docker-image-builds

This example bundles Dockerfiles with the Coder template, allowing the Docker host to build images itself instead of relying on an external registry.

For large use cases, we recommend building images using CI/CD pipelines and registries instead of at workspace runtime. However, this example is practical for tinkering and iterating on Dockerfiles.

Getting started

Run coder templates init. When prompted, select this template, and follow the on-screen instructions to proceed.

Adding images

Create a Dockerfile (e.g images/golang.Dockerfile):

vim images/golang.Dockerfile

# Start from base image (built on Docker host)
FROM coder-base:latest

# Install everything as root
USER root

# Install go
RUN curl -L "https://dl.google.com/go/go1.18.1.linux-amd64.tar.gz" | tar -C /usr/local -xzvf -

# Setup go env vars
ENV GOROOT /usr/local/go
ENV PATH $PATH:$GOROOT/bin

ENV GOPATH /home/coder/go
ENV GOBIN $GOPATH/bin
ENV PATH $PATH:$GOBIN

# Set back to coder user
USER coder

Edit the Terraform template (main.tf):

vim main.tf

Edit the validation to include the new image:

variable "docker_image" {
    description = "What Docker image would you like to use for your workspace?"
    default     = "base"

    # List of images available for the user to choose from.
    # Delete this condition to give users free text input.
    validation {
-       condition     = contains(["base", "java", "node"], var.docker_image)
+       condition     = contains(["base", "java", "node", "golang], var.docker_image)
        error_message = "Invalid Docker image!"
    }
}

Bump the image tag to a new version:

resource "docker_image" "coder_image" {
    name = "coder-base-${data.coder_workspace.me.owner}-${lower(data.coder_workspace.me.name)}"
    build {
        path       = "./images/"
        dockerfile = "${var.docker_image}.Dockerfile"
-        tag        = ["coder-${var.docker_image}:v0.1"]
+        tag        = ["coder-${var.docker_image}:v0.2"]
    }

    # Keep alive for other workspaces to use upon deletion
    keep_locally = true
}

Update the template:

coder template push docker-image-builds

You can also remove images from the validation list. Workspaces using older template versions will continue using the removed image until you update the workspace to the latest version.

Updating images

Edit the Dockerfile (or related assets):

vim images/node.Dockerfile

# Install Node
- RUN curl -sL https://deb.nodesource.com/setup_14.x | bash -
+ RUN curl -sL https://deb.nodesource.com/setup_16.x | bash -
RUN DEBIAN_FRONTEND="noninteractive" apt-get update -y && \
    apt-get install -y nodejs

Edit the Terraform template (main.tf)

vim main.tf

Bump the image tag to a new version:

resource "docker_image" "coder_image" {
    name = "coder-base-${data.coder_workspace.me.owner}-${lower(data.coder_workspace.me.name)}"
    build {
        path       = "./images/"
        dockerfile = "${var.docker_image}.Dockerfile"
-        tag        = ["coder-${var.docker_image}:v0.1"]
+        tag        = ["coder-${var.docker_image}:v0.2"]
    }

    # Keep alive for other workspaces to use upon deletion
    keep_locally = true
}

Update the template:

coder template push docker-image-builds

Optional: Update workspaces to the latest template version

coder ls
coder update [workspace name]

code-server

code-server is installed via the startup_script argument in the coder_agent resource block. The coder_app resource is defined to access code-server through the dashboard UI over localhost:13337.

Extending this template

See the kreuzwerker/docker Terraform provider documentation to add the following features to your Coder template:

SSH/TCP docker host
Build args
Volume mounts
Custom container spec
More

We also welcome all contributions!

4.2 KiB Raw Blame History