Teleport

Access Requests with Slack

This guide will explain how to set up Slack to receive Access Request messages from Teleport. Teleport's Slack integration notifies individuals and channels of Access Requests. Users can then approve and deny Access Requests from within Slack, making it easier to implement security best practices without compromising productivity.

Here is an example of sending an Access Request via Teleport's Slack plugin:

Prerequisites

A running Teleport cluster. For details on how to set this up, see our Enterprise Getting Started guide.
The tctl admin tool and tsh client tool version >= 10.1.2, which you can download by visiting the customer portal.
```
tctl version
Teleport v10.1.2 go1.18
tsh version
Teleport v10.1.2 go1.18
```

A Teleport Cloud account. If you do not have one, visit the sign up page to begin your free trial.
The tctl admin tool and tsh client tool version >= 9.3.10. To download these tools, visit the Downloads page.
```
tctl version
Teleport v9.3.10 go1.18
tsh version
Teleport v9.3.10 go1.18
```

Slack admin privileges to create an app and install it to your workspace. Your Slack profile must have the "Workspace Owner" or "Workspace Admin" banner below your profile picture.

To connect to Teleport, log in to your cluster using tsh, then use tctl remotely:

tsh login --proxy=teleport.example.com [email protected]
tctl status
Cluster  teleport.example.com
Version  10.1.2
CA pin   sha256:abdc1245efgh5678abdc1245efgh5678abdc1245efgh5678abdc1245efgh5678

You can run subsequent tctl commands in this guide on your local machine.

For full privileges, you can also run tctl commands on your Auth Service host.

To connect to Teleport, log in to your cluster using tsh, then use tctl remotely:

tsh login --proxy=myinstance.teleport.sh [email protected]
tctl status
Cluster  myinstance.teleport.sh
Version  9.3.10
CA pin   sha256:sha-hash-here

You must run subsequent tctl commands in this guide on your local machine.

Step 1/8. Define RBAC resources

Before you set up the Slack plugin, you will need to enable Access Requests in your Teleport cluster. For the purpose of this guide, we will define an editor-requester role, which can request the built-in editor role, and an editor-reviewer role that can review requests for the editor role.

Create a file called editor-request-rbac.yaml with the following content:

kind: role
version: v5
metadata:
  name: editor-reviewer
spec:
  allow:
    review_requests:
      roles: ['editor']
---
kind: role
version: v5
metadata:
  name: editor-requester
spec:
  allow:
    request:
      roles: ['editor']
      thresholds:
        - approve: 1
          deny: 1

Create the roles you defined:

tctl create -f editor-request-rbac.yaml
role 'editor-reviewer' has been created
role 'editor-requester' has been created

Allow yourself to review requests by users with the editor-requester role by assigning yourself the editor-reviewer role. First, retrieve your user definition:

TELEPORT_USER=$(tsh status --format=json | jq -r .active.username)
tctl get user/${TELEPORT_USER?} > user.yaml

Edit user.yaml to add the editor-reviewer role:

 spec:
   roles:
   - access
   - editor
+  - editor-reviewer

Update your user definition:

tctl create -f user.yaml

Log out of Teleport and log in again. You will now have the ability to review requests for the editor role.

Create a user called myuser who has the editor-requester role as well as the built-in access role and the ubuntu login. This user cannot edit your cluster configuration unless they request the editor role:

tctl users add myuser --roles=editor-requester

tctl will print an invitation URL to your terminal. Visit the URL and log in as myuser for the first time, registering credentials as configured for your Teleport cluster.

Later in this guide, you will have myuser request the editor role so you can review the request using the Teleport plugin.

Step 2/8. Install the Teleport Slack plugin

We currently only provide linux-amd64 binaries. You can also compile these plugins from source. You can run the plugin from a remote host or your local development machine.

We recommend installing Teleport plugins on the same host as the Teleport Proxy Service. This is an ideal location as plugins have a low memory footprint and will require access to both the public internet and the Teleport Auth Service.

curl -L -O https://get.gravitational.com/teleport-access-slack-v10.1.2-linux-amd64-bin.tar.gz
tar -xzf teleport-access-slack-v10.1.2-linux-amd64-bin.tar.gz
./teleport-access-slack/install

To install from source you need git and go >= 1.18 installed.

Check out the teleport-plugins repository
git clone https://github.com/gravitational/teleport-plugins.git
cd teleport-plugins/access/slack
make

Place the teleport-slack binary into an appropriate location within the sytem's PATH, e.g., /usr/local/bin:

mv ./build/teleport-slack /usr/local/bin

Make sure the binary is installed:

teleport-slack version
teleport-slack v10.1.2 git:teleport-slack-v10.1.2-fffffffff go1.18

Step 3/8. Create a user and role for the plugin

Teleport's Access Request plugins authenticate to your Teleport cluster as a user with permissions to list, read, and update Access Requests. This way, plugins can retrieve Access Requests from the Teleport Auth Service, present them to reviewers, and modify them after a review.

