initial commit

.devcontainer/devcontainer.json

@@ -0,0 +1,22 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the
+// README at: https://github.com/devcontainers/templates/tree/main/src/go
+{
+	"name": "Go",
+	// Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
+	"image": "mcr.microsoft.com/devcontainers/go:0-1-bullseye"
+
+	// Features to add to the dev container. More info: https://containers.dev/features.
+	// "features": {},
+
+	// Use 'forwardPorts' to make a list of ports inside the container available locally.
+	// "forwardPorts": [],
+
+	// Use 'postCreateCommand' to run commands after the container is created.
+	// "postCreateCommand": "go version",
+
+	// Configure tool-specific properties.
+	// "customizations": {},
+
+	// Uncomment to connect as root instead. More info: https://aka.ms/dev-containers-non-root.
+	// "remoteUser": "root"
+}

.gitignore

@@ -0,0 +1 @@
+build/

build.sh

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+#!/bin/sh
+
+userID=$(id -u)
+groupID=$(id -g)
+
+mkdir -p ./build
+
+echo "Building Docker image"
+imageID=$(docker build -f docker/Dockerfile --build-arg UID="${userID}" --build-arg GID="${groupID}" -q .)
+
+echo "Running build"
+docker run --rm -v ./build:/build "$imageID"
+
+echo "Removing image"
+docker image rm "$imageID"

docker/Dockerfile

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+FROM golang:latest
+
+ARG UID=1000
+ARG GID=1000
+
+RUN addgroup --gid ${GID} bobthebuilder && adduser --gid ${GID} --uid ${UID} bobthebuilder
+
+RUN mkdir /build
+RUN chown -Rv bobthebuilder:bobthebuilder /build
+
+COPY . /workspace
+RUN chown -Rv bobthebuilder:bobthebuilder /workspace
+
+USER bobthebuilder
+WORKDIR /workspace
+
+CMD [ "go", "build", "-o", "/build/docker_launcher", "." ]

go.mod

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+module docker_launcher
+
+go 1.20

main.go

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+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"log"
+	"os"
+	"regexp"
+)
+
+type config struct {
+	Files         []string
+	VariableRegex string
+	RegexGroup    int
+}
+
+var defaultVariableRegex = `\$\{([a-zA-Z0-9_-]+)\}`
+
+func loadConfig(path string) (*config, error) {
+	raw, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	var config config
+	err = json.Unmarshal(raw, &config)
+	if err != nil {
+		return nil, err
+	}
+
+	return &config, nil
+}
+
+func filterFile(path string, regex regexp.Regexp, regexGroup int) error {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return err
+	}
+
+	text := string(data)
+
+	text = regex.ReplaceAllStringFunc(text, func(s string) string {
+		matches := regex.FindStringSubmatch(text)
+		log.Println(matches)
+		return os.Getenv(matches[regexGroup])
+	})
+
+	log.Println(text)
+
+	return nil
+}
+
+func filterFiles(config config) error {
+	var regexString string
+	if len(config.VariableRegex) == 0 {
+		regexString = defaultVariableRegex
+	} else {
+		regexString = config.VariableRegex
+	}
+
+	var regexGroup int
+	if config.RegexGroup == 0 {
+		regexGroup = 1
+	} else {
+		regexGroup = config.RegexGroup
+	}
+
+	log.Println("Regex is:", regexString)
+
+	regex, err := regexp.Compile(regexString)
+	if err != nil {
+		return err
+	}
+
+	for _, file := range config.Files {
+		log.Println("Filtering file:", file)
+		err := filterFile(file, *regex, regexGroup)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func main() {
+	configPath := flag.String("config", "config.json", "Path to config file")
+	flag.Parse()
+
+	config, err := loadConfig(*configPath)
+	if err != nil {
+		log.Fatalln("Failed to load config:", err)
+	}
+
+	err = filterFiles(*config)
+	if err != nil {
+		log.Fatalln(err)
+	}
+}