FAQs | Coder Docs

FAQs

Frequently asked questions on Coder OSS and licensed deployments. These FAQs come from our community and customers, feel free to contribute to this page.

For other community resources, see our GitHub discussions, or join our Discord server.

How do I add a Premium trial license?

Visit https://coder.com/trial or contact

[email protected] to get a trial key.

You can add a license through the UI or CLI.

In the UI, click the Deployment tab -> Licenses and upload the jwt license file.

To add the license with the CLI, first install the Coder CLI and server to the latest release.

If the license is a text string:

coder licenses add -l 1f5...765

If the license is in a file:

coder licenses add -f <path/filename>

I'm experiencing networking issues, so want to disable Tailscale, STUN, Direct connections and force use of websocket

The primary developer use case is a local IDE connecting over SSH to a Coder workspace.

Coder's networking stack has intelligence to attempt a peer-to-peer or Direct connection between the local IDE and the workspace. However, this requires some additional protocols like UDP and being able to reach a STUN server to echo the IP addresses of the local IDE machine and workspace, for sharing using a Wireguard Coordination Server. By default, Coder assumes Internet and attempts to reach Google's STUN servers to perform this IP echo.

Operators experimenting with Coder may run into networking issues if UDP (which STUN requires) or the STUN servers are unavailable, potentially resulting in lengthy local IDE and SSH connection times as the Coder control plane attempts to establish these direct connections.

Setting the following flags as shown disables this logic to simplify troubleshooting.

Flag	Value	Meaning
`CODER_BLOCK_DIRECT`	`true`	Blocks direct connections
`CODER_DERP_SERVER_STUN_ADDRESSES`	`"disable"`	Disables STUN
`CODER_DERP_FORCE_WEBSOCKETS`	`true`	Forces websockets over Tailscale DERP

How do I configure NGINX as the reverse proxy in front of Coder?

This tutorial in our docs explains in detail how to configure NGINX with Coder so that our Tailscale Wireguard networking functions properly.

How do I hide some of the default icons in a workspace like VS Code Desktop, Terminal, SSH, Ports?

The visibility of Coder apps is configurable in the template. To change the default (shows all), add this block inside the coder_agent of a template and configure as needed:

  display_apps {
    vscode = false
    vscode_insiders = false
    ssh_helper = false
    port_forwarding_helper = false
    web_terminal = true
  }

This example will hide all built-in coder_app icons except the web terminal.

I want to allow code-server to be accessible by other users in my deployment.

It is not recommended to share a web IDE, but if required, the following deployment environment variable settings are required.

Set deployment (Kubernetes) to allow path app sharing

# allow authenticated users to access path-based workspace apps
- name: CODER_DANGEROUS_ALLOW_PATH_APP_SHARING
  value: "true"
# allow Coder owner roles to access path-based workspace apps
- name: CODER_DANGEROUS_ALLOW_PATH_APP_SITE_OWNER_ACCESS
  value: "true"

In the template, set coder_app share option to authenticated and when a workspace is built with this template, the pretty globe shows up next to path-based code-server:

resource "coder_app" "code-server" {
  ...
  share        = "authenticated"
  ...
}

I installed Coder and created a workspace but the icons do not load.

An important concept to understand is that Coder creates workspaces which have an agent that must be able to reach the coder server.

If the CODER_ACCESS_URL is not accessible from a workspace, the workspace may build, but the agent cannot reach Coder, and thus the missing icons. e.g., Terminal, IDEs, Apps.

By default, coder server automatically creates an Internet-accessible reverse proxy so that workspaces you create can reach the server.

If you are doing a standalone install, e.g., on a MacBook and want to build workspaces in Docker Desktop, everything is self-contained and workspaces (containers in Docker Desktop) can reach the Coder server.

coder server --access-url http://localhost:3000 --address 0.0.0.0:3000

Even coder server which creates a reverse proxy, will let you use http://localhost to access Coder from a browser.

I updated a template, and an existing workspace based on that template fails to start.

When updating a template, be aware of potential issues with input variables. For example, if a template prompts users to choose options like a code-server VS Code IDE release, a container image, or a VS Code extension, removing any of these values can lead to existing workspaces failing to start. This issue occurs because the Terraform state will not be in sync with the new template.

However, a lesser-known CLI sub-command, coder update, can resolve this issue. This command re-prompts users to re-enter the input variables, potentially saving the workspace from a failed status.

coder update --always-prompt <workspace name>

I'm running coder on a VM with systemd but latest release installed isn't showing up.

Take, for example, a Coder deployment on a VM with a 2 shared vCPU systemd service. In this scenario, it's necessary to reload the daemon and then restart the Coder service. This prevents the systemd daemon from trying to reference the previous Coder release service since the unit file has changed.

