Discovering connection strings
==============================

You can install PGD CLI on any system that can connect to the PGD
cluster. To use PGD CLI, you need a user with PGD superuser privileges
or equivalent. The PGD user with superuser privileges is the
 :ref:`bdr_superuser role and replication <bdr_superuser role and replication>`  . An example of an equivalent user is edb_admin on an EDB
BigAnimal distributed high-availability cluster.

PGD CLI and database connection strings
---------------------------------------

You might not need a database connection string. For example, when
Trusted Postgres Architect installs the PGD CLI on a system, it also
configures the connection to the PGD cluster. This means that PGD CLI
can connect to the cluster when run.

Getting your database connection string
---------------------------------------

Because of the range of different configurations that PGD supports,
every deployment method has a different way of deriving a connection
string for it. Generally, you can obtain the required information from
the configuration of your deployment. You can then assemble that
information into connection strings.

For a TPA-deployed PGD cluster
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Because TPA is so flexible, you have to derive your connection string
from your cluster configuration file (``config.yml`` ).

-  You need the name or IP address of a host with the role pgd-proxy
   listed for it. This host has a proxy you can connect to. Usually the
   proxy listens on port 6432. (Check the setting for
   ``default_pgd_proxy_options`` and ``listen_port`` in the config to
   confirm.)

-  The default database name is ``bdrdb`` . (Check the setting
   ``bdr_database`` in the config to confirm.)

-  The default PGD superuser is enterprisedb for EDB Postgres Advanced
   Server and postgres for PostgreSQL and EDB Postgres Extended Server.

You can then assemble a connection string based on that information:

::

   "host=<hostnameOrIPAddress> port=<portnumber> dbname=<databasename> user=<username> sslmode=require"

To illustrate this, here are some excerpts of a ``config.yml`` file for
a cluster:

.. code:: yaml

   ...
   cluster_vars:
     ...
     bdr_database: bdrdb
     ...
     default_pgd_proxy_options:
       listen_port: 6432
     ...

   instances:

   - Name: kaboom
     backup: kapok
     location: dc1
     node: 1
     role:
     - bdr
     - pgd-proxy
     networks:
     - ipv4_address: 192.168.100.2
       name: tpanet
   ...

The connection string for this cluster is:

::

   "host=192.168.100.2 port=6432 dbname=bdrdb user=enterprisedb sslmode=require"

..  Note Host name versus IP address::
   The example uses the IP address because the configuration is from a Docker TPA install with no name resolution available. Generally, you can use the host name as configured. !!!

For an EDB BigAnimal distributed high-availability cluster
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

1. Log in to the `BigAnimal clusters <https://portal.biganimal.com/clusters>`_  view.

2. In the filter, set **Cluster Type** to **Distributed High
   Availability** to show only clusters that work with PGD CLI.

3. Select your cluster.

4. In the view of your cluster, select the **Connect** tab.

5. Copy the read/write URI from the connection info. This is your
   connection string.

For a cluster deployed with EDB PGD for Kubernetes
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

As with TPA, EDB PGD for Kubernetes is very flexible, and there are
multiple ways to obtain a connection string. It depends, in large part,
on how the :ref:`services </postgres_distributed_for_kubernetes/latest/connectivity/#services>`  were configured for the deployment:

-  If you use the Node Service Template, direct connectivity to each
   node and proxy service is available.

-  If you use the Group Service Template, there’s a gateway service to
   each group.

-  If you use the Proxy Service Template, a single proxy provides an
   entry point to the cluster for all applications.

Consult your configuration file to determine this information.

Establish a host name or IP address, port, database name, and username.
The default database name is ``bdrdb`` , and the default username is
enterprisedb for EDB Postgres Advanced Server and postgres for
PostgreSQL and EDB Postgres Extended Server.

You can then assemble a connection string based on that information:

::

   "host=<hostnameOrIPAddress> port=<portnumber> dbname=<databasename> user=<username>"

If the deployment’s configuration requires it, add ``sslmode=<sslmode>``
.