Frequently Asked Questions

Q: How do I get help with Tilt?

For real-time support, find us on the Kubernetes slack. Get an invite at slack.k8s.io and find us in the #tilt channel.

You can also file an issue in our GitHub repo.

For help with private issues (like security vulnerabilities or just concerning non-public code), please email help@tilt.dev.

Common Error Messages

Q: When I run `tilt version`, I see “template engine not found for: version”. What do I do?

There is another project called Tilt for developing Ruby templates.

You’re accidentally running that Tilt instead.

Common fixes include deleting the other Tilt, always using an absolute path, or renaming Tilt to tlt to avoid the conflict. Tilt is a static binary so it is OK to rename it.

Q: I immediately get error messages like “WARNING: Image not used in any deploy config”. What does this mean?

To start your app, Tilt needs both:

1) Instructions on how to build an image (like a docker_build config)

2) Instructions on how to run your image (like a k8s_yaml config)

This error message means that your Tiltfile has instructions for building an image, but no instructions for how to run it. It’s like an “unused variable” warning.

Did you forget the Kubernetes YAML? Or did you just misspell the image name?

Q: I’m getting push errors like “unauthorized: You don’t have the needed permissions”. What do I do?

If Tilt is trying to do a push, that means it thinks you wanted to deploy to a remote cluster. See below on how to configure for a local cluster.

Q: Tilt fails with “Unable to connect to cluster” errors. What do I do?

The Kubernetes server that you’re trying to deploy to is misbehaving.

Two common things to try are:

Turn it off and turn it back on again (really!).
Reset the cluster state.

But the specific way to do these depend on your environment.

If you’re using Docker For Mac, click the Docker icon in the upper-right hand corner of your screen. Choose “Preferences…” to open a dialog. The “Kubernetes” tab has a button that allows you to enable/disable Kubernetes. The “Reset” tab has a button that allows you to reset the cluster state.

If you’re using Minikube, minikube stop and minikube start will restart the environment. minikube delete will reset the cluster state.

How do I…?

Q: How do I configure my app dynamically?

The Tiltfile API has several built-in functions for reading configuration:

Read an environment variable with os.environ.get('ENV_VAR', '')
Read a file with read_file('./path/to/file')
Read a JSON or YAML file with read_json('./path/to/file') or read_yaml('./path/to/file')
Use local() to run local shell commands.

You can even define your own flags to tilt up with the config api.

Q: Tilt says it’s building images. But I can’t find them with the Docker CLI. What’s going on?

If you are using Minikube or MicroK8s, Tilt will automatically connect to the Docker server inside the cluster. This helps performance because Tilt doesn’t need to waste time copying Docker images around.

To check which Docker server Tilt is connecting to, run:

tilt doctor

Tilt will print the Docker host. You can then run commands against that Docker host:

DOCKER_HOST=tcp://my-url/ docker images

Q: All the Tilt examples store the image at `gcr.io`. Isn’t it really slow to push images up to Google’s remote repository for local development?

You’re right, that would be slow!

Most local Kubernetes development solutions let you build images directly inside the cluster. There’s no need to push the image to a remote repository.

When you’re using Docker for Mac, Minikube, or MicroK8s, Tilt will automatically build the images in-cluster. When it detects this case, it will even modify your Kubernetes configs to set ImageNeverPull, so that Kubernetes will emit an error if it even tries to pull an image from a remote server.

Q: Docker BuildKit is cool! How do I use it?

BuildKit is a new build engine in Docker for building container images.

Tilt will automatically enable BuildKit if your local Docker installation supports it.

BuildKit is supported on Docker v18.06 when Experimental mode is enabled, and on Docker v18.09+

If you want to disable BuildKit manually, set DOCKER_BUILDKIT=0.

Q: How do I tell Tilt to build my images with a remote Docker server?

Tilt reads the same environment variables as the docker command for choosing a server. Specifically:

DOCKER_HOST: Set the url to the docker server.
DOCKER_API_VERSION: Set the version of the API.
DOCKER_CERT_PATH: Set the path to load the TLS certificates from.
DOCKER_TLS_VERIFY: To enable or disable TLS verification when using DOCKER_CERT_PATH, off by default.
DOCKER_DEFAULT_PLATFORM: To set the architecture of built images.

This is helpful if you have a more powerful machine in the cloud which you want to use to build your images.

Q: How do I change what Kubernetes cluster Tilt uses?

Tilt uses the default Kubernetes cluster configured in kubectl.

To see what cluster kubectl uses, run:

kubectl config current-context

To see what clusters are available, run:

kubectl config get-contexts

To change the cluster you’re deploying to, run:

kubectl config use-context docker-desktop

The most common options we see in local development are microk8s, docker-desktop (Docker For Mac stable), and docker-for-desktop (older Docker for Mac versions).

Q: What local Kubernetes solution should I choose?

Check out our Guide to Choosing a Local Cluster.

Q: How does Tilt know which local Kubernetes cluster I’m using?

To check which cluster Tilt is connecting to, run:

tilt doctor

The Env is the type of cluster Tilt has detected. Tilt uses this to determine which local dev features the cluster supports.

In the dev cluster community, a common convention is to use the cluster name prefix to indicate the cluster type. For example,

Docker uses the docker- prefix
GKE uses the gke_ prefix
KIND uses the kind- prefix
Minikube defaults to a cluster name minikube (if you use Minikube profiles, Tilt will accept any cluster name prefixed minikube-)

If Tilt can’t detect the type of your cluster, check the cluster name!