About hot reload in revel framework

[32key-takahashi]

I am developing an application using the revel framework of the go language on a mac, but even if I change the go source code locally, it will not be hot reloaded on the docker container side.
I was able to confirm that the code itself was changed on the container side.
It seems that docker desktop was able to hot reload with the same configuration.
This may be an orbstack specific problem, do you have any ideas how to fix it?

[kdrag0n]

Please share a reproducer built with the same stack/components.

[32key-takahashi]

Sorry for my late reply.

Since the source code used in business cannot be disclosed, I used a sample application using revel framework.
Hot reload was not enabled for this app either.

[32key-takahashi]

Method of verification

1, Please git clone the following repository
https://github.com/shirayee/sample-revel-docker.git

2, add go.mod

cd sample-revel-docker
vim go.mod

（go.mod）

module sample-revel-docker

go 1.17

require (
	github.com/revel/modules v1.1.0
	github.com/revel/revel v1.1.0
)

require (
	github.com/bradfitz/gomemcache v0.0.0-20220106215444-fb4bf637b56d // indirect
	github.com/fsnotify/fsnotify v1.5.1 // indirect
	github.com/go-stack/stack v1.8.1 // indirect
	github.com/gomodule/redigo v1.8.8 // indirect
	github.com/google/uuid v1.3.0 // indirect
	github.com/inconshreveable/log15 v0.0.0-20201112154412-8562bdadbbac // indirect
	github.com/mattn/go-colorable v0.1.12 // indirect
	github.com/mattn/go-isatty v0.0.14 // indirect
	github.com/patrickmn/go-cache v2.1.0+incompatible // indirect
	github.com/revel/config v1.0.0 // indirect
	github.com/revel/log15 v2.11.20+incompatible // indirect
	github.com/revel/pathtree v0.0.0-20140121041023-41257a1839e9 // indirect
	github.com/xeonx/timeago v1.0.0-rc4 // indirect
	golang.org/x/net v0.0.0-20220412020605-290c469a71a5 // indirect
	golang.org/x/sys v0.0.0-20220227234510-4e6760a101f9 // indirect
	gopkg.in/natefinch/lumberjack.v2 v2.0.0 // indirect
	gopkg.in/stack.v0 v0.0.0-20141108040640-9b43fcefddd0 // indirect
)

replace github.com/mattn/go-sqlite3 => github.com/mattn/go-sqlite3 v1.14.10

3, modify some files

（Dockerfile）

FROM golang:1.17

ENV GOPATH $GOPATH:/go/src

RUN apt-get update && \
    apt-get upgrade -y

RUN mkdir /go/src/sample-revel-docker
WORKDIR /go/src/sample-revel-docker

RUN go get github.com/revel/revel
RUN go get github.com/revel/cmd/revel    
RUN go get github.com/revel/modules/static
RUN go get github.com/garyburd/redigo/redis
RUN go get github.com/patrickmn/go-cache
RUN go get github.com/bradfitz/gomemcache/memcache

EXPOSE 9000

（docker-compose.yml）

version: '2'
services:
  app:
    build: .
    command: revel run
    ports:
      - 9000:9000
    volumes:
      - .:/go/src/sample-revel-docker

4. Launch the application

docker-compose build
docker-compose up -d

5. Access http://localhost:9000/ and confirm that "It works!" is displayed

6. Modify your local source code to add response headers

（app/init.go）

var HeaderFilter = func(c *revel.Controller, fc []revel.Filter) {
c.Response.Out.Header().Add("X-Frame-Options", "SAMEORIGIN")
c.Response.Out.Header().Add("X-XSS-Protection", "1; mode=block")
c.Response.Out.Header().Add("X-Content-Type-Options", "nosniff")
c.Response.Out.Header().Add("Referrer-Policy", "strict-origin-when-cross-origin")

c.Response.Out.Header().Add("TEST", "hot reload test")

7. Access http://localhost:9000/ again, but the response header did not change.

(supplement)
If I restarted the app once, the response headers were added correctly.

docker-compose restart

[32key-takahashi]

@kdrag0n
Please let me know if you need more information concerning this answer.
In order to solve the problem and investigate the cause, I will cooperate as much as possible if I can.

[32key-takahashi]

@kdrag0n
I will share it with you.

Our investigation revealed that the issue was not with the application, but with the editor that modifies the source code.

When I edit the source code from Visual Studio Code, it doesn't hot reload,
but when I edit it using Vim commands, it hot reloads successfully.

I'm using the latest version of Visual Studio Code.

code -v
1.81.1
6c3e3dba23e8fadc360aed75ce363ba185c49794
arm64

[kdrag0n]

Sorry for the delay, finally got around to testing this. Unfortunately it doesn't work:

sample-revel-docker-app-1  | Revel executing: run a Revel application
sample-revel-docker-app-1  | Downloading related packages ... completed.
sample-revel-docker-app-1  | ERROR 17:13:01  revel.go:113: Unable to execute                        error="Revel paths[error failed to load module.  Import of path failed modulePath:github.com/revel/modules/static error:no files found in import path: github.com/revel/modules/static ]"
sample-revel-docker-app-1 exited with code 1

Edit: fixed, looking into it now.

[kdrag0n]

Fixed for the next version. Thanks for the reproducer!

#632

[32key-takahashi]

We have confirmed that hot reloading can be successfully performed with version 0.17.2.
Thank you very much for your response.