Routing, Proxying, and Load Balancing

Routes

A Route defines how to access a service running behind Pomerium. This includes authentication (both for Pomerium and passed through to the service), rewrites, header management, load balancing, etc.

When first installing Pomerium Enterprise, users may want to import existing routes from the open-source Pomerium core. The Import Routes button accepts the open-source config.yaml file and imports routes from it to Pomerium Enterprise.

From the main Routes page you can view and manage existing routes. From the table of routes you can:

filter visible routes,
delete one or more routes,
move routes between Namespaces,
export one or more route definitions to a CSV file

create a JSON-formatted policy report on one or more selected routes.

The sections below cover the options available when creating or editing a route.

General

The General tab defines the route path, both from the internet and to the internal service, and the policies attached. Note that policies enforced on a [Namespace][namespace-reference] the route resides in will also be applied.

Name

This value is only visible in the Console UI.

From

From is the externally accessible URL for the proxied request.

Specifying tcp+https for the scheme enables TCP proxying support for the route. You may map more than one port through the same hostname by specifying a different :port in the URL.

danger

Only secure schemes (https and tcp+https) are supported.

Metrics Name

Once a Route is created, the Metric Name field will populate. You can use this name to scrape the Prometheus service for metrics on this Route when making custom dashboards.

To

To is the destination(s) of a proxied request. It can be an internal resource, or an external resource. Multiple upstream resources can be targeted by using a list instead of a single URL:

- from: https://example.com
  to:
    - https://a.example.com
    - https://b.example.com

A load balancing weight may be associated with a particular upstream by appending ,[weight] to the URL. The exact behavior depends on your lb_policy setting. See Load Balancing for example configurations.

Must be tcp if from is tcp+https.

danger

Be careful with trailing slash.

With rule:

- from: https://verify.corp.example.com
  to: https://verify.pomerium.com/anything

Requests to https://verify.corp.example.com will be forwarded to https://verify.pomerium.com/anything, while requests to https://verify.corp.example.com/foo will be forwarded to https://verify.pomerium.com/anythingfoo.To make the request forwarded to https://httbin.org/anything/foo, you can use double slashes in your request https://httbin.corp.example.com//foo.

While the rule:

- from: https://verify.corp.example.com
  to: https://verify.pomerium.com/anything/

All requests to https://verify.corp.example.com/* will be forwarded to https://verify.pomerium.com/anything/*. That means accessing to https://verify.corp.example.com will be forwarded to https://verify.pomerium.com/anything/. That said, if your application does not handle trailing slash, the request will end up with 404 not found.

Either redirect or to must be set.

Redirect

Redirect is used to redirect incoming requests to a new URL. The redirect field is an object with several possible options:

https_redirect (boolean): the incoming scheme will be swapped with "https".
scheme_redirect (string): the incoming scheme will be swapped with the given value.
host_redirect (string): the incoming host will be swapped with the given value.
port_redirect (integer): the incoming port will be swapped with the given value.
path_redirect (string): the incoming path portion of the URL will be swapped with the given value.
prefix_rewrite (string): the incoming matched prefix will be swapped with the given value.
response_code (integer): the response code to use for the redirect. Defaults to 301.
strip_query (boolean): indicates that during redirection, the query portion of the URL will be removed. Defaults to false.

Either redirect or to must be set.

Pass Identity Headers

When enabled, this option will pass identity headers to upstream applications. These headers include:

X-Pomerium-Jwt-Assertion
X-Pomerium-Claim-*

Policies

Add or remove Policies to be applied to the Route. Note that Policies enforced in the Route's Namespace will be applied automatically.

Enable Google Cloud Serverless Authentication

Enable sending a signed Authorization Header to upstream GCP services.

Requires setting Google Cloud Serverless Authentication Service Account or running Pomerium in an environment with a GCP service account present in default locations.

Matchers

Path

If set, the route will only match incoming requests with a path that is an exact match for the specified path.

Regex

If set, the route will only match incoming requests with a path that matches the specified regular expression. The supported syntax is the same as the Go regexp package which is based on re2.

Regex Rewrite Pattern

The pattern to match before rewriting, ex: ^/service/([^/]+)(/.*)$.

Regex Rewrite Substitution

The substitution for your regex pattern, ex: \\2/instance/\\1.

Prefix

If set, the route will only match incoming requests with a path that begins with the specified prefix.

Prefix Rewrite

If set, indicates that during forwarding, the matched prefix (or path) should be swapped with this value. For example, given this policy:

from: https://from.example.com
to: https://to.example.com
prefix: /admin
prefix_rewrite: /

A request to https://from.example.com/admin would be forwarded to https://to.example.com/.

