validating-webhook-key=/usr/local/certificates/key
          securityContext:
            capabilities:
              drop:
                - ALL
              add:
                - NET_BIND_SERVICE
            runAsUser: 101
            allowPrivilegeEscalation: true
          env:
            - name: POD_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
          livenessProbe:
            httpGet:
              path: /healthz
              port: 10254
              scheme: HTTP
            initialDelaySeconds: 10
            periodSeconds: 10
            timeoutSeconds: 1
            successThreshold: 1
            failureThreshold: 3
          readinessProbe:
            httpGet:
              path: /healthz
              port: 10254
              scheme: HTTP
            initialDelaySeconds: 10
            periodSeconds: 10
            timeoutSeconds: 1
            successThreshold: 1
            failureThreshold: 3
          ports:
            - name: http
              containerPort: 80
              protocol: TCP
            - name: https
              containerPort: 443
              protocol: TCP
            - name: webhook
              containerPort: 8443
              protocol: TCP
          volumeMounts:
            - name: webhook-cert
              mountPath: /usr/local/certificates/
              readOnly: true
          resources:
            requests:
              cpu: 100m
              memory: 90Mi
      serviceAccountName: ingress-nginx
      terminationGracePeriodSeconds: 300
      volumes:
        - name: webhook-cert
          secret:
            secretName: ingress-nginx-admission
---
# Source: ingress-nginx/templates/admission-webhooks/validating-webhook.yaml
apiVersion: admissionregistration.k8s.io/v1beta1
kind: ValidatingWebhookConfiguration
metadata:
  labels:
    helm.sh/chart: ingress-nginx-2.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.31.1
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  name: ingress-nginx-admission
  namespace: ingress-nginx
webhooks:
  - name: validate.nginx.ingress.kubernetes.io
    rules:
      - apiGroups:
          - extensions
          - networking.k8s.io
        apiVersions:
          - v1beta1
        operations:
          - CREATE
          - UPDATE
        resources:
          - ingresses
    failurePolicy: Fail
    clientConfig:
      service:
        namespace: ingress-nginx
        name: ingress-nginx-controller-admission
        path: /extensions/v1beta1/ingresses
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/clusterrole.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: ingress-nginx-admission
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-2.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.31.1
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  namespace: ingress-nginx
rules:
  - apiGroups:
      - admissionregistration.k8s.io
    resources:
      - validatingwebhookconfigurations
    verbs:
      - get
      - update
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/clusterrolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: ingress-nginx-admission
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-2.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.31.1
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  namespace: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: ingress-nginx-admission
subjects:
  - kind: ServiceAccount
    name: ingress-nginx-admission
    namespace: ingress-nginx
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/job-createSecret.yaml
apiVersion: batch/v1
kind: Job
metadata:
  name: ingress-nginx-admission-create
  annotations:
    helm.sh/hook: pre-install,pre-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-2.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.31.1
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  namespace: ingress-nginx
spec:
  template:
    metadata:
      name: ingress-nginx-admission-create
      labels:
        helm.sh/chart: ingress-nginx-2.0.1
        app.kubernetes.io/name: ingress-nginx
        app.kubernetes.io/instance: ingress-nginx
        app.kubernetes.io/version: 0.31.1
        app.kubernetes.io/managed-by: Helm
        app.kubernetes.io/component: admission-webhook
    spec:
      containers:
        - name: create
          image: jettech/kube-webhook-certgen:v1.0.0
          imagePullPolicy: IfNotPresent
          args:
            - create
            - --host=ingress-nginx-controller-admission,ingress-nginx-controller-admission.ingress-nginx.svc
            - --namespace=ingress-nginx
            - --secret-name=ingress-nginx-admission
      restartPolicy: OnFailure
      serviceAccountName: ingress-nginx-admission
      securityContext:
        runAsNonRoot: true
        runAsUser: 2000
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/job-patchWebhook.yaml
apiVersion: batch/v1
kind: Job
metadata:
  name: ingress-nginx-admission-patch
  annotations:
    helm.sh/hook: post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-2.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.31.1
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  namespace: ingress-nginx
spec:
  template:
    metadata:
      name: ingress-nginx-admission-patch
      labels:
        helm.sh/chart: ingress-nginx-2.0.1
        app.kubernetes.io/name: ingress-nginx
        app.kubernetes.io/instance: ingress-nginx
        app.kubernetes.io/version: 0.31.1
        app.kubernetes.io/managed-by: Helm
        app.kubernetes.io/component: admission-webhook
    spec:
      containers:
        - name: patch
          image: jettech/kube-webhook-certgen:v1.0.0
          imagePullPolicy:
          args:
            - patch
            - --webhook-name=ingress-nginx-admission
            - --namespace=ingress-nginx
            - --patch-mutating=false
            - --secret-name=ingress-nginx-admission
            - --patch-failure-policy=Fail
      restartPolicy: OnFailure
      serviceAccountName: ingress-nginx-admission
      securityContext:
        runAsNonRoot: true
        runAsUser: 2000
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/role.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: ingress-nginx-admission
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-2.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.31.1
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  namespace: ingress-nginx
rules:
  - apiGroups:
      - ''
    resources:
      - secrets
    verbs:
      - get
      - create
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/rolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: ingress-nginx-admission
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-2.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.31.1
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  namespace: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: ingress-nginx-admission
subjects:
  - kind: ServiceAccount
    name: ingress-nginx-admission
    namespace: ingress-nginx
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/serviceaccount.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  name: ingress-nginx-admission
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-2.0.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.31.1
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  namespace: ingress-nginx

