Docker Images For Development Purposes

This repository gather some Docker images that helps for development. They all basically watch a folder for changes, and rebuild/reload sources whenever an event occurs. Those images can be found very useful when running a micro-services local environment with Docker Compose.

All those images are based on respective official Docker images (the Alpine version when available).

List Of Images

• Golang
• PostgreSQL

Building Images

Each image have an associated Docker Hub repository, but you can also modify and build your own images.

Prerequisites

• Docker
• Make

Build

To build a image, you just need to run :

make <folder_name>
make golang # to build the golang image

To build all images, run make all.

You can change versions by editing the Makefile.

Golang

Golang's website - Base image

This image watches for changes in the/go/src folder, and when an event occurs it recompiles the programm and runs it if the build is successfull (the old version will not be stopped if the build fails). Watch can also be disabled (with the NO_WATCH environment variable), so compilations will have to be triggered manually (see the commands section below).

Configuration

Environment variables

• APP_FOLDER: is the path of your application (main package), from the src folder. In previous example, the test folder should be located at <your_project_folder>/src/test (/go/src/test in the container).
• APP_ARGS (optional): arguments to pass to your app when ran.
• COMPILE_ONLY (boolean, optional): do not run your software once compiled. In this case, your compiled program will sit under /go/bin (inside the Docker container). When active, you should also set the UID parameter to make sure you are the owner of the ouput program.
• COMPILATION_EXTRA_ARGS (string, optional): optionaly define some extra agurments that you want to pass on to the golang compiler.
• NO_WATCH (boolean, optional): Does not watch for any file change. Compilations will have to be triggered manually (see the commands section below). This option is incompatible with the WATCH_FOLDER option.
• WATCH_FOLDER (optional): Witch folder to watch for changes (to trigger rebuild). If the path doesn't start with a /, /go/src/ will be prefixed to the variable. Defaults to /go/src.
• APP_UID (optional): the id of the user the program should be ran with. If COMPILE_ONLY is set to true, then it will change the owner of the output binary. This can be usefull if the application writes data to a binded folder (so you do not have to deal with access rights).
• APP_GID (optional, defaults to the same value of APP_UID, if set): the id of the user group the program should be ran with. Only works if APP_UID is set.
• STOP_TIMEOUT (optional, defaults to 5): the maximum number of seconds we should wait for the program to stop (after sending the SIGTERM signal) Once the timeout reach, the program will be kill with the SIGKILL signal.

Volumes

• <your_project_folder>: (mandatory), this folder contains your Golang project (can be in a sub-folder).
• <your_gopath>: (optional), add it if your project contains depencies that are included in your gopath.

Since building will be really frequent, we recommend you mounting both /go/bin and /go/pkg as tmpfs (docker documentation).

Run

docker run -ti -e APP_FOLDER=test \
	-v <your_project_folder>/src:/go/src:ro \
	-v <your_gopath>:/gopath:ro \
	kanshiroron/docker-dev-golang:1.22

Commands

The Golang image comes with three binaries, one to trigger a rebuild, another to trigger a restart of the application and the last to stop the application (if running). Those three binaries can be found under the /usr/local/bin/ folder of the docker image. This folder is part of the PATH, so they are accessible everywhere.

• recompile: recompiles the application and restarts it if the compilation succeeds (and if COMPILE_ONLY is not set to true). This may be usefull when modifications made are outside of the watched folder (like in the GOPATH).
• restart: stops the running application and starts it again (has no effect if COMPILE_ONLY is set to true).
• stop: stops the running application.

Example:

docker exec <mycontainername> recompile

PostgreSQL

PostgreSQL's website - Base image

Watch for changes in each of /psql's subfolders, and when a event occurs it closes all db connections (for the specific database only), drops the current database and reload all sources. By default, the name of the subfolder becomes the name of the database, the name of the user and its password (see the Configuration section for more options).

Your database folders can't contain any space or special characters in their name otherwise PostgreSQL will throw an error.

Since the order of resources creation is important in PostgreSQL, you need to have a file named order at the root of each subfolders which lists every SQL files you want to import (one file per line). This order file may reference another order file (the name of the other file must also be named order).

Configuration

All configuration is done via environment variables.

• POSTGRES_USER: PosgreSQL user name. Optional, defaults to postgres
• POSTGRES_PASSWORD: PosgreSQL user password. Optional, defaults to password
• <FOLDER_NAME | UPPERCASE>_DB: Name of the database for the FOLDER_NAME service. Optional, defaults to the folder name, lower case.
• <FOLDER_NAME | UPPERCASE>_USER: Name of the database user for the FOLDER_NAME service. Optional, defaults to the folder name, lower case.
• <FOLDER_NAME | UPPERCASE>_PASSWORD: Name of the database user password for the FOLDER_NAME service. Optional, defaults to the folder name, lower case.
• POSTGRES_USER_UID: Change the default user id for the postgres user (useful if you need to mount data volumes or certificates).
• POSTGRES_USER_GID: Change the default group id for the postgres user (useful if you need to mount data volumes or certificates).

You can also use other options listed in the base PostgreSQL image.

Run

In this example the service1 application will have the default database name, user and password service1, and service2 will has the database named myservice, the user myserviceuser and password myservicepassword.

docker run -ti -e POSTGRES_USER=myuser -e POSTGRES_PASSWORD=mypassword \
	-v $(pwd)/service1/sql:/psql/service1:ro \
	-v $(pwd)/service2/sql:/psql/service2:ro \
	-e SERVICE2_DB=myservice -e SERVICE2_USER=myserviceuser -e SERVICE2_PASSWORD=myservicepassword \
	kanshiroron/docker-dev-postgresql:16

License

The Integration Toolbox WebServer is released under the GPL3 license, allowing you to use and modify it freely for your testing needs.

Credits

Authors

• Kanshiroron