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What is Nocalhost Config?

Overview / What is Nocalhost Config?

Nocalhost —— What is it? How to configure it? What features it has?

We will introduce the configuration of Nocalhost, how to modify it and its features, etc. If you don't have a concept of the configuration of Nocalhost, or want to know more about its structure and features, please read this section.

Nocalhost Configuration#

Development configuration is set around DevMode, such as which image should be used to enter DevMode, whether the persistence is needed in the development container, which files should be synchronized to the development container, how to debug and run the service in the container by one-click, etc. The DevMode in Nocalhost will be more easier to use with correct and appropriate development configuration.

Overall, development configuration is to better define the behavior of DevMode .

Development Configuration and Deployment Configuration

The configuration of Nocalhost can be divided into two parts: development configuration and deployment configuration.

  • Deployment configuration defines how K8s applications deployed, including dependency control, variable injection, etc.

  • Development configuration is set around DevMode, such as which image should be used in DevMode, whether the persistence is needed in the development container, which files should be synchronized to the development container, how to debug and run the service in the container by one-click, etc.

Normally, only Development configuration needs to be concerned. In the configuration document, the configuration we mention refers to the development configuration unless noted otherwise.

View and Save Configuration#

View Configuration#

If you have never configured Nocalhost for any workload, right-click it and select Dev Config, then you will see the empty configurations as below, which are all commonly used in the DevMode of Nocalhost.

Configuration is not a must

You can enter DevMode without any configuration.

name: corednsserviceType: deploymentcontainers:  - name: ""    dev:        gitUrl: ""        image: ""        shell: ""        workDir: /home/nocalhost-dev        storageClass: ""        resources: null        persistentVolumeDirs: []        command: null        debug: null        sync: null        env: []        portForward: []

Update Configuration#

We can make any changes and use Comm+S or Ctrl+S on the IDE plugin side to save them.

The Structure of Nocalhost Configuration#

The name and serviceType at the top level of the configuration indicate that this configuration belongs to the deployment of coredns . The content of the configuration is in containers , which is an array and can set different configurations for multiple containers in one workload.

Correctly Configure the Container#

First, you have to declare the name of each container in containers.[].name to distinguish each container.#

For example, if there are two containers in the workload, ContainerA and ContainerB (note that this is just an example, and the container should be named according to your real workload) , then you need to declare the names as follows:

name: corednsserviceType: deploymentcontainers:
  - name: "ContainerA"    dev:        image: "example:latest"        ..........          - name: "ContainerB"    dev:        image: "foo:bar"        ..........

Surely, if you only need to develop ContainerB , you can configure it only. As follows:

name: corednsserviceType: deploymentcontainers:          - name: "ContainerB"    dev:        image: ""        ..........

How to configure each configuration item?#

This part indeed requires a long and detailed explanation, but we first give a simple example here to offer a quick start for Nocalhost configuration.

Need an application to operate?

If there is no workload to operate, you can use the following command to install a demo application:

kubectl apply -f

Right-click a workload that has never been configured, such as details-v1. Click DevConfig, then you will see an empty template. Let's make some changes, such as adding an additional env to the development container (the development container will inherit the environment variables from the original container):

name: details-v1serviceType: deploymentcontainers:  - name: details    dev:      env:        - name: nocalhost          value: example

Using Comm+S or Ctrl+S to save the changes, and then enter the DevMode. Since it is just a demonstration of the configuration process, you can select any local directory here and its content will be synchronized to the development container, and then you can select any development image.

Type env | grep nocalhost in the terminal after initiating the DevMode. As you can see, the environment variables have been injected correctly.

>  env | grep nocalhostPWD=/home/nocalhost-devOLDPWD=/home/nocalhost-devnocalhost=example
More information

To learn more about configuration items and corresponding functions, see What configurations does Nocalhost offer?

The Features of Development Configuration#

In addition, the design of the Nocalhost configuration also brings some features. Knowing these features may help you better use Nocalhost.

Take Effect#

The development configuration of nocalhost does not take effect immediately. It needs to be saved and then re-enter the DevMode to make it work.

Life Cycle#

Nocalhost will create a secret in each namespace as a "mini database", prefixed with dev.nocalhost.application.. The configuration will be saved in this secret .

Data will be remained in this secret until it is destroyed.

HELM application

If it is a HELM application, for example, its Release.Name is bookinfo, this secret will be named dev.nocalhost.application.bookinfo. Moreover, the data stored in this secret will be destroyed after uninstalling bookinfo .


From the storage design, you can find that the configuration of Nocalhost is shared. Specifically, in the same namespace of the same cluster, the configuration of one workload is visible on any device and can be modified (with the modification permission of the secret of RBAC ). The configuration all devices get is from the same duplicate.