cURL

cURL is a command-line tool and application library used to transfer data to or from a server.

cURL is a command-line tool and application library used to transfer data to or from a server. All API requests sent to a Vertica server must be made with HTTPS.

There are four HTTP requests that can be passed using cURL to call API methods:

GET: Retrieves data.
PUT: Updates data.
POST: Creates new data.
DELETE: Deletes data.

Syntax

curl https://<NODE>:5444/

Options

The following is a truncated list of options. For a complete list, see the cURL documentation.

`-h --help`	Lists all available options.
`-H --header`	Specifies custom headers. This is useful for sending a request that requires a Vertica API key. Example: `$ curl -H "VerticaApiKey: ValidAPIKey" https://<NODE>:5444/`
`-k --insecure`	Connects with TLS without validating the database's server certificate. Example: `$ curl -k https://<NODE>:5444/`
`-X --request`	Specifies a request type, one of the following: GET (default) PUT POST DELETE Example: `$ curl -X REQUEST https://<NODE>:5444/`

Configuring HTTPS

HTTPS encrypts your connection with TLS. The following procedure enables HTTPS by using the predefined server TLS Configuration. To create a custom TLS Configuration, see TLS configurations.

Generate or import the following according to your use case:
- Server Mode: server certificate private key, server certificate
- Mutual Mode: server certificate private key, server certificate, CA certificate(s)
Run the following commands according to your desired configuration. New connections will use TLS.
- To use Server Mode, set the server certificate for the server TLS Configuration:
```
=> ALTER TLS CONFIGURATION server CERTIFICATE server_cert;
```
- To use Mutual Mode, set a server and CA certificate. This CA certificate is used to verify client certificates:
```
=> ALTER TLS CONFIGURATION server CERTIFICATE server_cert ADD CA CERTIFICATES ca_cert;
```
  To use multiple CA certificates, separate them with commas:
```
=> ALTER TLS CONFIGURATION server CERTIFICATE server_cert
   ADD CA CERTIFICATES intermediate_ca_cert, ca_cert;
```
Enable TLS (disabled by default). Choose one of the following TLSMODEs, listed in ascending security.
- DISABLE: Disables TLS. All other options for this parameter enable TLS.
- ENABLE: Enables TLS. Vertica does not check client certificates.
- TRY_VERIFY: Establishes a TLS connection if one of the following is true:
  - the client presents a valid certificate
  - the client doesn't present a certificate
  If the client presents an invalid certificate, the connection will use plaintext.
- VERIFY_CA: Connection succeeds if Vertica verifies that the client certificate is from a trusted CA. If the client does not present a client certificate, the connection uses plaintext.
TLS Configurations also support the TLSMODE VERIFY_FULL, but this TLSMODE is unsupported for HTTPS and behaves like VERIFY_CA.

For Server Mode, choose ENABLE:
```
=> ALTER TLS CONFIGURATION server TLSMODE 'ENABLE';
```
For Mutual Mode, choose TRY_VERIFY or higher:
```
=> ALTER TLS CONFIGURATION server TLSMODE 'VERIFY_CA';
```

Verify that the HttpsTLSConfig parameters is set to the server TLS Configuration:

=> SHOW CURRENT HttpsTLSConfig;
  level  |      name       | setting
---------+-----------------+---------
 DEFAULT | HttpsTLSConfig  | server
(1 row)

If not, set the HttpsTLSConfig parameter:

=> ALTER DATABASE DEFAULT SET HttpsTLSConfig = 'server';