Authentication

By default, Coder is accessible via password authentication. Coder does not recommend using password authentication in production, and recommends using an authentication provider with properly configured multi-factor authentication (MFA). It is your responsibility to ensure the auth provider enforces MFA correctly.

The following steps explain how to set up GitHub OAuth or OpenID Connect.

GitHub

Step 1: Configure the OAuth application in GitHub

First, register a GitHub OAuth app. GitHub will ask you for the following Coder parameters:

• Homepage URL: Set to your Coder deployments CODER_ACCESS_URL (e.g. https://coder.domain.com)
• User Authorization Callback URL: Set to https://coder.domain.com

Note: If you want to allow multiple coder deployments hosted on subdomains e.g. coder1.domain.com, coder2.domain.com, to be able to authenticate with the same GitHub OAuth app, then you can set User Authorization Callback URL to the https://domain.com

Note the Client ID and Client Secret generated by GitHub. You will use these values in the next step.

Coder will need permission to access user email addresses. Find the "Account Permissions" settings for your app and select "read-only" for "Email addresses".

Step 2: Configure Coder with the OAuth credentials

Navigate to your Coder host and run the following command to start up the Coder server:

For GitHub Enterprise support, specify the --oauth2-github-enterprise-base-url flag.

Alternatively, if you are running Coder as a system service, you can achieve the same result as the command above by adding the following environment variables to the /etc/coder.d/coder.env file:

Note: To allow everyone to signup using GitHub, set:

Once complete, run sudo service coder restart to reboot Coder.

If deploying Coder via Helm, you can set the above environment variables in the values.yaml file as such:

To upgrade Coder, run:

We recommend requiring and auditing MFA usage for all users in your GitHub organizations. This can be enforced from the organization settings page in the "Authentication security" sidebar tab.

OpenID Connect

The following steps through how to integrate any OpenID Connect provider (Okta, Active Directory, etc.) to Coder.

Step 1: Set Redirect URI with your OIDC provider

Your OIDC provider will ask you for the following parameter:

• Redirect URI: Set to https://coder.domain.com/api/v2/users/oidc/callback

Step 2: Configure Coder with the OpenID Connect credentials

Navigate to your Coder host and run the following command to start up the Coder server:

If you are running Coder as a system service, you can achieve the same result as the command above by adding the following environment variables to the /etc/coder.d/coder.env file:

Once complete, run sudo service coder restart to reboot Coder.

If deploying Coder via Helm, you can set the above environment variables in the values.yaml file as such:

To upgrade Coder, run:

OIDC Claims

When a user logs in for the first time via OIDC, Coder will merge both the claims from the ID token and the claims obtained from hitting the upstream provider's userinfo endpoint, and use the resulting data as a basis for creating a new user or looking up an existing user.

To troubleshoot claims, set CODER_VERBOSE=true and follow the logs while signing in via OIDC as a new user. Coder will log the claim fields returned by the upstream identity provider in a message containing the string got oidc claims, as well as the user info returned.

Note: If you need to ensure that Coder only uses information from the ID token and does not hit the UserInfo endpoint, you can set the configuration option CODER_OIDC_IGNORE_USERINFO=true.

Email Addresses

By default, Coder will look for the OIDC claim named email and use that value for the newly created user's email address.

If your upstream identity provider users a different claim, you can set CODER_OIDC_EMAIL_FIELD to the desired claim.

Note If this field is not present, Coder will attempt to use the claim field configured for username as an email address. If this field is not a valid email address, OIDC logins will fail.

Email Address Verification

Coder requires all OIDC email addresses to be verified by default. If the email_verified claim is present in the token response from the identity provider, Coder will validate that its value is true. If needed, you can disable this behavior with the following setting:

Note: This will cause Coder to implicitly treat all OIDC emails as "verified", regardless of what the upstream identity provider says.

Usernames

When a new user logs in via OIDC, Coder will by default use the value of the claim field named preferred_username as the the username.

If your upstream identity provider uses a different claim, you can set CODER_OIDC_USERNAME_FIELD to the desired claim.

Note: If this claim is empty, the email address will be stripped of the domain, and become the username (e.g. [email protected] becomes example). To avoid conflicts, Coder may also append a random word to the resulting username.

OIDC Login Customization

If you'd like to change the OpenID Connect button text and/or icon, you can configure them like so:

To change the icon and text above the OpenID Connect button, see application name and logo url in appearance settings.

Disable Built-in Authentication

To remove email and password login, set the following environment variable on your Coder deployment:

SCIM

Enterprise

Premium

Coder supports user provisioning and deprovisioning via SCIM 2.0 with header authentication. Upon deactivation, users are suspended and are not deleted. Configure your SCIM application with an auth key and supply it the Coder server.

TLS

If your OpenID Connect provider requires client TLS certificates for authentication, you can configure them like so:

Group Sync

Enterprise

Premium

If your OpenID Connect provider supports group claims, you can configure Coder to synchronize groups in your auth provider to groups within Coder. To enable group sync, ensure that the groups claim is being sent by your OpenID provider. You might need to request an additional scope or additional configuration on the OpenID provider side.

If group sync is enabled, the user's groups will be controlled by the OIDC provider. This means manual group additions/removals will be overwritten on the next user login.

There are two ways you can configure group sync:

Group allowlist

You can limit which groups from your identity provider can log in to Coder with CODER_OIDC_ALLOWED_GROUPS. Users who are not in a matching group will see the following error:

Role sync

Enterprise

Premium

If your OpenID Connect provider supports roles claims, you can configure Coder to synchronize roles in your auth provider to roles within Coder.

