# Managing Connections

Airflow needs to know how to connect to your environment. Information such as hostname, port, login and passwords to other systems and services is handled in the `Admin->Connection` section of the UI. The pipeline code you will author will reference the ‘conn_id’ of the Connection objects.

Connections can be created and managed using either the UI or environment variables.

See the Connenctions Concepts documentation for more information.

## Creating a Connection with the UI

Open the `Admin->Connection` section of the UI. Click the `Create` link to create a new connection.

1. Fill in the `Conn Id` field with the desired connection ID. It is recommended that you use lower-case characters and separate words with underscores.
2. Choose the connection type with the `Conn Type` field.
3. Fill in the remaining fields. See Connection Types for a description of the fields belonging to the different connection types.
4. Click the `Save` button to create the connection.

## Editing a Connection with the UI

Open the `Admin->Connection` section of the UI. Click the pencil icon next to the connection you wish to edit in the connection list.

Modify the connection properties and click the `Save` button to save your changes.

## Creating a Connection with Environment Variables

Connections in Airflow pipelines can be created using environment variables. The environment variable needs to have a prefix of `AIRFLOW_CONN_` for Airflow with the value in a URI format to use the connection properly.

When referencing the connection in the Airflow pipeline, the `conn_id` should be the name of the variable without the prefix. For example, if the `conn_id` is named `postgres_master` the environment variable should be named `AIRFLOW_CONN_POSTGRES_MASTER` (note that the environment variable must be all uppercase). Airflow assumes the value returned from the environment variable to be in a URI format (e.g. `postgres://user:password@localhost:5432/master` or `s3://accesskey:secretkey@S3`).

## Connection Types

### Google Cloud Platform

The Google Cloud Platform connection type enables the GCP Integrations.

#### Authenticating to GCP

There are two ways to connect to GCP using Airflow.

1. Use Application Default Credentials, such as via the metadata server when running on Google Compute Engine.
2. Use a service account key file (JSON format) on disk.

#### Default Connection IDs

The following connection IDs are used by default.

    bigquery_default

Used by the `BigQueryHook` hook.

    google_cloud_datastore_default

Used by the `DatastoreHook` hook.

    google_cloud_default

Used by the `GoogleCloudBaseHook`, `DataFlowHook`, `DataProcHook`, `MLEngineHook`, and `GoogleCloudStorageHook` hooks.

#### Configuring the Connection

    Project Id (required)

The Google Cloud project ID to connect to.

    Keyfile Path

Path to a service account key file (JSON format) on disk.

Not required if using application default credentials.

    Keyfile JSON

Contents of a service account key file (JSON format) on disk. It is recommended to Secure your connections if using this method to authenticate.

Not required if using application default credentials.

    Scopes (comma separated)

A list of comma-separated Google Cloud scopes to authenticate with.

Note

Scopes are ignored when using application default credentials. See issue AIRFLOW-2522.