Here is the ingress resources :

Keycloak :

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: "keycloak-ingress"
  annotations:
    kubernetes.io/ingress.class: nginx
  labels:
    app: keycloak-ingress
spec:
  rules:
    - http:
        paths: 
          - path: /auth
            backend:
              serviceName: keycloak
              servicePort: 8080

Sentry :

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: "sentry-ingress"
  namespace: "tools"
  annotations:
    kubernetes.io/ingress.class: sentry-nginx
    nginx.ingress.kubernetes.io/force-ssl-redirect: "true"
  labels:
    app: sentry-ingress
spec:
  rules:
    - http:
        paths:
          - path: /
            backend:
              serviceName: "sentry"
              servicePort: 9000

Solution

keycloak is exposed on "/auth" which is the default web-context.

I understand that as default web-context, means that you want everything sent to / should be redirected to keycloak.
So you need to set a different target for Sentry, like /sentry.
kubernetes.io/ingress.class: sentry-nginx is not a valid ingress.class in kubernetes.io that's probably why your ingress is not being considered.
Only one deployment of Nginx-Ingress is needed to proxy traffic between multiple apps.
The trick here is to expose sentry as mydomain.com/sentry and the app itself receives the connection directly on / as required.

In order to achieve it you can use rewrite-target, learn more here.

It will create a capture group and send to the appropriate service.
This is what your ingress should look like:

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: "my-ingress"
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/rewrite-target: /$2
  labels:
    app: my-ingress
spec:
  rules:
    - http:
        paths: 
          - path: /(.*)
            backend:
              serviceName: keycloak
              servicePort: 8080
          - path: /sentry(/|$)(.*)
            backend:
              serviceName: sentry
              servicePort: 9000

This will do the following:

Requests to / will be delivered to keycloak as /
Requests to /auth will be delivered to keycloak as /
Requests to /auth/foo will be delivered to keycloak as /foo
Requests to /sentry will be delivered to sentry as /
Requests to /sentry/bar will be delivered to sentry as /bar
Nginx Ingress uses Path Priority:

In NGINX, regular expressions follow a first match policy. In order to enable more accurate path matching, ingress-nginx first orders the paths by descending length before writing them to the NGINX template as location blocks.

Example:

this is the ingress in my example echo-ingress.yaml:

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: echo-ingress
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/rewrite-target: /$2
spec:
  rules:
    - host: mydomain.com
      http:
        paths:
          - path: /(.*)
            backend:
              serviceName: echo1-svc
              servicePort: 80
          - path: /sentry(/|$)(.*)
            backend:
              serviceName: echo2-svc
              servicePort: 80

I created 2 echo apps, to demonstrate it:

echo1-deploy.yaml: emulates your keycloak

apiVersion: apps/v1
kind: Deployment
metadata:
 name: echo1-deploy
spec:
 selector:
   matchLabels:
     app: echo1-app
 template:
   metadata:
     labels:
       app: echo1-app
   spec:
     containers:
     - name: echo1-app
       image: mendhak/http-https-echo
       ports:
       - name: http
         containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
 name: echo1-svc
spec:
 selector:
   app: echo1-app
 ports:
   - protocol: TCP
     port: 80
     targetPort: 80

echo2-deploy.yaml: emulates your sentry

apiVersion: apps/v1
kind: Deployment
metadata:
 name: echo2-deploy
spec:
 selector:
   matchLabels:
     app: echo2-app
 template:
   metadata:
     labels:
       app: echo2-app
   spec:
     containers:
     - name: echo2-app
       image: mendhak/http-https-echo
       ports:
       - name: http
         containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
 name: echo2-svc
spec:
 selector:
   app: echo2-app
 ports:
   - protocol: TCP
     port: 80
     targetPort: 80

Let's apply and test the outcome:

$ kubectl apply -f echo1-deploy.yaml 
deployment.apps/echo1-deploy created
service/echo1-svc created

$ kubectl apply -f echo2-deploy.yaml 
deployment.apps/echo2-deploy created
service/echo2-svc created

$ kubectl apply -f echo-ingress.yaml 
ingress.networking.k8s.io/echo-ingress created

$ kubectl get ingress
NAME           HOSTS          ADDRESS        PORTS   AGE
echo-ingress   mydomain.com   35.188.7.149   80      48s

$ tail -n 1 /etc/hosts
35.188.7.149 mydomain.com

$ curl mydomain.com/sentry
{"path": "/",
...suppressed output...
  "os": {"hostname": "echo2-deploy-7bcb8f8d5f-dwzkr"}
}
$ curl mydomain.com/auth
{"path": "/",
...suppressed output...
  "os": {"hostname": "echo1-deploy-764d5df7cf-6m5nz"}
}

$ curl mydomain.com
{"path": "/",
  "os": {"hostname": "echo1-deploy-764d5df7cf-6m5nz"}
}

We can see that the requested were correctly forwarded to the pod responsible for the app set in the ingress with the rewrite target.

Considerations:

Sentry "can only be exposed on rootPath "/"

I found out that Sentry can be exposed on other paths, check here and here, it might be worth checking.
If I got wrong your environment or you have any question let me know in the comments and I'll modify it =)