Add HTTP Provider

* feat: add HTTP provider implementation

* refactor: add SetDefaults and struct tag for the new file parser

* feat: add TLS configuration property

* refactor: rework HTTP provider implementation

* feat: provide config only once if fetched config is unchanged

* style: lint

* ui: add HTTP provider icon

* tests: simplify and fix integration test

* docs: add reference config for file

* docs: move http reference config for file

Co-authored-by: Daniel Tomcej <daniel.tomcej@gmail.com>

docs/content/providers/http.md

@@ -0,0 +1,189 @@
+# Traefik & HTTP
+
+Provide your [dynamic configuration](./overview.md) via an HTTP(s) endpoint and let Traefik do the rest!
+
+## Routing Configuration
+
+The HTTP provider uses the same configuration as the [File Provider](./file.md) in YAML or JSON format.
+
+## Provider Configuration
+
+### `endpoint`
+
+_Required_
+
+Defines the HTTP(s) endpoint to poll.
+
+```toml tab="File (TOML)"
+[providers.http]
+  endpoint = "http://127.0.0.1:9000/api"
+```
+
+```yaml tab="File (YAML)"
+providers:
+  http:
+    endpoint:
+      - "http://127.0.0.1:9000/api"
+```
+
+```bash tab="CLI"
+--providers.http.endpoint=http://127.0.0.1:9000/api
+```
+
+### `pollInterval`
+
+_Optional, Default="5s"_
+
+Defines the polling interval.
+
+```toml tab="File (TOML)"
+[providers.http]
+  pollInterval = "5s"
+```
+
+```yaml tab="File (YAML)"
+providers:
+  http:
+    pollInterval: "5s"
+```
+
+```bash tab="CLI"
+--providers.http.pollInterval=5s
+```
+
+### `pollTimeout`
+
+_Optional, Default="5s"_
+
+Defines the polling timeout when connecting to the configured endpoint.
+
+```toml tab="File (TOML)"
+[providers.http]
+  pollTimeout = "5s"
+```
+
+```yaml tab="File (YAML)"
+providers:
+  http:
+    pollTimeout: "5s"
+```
+
+```bash tab="CLI"
+--providers.http.pollTimeout=5s
+```
+
+### `tls`
+
+_Optional_
+
+#### `tls.ca`
+
+Certificate Authority used for the secured connection to the configured Endpoint.
+
+```toml tab="File (TOML)"
+[providers.http.tls]
+  ca = "path/to/ca.crt"
+```
+
+```yaml tab="File (YAML)"
+providers:
+  http:
+    tls:
+      ca: path/to/ca.crt
+```
+
+```bash tab="CLI"
+--providers.http.tls.ca=path/to/ca.crt
+```
+
+#### `tls.caOptional`
+
+Policy followed for the secured connection with TLS Client Authentication to the configured Endpoint.
+Requires `tls.ca` to be defined.
+
+- `true`: VerifyClientCertIfGiven
+- `false`: RequireAndVerifyClientCert
+- if `tls.ca` is undefined NoClientCert
+
+```toml tab="File (TOML)"
+[providers.http.tls]
+  caOptional = true
+```
+
+```yaml tab="File (YAML)"
+providers:
+  http:
+    tls:
+      caOptional: true
+```
+
+```bash tab="CLI"
+--providers.http.tls.caOptional=true
+```
+
+#### `tls.cert`
+
+Public certificate used for the secured connection to the configured Endpoint.
+
+```toml tab="File (TOML)"
+[providers.http.tls]
+  cert = "path/to/foo.cert"
+  key = "path/to/foo.key"
+```
+
+```yaml tab="File (YAML)"
+providers:
+  http:
+    tls:
+      cert: path/to/foo.cert
+      key: path/to/foo.key
+```
+
+```bash tab="CLI"
+--providers.http.tls.cert=path/to/foo.cert
+--providers.http.tls.key=path/to/foo.key
+```
+
+#### `tls.key`
+
+Private certificate used for the secured connection to the configured Endpoint.
+
+```toml tab="File (TOML)"
+[providers.http.tls]
+  cert = "path/to/foo.cert"
+  key = "path/to/foo.key"
+```
+
+```yaml tab="File (YAML)"
+providers:
+  http:
+    tls:
+      cert: path/to/foo.cert
+      key: path/to/foo.key
+```
+
+```bash tab="CLI"
+--providers.http.tls.cert=path/to/foo.cert
+--providers.http.tls.key=path/to/foo.key
+```
+
+#### `tls.insecureSkipVerify`
+
+If `insecureSkipVerify` is `true`, TLS connection to the configured Endpoint accepts any certificate presented by the 
+server and any host name in that certificate.
+
+```toml tab="File (TOML)"
+[providers.http.tls]
+  insecureSkipVerify = true
+```
+
+```yaml tab="File (YAML)"
+providers:
+  http:
+    tls:
+      insecureSkipVerify: true
+```
+
+```bash tab="CLI"
+--providers.http.tls.insecureSkipVerify=true
+```

docs/content/providers/overview.md

@@ -35,9 +35,10 @@ Below is the list of the currently supported providers in Traefik.
 | [Rancher](./rancher.md)               | Orchestrator | Label                      |
 | [File](./file.md)                     | Manual       | TOML/YAML format           |
 | [Consul](./consul.md)                 | KV           | KV                         |
-| [etcd](./etcd.md)                     | KV           | KV                         |
+| [Etcd](./etcd.md)                     | KV           | KV                         |
 | [Redis](./redis.md)                   | KV           | KV                         |
 | [ZooKeeper](./zookeeper.md)           | KV           | KV                         |
+| [HTTP](./http.md)                     | Manual       | JSON format                |
 
 !!! info "More Providers"