[[connecting]]
== Connecting

This page contains the information you need to connect and use the Client with 
{es}.

**On this page**

* <<authentication, Authentication options>>
* <<client-usage, Using the client>>


[discrete]
[[authentication]]
=== Authentication

This section contains code snippets to show you how to connect to various {es} 
providers.

[discrete]
[[auth-ec]]
==== Elastic Cloud

You can connect to Elastic Cloud using **Basic authentication**:

[source,php]
----
$client = ClientBuilder::create()
   ->setElasticCloudId('<cloud-id>')
   ->setBasicAuthentication('<username>', '<password>')
   ->build();
----

Where <cloud-id> is reported in the Deployment UI, and <username>, <password> 
are generated when you deploy a new cloud instance. You need to store the 
<username> and <password> since they will not be available via UI.

Or using an **API key**:

[source,php]
----
$client = ClientBuilder::create()
   ->setElasticCloudId('<cloud-id>')
   ->setApiKey('<id>', '<key>')
   ->build();
----

Where <id> and <key> are generated when you create a new API key. The API key is 
equivalent to Base64(<id>:<key>). You need to store the API key since it will 
not be available via UI.


[discrete]
[[auth-http]]
==== HTTP Authentication

If your {es} server is protected by HTTP authentication, you need to provide the 
credentials to ES-PHP so that requests can be authenticated server-side. 
Authentication credentials are provided as part of the host array when 
instantiating the client:

[source,php]
----
$hosts = [
    'http://user:pass@localhost:9200',       // HTTP Basic Authentication
    'http://user2:pass2@other-host.com:9200' // Different credentials on different host
];

$client = ClientBuilder::create()
                    ->setHosts($hosts)
                    ->build();
----

Credentials are provided per-host, which allows each host to have their own set 
of credentials. All requests sent to the cluster use the appropriate credentials 
depending on the node being talked to.


[discrete]
[[auth-apikey]]
==== ApiKey authentication

If your {es} cluster is secured by API keys as described 
{ref-7x}/security-api-create-api-key.html[here], you can use these values to 
connect the client with your cluster, as illustrated in the following code 
snippet.

[source,php]
----
$client = ClientBuilder::create()
                    ->setApiKey('id', 'api_key') <1>
                    ->build();
----
<1> ApiKey pair of `id` and `api_key` from the create API key response.


[discrete]
[[ssl-encryption]]
==== SSL encryption

Configuring SSL is a little more complex. You need to identify if your 
certificate has been signed by a public Certificate Authority (CA), or if it is 
a self-signed certificate.

[NOTE]
.A note on libcurl version
=================
If you believe the client is configured to correctly use SSL, but it simply is 
not working, check your libcurl version. On certain platforms, various features 
may or may not be available depending on version number of libcurl. For example, 
the `--cacert` option was not added to the OSX version of libcurl until version 
7.37.1. The `--cacert` option is equivalent to PHP's `CURLOPT_CAINFO` constant, 
meaning that custom certificate paths will not work on lower versions.

If you are encountering problems, update your libcurl version and/or check the 
http://curl.haxx.se/changes.html[curl changelog].
=================


[discrete]
===== Public CA Certificates

If your certificate has been signed by a public Certificate Authority and your 
server has up-to-date root certificates, you only need to use `https` in the 
host path. The client automatically verifies SSL certificates:

[source,php]
----
$hosts = [
    'https://localhost:9200' <1>
];

$client = ClientBuilder::create()
                    ->setHosts($hosts)
                    ->build();
----
<1> Note that `https` is used, not `http`


If your server has out-dated root certificates, you may need to use a 
certificate bundle. For PHP clients, the best way is to use 
https://github.com/composer/ca-bundle[composer/ca-bundle]. Once installed, you 
need to tell the client to use your certificates instead of the system-wide 
bundle. To do this, specify the path to verify:

[source,php]
----
$hosts = ['https://localhost:9200'];
$caBundle = \Composer\CaBundle\CaBundle::getBundledCaBundlePath();

$client = ClientBuilder::create()
                    ->setHosts($hosts)
                    ->setSSLVerification($caBundle)
                    ->build();
----


[discrete]
===== Self-signed Certificates

Self-signed certificates are certs that have not been signed by a public CA. 
They are signed by your own organization. Self-signed certificates are often 
used for internal purposes, when you can securely spread the root certificate
yourself. It should not be used when being exposed to public consumers, since 
this leaves the client vulnerable to man-in-the-middle attacks.

If you are using a self-signed certificate, you need to provide the certificate 
to the client. This is the same syntax as specifying a new root bundle, but 
instead you point to your certificate:

[source,php]
----
$hosts = ['https://localhost:9200'];
$myCert = 'path/to/cacert.pem';

$client = ClientBuilder::create()
                    ->setHosts($hosts)
                    ->setSSLVerification($myCert)
                    ->build();
----


[discrete]
[[http-ssl]]
==== Using authentication with SSL

It is possible to use HTTP authentication with SSL. Simply specify `https` in 
the URI, configure SSL settings as required and provide authentication 
credentials. For example, this snippet authenticates using Basic HTTP auth and a 
self-signed certificate:

[source,php]
----
$hosts = ['https://user:pass@localhost:9200'];
$myCert = 'path/to/cacert.pem';

$client = ClientBuilder::create()
                    ->setHosts($hosts)
                    ->setSSLVerification($myCert)
                    ->build();
----


[discrete]
[[client-comp]]
=== Enabling the Compatibility Mode

The Elasticsearch server version 8.0 is introducing a new compatibility mode that
allows you a smoother upgrade experience from 7 to 8. In a nutshell, you can use
the latest 7.x Elasticsearch client with an 8.x Elasticsearch server, giving more
room to coordinate the upgrade of your codebase to the next major version.

