initial PoC for out binary

go.mod

@@ -0,0 +1,3 @@
+module github.com/cioplenu/concourse-nomad-resource
+
+go 1.14

out/main.go

@@ -0,0 +1,93 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"text/template"
+)
+
+type SourceConfig struct {
+	URL   string `json:"url"`
+	Name  string `json:"name"`
+	Token string `json:"token"`
+}
+
+type ParamsConfig struct {
+	JobPath  string            `json:"job_path"`
+	Vars     map[string]string `json:"vars"`
+	VarFiles map[string]string `json:"var_files"`
+}
+
+type OutConfig struct {
+	Source SourceConfig `json:"source"`
+	Params ParamsConfig `json:"params"`
+}
+
+func check(err error, msg string) {
+	if err != nil {
+		fmt.Fprintf(os.Stderr, msg+": %s\n", err)
+		os.Exit(1)
+	}
+}
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Fprintf(os.Stderr, "usage: %s <sources directory>\n", os.Args[0])
+		os.Exit(1)
+	}
+	sourceDir := os.Args[1]
+
+	var config OutConfig
+	err := json.NewDecoder(os.Stdin).Decode(&config)
+	check(err, "Error parsing configuration")
+
+	templPath := filepath.Join(sourceDir, config.Params.JobPath)
+	templFile, err := ioutil.ReadFile(templPath)
+	check(err, "Could not read input file "+templPath)
+	tmpl, err := template.New("job").Parse(string(templFile))
+	check(err, "Error parsing template")
+
+	for name, path := range config.Params.VarFiles {
+		varPath := filepath.Join(sourceDir, path)
+		varFile, err := ioutil.ReadFile(varPath)
+		check(err, "Error reading var file")
+		config.Params.Vars[name] = strings.TrimSpace(string(varFile))
+	}
+
+	buf := new(bytes.Buffer)
+
+	err = tmpl.Execute(buf, config.Params.Vars)
+	check(err, "Error executing template")
+
+	outFile, err := os.Create(templPath)
+	check(err, "Error creating output file")
+	defer outFile.Close()
+	_, err = outFile.Write(buf.Bytes())
+	check(err, "Error writing output file")
+
+	cmd := exec.Command(
+		"nomad",
+		"job",
+		"run",
+		"-address="+config.Source.URL,
+		"-token="+config.Source.Token,
+		templPath,
+	)
+	var out bytes.Buffer
+	cmd.Stdout = &out
+	cmd.Stderr = &out
+	err = cmd.Run()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error executing nomad: %s\n", err)
+		fmt.Fprint(os.Stderr, out.String())
+		os.Exit(1)
+	}
+
+	fmt.Println(out.String())
+}