Add ingress to docs

Fixes: #336

docs/reference/schema.md

@@ -48,7 +48,8 @@ name: myapplication
 registry: exampleuser
 namespace: examplenamespace
 network: examplenetwork
-services:
+ingress: ...
+services: ...
 ```
 
 ### Root Properties
@@ -84,6 +85,10 @@ Allows configuring the Docker network used for `tye run`.
 
 If a network is configured, then all services running in containers will connect to the specified network. Otherwise a Docker network will be created with a generated name, and used to connect all containers.
 
+#### `ingress` (`Ingress[]`)
+
+Specifies the list of ingresses.
+
 #### `services` (`Service[]`) *required*
 
 Specifies the list of services. Applications must have at least one service.
@@ -226,7 +231,7 @@ The name of the environment variable.
 
 The value of the environment variable.
 
-## Bindings
+## Binding
 
 `Binding` elements appear in a list inside the `bindings` property of a `Service`.
 
@@ -322,3 +327,134 @@ A named docker volume.
 #### `target` (string) *required*
 
 The destination path within the container.
+
+## Ingress
+
+`Ingress` elements appear in a list within the `ingress` root property.
+
+Each ingress element represents an HTTP (L7) network proxy, capable of accepting public traffic from the internet:
+
+- In development: a local proxy is used for testing purposes
+- In deployed applications: a real load-balancer/proxy accepting traffic from outside the cluster is used
+
+### Ingress Example
+
+```yaml
+ingress:
+- name: example
+  bindings:
+  - port: 8080
+  rules:
+  - host: a.example.com
+    service: app-a
+  - host: b.example.com
+    service: app-b 
+```
+
+This example configures a single ingress named `example` that routes traffic to `app-a` or `app-b` based on the `Host` header. The port `8080` will be used during local development.
+
+### Ingress Properties
+
+#### `name` (`string`) *required*
+
+The name of the ingress.
+
+#### `bindings` (`IngressBinding`)
+
+The bindings of the ingress service when running locally. Ignored for deployed applications.
+
+#### `rules` (`IngressRule`)
+
+The rules used to route traffic for the ingress.
+
+## IngressBinding
+
+`IngressBinding` elements appear in an array within the `bindings` property of an `Ingress` element. The bindings of an ingress specify the ports of the ingress service when running locally. Bindings are ignored when deploying applications.
+
+### IngressBinding Example
+
+```yaml
+ingress:
+- name: example
+  bindings:
+
+  # An IngressBinding
+  - port: 8080
+    protocol: http
+
+  rules:
+  - host: a.example.com
+    service: app-a
+  - host: b.example.com
+    service: app-b 
+```
+
+In this example the binding specifies that the ingress service should listen for `HTTP` on port 8080 when running locally for development.
+
+### IngressBinding Properties
+
+#### `name` (`string`)
+
+The name of the binding.
+
+#### `port` (`integer`)
+
+The port of the binding.
+
+#### `protocol` (`string`)
+
+The protocol (`http` or `https`).
+
+## IngressRule
+
+`IngressRule` elements appear in an array within the `rules` property of the `Ingress` element. Rules configure the routing behavior of the ingress proxy.
+
+Rules can configure routing based on path-prefix, or based on host (HTTP `Host` header) or both. 
+
+- A rule without a `path` is considered to match all paths, which is the same as specifying `path: '/'`
+- A rule without a `host` is considered to match all hosts.
+
+### IngressRule Example
+
+```yaml
+ingress:
+- name: example
+  bindings:
+  - port: 8080
+    protocol: http
+  rules:
+
+  # Example IngressRules
+  - host: a.example.com
+    service: app-a
+  - host: b.example.com
+    path: /mypath
+    service: app-b
+```
+
+### IngressRule Properties
+
+#### `service` (`string`) *required*
+
+The service to route traffic to. Must be the name of a service that is part of this application.
+
+#### `path` (`string`)
+
+The path-prefix to match. Matching is case-insensitive.
+
+The `path` must begin with `/`:
+
+- `/mypath` is value
+- `mypath` is invalid
+
+The `path` may end with a trailing slash - the behavior is the same whether or not a trailing slash appears.
+
+The path `/mypath` or `/mypath/` will match:
+
+- `/mypath`
+- `/mypath/`
+- `/MYPATH/something/else`
+
+#### `host` (`string`)
+
+The host to match. 

src/schema/tye-schema.json

@@ -21,6 +21,14 @@
             "description": "The Docker network to use.",
             "type": "string"
         },
+        "ingress": {
+            "description": "The application's ingresses.",
+            "type": "array",
+            "minItems": 1,
+            "items": {
+                "$ref": "#/definitions/ingress"
+            }
+        },
         "services": {
             "description": "The application's services.",
             "type": "array",
@@ -197,6 +205,66 @@
                 "image"
             ]
         },
+        "ingress": {
+            "type": "object",
+            "properties": {
+                "name": {
+                    "description": "The ingress name.",
+                    "type": "string"
+                },
+                "bindings": {
+                    "description": "Bindings for the ingress in local development.",
+                    "type": "array",
+                    "items": {
+                        "$ref": "#/definitions/ingress-binding"
+                    }
+                },
+                "rules": {
+                    "description": "Rules for ingress routing.",
+                    "type": "array",
+                    "items": {
+                        "$ref": "#/definitions/ingress-rule"
+                    }
+                }
+            }
+        },
+        "ingress-binding": {
+            "type": "object",
+            "properties": {
+                "name": {
+                    "description": "The binding name.",
+                    "type": "string"
+                },
+                "port": {
+                    "description": "The binding port.",
+                    "type": "integer"
+                },
+                "protocol": {
+                    "description": "The protocol used by the binding",
+                    "type": "string"
+                }
+            }
+        },
+        "ingress-rule": {
+            "type": "object",
+            "properties": {
+                "service": {
+                    "description": "The service to route traffic when the rule matches.",
+                    "type": "string"
+                },
+                "path": {
+                    "description": "The path prefix to match.",
+                    "type": "string"
+                },
+                "host": {
+                    "description": "The hostname to match.",
+                    "type": "string"
+                }
+            },
+            "required": [
+                "service"
+            ]
+        },
         "project": {
             "type": "object",
             "properties": {