# Configure Control Plane Access

Coder server's primary configuration is done via environment variables. For a
full list of the options, run `coder server --help` or see our
[CLI documentation](../../reference/cli/server.md).

## Access URL

`CODER_ACCESS_URL` is required if you are not using the tunnel. Set this to the
external URL that users and workspaces use to connect to Coder (e.g.
<https://coder.example.com>). This should not be localhost.

> Access URL should be an external IP address or domain with DNS records
> pointing to Coder.

### Tunnel

If an access URL is not specified, Coder will create a publicly accessible URL
to reverse proxy your deployment for simple setup.

## Address

You can change which port(s) Coder listens on.

```shell
# Listen on port 80
export CODER_HTTP_ADDRESS=0.0.0.0:80

# Enable TLS and listen on port 443)
export CODER_TLS_ENABLE=true
export CODER_TLS_ADDRESS=0.0.0.0:443

## Redirect from HTTP to HTTPS
export CODER_REDIRECT_TO_ACCESS_URL=true

# Start the Coder server
coder server
```

## Wildcard access URL

`CODER_WILDCARD_ACCESS_URL` is necessary for
[port forwarding](../networking/port-forwarding.md#dashboard) via the dashboard
or running [coder_apps](../templates/index.md) on an absolute path. Set this to
a wildcard subdomain that resolves to Coder (e.g. `*.coder.example.com`).

> Note: We do not recommend using a top-level-domain for Coder wildcard access
> (for example `*.workspaces`), even on private networks with split-DNS. Some
> browsers consider these "public" domains and will refuse Coder's cookies,
> which are vital to the proper operation of this feature.

If you are providing TLS certificates directly to the Coder server, either

1. Use a single certificate and key for both the root and wildcard domains.
1. Configure multiple certificates and keys via
   [`coder.tls.secretNames`](https://github.com/coder/coder/blob/main/helm/coder/values.yaml)
   in the Helm Chart, or
   [`--tls-cert-file`](../../reference/cli/server.md#--tls-cert-file) and
   [`--tls-key-file`](../../reference/cli/server.md#--tls-key-file) command line
   options (these both take a comma separated list of files; list certificates
   and their respective keys in the same order).

## TLS & Reverse Proxy

The Coder server can directly use TLS certificates with `CODER_TLS_ENABLE` and
accompanying configuration flags. However, Coder can also run behind a
reverse-proxy to terminate TLS certificates from LetsEncrypt.

- [Apache](../../tutorials/reverse-proxy-apache.md)
- [Caddy](../../tutorials/reverse-proxy-caddy.md)
- [NGINX](../../tutorials/reverse-proxy-nginx.md)

### Kubernetes TLS configuration

Below are the steps to configure Coder to terminate TLS when running on
Kubernetes. You must have the certificate `.key` and `.crt` files in your
working directory prior to step 1.

1. Create the TLS secret in your Kubernetes cluster

   ```shell
   kubectl create secret tls coder-tls -n <coder-namespace> --key="tls.key" --cert="tls.crt"
   ```

   You can use a single certificate for the both the access URL and wildcard access URL. The certificate CN must match the wildcard domain, such as `*.example.coder.com`.

1. Reference the TLS secret in your Coder Helm chart values

   ```yaml
   coder:
     tls:
         secretName:
         - coder-tls

     # Alternatively, if you use an Ingress controller to terminate TLS,
     # set the following values:
     ingress:
         enable: true
         secretName: coder-tls
         wildcardSecretName: coder-tls
   ```

## PostgreSQL Database

Coder uses a PostgreSQL database to store users, workspace metadata, and other
deployment information. Use `CODER_PG_CONNECTION_URL` to set the database that
Coder connects to. If unset, PostgreSQL binaries will be downloaded from Maven
(<https://repo1.maven.org/maven2>) and store all data in the config root.

> Postgres 13 is the minimum supported version.

If you are using the built-in PostgreSQL deployment and need to use `psql` (aka
the PostgreSQL interactive terminal), output the connection URL with the
following command:

```console
$ coder server postgres-builtin-url
psql "postgres://coder@localhost:49627/coder?sslmode=disable&password=feU...yI1"
```

### Migrating from the built-in database to an external database

To migrate from the built-in database to an external database, follow these
steps:

1. Stop your Coder deployment.
1. Run `coder server postgres-builtin-serve` in a background terminal.
1. Run `coder server postgres-builtin-url` and copy its output command.
1. Run `pg_dump <built-in-connection-string> > coder.sql` to dump the internal
   database to a file.
1. Restore that content to an external database with
   `psql <external-connection-string> < coder.sql`.
1. Start your Coder deployment with
   `CODER_PG_CONNECTION_URL=<external-connection-string>`.

## Configuring Coder behind a proxy

To configure Coder behind a corporate proxy, set the environment variables
`HTTP_PROXY` and `HTTPS_PROXY`. Be sure to restart the server. Lowercase values
(e.g. `http_proxy`) are also respected in this case.

## External Authentication

Coder supports external authentication via OAuth2.0. This allows enabling
integrations with Git providers, such as GitHub, GitLab, and Bitbucket.

External authentication can also be used to integrate with external services
like JFrog Artifactory and others.

Please refer to the [external authentication](../external-auth.md) section for
more information.

## Up Next

- [Setup and manage templates](../templates/index.md)
- [Setup external provisioners](../provisioners.md)