# Ingress Configuration

Argo CD runs both a gRPC server (used by the CLI), as well as a HTTP/HTTPS server (used by the UI).
Both protocols are exposed by the argocd-server service object on the following ports:

* 443 - gRPC/HTTPS
* 80 - HTTP (redirects to HTTPS)

There are several ways how Ingress can be configured.

## [Ambassador](https://www.getambassador.io/)

The Ambassador Edge Stack can be used as a Kubernetes ingress controller with [automatic TLS termination](https://www.getambassador.io/docs/latest/topics/running/tls/#host) and routing capabilities for both the CLI and the UI.

The API server should be run with TLS disabled. Edit the `argocd-server` deployment to add the `--insecure` flag to the argocd-server command. Given the `argocd` CLI includes the port number in the request `host` header, 2 Mappings are required.

### Option 1: Mapping CRD for Host-based Routing
```yaml
apiVersion: getambassador.io/v2
kind: Mapping
metadata:
  name: argocd-server-ui
  namespace: argocd
spec:
  host: argocd.example.com
  prefix: /
  service: argocd-server:443
---
apiVersion: getambassador.io/v2
kind: Mapping
metadata:
  name: argocd-server-cli
  namespace: argocd
spec:
  host: argocd.example.com:443
  prefix: /
  service: argocd-server:443
```

Login with the `argocd` CLI using the extra `--grpc-web-root-path` flag for gRPC-web.

```shell
argocd login <host>:<port> --grpc-web-root-path /
```

### Option 2: Mapping CRD for Path-based Routing

The API server must be configured to be available under a non-root path (e.g. `/argo-cd`). Edit the `argocd-server` deployment to add the `--rootpath=/argo-cd` flag to the argocd-server command.

```yaml
apiVersion: getambassador.io/v2
kind: Mapping
metadata:
  name: argocd-server
  namespace: argocd
spec:
  prefix: /argo-cd
  rewrite: /argo-cd
  service: argocd-server:443
```

Login with the `argocd` CLI using the extra `--grpc-web-root-path` flag for non-root paths.

```shell
argocd login <host>:<port> --grpc-web-root-path /argo-cd
```

## [Contour](https://projectcontour.io/)
The Contour ingress controller can terminate TLS ingress traffic at the edge.

The Argo CD API server should be run with TLS disabled. Edit the `argocd-server` Deployment to add the `--insecure` flag to the argocd-server container command.

It is also possible to provide an internal-only ingress path and an external-only ingress path by deploying two instances of Contour: one behind a private-subnet LoadBalancer service and one behind a public-subnet LoadBalancer service. The private Contour deployment will pick up Ingresses annotated with `kubernetes.io/ingress.class: contour-external` and the public Contour deployment will pick up Ingresses annotated with `kubernetes.io/ingress.class: contour-external`.

This provides the opportunity to deploy the Argo CD UI privately but still allow for SSO callbacks to succeed.

### Private Argo CD UI with  Multiple Ingress Objects and BYO Certificate
Since Contour Ingress supports only a single protocol per Ingress object, define three Ingress objects. One for private HTTP/HTTPS, one for private gRPC, and one for public HTTPS SSO callbacks.

Internal HTTP/HTTPS Ingress:
```yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: argocd-server-http
  annotations:
    kubernetes.io/ingress.class: contour-internal
    ingress.kubernetes.io/force-ssl-redirect: "true"
spec:
  rules:
  - host: internal.path.to.argocd.io
    http:
      paths:
      - backend:
          serviceName: argocd-server
          servicePort: http
  tls:
  - hosts:
    - internal.path.to.argocd.io
    secretName: your-certificate-name
```

Internal gRPC Ingress:
```yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: argocd-server-grpc
  annotations:
    kubernetes.io/ingress.class: contour-internal
spec:
  rules:
  - host: grpc-internal.path.to.argocd.io
    http:
      paths:
      - backend:
          serviceName: argocd-server
          servicePort: https
  tls:
  - hosts:
    - grpc-internal.path.to.argocd.io
    secretName: your-certificate-name
```

