Watch not triggering build when file changed inside Docker

[benedictdudel]

Description

I created a minimal Dockerfile for developing a Gatsby page. Unfortunately changes in files do not trigger a rebuild inside a Docker container. See below for the minimal Dockerfile.

While debugging the problem I have noticed that the container and host both got a different timezone. So files in the container have a different timestamp:

Container:
-rw-r--r-- 1 node staff 245 Feb 17 14:17 page-2.js

Host:
-rw-r--r-- 1 user 370035326 245 17 Feb 15:17 page-2.js

Maybe the different timezones causing the problem but I never encountered any problem with other "watchers".

Environment

Gatsby version: latest
Node.js version: LTS
Operating System: macOS (host) / Debian (container)

Actual result

A changed file doesn't trigger the rebuild.

Expected behavior

A changed file should trigger the rebuild.

Steps to reproduce

1. Create a Dockerfile with the following content

FROM node:carbon

WORKDIR /var/www

COPY package.json ./

RUN yarn global add gatsby-cli
RUN yarn install

COPY gatsby-*.js ./

EXPOSE 8000

ENV NODE_ENV=development

CMD ["gatsby", "develop", "--host", "0.0.0.0", "--port", "8000"]

2. Build the container

$ docker build -t gatsby .

3. Create a container

$ docker run -v $(pwd)/src:/var/www/src --interactive --tty --detach --name test --publish 8000:8000 gatsby

4. Change any file in src directory and verify file changed in the container

$ docker exec -it test bash
$ ls -l src

[m-allanson]

@aripalo recently added a Gatsby Dockerfile at https://github.com/aripalo/gatsby-docker/. What happens if you try your site with that Docker image, do you see the same issue?

[benedictdudel]

Thanks for you tip. But unfortunately I had encountered the same behaviour with the Dockerfile of @aripalo. The file in the container changed but doesn't trigger the build.

[m-allanson]

Hmm I can't replicate the issue you've described, using your container or the gatsby-docker container.

Changing files in the src folder will trigger a rebuild. Doing either of:

• running the container without the --detached flag
• using docker logs -f

will show gatsby develop's output, showing the 'Compiling' message after a file change. Here's a screenshot of my terminal output, running without --detached:

You can see the two file changes at the bottom, each one trggering a new pair of 'Compiling... Compiled' messages.

I'm running macOS and Docker Version 17.12.0-ce-mac49 (21995). Is there something else in your setup that could be causing this?

[benedictdudel]

Yesterday I tried the following things:

• removed docker & docker-machine
• installed current version via homebrew cask
• deleted the default machine of docker-machine

But unfortunately no luck. I don't know where a difference between yours and my setup could be..

[m-allanson]

Hmm I'm not sure what else to suggest. Here's the output from my docker version, maybe that helps?

docker version
Client:
 Version:	17.12.0-ce
 API version:	1.35
 Go version:	go1.9.2
 Git commit:	c97c6d6
 Built:	Wed Dec 27 20:03:51 2017
 OS/Arch:	darwin/amd64

Server:
 Engine:
  Version:	17.12.0-ce
  API version:	1.35 (minimum version 1.12)
  Go version:	go1.9.2
  Git commit:	c97c6d6
  Built:	Wed Dec 27 20:12:29 2017
  OS/Arch:	linux/amd64
  Experimental:	true

[m-allanson]

I think I installed docker "the old fashioned way", by downloading Docker for Mac from https://docs.docker.com/docker-for-mac/install/

[benedictdudel]

Soo... I've came across with some other troubles when using Docker for other applications and it seems like that the problem did had something to do with docker-machine. I have now installed the edge version of Docker for Mac and skipped using docker-machine for my containers. Et voilá my Dockerfile from above is working fine now. Changes are now triggerd :)

Thank you very much for your effort and keep up the good work :)

[m-allanson]

Great! I'm glad it worked out :)

[onichandame]

@benedictdudel I am seeing the exactly same issue on Windows. Would you mind sharing the detailed steps? I have the latest nightly built Docker desktop with wsl 2 enabled.

[jscontreras]

When webpack dev server tries to look for changes and you are using wsl or docker the fsevents are not going to be fired (taht's why it doesn't trigger the refresh) so you need to override the watch webpack dev server options a little bit.
(in your gabsy-node.js)

/**
 * Implement Gatsby's Node APIs in this file.
 *
 * See: https://www.gatsbyjs.org/docs/node-apis/
 */

// You can delete this file if you're not using it
const path = require('path');

exports.onCreateWebpackConfig = ({ actions, getConfig }) => {
  const config = getConfig();
  config.devServer = {
    watchOptions: {
      aggregateTimeout: 500, // delay before reloading
      poll: 1000 // enable polling since fsevents are not supported in docker
    }
  };
  actions.replaceWebpackConfig(config);
};

[florent-andre]

As of gatsby 4.22 in docker on linux, I get this working with:

export function onCreateWebpackConfig({ actions }){
  const watchConf = {
    watchOptions: {
      aggregateTimeout: 500, // delay before reloading
      poll: 1000, // enable polling since fsevents are not supported in docker
      ignored: ['**/node_modules', '**/public'] // keep CPU usage minimal
    }
  }
  actions.setWebpackConfig(watchConf)
}

• setWebpackConfig seems prefered to replaceWebpackConfig by docs

Thanks to you all for this long path of help !