Define a user and role called access-plugin by adding the following content to a file called access-plugin.yaml:

kind: role
version: v5
metadata:
  name: access-plugin
spec:
  allow:
    rules:
      - resources: ['access_request']
        verbs: ['list', 'read', 'update']
      - resources: ['access_plugin_data']
        verbs: ['update']
---
kind: user
metadata:
  name: access-plugin
spec:
  roles: ['access-plugin']
version: v2

Create the user and role:

tctl create -f access-plugin.yaml

As with all Teleport users, the Teleport Auth Service authenticates the access-plugin user by issuing short-lived TLS credentials. In this case, we will need to request the credentials manually by impersonating the access-plugin role and user.

If you are using tctl from the Auth Service host, you will already have impersonation privileges.

To grant your user impersonation privileges for access-plugin, define a role called access-plugin-impersonator by pasting the following YAML document into a file called access-plugin-impersonator.yaml:

kind: role
version: v5
metadata:
  name: access-plugin-impersonator
spec:
  allow:
    impersonate:
      roles:
      - access-plugin
      users:
      - access-plugin

Create the access-plugin-impersonator role:

tctl create -f access-plugin-impersonator.yaml

Retrieve your user definition:

TELEPORT_USER=$(tsh status --format=json | jq -r .active.username)
tctl get users/${TELEPORT_USER?} > myuser.yaml

Edit myuser.yaml to include the role you just created:

  roles:
   - access
   - auditor
   - editor
+  - access-plugin-impersonator

Apply your changes:

tctl create -f myuser.yaml

Log out of your Teleport cluster and log in again. You will now be able to generate signed certificates for the access-plugin role and user.

Step 4/8. Export the access plugin identity

Like all Teleport users, access-plugin needs signed credentials in order to connect to your Teleport cluster. You will use the tctl auth sign command to request these credentials for your plugin.

The format of the credentials depends on whether you have set up your network to give the plugin direct access to the Teleport Auth Service, or if all Teleport clients and services connect to the Teleport Proxy Service instead.

The following tctl auth sign command impersonates the access-plugin user, generates signed credentials, and writes an identity file to the local directory:

tctl auth sign --user=access-plugin --out=auth.pem

Teleport's Access Request plugins listen for new and updated Access Requests by connecting to the Teleport Auth Service's gRPC endpoint over TLS.

The identity file, auth.pem, includes both TLS and SSH credentials. Your Access Request plugin uses the SSH credentials to connect to the Proxy Service, which establishes a reverse tunnel connection to the Auth Service. The plugin uses this reverse tunnel, along with your TLS credentials, to connect to the Auth Service's gRPC endpoint.

You will refer to this file later when configuring the plugin.

If your network allows your plugin to access the Auth Service directly, e.g., you are running the plugin on the Auth Service host, the plugin uses TLS credentials to connect to the Auth Service's gRPC endpoint and listen for new and updated Access Requests.

You can generate TLS credentials with the following command:

tctl auth sign --format=tls --user=access-plugin --out=auth

This command should result in three PEM-encoded files: auth.crt, auth.key, and auth.cas (certificate, private key, and CA certs respectively). Later, you will configure the plugin to use these credentials to connect to the Auth Service directly.

Certificate Lifetime

By default, tctl auth sign produces certificates with a relatively short lifetime. For production deployments, you can use the --ttl flag to ensure a more practical certificate lifetime, e.g., --ttl=8760h to export a one-year certificate.

The rest of this guide assumes that you have placed any files generated by this command into /var/lib/teleport/plugins/slack for later reference when configuring the plugin:

create a data directory to hold certificate files for the plugin.
sudo mkdir -p /var/lib/teleport/plugins/slack
sudo mv auth.* /var/lib/teleport/plugins/slack

Step 5/8. Register a Slack app

The Access Request plugin for Slack receives Access Request events from the Teleport Auth Service, formats them into Slack messages, and sends them to the Slack API to post them in your workspace. For this to work, you must register a new app with the Slack API.

Create your app

Visit https://api.slack.com/apps to create a new Slack app. Click "Create an App", then "From scratch". Fill in the form as shown below:

The "App Name" should be "Teleport". Click the "Development Slack Workspace" dropdown and choose the workspace where you would like to see Access Request messages.

Generate an OAuth token with scopes

Next, configure your application to authenticate to the Slack API. We will do this by generating an OAuth token that the plugin will present to the Slack API.