The following commands can be used to update Coder and refresh the service:

curl -fsSL https://coder.com/install.sh | sh
sudo systemctl daemon-reload
sudo systemctl restart coder.service

I'm using the built-in Postgres database and forgot admin email I set up.

Run the coder server command below to retrieve the psql connection URL which includes the database user and password.
psql into Postgres, and do a select query on the users table.
Restart the coder server, pull up the Coder UI and log in (you will still need your password)

coder server postgres-builtin-url
psql "postgres://coder@localhost:53737/coder?sslmode=disable&password=I2S...pTk"

How to find out Coder's latest Terraform provider version?

Coder is on the HashiCorp's Terraform registry. Check this frequently to make sure you are on the latest version.

Sometimes, the version may change and resource configurations will either become deprecated or new ones will be added when you get warnings or errors creating and pushing templates.

How can I set up TLS for my deployment and not create a signed certificate?

Caddy is an easy-to-configure reverse proxy that also automatically creates certificates from Let's Encrypt. Install docs here You can start Caddy as a systemd service.

The Caddyfile configuration will appear like this where 127.0.0.1:3000 is your CODER_ACCESS_URL:

coder.example.com {

  reverse_proxy 127.0.0.1:3000

  tls {

    issuer acme {
      email [email protected]
    }

  }
}

I'm using Caddy as my reverse proxy in front of Coder. How do I set up a wildcard domain for port forwarding?

Caddy requires your DNS provider's credentials to create wildcard certificates. This involves building the Caddy binary from source with the DNS provider plugin added. e.g., Google Cloud DNS provider here

To compile Caddy, the host running Coder requires Go. Once installed, replace the existing Caddy binary in usr/bin and restart the Caddy service.

The updated Caddyfile configuration will look like this:

*.coder.example.com, coder.example.com {

  reverse_proxy 127.0.0.1:3000

  tls {
    issuer acme {
      email [email protected]
      dns googleclouddns {
        gcp_project my-gcp-project
      }
    }
  }

}

Can I use local or remote Terraform Modules in Coder templates?

One way is to reference a Terraform module from a GitHub repo to avoid duplication and then just extend it or pass template-specific parameters/resources:

# template1/main.tf
module "central-coder-module" {
  source = "github.com/org/central-coder-module"
  myparam = "custom-for-template1"
}

resource "ebs_volume" "custom_template1_only_resource" {
}

# template2/main.tf
module "central-coder-module" {
  source = "github.com/org/central-coder-module"
  myparam = "custom-for-template2"
  myparam2 = "bar"
}

resource "aws_instance" "custom_template2_only_resource" {
}

Another way using local modules is to symlink the module directory inside the template directory and then tar the template.

ln -s modules template_1/modules
tar -cvh -C ./template_1 | coder templates <push|create> -d - <name>

References:

Can I run Coder in an air-gapped or offline mode? (no Internet)?

Yes, Coder can be deployed in air-gapped or offline mode.

Our product bundles with the Terraform binary so assume access to terraform.io during installation. The docs outline rebuilding the Coder container with Terraform built-in as well as any required Terraform providers.

Direct networking from local SSH to a Coder workspace needs a STUN server. Coder defaults to Google's STUN servers, so you can either create your STUN server in your network or disable and force all traffic through the control plane's DERP proxy.

Create a randomized computer_name for an Azure VM

Azure VMs have a 15 character limit for the computer_name which can lead to duplicate name errors.

This code produces a hashed value that will be difficult to replicate.

locals {
  concatenated_string = "${data.coder_workspace.me.name}+${data.coder_workspace_owner.me.name}"
  hashed_string = md5(local.concatenated_string)
  truncated_hash = substr(local.hashed_string, 0, 16)
}

Do you have example JetBrains Gateway templates?

In August 2023, JetBrains certified the Coder plugin signifying enhanced stability and reliability.

The Coder plugin will appear in the Gateway UI when opened.

Selecting the most suitable template depends on how the deployment manages JetBrains IDE versions. If downloading from jetbrains.com is acceptable, see the example templates below which specifies the product code, IDE version and build number in the coder_app resource. This will present an icon in the workspace dashboard which when clicked, will look for a locally installed Gateway, and open it. Alternatively, the IDE can be baked into the container image and manually open Gateway (or IntelliJ which has Gateway built-in), using a session token to Coder and then open the IDE.

What options do I have for adding VS Code extensions into code-server, VS Code Desktop or Microsoft's Code Server?

Coder has an open-source project called code-marketplace which is a private VS Code extension marketplace. There is even integration with JFrog Artifactory.

See this example template where the agent specifies the URL and config environment variables which code-server picks up and points the developer to.

Another option is to use Microsoft's code-server - which is like Coder's, but it can connect to Microsoft's extension marketplace so Copilot and chat can be retrieved there.

