Exposing the Dashboard
Instead of using linkerd viz dashboard every time you’d like to see what’s
going on, you can expose the dashboard via an ingress. This will also expose
Grafana.
Nginx
Nginx with basic auth
A sample ingress definition is:
apiVersion: v1
kind: Secret
type: Opaque
metadata:
name: web-ingress-auth
namespace: linkerd-viz
data:
auth: YWRtaW46JGFwcjEkbjdDdTZnSGwkRTQ3b2dmN0NPOE5SWWpFakJPa1dNLgoK
---
# apiVersion: networking.k8s.io/v1beta1 # for k8s < v1.19
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: web-ingress
namespace: linkerd-viz
annotations:
nginx.ingress.kubernetes.io/upstream-vhost: $service_name.$namespace.svc.cluster.local:8084
nginx.ingress.kubernetes.io/configuration-snippet: |
proxy_set_header Origin "";
proxy_hide_header l5d-remote-ip;
proxy_hide_header l5d-server-id;
nginx.ingress.kubernetes.io/auth-type: basic
nginx.ingress.kubernetes.io/auth-secret: web-ingress-auth
nginx.ingress.kubernetes.io/auth-realm: 'Authentication Required'
spec:
ingressClassName: nginx
rules:
- host: dashboard.example.com
http:
paths:
- path: /
pathType: Prefix
backend:
service:
name: web
port:
number: 8084
This exposes the dashboard at dashboard.example.com and protects it with basic
auth using admin/admin. Take a look at the ingress-nginx
documentation for details on how to change the username and password.
Nginx with oauth2-proxy
A more secure alternative to basic auth is using an authentication proxy, such as oauth2-proxy.
For reference on how to deploy and configure oauth2-proxy in kubernetes, see this blog post by Don Bowman.
tl;dr: If you deploy oauth2-proxy via the helm chart, the following values are required:
config:
existingSecret: oauth2-proxy
configFile: |-
email_domains = [ "example.com" ]
upstreams = [ "file:///dev/null" ]
ingress:
enabled: true
annotations:
kubernetes.io/ingress.class: nginx
path: /oauth2
ingress:
hosts:
- linkerd.example.com
Where the oauth2-proxy secret would contain the required oauth2
config
such as, client-id client-secret and cookie-secret.
Once setup, a sample ingress would be:
# apiVersion: networking.k8s.io/v1beta1 # for k8s < v1.19
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: web
namespace: linkerd-viz
annotations:
nginx.ingress.kubernetes.io/upstream-vhost: $service_name.$namespace.svc.cluster.local:8084
nginx.ingress.kubernetes.io/configuration-snippet: |
proxy_set_header Origin "";
proxy_hide_header l5d-remote-ip;
proxy_hide_header l5d-server-id;
nginx.ingress.kubernetes.io/auth-signin: https://$host/oauth2/start?rd=$escaped_request_uri
nginx.ingress.kubernetes.io/auth-url: https://$host/oauth2/auth
spec:
ingressClassName: nginx
rules:
- host: linkerd.example.com
http:
paths:
- path: /
pathType: Prefix
backend:
service:
name: web
port:
number: 8084
Traefik
A sample ingress definition is:
apiVersion: v1
kind: Secret
type: Opaque
metadata:
name: web-ingress-auth
namespace: linkerd-viz
data:
auth: YWRtaW46JGFwcjEkbjdDdTZnSGwkRTQ3b2dmN0NPOE5SWWpFakJPa1dNLgoK
---
# apiVersion: networking.k8s.io/v1beta1 # for k8s < v1.19
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: web-ingress
namespace: linkerd-viz
annotations:
ingress.kubernetes.io/custom-request-headers: l5d-dst-override:web.linkerd-viz.svc.cluster.local:8084
traefik.ingress.kubernetes.io/auth-type: basic
traefik.ingress.kubernetes.io/auth-secret: web-ingress-auth
spec:
ingressClassName: traefik
rules:
- host: dashboard.example.com
http:
paths:
- path: /
pathType: Prefix
backend:
service:
name: web
port:
number: 8084
This exposes the dashboard at dashboard.example.com and protects it with basic
auth using admin/admin. Take a look at the Traefik documentation
for details on how to change the username and password.
Ambassador
Ambassador works by defining a mapping as an annotation on a service.
The below annotation exposes the dashboard at dashboard.example.com.
annotations:
getambassador.io/config: |-
---
apiVersion: getambassador.io/v2
kind: Mapping
name: web-mapping
host: dashboard.example.com
prefix: /
host_rewrite: web.linkerd-viz.svc.cluster.local:8084
service: web.linkerd-viz.svc.cluster.local:8084
DNS Rebinding Protection
To prevent DNS-rebinding attacks,
the dashboard rejects any request whose Host header is not localhost,
127.0.0.1 or the service name web.linkerd-viz.svc.
Note that this protection also covers the Grafana dashboard.
The ingress-nginx config above uses the
nginx.ingress.kubernetes.io/upstream-vhost annotation to properly set the
upstream Host header. Traefik on the other hand doesn’t offer that option, so
you’ll have to manually set the required Host as explained below.
Tweaking Host Requirement
If your HTTP client (Ingress or otherwise) doesn’t allow to rewrite the Host
header, you can change the validation regexp that the dashboard server uses,
which is fed into the web deployment via the enforced-host container
argument.
If you’re managing Linkerd with Helm, then you can set the host using the
enforcedHostRegexp value.
Another way of doing that is through Kustomize, as explained in Customizing Installation, using an overlay like this one:
apiVersion: apps/v1
kind: Deployment
metadata:
name: web
spec:
template:
spec:
containers:
- name: web
args:
- -linkerd-controller-api-addr=linkerd-controller-api.linkerd.svc.cluster.local:8085
- -linkerd-metrics-api-addr=metrics-api.linkerd-viz.svc.cluster.local:8085
- -cluster-domain=cluster.local
- -grafana-addr=grafana.linkerd-viz.svc.cluster.local:3000
- -controller-namespace=linkerd
- -viz-namespace=linkerd-viz
- -log-level=info
- -enforced-host=^dashboard\.example\.com$
If you want to completely disable the Host header check, simply use a
catch-all regexp .* for -enforced-host.