We will restrict the plugin to the norrowest possible permissions by using OAuth scopes. The Slack plugin needs to post messages to your workspace. It also needs to read usernames and email addresses in order to direct Access Request notifications from the Auth Service to the appropriate Teleport users in Slack.

After creating your app, the Slack website will open a console where you can specify configuration options. On the sidebar menu under "Features", click "OAuth & Permissions".

Scroll to the "Scopes" section and click "Add an OAuth Scope" for each of the following scopes:

chat:write
incoming-webhook
users:read
users:read.email

The result should look like this:

After you have configured scopes for your plugin, scroll back to the top of the OAuth & Permissions page, find the "OAuth Tokens for Your Workspace" section, and click "Install to Workspace". You will see a summary of the permission you configured for the Slack plugin earlier.

In "Where should Teleport post?", choose "Slackbot" as the default channel the plugin will post to. The plugin will post here when sending direct messages. Later in this guide, we will configure the plugin to post in other channels as well.

After submitting this form, you will see an OAuth token in the "OAuth & Permissions" tab under "Tokens for Your Workspace":

You will use this token later when configuring the Slack plugin.

Step 6/8. Configure the Teleport Slack plugin

At this point, the Teleport Slack plugin has the credentials it needs to communicate with your Teleport cluster and the Slack API. In this step, you will configure the Slack plugin to use these credentials. You will also configure the plugin to notify the right Slack channels when it receives an Access Request update.

Generate a config file

The Teleport Slack plugin uses a config file in TOML format. Generate a boilerplate config by running the following command (the plugin will not run unless the config file is in /etc/teleport-slack.toml):

teleport-slack configure | sudo tee /etc/teleport-slack.toml > /dev/null

This should result in a config file like the one below:

# Copied from https://github.com/gravitational/teleport-plugins/blob/master/access/slack/example_config.toml

# Example Slack plugin configuration TOML file

[teleport]
# This section 

# Teleport Auth/Proxy Server address.
# addr = "example.com:3025"
#
# Should be port 3025 for Auth Server and 3080 or 443 for Proxy.
# For Teleport Cloud, should be in the form "your-account.teleport.sh:443".

# Credentials generated with `tctl auth sign`.
#
# When using --format=file:
# identity = "/var/lib/teleport/plugins/slack/auth_id"    # Identity file
#
# When using --format=tls:
# client_key = "/var/lib/teleport/plugins/slack/auth.key" # Teleport TLS secret key
# client_crt = "/var/lib/teleport/plugins/slack/auth.crt" # Teleport TLS certificate
# root_cas = "/var/lib/teleport/plugins/slack/auth.cas"   # Teleport CA certs

[slack]
# Slack Bot OAuth token
# You can also use an absolute path to a token file, e.g., 
# "/var/lib/teleport/token"
token = "xoxb-11xx"

[role_to_recipients]
# Map roles to recipients.
#
# Provide slack user_email/channel recipients for access requests for specific roles. 
# role.suggested_reviewers will automatically be treated as additional email recipients.
# "*" must be provided to match non-specified roles.
#
# "dev" = "devs-slack-channel"
# "*" = ["[email protected]", "admin-slack-channel"]

[log]
output = "stderr" # Logger output. Could be "stdout", "stderr" or "/var/lib/teleport/slack.log"
severity = "INFO" # Logger severity. Could be "INFO", "ERROR", "DEBUG" or "WARN".

Edit the config file

Edit the teleport-slack.toml file you created earlier to update the following fields:

[teleport]

The Slack plugin uses this section to connect to the Teleport Auth Service.

The address and credentials you configure depend on whether your plugin can access the Auth Service directly:

Set addr to the address and port of your Auth Service. This address must be reachable from the Teleport Slack Plugin.

Set client_key, client_crt, and root_cas to the identity files generated earlier:

[teleport]
addr = "localhost:3025"
client_key = "/var/lib/teleport/plugins/slack/auth.key" # Teleport GRPC client secret key
client_crt = "/var/lib/teleport/plugins/slack/auth.crt" # Teleport GRPC client certificate
root_cas = "/var/lib/teleport/plugins/slack/auth.cas"   # Teleport cluster CA certs

Set addr to your Proxy Service address with port 443.

Set identity to the identity file generated earlier:

[teleport]
addr = "mytenant.teleport.sh:443"
identity = "/var/lib/teleport/plugins/slack/auth.pem"

[slack]

token: Open https://api.slack.com/apps, find the Slack app you created earlier, navigate to the "OAuth & Permissions" tab, copy the "Bot User OAuth Token", and paste it into this field.

[role_to_recipients]

The role_to_recipients map configure the channels that the Slack plugin will notify when a user requests access to a specific role. When the Slack plugin receives an Access Request from the Auth Service, it will look up the role being requested and identify the Slack channels to notify.