External HTTPS SSO Callback Ingress:
```yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: argocd-server-external-callback-http
  annotations:
    kubernetes.io/ingress.class: contour-external
    ingress.kubernetes.io/force-ssl-redirect: "true"
spec:
  rules:
  - host: external.path.to.argocd.io
    http:
      paths:
      - path: /api/dex/callback
        backend:
          serviceName: argocd-server
          servicePort: http
  tls:
  - hosts:
    - external.path.to.argocd.io
    secretName: your-certificate-name
```

The argocd-server Service needs to be annotated with `projectcontour.io/upstream-protocol.h2c: "https,443"` to wire up the gRPC protocol proxying.

The API server should then be run with TLS disabled. Edit the `argocd-server` deployment to add the
`--insecure` flag to the argocd-server command:

```yaml
spec:
  template:
    spec:
      containers:
      - name: argocd-server
        command:
        - /argocd-server
        - --repo-server
        - argocd-repo-server:8081
        - --insecure
```

## [kubernetes/ingress-nginx](https://github.com/kubernetes/ingress-nginx)

### Option 1: SSL-Passthrough

Argo CD serves multiple protocols (gRPC/HTTPS) on the same port (443), this provides a
challenge when attempting to define a single nginx ingress object and rule for the argocd-service,
since the `nginx.ingress.kubernetes.io/backend-protocol` [annotation](https://kubernetes.github.io/ingress-nginx/user-guide/nginx-configuration/annotations/#backend-protocol)
accepts only a single value for the backend protocol (e.g. HTTP, HTTPS, GRPC, GRPCS).

In order to expose the Argo CD API server with a single ingress rule and hostname, the
`nginx.ingress.kubernetes.io/ssl-passthrough` [annotation](https://kubernetes.github.io/ingress-nginx/user-guide/nginx-configuration/annotations/#ssl-passthrough)
must be used to passthrough TLS connections and terminate TLS at the Argo CD API server.

```yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: argocd-server-ingress
  namespace: argocd
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/force-ssl-redirect: "true"
    nginx.ingress.kubernetes.io/ssl-passthrough: "true"
spec:
  rules:
  - host: argocd.example.com
    http:
      paths:
      - backend:
          serviceName: argocd-server
          servicePort: https
```

The above rule terminates TLS at the Argo CD API server, which detects the protocol being used,
and responds appropriately. Note that the `nginx.ingress.kubernetes.io/ssl-passthrough` annotation
requires that the `--enable-ssl-passthrough` flag be added to the command line arguments to
`nginx-ingress-controller`.

#### SSL-Passthrough with cert-manager and Let's Encrypt

```yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: argocd-server-ingress
  namespace: argocd
  annotations:
    cert-manager.io/cluster-issuer: letsencrypt-prod
    kubernetes.io/ingress.class: nginx
    kubernetes.io/tls-acme: "true"
    nginx.ingress.kubernetes.io/ssl-passthrough: "true"
    # If you encounter a redirect loop or are getting a 307 response code 
    # then you need to force the nginx ingress to connect to the backend using HTTPS.
    #
    nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
spec:
  rules:
  - host: argocd.example.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service: 
            name: argocd-server
            port:
              name: https
  tls:
  - hosts:
    - argocd.example.com
    secretName: argocd-secret # do not change, this is provided by Argo CD
```

### Option 2: Multiple Ingress Objects And Hosts

Since ingress-nginx Ingress supports only a single protocol per Ingress object, an alternative
way would be to define two Ingress objects. One for HTTP/HTTPS, and the other for gRPC:

HTTP/HTTPS Ingress:
```yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: argocd-server-http-ingress
  namespace: argocd
  annotations:
    kubernetes.io/ingress.class: "nginx"
    nginx.ingress.kubernetes.io/force-ssl-redirect: "true"
    nginx.ingress.kubernetes.io/backend-protocol: "HTTP"
spec:
  rules:
  - http:
      paths:
      - backend:
          serviceName: argocd-server
          servicePort: http
    host: argocd.example.com
  tls:
  - hosts:
    - argocd.example.com
    secretName: argocd-secret # do not change, this is provided by Argo CD
```

gRPC Ingress:
```yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: argocd-server-grpc-ingress
  namespace: argocd
  annotations:
    kubernetes.io/ingress.class: "nginx"
    nginx.ingress.kubernetes.io/backend-protocol: "GRPC"
spec:
  rules:
  - http:
      paths:
      - backend:
          serviceName: argocd-server
          servicePort: https
    host: grpc.argocd.example.com
  tls:
  - hosts:
    - grpc.argocd.example.com
    secretName: argocd-secret # do not change, this is provided by Argo CD
```

The API server should then be run with TLS disabled. Edit the `argocd-server` deployment to add the
`--insecure` flag to the argocd-server command:

```yaml
spec:
  template:
    spec:
      containers:
      - name: argocd-server
        command:
        - argocd-server
        - --repo-server
        - argocd-repo-server:8081
        - --insecure
```

The obvious disadvantage to this approach is that this technique requires two separate hostnames for
the API server -- one for gRPC and the other for HTTP/HTTPS. However it allows TLS termination to
happen at the ingress controller.


## [Traefik (v2.2)](https://docs.traefik.io/)

Traefik can be used as an edge router and provide [TLS](https://docs.traefik.io/user-guides/grpc/) termination within the same deployment.

It currently has an advantage over NGINX in that it can terminate both TCP and HTTP connections _on the same port_ meaning you do not require multiple hosts or paths.

The API server should be run with TLS disabled. Edit the `argocd-server` deployment to add the `--insecure` flag to the argocd-server command.

### IngressRoute CRD
```yaml
apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: argocd-server
  namespace: argocd
spec:
  entryPoints:
    - websecure
  routes:
    - kind: Rule
      match: Host(`argocd.example.com`)
      priority: 10
      services:
        - name: argocd-server
          port: 80
    - kind: Rule
      match: Host(`argocd.example.com`) && Headers(`Content-Type`, `application/grpc`)
      priority: 11
      services:
        - name: argocd-server
          port: 80
          scheme: h2c
  tls:
    certResolver: default
    options: {}
```

## AWS Application Load Balancers (ALBs) And Classic ELB (HTTP Mode)
AWS ALBs can be used as an L7 Load Balancer for both UI and gRPC traffic, whereas Classic ELBs and NLBs can be used as L4 Load Balancers for both. 

When using an ALB, you'll want to create a second service for argocd-server. This is necessary because we need to tell the ALB to send the GRPC traffic to a different target group then the UI traffic, since the backend protocol is HTTP2 instead of HTTP1.

```yaml
apiVersion: v1
kind: Service
metadata:
  annotations:
    alb.ingress.kubernetes.io/backend-protocol-version: HTTP2 #This tells AWS to send traffic from the ALB using HTTP2. Can use GRPC as well if you want to leverage GRPC specific features
  labels:
    app: argogrpc
  name: argogrpc
  namespace: argocd
spec:
  ports:
  - name: "443"
    port: 443
    protocol: TCP
    targetPort: 8080
  selector:
    app.kubernetes.io/name: argocd-server
  sessionAffinity: None
  type: NodePort
```