Timeouts

Allow Websockets

If set, enables proxying of websocket connections.

danger

Use with caution: websockets are long-lived connections, so global timeouts are not enforced (though the policy-specific timeout is enforced). Allowing websocket connections to the proxy could result in abuse via DOS attacks.

Allow SPDY

If set, enables proxying of SPDY protocol upgrades.

Timeout

Policy timeout establishes the per-route timeout value. Cannot exceed global timeout values.

Idle Timeout

If you are proxying long-lived requests that employ streaming calls such as websockets or gRPC, set this to either a maximum value there may be no data exchange over a connection (recommended), or set it to unlimited (0s). If idle_timeout is specified, and timeout is not explicitly set, then timeout would be unlimited (0s). You still may specify maximum lifetime of the connection using timeout value (i.e. to 1 day).

Headers

Host Headers

The host header can be preserved via the preserve_host_header setting or customized via three mutually exclusive options:

preserve_host_header will, when enabled, this option will pass the host header from the incoming request to the proxied host, instead of the destination hostname. It's an optional parameter of type bool that defaults to false.
See ProxyPreserveHost.
host_rewrite, which will rewrite the host to a new literal value.
host_rewrite_header, which will rewrite the host to match an incoming header value.
host_path_regex_rewrite_pattern & host_path_regex_rewrite_substitution, which will rewrite the host according to a regex matching the path. For example with the following config:
```
host_path_regex_rewrite_pattern: '^/(.+)/.+$'
host_path_regex_rewrite_substitution: \1
```
Would rewrite the host header to example.com given the path /example.com/some/path.

The 2nd, 3rd and 4th options correspond to the Envoy route action host related options, which can be found here.

Set Request Headers

Set Request Headers allows you to set static values for given request headers. This can be useful if you want to pass along additional information to downstream applications as headers, or set authentication header to the request. For example:

- from: https://verify.corp.example.com
  to: https://verify.pomerium.com
  policy:
    - allow:
        or:
          - email:
              is: user@example.com
  set_request_headers:
    # works auto-magically!
    # https://verify.corp.example.com/basic-auth/root/hunter42
    Authorization: Basic cm9vdDpodW50ZXI0Mg==
    X-Your-favorite-authenticating-Proxy: 'Pomerium'

danger

Neither :-prefixed pseudo-headers nor the Host: header may be modified via this mechanism. Those headers may instead be modified via mechanisms such as prefix_rewrite, regex_rewrite, and host_rewrite.

Remove Request Headers

Remove Request Headers allows you to remove given request headers. This can be useful if you want to prevent privacy information from being passed to downstream applications. For example:

- from: https://verify.corp.example.com
  to: https://verify.pomerium.com
  policy:
    - allow:
        or:
          - email:
              is: user@example.com
  remove_request_headers:
    - X-Email
    - X-Username

Rewrite Response Headers

Rewrite Response Headers allows you to modify response headers before they are returned to the client. The header field will match the HTTP header name, and prefix will be replaced with value. For example, if the downstream server returns a header:

Location: http://localhost:8000/two/some/path/

And the policy has this config:

rewrite_response_headers:
  - header: Location
    prefix: http://localhost:8000/two/
    value: http://frontend/one/

The browser would be redirected to: http://frontend/one/some/path/. This is similar to nginx's proxy_redirect option, but can be used for any header.

Load Balancer

Multiple Upstreams

You may specify multiple servers for your upstream application, and Pomerium would load balance user requests between them.

routes:
  - from: https://myapp.localhost.pomerium.io
    to:
      - http://myapp-srv-1:8080
      - http://myapp-srv-2:8080

tip

In the presence of multiple upstreams, make sure to specify either an active or passive health check, or both, to avoid requests being served to an unhealthy backend.

Active Health Checks

Active health checks issue periodic requests to each upstream to determine its health. See Health Checking for a comprehensive overview.