Here is an example of a role_to_recipients map:

[role_to_recipients]
"*" = "admin-slack-channel"
"dev" = ["dev-slack-channel", "admin-slack-channel"]
"dba" = "[email protected]"

In the role_to_recipients map, each key is the name of a Teleport role. Each value configures the Slack channel (or channels) to notify. The value can be a single string or an array of strings. Each string must be either the name of a Slack channel (including a user's direct message channel) or the email address of a Slack user. If the recipient is an email address, the Slack plugin will use that email address to look up a direct message channel.

The role_to_recipients map must also include an entry for "*", which the plugin looks up if no other entry matches a given role name. In the example above, requests for roles aside from dev and dba will notify the admin-slack-channel channel.

Users can suggest reviewers when they create an Access Request, e.g.,:

tsh request create --roles=dbadmin [email protected],[email protected]

If an Access Request includes suggested reviewers, the Slack plugin will add these to the list of channels to notify. If a suggested reviewer is an email address, the plugin will look up the the direct message channel for that address and post a message in that channel.

Configure the Slack plugin to notify you when a user requests the editor role by adding the following to your role_to_recipients config (replace TELEPORT_USERNAME with the user you assigned the editor-reviewer role earlier):

[role_to_recipients]
"*" = "access-requests"
"editor" = "TELEPORT_USERNAME"

Either create an access-requests channel in your Slack workspace or rename the value of the "*" key to an existing channel.

Invite your Slack app

Once you have configured the channels that the Slack plugin will notify when it receives an Access Request, you will need to ensure that the plugin can post in those channels.

You have already configured the plugin to send direct messages as Slackbot. For any other channel you mention in your role_to_recipients map, you will need to invite the plugin to that channel. Navigate to each channel and enter /invite @teleport in the message box.

Step 7/8. Test your Slack app

Once Teleport is running, you've created the Slack app, and the plugin is configured, you can now run the plugin and test the workflow.

Start the plugin:

teleport-slack start

If everything works fine, the log output should look like this:

teleport-slack start
INFO   Starting Teleport Access Slack Plugin 7.2.1: slack/app.go:80
INFO   Plugin is ready slack/app.go:101

Create an Access Request and check if the plugin works as expected with the following steps.

Create an Access Request

A Teleport admin can create an Access Request for another user with tctl.

tctl request create myuser --roles=editor

Users can use tsh to create an Access Request and log in with approved roles.

tsh request new --roles=editor
Seeking request approval... (id: 8f77d2d1-2bbf-4031-a300-58926237a807)

Users can request access using the Web UI by visiting the "Access Requests" tab and clicking "New Request":

The user you configured earlier to review the request should receive a direct message from "Teleport" in Slack allowing them to visit a link in the Teleport Web UI and either approve or deny the request.

Resolve the request

Once you receive the review request in Slack, click the link to visit the Web UI and approve or deny the request:

You can also review an Access Request from the command line:

Replace REQUEST_ID with the id of the request
tctl request approve REQUEST_ID
tctl request deny REQUEST_ID

Replace REQUEST_ID with the id of the request
tsh request review --approve REQUEST_ID
tsh request review --deny REQUEST_ID

Once the request is resolved, the Slack bot will add an emoji reaction of ✅ or ❌ to the Slack message for the Access Request, depending on whether the request was approved or denied.

Auditing Access Requests

When the Slack plugin posts an Access Request notification to a channel, anyone with access to the channel can view the notification and follow the link. While users must be authorized via their Teleport roles to review Access Requests, you should still check the Teleport audit log to ensure that the right users are reviewing the right requests.

When auditing Access Request reviews, check for events with the type Access Request Reviewed in the Teleport Web UI and access_request.review if reviewing the audit log on the Auth Service host.

Step 8/8. Set up systemd

In production, we recommend starting the Teleport plugin daemon via an init system like systemd. Here's the recommended Teleport plugin service unit file for systemd:

[Unit]
Description=Teleport Slack Plugin
After=network.target

[Service]
Type=simple
Restart=on-failure
ExecStart=/usr/local/bin/teleport-slack start --config=/etc/teleport-slack.toml
ExecReload=/bin/kill -HUP $MAINPID
PIDFile=/run/teleport-slack.pid

[Install]
WantedBy=multi-user.target

Save this as teleport-slack.service in either /usr/lib/systemd/system/ or another unit file load path supported by systemd.

Enable and start the plugin:

sudo systemctl enable teleport-slack
sudo systemctl start teleport-slack

Next steps

Read our guides to configuring Resource Access Requests and Role Access Requests so you can get the most out of your Access Request plugins.

Feedback

If you have any issues with this plugin, please create a GitHub issue in our gravitational/teleport-plugins repo.

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