If you want to leverage this functionality, please make sure that you are using the
latest 7.x client and set the environment variable `ELASTIC_CLIENT_APIVERSIONING`
to `true`. The client is handling the rest internally. For every 8.0 and beyond
client, you're all set! The compatibility mode is enabled by default.


[discrete]
[[client-usage]]
=== Usage 

This section is a crash-course overview of the client and its syntax. If you 
are familiar with {es}, you'll notice that the methods are named just like REST 
endpoints.

You may also notice that the client is configured in a manner that facilitates 
easy discovery via your IDE. All core actions are available under the `$client` 
object (indexing, searching, getting, etc). Index and cluster management are 
located under the `$client->indices()` and `$client->cluster()` objects, 
respectively.


[discrete]
==== Indexing a document

In elasticsearch-php, almost everything is configured by associative arrays. The 
REST endpoint, document and optional parameters - everything is an associative 
array.

To index a document, we need to specify three pieces of information: index, id 
and a document body. This is done by constructing an associative array of 
key:value pairs. The request body is itself an associative array with key:value 
pairs corresponding to the data in your document:

[source,php]
----------------------------
$params = [
    'index' => 'my_index',
    'id'    => 'my_id',
    'body'  => ['testField' => 'abc']
];

$response = $client->index($params);
print_r($response);
----------------------------

The response that you get back indicates that the document was created in the 
index that you specified. The response is an associative array containing a 
decoded version of the JSON that {es} returns:


[source,php]
----------------------------
Array
(
    [_index] => my_index
    [_type] => _doc
    [_id] => my_id
    [_version] => 1
    [created] => 1
)

----------------------------


[discrete]
==== Getting a document

Let's get the document that we just indexed. This returns the document:

[source,php]
----------------------------
$params = [
    'index' => 'my_index',
    'id'    => 'my_id'
];

$response = $client->get($params);
print_r($response);
----------------------------


The response contains metadata such as index, version, and so on as well as a 
`_source` field, which is the original document you sent to {es}.

[source,php]
----------------------------
Array
(
    [_index] => my_index
    [_type] => _doc
    [_id] => my_id
    [_version] => 1
    [found] => 1
    [_source] => Array
        (
            [testField] => abc
        )

)
----------------------------


[discrete]
==== Searching for a document

Searching is a hallmark of {es}, so let's perform a search. We are going to use 
the `match` query as a demonstration:

[source,php]
----------------------------
$params = [
    'index' => 'my_index',
    'body'  => [
        'query' => [
            'match' => [
                'testField' => 'abc'
            ]
        ]
    ]
];

$response = $client->search($params);
print_r($response);
----------------------------

The response here is different from the previous ones. You can see metadata 
(`took`, `timed_out`, etc.) and an array named `hits`. This represents your 
search results. Inside of `hits` is another array named `hits`, which contains 
individual search results:

[source,php]
----------------------------
Array
(
    [took] => 1
    [timed_out] =>
    [_shards] => Array
        (
            [total] => 5
            [successful] => 5
            [failed] => 0
        )

    [hits] => Array
        (
            [total] => 1
            [max_score] => 0.30685282
            [hits] => Array
                (
                    [0] => Array
                        (
                            [_index] => my_index
                            [_type] => _doc
                            [_id] => my_id
                            [_score] => 0.30685282
                            [_source] => Array
                                (
                                    [testField] => abc
                                )
                        )
                )
        )
)
----------------------------


[discrete]
==== Deleting a document

Alright, let's go ahead and delete the document that we added previously:

[source,php]
----------------------------
$params = [
    'index' => 'my_index',
    'id'    => 'my_id'
];

$response = $client->delete($params);
print_r($response);
----------------------------

This syntax is identical to the `get` syntax. The only difference is the 
operation: `delete` instead of `get`. The response confirms the document is 
deleted:

[source,php]
----------------------------
Array
(
    [found] => 1
    [_index] => my_index
    [_type] => _doc
    [_id] => my_id
    [_version] => 2
)
----------------------------


[discrete]
==== Deleting an index

Due to the dynamic nature of {es}, the first document you added automatically 
built an index with some default settings. Delete that index and specify your 
own settings later:

[source,php]
----------------------------
$deleteParams = [
    'index' => 'my_index'
];
$response = $client->indices()->delete($deleteParams);
print_r($response);
----------------------------

The response:


[source,php]
----------------------------
Array
(
    [acknowledged] => 1
)
----------------------------


[discrete]
==== Creating an index

Now that you are starting fresh (no data or index), add a new index with custom 
settings:

[source,php]
----------------------------
$params = [
    'index' => 'my_index',
    'body' => [
        'settings' => [
            'number_of_shards' => 2,
            'number_of_replicas' => 0
        ]
    ]
];

$response = $client->indices()->create($params);
print_r($response);
----------------------------

{es} now creates that index with your chosen settings and return an 
acknowledgement:

[source,php]
----------------------------
Array
(
    [acknowledged] => 1
)
----------------------------