HTTP Example

routes:
  - from: https://myapp.localhost.pomerium.io
    to:
      - http://myapp-srv-1:8080
      - http://myapp-srv-2:8080
    health_checks:
      - timeout: 10s
        interval: 60s
        healthy_threshold: 1
        unhealthy_threshold: 2
        http_health_check:
          path: '/'

TCP Example

routes:
  - from: tcp+https://tcp-service.localhost.pomerium.io
    to:
      - tcp://tcp-1.local
      - tcp://tcp-2.local
    health_checks:
      - timeout: 1s
        interval: 5s
        unhealthy_threshold: 3
        healthy_threshold: 1
        tcp_health_check:
          send:
            text: '50494E47' #PING
          receive:
            text: '504F4E47' #PONG

Passive Health Checks

Passive health check tries to deduce upstream server health based on recent observed responses. See Outlier Detection for comprehensive overview.

routes:
  - from: https://myapp.localhost.pomerium.io
    to:
      - http://myapp-srv-1:8080
      - http://myapp-srv-2:8080
    outlier_detection: {}

Load Balancing Method

lb_policy should be set to one of the values:

ROUND_ROBIN (default)
LEAST_REQUEST and may be further configured using least_request_lb_config
RING_HASH and may be further configured using ring_hash_lb_config option
RANDOM
MAGLEV and may be further configured using maglev_lb_config option

Example

routes:
  - from: https://myapp.localhost.pomerium.io
    to:
      - http://myapp-srv-1:8080
      - http://myapp-srv-2:8080
      - http://myapp-srv-3:8080
      - http://myapp-srv-4:8080
      - http://myapp-srv-5:8080
    lb_policy: LEAST_REQUEST
    least_request_lb_config:
      choice_count: 2 # current envoy default

Load Balancing Weight

When a list of upstream URLs is specified in the to field, you may append an optional load balancing weight parameter. The individual lb_policy settings will take this weighting into account when making routing decisions.

Example

This configuration uses the default round_robin load balancer policy but specifies different frequency of selection be applied to the upstreams.

routes:
  - from: https://myapp.localhost.pomerium.io
    to:
      - http://myapp-srv-1:8080,10
      - http://myapp-srv-2:8080,20
      - http://myapp-srv-3:8080,30
      - http://myapp-srv-4:8080,20
      - http://myapp-srv-5:8080,10

Certificates

Certificates are the x509 public-key and private-key used to establish secure HTTP and gRPC connections. Any combination of the above can be used together, and are additive. You can also use any of these settings in conjunction with Autocert to get OCSP stapling.

Certificates loaded into Pomerium from these config values are used to attempt secure connections between end users and services, between Pomerium services, and to upstream endpoints.

For example, if specifying multiple certificates at once:

certificates:
  - cert: '$HOME/.acme.sh/authenticate.example.com_ecc/fullchain.cer'
    key: '$HOME/.acme.sh/authenticate.example.com_ecc/authenticate.example.com.key'
  - cert: '$HOME/.acme.sh/verify.example.com_ecc/fullchain.cer'
    key: '$HOME/.acme.sh/verify.example.com_ecc/verify.example.com.key'
  - cert: '$HOME/.acme.sh/prometheus.example.com_ecc/fullchain.cer'
    key: '$HOME/.acme.sh/prometheus.example.com_ecc/prometheus.example.com.key'

Or to set a single certificate and key covering multiple domains and/or a wildcard subdomain:

certificate_file: '$HOME/.acme.sh/*.example.com/fullchain.crt'
certificate_key: '$HOME/.acme.sh/*.example.com/*.example.com.key'

Note: Pomerium will check your system's trust/key store for valid certificates first. If your certificate solution imports into the system store, you don't need to also specify them with these configuration keys.

Routing, Proxying, and Load Balancing

Routes​

General​

Name​

From​

Metrics Name​

To​

Redirect​

Pass Identity Headers​

Policies​

Enable Google Cloud Serverless Authentication​

Matchers​

Path​

Regex​

Regex Rewrite Pattern​

Regex Rewrite Substitution​

Prefix​

Prefix Rewrite​

Timeouts​

Allow Websockets​

Allow SPDY​

Timeout​

Idle Timeout​

Headers​

Host Headers​

Set Request Headers​

Remove Request Headers​

Rewrite Response Headers​

Load Balancer​

Multiple Upstreams​

Active Health Checks​

HTTP Example​

TCP Example​

Passive Health Checks​

Load Balancing Method​

Example​

Load Balancing Weight​

Example​

Further reading​

Load Balancing Policy​

Certificates​

Routes

General

Name

From

Metrics Name

To

Redirect

Pass Identity Headers

Policies

Enable Google Cloud Serverless Authentication

Matchers

Path

Regex

Regex Rewrite Pattern

Regex Rewrite Substitution

Prefix

Prefix Rewrite

Timeouts

Allow Websockets

Allow SPDY

Timeout

Idle Timeout

Headers

Host Headers

Set Request Headers

Remove Request Headers

Rewrite Response Headers

Load Balancer

Multiple Upstreams

Active Health Checks

HTTP Example

TCP Example

Passive Health Checks

Load Balancing Method

Example

Load Balancing Weight

Example

Further reading

Load Balancing Policy

Certificates