Clever Cloud offers support for Docker containers. These are deployed inside virtual machines to guarantee a secure level of isolation.
Docker containers can encapsulate any payload, and will run consistently on and between virtually any server. The same container that a developer builds and tests on a laptop will run at scale, in production, on VMs, bare-metal servers, public instances, or combinations of the above.
Clever Cloud allows you to deploy any application running inside a Docker container. This page will explain how to set up your application to run it on our service.
- Go to the Clever Cloud console, and find the app you want to fine tune under it’s organization.
- Find the Environment variables menu and select it.
- In this menu, you will see a form with VARIABLE_NAME and variable value fields.
- Fill them with the desired values then select Add.
- Don’t forget to “Update Changes” at the end of the menu.
- Make sure you have clever-tools installed locally. Refer to our CLI getting started.
- In your code folder, do
clever env set <variable-name> <variable-value>
Refer to environment variables reference for more details on available environment variables on Clever Cloud.
You can of course create custom ones with the interface we just demonstrated, they will be available for your application.
Be sure that you:
- push on the master branch.
- have and commit a file named Dockerfile or use the CC_DOCKERFILE environment variable if your Dockerfile has a different name, Here is what it will look like.
- run the application with
ENTRYPOINTin your Dockerfile.
- listen on HTTP port 8080 by default (you can set your own port using
You can virtually put everything you want in your Dockerfile. The only mandatory (for us) instruction to put in it is:
CMD <command to run>
command to run: this is the command that starts your application. Your application must listen on port 8080. It can be easier for you to put a script in your docker image and call it with the CMD instruction.
If the building step of your app crashes because it uses more memory that it’s available, you’ll have to split the building and running steps and enable Dedicated build instance
# The base image
# Run the memory intensive build on an instance with 4 GB of memory (M)
RUN yarn install && yarn build
# Start the app on a smaller instance (nano)
CMD yarn start
Clever Cloud enables you to use TCP over Docker applications using using the environment variable
CC_DOCKER_EXPOSED_TCP_PORT=<port>. Refer to the documentation page to know how to create [TCP redirections](https://developers.clever-cloud.com/doc/administrate/tcp-redirections/].
Some containers require access to the docker socket, to spawn sibling containers for instance.
You can make the docker socket available from inside the container by adding the
CC_MOUNT_DOCKER_SOCKET=true environment variable. In that case, docker is started in the namespaced mode, and in bridge network mode.
We support pulling private images through the
docker build command. To login to a private registry, you need to set a few environment variables:
CC_DOCKER_LOGIN_USERNAME: the username to use to login
CC_DOCKER_LOGIN_PASSWORD: the password of your username
CC_DOCKER_LOGIN_SERVER(optional): the server of your private registry. Defaults to Docker’s public registry.
This uses the
docker login command under the hood.
You can activate the support of IPv6 with a IPv6 subnet in the docker daemon by adding the
CC_DOCKER_FIXED-CIDR-V6=<IP> environment variable.
You can use the ARG instruction to define build-time environment variables.
Every environment variable defined for your application will be passed as a build environment variable using the
--build-arg=<ENV> parameter during the
docker build phase.
To make your dockerized application run on clever Cloud, you need to:
- expose port 8080 in your docker file
- run the application with
For instance, here is the
Dockerfile used for the Rust application:
Since the two servers are running as daemons, we need to start a long-running process. In this case we use
tail -f. We then add
start.sh as the
CMD in the
We provide a few examples of dockerized applications on Clever Cloud.
Clever Cloud injects environment variables from your application settings as mentioned in setting up environment variables and is also injecting in your application production environment, those from your linked add-ons.
On Clever Cloud you can define some build configuration: like the app folder to deploy or the path to validate your application deployment is ready To do that follow the documentation here and add the environement variable you need.
You need Git on your computer to deploy via this tool. Here is the official website of Git to get more information: git-scm.com
The “Information” page of your app gives you your Git deployment URL, it looks like this:
- Copy it in your clipboard
Locally, under your code folder, type in
git initto set up a new git repository or skip this step if you already have one
Add the deploy URL with
git remote add <name> <your-git-deployment-url>
Add your files via
git add <files path>and commit them via
git commit -m <your commit message>
Now push your application on Clever Cloud with
git push <name> master
Refer to git deployments for more details.
By linking an application to an add-on, the application has the add-on environment variables in its own environment by default.
Many add-ons do exist on Clever Cloud: refer to the full list and check add-ons dedicated pages for full instructions.
During add-on creation, an Applications screen appears, with a list of your applications. You can toggle the button to Link and click next. If you finish the process of add-on creation, the application is automatically linked to it.
In the Clever Cloud console, under the Service Dependencies menu of your application, you can use the Link add-ons dropdown menu to select the name of the add-on you want to link and use the add button to finish the process.
You can also link another application from the same page in the Clever Cloud console, using the Link applications dropdown menu.
Need more configuration? To run a script at the end of your deployment? To add your private SSH key to access private dependencies?
Go check the Common configuration page.
You may want to have an advanced usage of your application, in which case we recommend you to read the Administrate documentation section.
If you can’t find something or have a specific need like using a non supported version of a particular software, please reach out to the support.
The healthcheck allows you to limit downtimes. Indeed, you can provide us with paths to check. If these paths return something other than 200, we will consider the deployment as failed.
All you need is add one (or several) environment variable as such:
The deployment process will check all given paths. All of them must reply with a
200 OK response code.
Using the path listed above, below are the expected logs:
Response from GET /my/awesome/path is 200
Response from GET /my/other/path is 500
Health check failed:
- GET /my/other/path returned 500.
If the deployment fails after this message, please update your configuration and redeploy.
In this example, the 1st path is OK, but the 2nd one failed. This give you a hint on what failed in your application.
To make the most of a healthcheck endpoint, you should have it check your critical dependencies. For example:
SELECT 1 + 1;on your database
- retrieve a specific Cellar file
- ping a specific IP through a VPN