There are 2 ways to do role sync. Server Flags assign site wide roles, and runtime org role sync assigns organization roles

Organization Sync

Premium

Note: In a future Coder release, this can be managed via the Coder UI instead of server flags.

If your OpenID Connect provider supports groups/role claims, you can configure Coder to synchronize claims in your auth provider to organizations within Coder.

First, confirm that your OIDC provider is sending clainms by logging in with OIDC and visiting the following URL with an Owner account:

You should see a field in either id_token_claims, user_info_claims or both followed by a list of the user's OIDC groups in the response. This is the claim sent by the OIDC provider. See Troubleshooting to debug this.

Depending on the OIDC provider, this claim may be named differently. Common ones include groups, memberOf, and roles.

Next configure the Coder server to read groups from the claim name with the OIDC organization field server flag:

Next, fetch the corresponding organization IDs using the following endpoint:

Set the following in your Coder server configuration.

One claim value from your identity provider can be mapped to many organizations in Coder (e.g. the example above maps to 2 organizations in Coder.)

By default, all users are assigned to the default (first) organization. You can disable that with:

Troubleshooting group/role/organization sync

Some common issues when enabling group/role sync.

General guidelines

If you are running into issues with group/role sync, is best to view your Coder server logs and enable verbose mode. To reduce noise, you can filter for only logs related to group/role sync:

Be sure to restart the server after changing these configuration values. Then, attempt to log in, preferably with a user who has the Owner role.

The logs for a successful group sync look like this (human-readable):

To view the full claim, the Owner role can visit this endpoint on their Coder deployment after logging in:

User not being assigned / Group does not exist

If you want Coder to create groups that do not exist, you can set the following environment variable. If you enable this, your OIDC provider might be sending over many unnecessary groups. Use filtering options on the OIDC provider to limit the groups sent over to prevent creating excess groups.

A basic regex filtering option on the Coder side is available. This is applied after the group mapping (CODER_OIDC_GROUP_MAPPING), meaning if the group is remapped, the remapped value is tested in the regex. This is useful if you want to filter out groups that do not match a certain pattern. For example, if you want to only allow groups that start with my-group- to be created, you can set the following environment variable.

Invalid Scope

If you see an error like the following, you may have an invalid scope.

This can happen because the identity provider has a different name for the scope. For example, Azure AD uses GroupMember.Read.All instead of groups. You can find the correct scope name in the IDP's documentation. Some IDP's allow configuring the name of this scope.

The solution is to update the value of CODER_OIDC_SCOPES to the correct value for the identity provider.

No group claim in the got oidc claims log

Steps to troubleshoot.

1. Ensure the user is a part of a group in the IDP. If the user has 0 groups, no groups claim will be sent.
2. Check if another claim appears to be the correct claim with a different name. A common name is memberOf instead of groups. If this is present, update CODER_OIDC_GROUP_FIELD=memberOf.
3. Make sure the number of groups being sent is under the limit of the IDP. Some IDPs will return an error, while others will just omit the groups claim. A common solution is to create a filter on the identity provider that returns less than the limit for your IDP.
   • Azure AD limit is 200, and omits groups if exceeded.
   • Okta limit is 100, and returns an error if exceeded.

Provider-Specific Guides

Below are some details specific to individual OIDC providers.

Active Directory Federation Services (ADFS)

Note: Tested on ADFS 4.0, Windows Server 2019

1. In your Federation Server, create a new application group for Coder. Follow the steps as described here.

   • Server Application: Note the Client ID.
   • Configure Application Credentials: Note the Client Secret.
   • Configure Web API: Set the Client ID as the relying party identifier.
   • Application Permissions: Allow access to the claims openid, email, profile, and allatclaims.

2. Visit your ADFS server's /.well-known/openid-configuration URL and note the value for issuer.

   Note: This is usually of the form https://adfs.corp/adfs/.well-known/openid-configuration

3. In Coder's configuration file (or Helm values as appropriate), set the following environment variables or their corresponding CLI arguments:

   • CODER_OIDC_ISSUER_URL: the issuer value from the previous step.

   • CODER_OIDC_CLIENT_ID: the Client ID from step 1.

   • CODER_OIDC_CLIENT_SECRET: the Client Secret from step 1.

   • CODER_OIDC_AUTH_URL_PARAMS: set to

     {"resource":"$CLIENT_ID"}

     where $CLIENT_ID is the Client ID from step 1 (see here). This is required for the upstream OIDC provider to return the requested claims.

   • CODER_OIDC_IGNORE_USERINFO: Set to true.

4. Configure Issuance Transform Rules on your federation server to send the following claims:

   • preferred_username: You can use e.g. "Display Name" as required.

   • email: You can use e.g. the LDAP attribute "E-Mail-Addresses" as required.

   • email_verified: Create a custom claim rule:

     => issue(Type = "email_verified", Value = "true")

   • (Optional) If using Group Sync, send the required groups in the configured groups claim field. See here for an example.

Keycloak

The access_type parameter has two possible values: "online" and "offline." By default, the value is set to "offline". This means that when a user authenticates using OIDC, the application requests offline access to the user's resources, including the ability to refresh access tokens without requiring the user to reauthenticate.

To enable the offline_access scope, which allows for the refresh token functionality, you need to add it to the list of requested scopes during the authentication flow. Including the offline_access scope in the requested scopes ensures that the user is granted the necessary permissions to obtain refresh tokens.

By combining the {"access_type":"offline"} parameter in the OIDC Auth URL with the offline_access scope, you can achieve the desired behavior of obtaining refresh tokens for offline access to the user's resources.