///

Ao construir uma API, o "path" é a principal forma de separar "preocupações" e "recursos".

#### Operação { #operation }

"Operação" aqui se refere a um dos "métodos" HTTP.

Um dos:

* `POST`
* `GET`
* `PUT`
* `DELETE`

...e os mais exóticos:

* `OPTIONS`
* `HEAD`
* `PATCH`
* `TRACE`

    return () -> newTraversal().preOrder(validated.iterator());
  }

  /**
   * Returns an unmodifiable {@code Iterable} over the nodes reachable from {@code startNode}, in
   * the order of a depth-first post-order traversal. "Post-order" implies that nodes appear in the
   * {@code Iterable} in the order in which they are visited for the last time.
   *

     * @param dictId the dictionary ID
     * @param body the request body containing synonym item information
     * @return JSON response with result status
     */
    // POST /api/admin/dict/synonym/setting/{dictId}
    @Execute
    public JsonResponse<ApiResult> post$setting(final String dictId, final CreateBody body) {
        body.dictId = dictId;
        validateApi(body, messages -> {});
        body.crudMode = CrudMode.CREATE;

        ).build()

    val request =
      Request
        .Builder()
        .header("Authorization", "Client-ID $IMGUR_CLIENT_ID")
        .url("https://api.imgur.com/3/image")
        .post(requestBody)
        .build()

    client.newCall(request).execute().use { response ->
      if (!response.isSuccessful) throw IOException("Unexpected code $response")

      println(response.body.string())
    }

	ctx := r.Context()

	addOrUpdateIDPHandler(ctx, w, r, false)
}

// UpdateIdentityProviderCfg: updates an existing IDP config for openid/ldap.
//
// POST <admin-prefix>/idp-cfg/openid/dex1 -> update named config `dex1`
//
// POST <admin-prefix>/idp-cfg/openid/_ -> update (default) named config `_`
func (a adminAPIHandlers) UpdateIdentityProviderCfg(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()

    target_match:
      severity: 'warning'
    equal: ['alertname', 'dev', 'instance']
```

This sample configuration uses a `webhook` at http://127.0.0.1:8010/webhook to post the alerts.
Start the AlertManager and it listens on port `9093` by default. Make sure your webhook is up and listening for the alerts.

## Configure Prometheus to use AlertManager

Add below section to your `prometheus.yml`
```yaml
alerting:

matchLabels: app: {{ template "minio.name" . }} {{- end }} minio/templates/post-install-create-bucket-job.yaml {{- if .Values.buckets }} apiVersion: batch/v1 kind: Job metadata: name: {{ template "minio.fullname" . }}-make-bucket-job labels: app: {{ template "minio.name" . }}-make-bucket-job chart: {{ template "minio.chart" . }} release: {{ .Release.Name }} heritage: {{ .Release.Service }} annotations: "helm.sh/hook": post-install,post-upgrade "helm.sh/hook-delete-policy": hook-succeeded,before-hook-creation...

matchLabels: app: {{ template "minio.name" . }} {{- end }} minio/templates/post-install-create-bucket-job.yaml {{- if .Values.buckets }} apiVersion: batch/v1 kind: Job metadata: name: {{ template "minio.fullname" . }}-make-bucket-job labels: app: {{ template "minio.name" . }}-make-bucket-job chart: {{ template "minio.chart" . }} release: {{ .Release.Name }} heritage: {{ .Release.Service }} annotations: "helm.sh/hook": post-install,post-upgrade "helm.sh/hook-delete-policy": hook-succeeded,before-hook-creation...

matchLabels: app: {{ template "minio.name" . }} {{- end }} minio/templates/post-install-create-bucket-job.yaml {{- if .Values.buckets }} apiVersion: batch/v1 kind: Job metadata: name: {{ template "minio.fullname" . }}-make-bucket-job labels: app: {{ template "minio.name" . }}-make-bucket-job chart: {{ template "minio.chart" . }} release: {{ .Release.Name }} heritage: {{ .Release.Service }} annotations: "helm.sh/hook": post-install,post-upgrade "helm.sh/hook-delete-policy": hook-succeeded,before-hook-creation...

我們用一個例子來看。

想像你開發了一個允許建立發票的應用。

這些發票會有 `id`、`title`（可選）、`customer` 和 `total`。

你的 API 的使用者（外部開發者）會透過一個 POST 請求在你的 API 中建立一張發票。

然後你的 API 會（讓我們想像）：

* 將發票寄給該外部開發者的某位客戶。
* 代收款項。
* 再把通知回傳給 API 使用者（外部開發者）。
    * 這會透過從「你的 API」向該外部開發者提供的「外部 API」送出 POST 請求完成（這就是「回呼」）。

## 一般的 **FastAPI** 應用 { #the-normal-fastapi-app }

先看看在加入回呼之前，一個一般的 API 應用會長什麼樣子。