Simplify anonymous access & embedding docs. (#90409) (#92353)

Co-authored-by: Aleh Zasypkin <aleh.zasypkin@gmail.com>

docs/settings/security-settings.asciidoc

@@ -264,7 +264,7 @@ You can configure the following settings in the `kibana.yml` file.
   this to `true` if SSL is configured outside of {kib} (for example, you are
   routing requests through a load balancer or proxy).
 
-| `xpack.security.sameSiteCookies` {ess-icon}
+| [[xpack-security-sameSiteCookies]] `xpack.security.sameSiteCookies` {ess-icon}
   | Sets the `SameSite` attribute of the session cookie. This allows you to declare whether your cookie should be restricted to a first-party or same-site context.
   Valid values are `Strict`, `Lax`, `None`.
   This is *not set* by default, which modern browsers will treat as `Lax`. If you use Kibana embedded in an iframe in modern browsers, you might need to set it to `None`. Setting this value to `None` requires cookies to be sent over a secure connection by setting <<xpack-security-secureCookies, `xpack.security.secureCookies`>>: true`. Some old versions of IE11 do not support `SameSite: None`.

docs/setup/embedding.asciidoc

@@ -0,0 +1,55 @@
+[[embedding]]
+== Embed {kib} content in a web page
+
+Once you create a dashboard or a visualization, you might want to share it with your colleagues or friends. The easiest way to do this is to share a direct link to your dashboard or visualization. However, some users might not have access to your {kib}.
+
+With the {kib} embedding functionality, you can display the content you created in {kib} to an internal company website or a personal web page. From *Dashboard* or *Visualize*, open the *Share > Embed code* menu, and then click *Copy iFrame code* to generate an HTML code snippet. You can embed this snippet in your web page, and then add analysis, images, and links to give more context to the object you're sharing.
+
+image::images/embed-kibana.png[Generate an HTML snippet to embed {kib}, align=center]
+
+NOTE: Embedding of any other part of {kib} is also generally possible, but you might need to craft the proper HTML code manually.
+
+[float]
+[[embedding-security]]
+=== Configure security
+
+Embedding content through iframes requires careful consideration to minimize security risks. By default, modern web browsers enforce the
+https://developer.mozilla.org/en-US/docs/Web/Security/Same-origin_policy[same-origin policy] to restrict the behavior of framed pages. When
+{stack-security-features} are enabled on your cluster, you must relax this constraint for cookies as described in <<embedding-cookies, Cookies>> for {kib} to function
+in an iframe. Refer to https://developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe[iframe] and
+https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie/SameSite[SameSite cookies] for more information.
+
+[float]
+==== Authentication
+If you're embedding {kib} in a website that supports Single Sign-On with SAML, OpenID Connect, Kerberos, or PKI, it's highly advisable to configure {kib} as a part of the Single Sign-On setup. Operating in a single and properly configured security domain provides you with the most secure and seamless user experience. You can read more at <<kibana-authentication, Authentication in {kib}>>.
+
+If you want users to access embedded {kib} by skipping the login step, and Single Sign-On isn't an option for you, consider configuring <<anonymous-authentication, anonymous access>>. It is already natively integrated into the workflow for embedding dashboards and visualizations.
+
+If you have multiple authentication providers enabled, and you want to automatically log in anonymous users when embedding anything other than dashboards and visualizations, then you will need to add the `auth_provider_hint=<anonymous-provider-name>` query string parameter to the {kib} URL that you're embedding.
+
+For example, if you craft the iframe code to embed {kib}, it might look like this:
+
+```html
+<iframe src="https://localhost:5601/app/monitoring#/elasticsearch/nodes?embed=true&_g=(....)" height="600" width="800"></iframe>
+```
+
+To make this iframe leverage anonymous access automatically, you will need to modify a link to {kib} in the `src` iframe attribute to look like this:
+
+```html
+<iframe src="https://localhost:5601/app/monitoring?auth_provider_hint=anonymous1#/elasticsearch/nodes?embed=true&_g=(....)" height="600" width="800"></iframe>
+```
+
+Note that the `auth_provider_hint` query string parameter goes *before* the hash URL fragment.
+
+[float]
+[[embedding-cookies]]
+==== Cookies
+
+Regardless of the authentication type that you're using for the embedded {kib}, you must make sure that the browsers can transmit session cookies to a {kib} server. The setting you need to be aware of is <<xpack-security-sameSiteCookies, `xpack.security.sameSiteCookies`>>. To support modern browsers, you must set it to `None`:
+
+[source,yaml]
+--
+xpack.security.sameSiteCookies: "None"
+--
+
+For more information about possible values and implications, go to <<xpack-security-sameSiteCookies, xpack.security.sameSiteCookies>>.

docs/user/security/authentication/index.asciidoc

@@ -383,21 +383,13 @@ xpack.security.authc.providers:
 
 One of the most popular use cases for anonymous access is when you embed {kib} into other applications and don't want to force your users to log in to view it. If you configured {kib} to use anonymous access as the sole authentication mechanism, you don't need to do anything special while embedding {kib}.
 
-If you have multiple authentication providers enabled, and you want to automatically log in anonymous users when embedding, then you will need to add the `auth_provider_hint=<anonymous-provider-name>` query string parameter to the {kib} URL that you're embedding.
+If you have multiple authentication providers enabled, and you want to automatically log in anonymous users when embedding dashboards and visualizations, then toggle *Public URL* in the *Share > Embed code* menu in  *Dashboard* or *Visualize*.
 
-For example, if you generate the iframe code to embed {kib}, it will look like this:
+You can also use the *Public URL* toggle when you're generating permanent links to dashboards, visualizations, and saved searches.
 
-```html
-<iframe src="https://localhost:5601/app/dashboards#/view/722b74f0-b882-11e8-a6d9-e546fe2bba5f?embed=true&_g=(....)" height="600" width="800"></iframe>
-```
+NOTE:  The *Public URL* toggle is only available if anonymous access is properly configured and your anonymous service account has privileges to access what you want to embed or share.
 
-To make this iframe leverage anonymous access automatically, you will need to modify a link to {kib} in the `src` iframe attribute to look like this:
-
-```html
-<iframe src="https://localhost:5601/app/dashboards?auth_provider_hint=anonymous1#/view/722b74f0-b882-11e8-a6d9-e546fe2bba5f?embed=true&_g=(....)" height="600" width="800"></iframe>
-```
-
-Note that `auth_provider_hint` query string parameter goes *before* the hash URL fragment.
+For more information, refer to <<embedding, Embed {kib} content in a web page>>.
 
 [[http-authentication]]
 ==== HTTP authentication

docs/user/setup.asciidoc

@@ -59,3 +59,5 @@ include::{kib-repo-dir}/setup/connect-to-elasticsearch.asciidoc[]
 include::{kib-repo-dir}/setup/production.asciidoc[]
 
 include::{kib-repo-dir}/setup/upgrade.asciidoc[]
+
+include::{kib-repo-dir}/setup/embedding.asciidoc[]