Once we create this service, we can configure the Ingress to conditionally route all `application/grpc` traffic to the new HTTP2 backend, using the `alb.ingress.kubernetes.io/conditions` annotation, as seen below. Note: The value after the . in the condition annotation _must_ be the same name as the service that you want traffic to route to - and will be applied on any path with a matching serviceName. 

```yaml
  apiVersion: networking.k8s.io/v1 # Use extensions/v1beta1 for Kubernetes 1.18 and older
  kind: Ingress
  metadata:
    annotations:
      alb.ingress.kubernetes.io/backend-protocol: HTTPS
      # Use this annotation (which must match a service name) to route traffic to HTTP2 backends. 
      alb.ingress.kubernetes.io/conditions.argogrpc: |
        [{"field":"http-header","httpHeaderConfig":{"httpHeaderName": "Content-Type", "values":["application/grpc"]}}]
      alb.ingress.kubernetes.io/listen-ports: '[{"HTTPS":443}]'
    name: argocd
    namespace: argocd
  spec:
    rules:
    - host: argocd.argoproj.io
      http:
        paths:
        - backend:
            serviceName: argogrpc
            servicePort: 443
          pathType: ImplementationSpecific
        - backend:
            serviceName: argocd-server
            servicePort: 443
          pathType: ImplementationSpecific
    tls:
    - hosts:
      - argocd.argoproj.io
```

## Authenticating through multiple layers of authenticating reverse proxies

ArgoCD endpoints may be protected by one or more reverse proxies layers, in that case, you can provide additional headers through the `argocd` CLI `--header` parameter to authenticate through those layers.

```shell
$ argocd login <host>:<port> --header 'x-token1:foo' --header 'x-token2:bar' # can be repeated multiple times
$ argocd login <host>:<port> --header 'x-token1:foo,x-token2:bar' # headers can also be comma separated
```
## ArgoCD Server and UI Root Path (v1.5.3)

ArgoCD server and UI can be configured to be available under a non-root path (e.g. `/argo-cd`).
To do this, add the `--rootpath` flag into the `argocd-server` deployment command:

```yaml
spec:
  template:
    spec:
      name: argocd-server
      containers:
      - command:
        - /argocd-server
        - --repo-server
        - argocd-repo-server:8081
        - --rootpath
        - /argo-cd
```
NOTE: The flag `--rootpath` changes both API Server and UI base URL. 
Example nginx.conf:

```
worker_processes 1;

events { worker_connections 1024; }

http {

    sendfile on;

    server {
        listen 443;

        location /argo-cd/ {
            proxy_pass         https://localhost:8080/argo-cd/;
            proxy_redirect     off;
            proxy_set_header   Host $host;
            proxy_set_header   X-Real-IP $remote_addr;
            proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header   X-Forwarded-Host $server_name;
            # buffering should be disabled for api/v1/stream/applications to support chunked response
            proxy_buffering off;
        }
    }
}
```
Flag ```--grpc-web-root-path ``` is used to provide a non-root path (e.g. /argo-cd)

```shell
$ argocd login <host>:<port> --grpc-web-root-path /argo-cd
```

## UI Base Path

If the Argo CD UI is available under a non-root path (e.g. `/argo-cd` instead of `/`) then the UI path should be configured in the API server.
To configure the UI path add the `--basehref` flag into the `argocd-server` deployment command:

```yaml
spec:
  template:
    spec:
      name: argocd-server
      containers:
      - command:
        - /argocd-server
        - --repo-server
        - argocd-repo-server:8081
        - --basehref
        - /argo-cd
```

NOTE: The flag `--basehref` only changes the UI base URL. The API server will keep using the `/` path so you need to add a URL rewrite rule to the proxy config.
Example nginx.conf with URL rewrite:

```
worker_processes 1;

events { worker_connections 1024; }

http {

    sendfile on;

    server {
        listen 443;

        location /argo-cd {
            rewrite /argo-cd/(.*) /$1  break;
            proxy_pass         https://localhost:8080;
            proxy_redirect     off;
            proxy_set_header   Host $host;
            proxy_set_header   X-Real-IP $remote_addr;
            proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header   X-Forwarded-Host $server_name;
            # buffering should be disabled for api/v1/stream/applications to support chunked response
            proxy_buffering off;
        }
    }
}
```