Another option is to use VS Code Desktop (local) and that connects to Microsoft's marketplace.

Note: these are example templates with no SLAs on them and are not guaranteed for long-term support.

I want to run Docker for my workspaces but not install Docker Desktop.

Colima is a Docker Desktop alternative.

This example is meant for a users who want to try out Coder on a macOS device.

Install Colima and docker with:

brew install colima
brew install docker

Start Colima:

colima start

Start Colima with specific compute options:

colima start --cpu 4 --memory 8

Starting Colima on a M3 MacBook Pro:

colima start --arch x86_64  --cpu 4 --memory 8 --disk 10

Colima will show the path to the docker socket so we have a community template that prompts the Coder admin to enter the docker socket as a Terraform variable.

How to make a `coder_app` optional?

An example use case is the user should decide if they want a browser-based IDE like code-server when creating the workspace.

Add a coder_parameter with type bool to ask the user if they want the code-server IDE

data "coder_parameter" "code_server" {
  name        = "Do you want code-server in your workspace?"
  description = "Use VS Code in a browser."
  type        = "bool"
  default     = false
  mutable     = true
  icon        = "/icon/code.svg"
  order       = 6
}

Add conditional logic to the startup_script to install and start code-server depending on the value of the added coder_parameter

# install and start code-server, VS Code in a browser

if [ ${data.coder_parameter.code_server.value} = true ]; then
  echo "🧑🏼‍💻 Downloading and installing the latest code-server IDE..."
  curl -fsSL https://code-server.dev/install.sh | sh
  code-server --auth none --port 13337 >/dev/null 2>&1 &
fi

Add a Terraform meta-argument count in the coder_app resource so it will only create the resource if the coder_parameter is true

# code-server
resource "coder_app" "code-server" {
  count         = data.coder_parameter.code_server.value ? 1 : 0
  agent_id      = coder_agent.coder.id
  slug          = "code-server"
  display_name  = "code-server"
  icon          = "/icon/code.svg"
  url           = "http://localhost:13337?folder=/home/coder"
  subdomain = false
  share     = "owner"

  healthcheck {
    url       = "http://localhost:13337/healthz"
    interval  = 3
    threshold = 10
  }
}

Why am I getting this "remote host doesn't meet VS Code Server's prerequisites" error when opening up VSCode remote in a Linux environment?

It is because, more than likely, the supported OS of either the container image or VM/VPS doesn't have the proper C libraries to run the VS Code Server. For instance, Alpine is not supported at all. If so, you need to find a container image or supported OS for the VS Code Server. For more information on OS prerequisites for Linux, please look at the VSCode docs. https://code.visualstudio.com/docs/remote/linux#_local-linux-prerequisites

How can I resolve disconnects when connected to Coder via JetBrains Gateway?

If your JetBrains IDE is disconnected for a long period of time due to a network change (for example turning off a VPN), you may find that the IDE will not reconnect once the network is re-established (for example turning a VPN back on). When this happens a persistent message will appear similar to the below:

No internet connection. Changes in the document might be lost. Trying to reconnect…

To resolve this, add this entry to your SSH config file on your local machine:

Host coder-jetbrains--*
  ServerAliveInterval 5

This will make SSH check that it can contact the server every five seconds. If it fails to do so ServerAliveCountMax times (3 by default for a total of 15 seconds) then it will close the connection which forces JetBrains to recreate the hung session. You can tweak ServerAliveInterval and ServerAliveCountMax to increase or decrease the total timeout.

Note that the JetBrains Gateway configuration blocks for each host in your SSH config file will be overwritten by the JetBrains Gateway client when it re-authenticates to your Coder deployment so you must add the above config as a separate block and not add it to any existing ones.

How can I restrict inbound/outbound file transfers from Coder workspaces?

In certain environments, it is essential to keep confidential files within workspaces and prevent users from uploading or downloading resources using tools like scp or rsync.

To achieve this, template admins can use the environment variable CODER_AGENT_BLOCK_FILE_TRANSFER to enable additional SSH command controls. This variable allows the system to check if the executed application is on the block list, which includes scp, rsync, ftp, and nc.

resource "docker_container" "workspace" {
  ...
  env = [
    "CODER_AGENT_TOKEN=${coder_agent.main.token}",
    "CODER_AGENT_BLOCK_FILE_TRANSFER=true",
    ...
  ]
}

Important Notice

This control operates at the ssh-exec level or during sftp sessions. While it can help prevent automated file transfers using the specified tools, users can still SSH into the workspace and manually initiate file transfers. The primary purpose of this feature is to warn and discourage users from downloading confidential resources to their local machines.

For more advanced security needs, consider adopting an endpoint security solution.

See an opportunity to improve our docs? Make an edit.