Merge pull request #27 from ckaznocha/replacement_files

Replacement files

README.md

@@ -47,6 +47,8 @@ Given a JSON file specified by `app_json`, post it to Marathon to deploy the app
 
 *   `replacements`: *Optional.* A `name`/`value` list of templated strings in the app.json to replace during the deploy. Useful for things such as passwords or urls that change.
 
+*   `replacement_files`: *Optional.* Similar to `replacements` except value is a path to a file who's content will be used in the replace.
+
 *   `restart_if_no_update`: *Optional.* If Marathon doesn't detect any change in your app.json it won't deploy a new version. Setting this to `true` will restart an existing app causing a new version. Default is `false`.
 
 ## Example Configuration

cmd/marathon-resource/behaviors/behaviors.go

@@ -14,6 +14,7 @@ type Params struct {
 	AppJSON           string     `json:"app_json"`
 	TimeOut           int        `json:"time_out"`
 	Replacements      []Metadata `json:"replacements"`
+	ReplacementFiles  []Metadata `json:"replacement_files"`
 	RestartIfNoUpdate bool       `json:"restart_if_no_update"`
 }
 

cmd/marathon-resource/behaviors/template.go

@@ -2,25 +2,31 @@ package behaviors
 
 import (
 	"bytes"
+	"fmt"
 	"io"
+	"io/ioutil"
 	"path/filepath"
+	"strings"
 
 	"github.com/aymerick/raymond"
 )
 
 func parsePayload(p Params, path string) (io.Reader, error) {
 	var (
-		replacments = map[string]string{}
-		buf         = bytes.NewBuffer([]byte{})
+		replacements = map[string]string{}
+		buf          = bytes.NewBuffer([]byte{})
 	)
-	for _, v := range p.Replacements {
-		replacments[v.Name] = v.Value
+	replacements = replaceStrings(p.Replacements, replacements)
+	replacements, err := replaceFiles(p.ReplacementFiles, replacements, path)
+	if err != nil {
+		return nil, err
 	}
+
 	tmpl, err := raymond.ParseFile(filepath.Join(path, p.AppJSON))
 	if err != nil {
 		return nil, err
 	}
-	app, err := tmpl.Exec(replacments)
+	app, err := tmpl.Exec(replacements)
 	if err != nil {
 		return nil, err
 	}
@@ -30,3 +36,34 @@ func parsePayload(p Params, path string) (io.Reader, error) {
 	}
 	return buf, nil
 }
+
+func replaceStrings(
+	metadata []Metadata,
+	replacements map[string]string,
+) map[string]string {
+	for _, v := range metadata {
+		replacements[v.Name] = v.Value
+	}
+
+	return replacements
+}
+
+func replaceFiles(
+	metadata []Metadata,
+	replacements map[string]string,
+	path string,
+) (map[string]string, error) {
+	for _, v := range metadata {
+		fileValue, err := ioutil.ReadFile(filepath.Join(path, v.Value))
+		if err != nil {
+			return replacements, fmt.Errorf(
+				"Error replaceing %s from replacement_files: %v",
+				v.Name,
+				err,
+			)
+		}
+		replacements[v.Name] = strings.TrimSpace(string(fileValue))
+	}
+
+	return replacements, nil
+}

cmd/marathon-resource/behaviors/template_test.go

@@ -19,6 +19,8 @@ func Test_parsePayload(t *testing.T) {
 	}{
 		{"Reads file with no replacements", args{Params{AppJSON: "app.json"}, "../fixtures"}, []byte{123, 10, 32, 32, 32, 32, 34, 102, 111, 111, 34, 58, 32, 34, 98, 97, 114, 34, 10, 125, 10}, false},
 		{"Reads file with replacements", args{Params{AppJSON: "app_template.json", Replacements: []Metadata{{"foo", "bar"}}}, "../fixtures"}, []byte{123, 10, 32, 32, 32, 32, 34, 102, 111, 111, 34, 58, 32, 34, 98, 97, 114, 34, 10, 125, 10}, false},
+		{"Reads file with replacement files", args{Params{AppJSON: "app_template.json", ReplacementFiles: []Metadata{{"foo", "foo.txt"}}}, "../fixtures"}, []byte{123, 10, 32, 32, 32, 32, 34, 102, 111, 111, 34, 58, 32, 34, 98, 97, 114, 34, 10, 125, 10}, false},
+		{"Reads file with missing replacement files", args{Params{AppJSON: "app_template.json", ReplacementFiles: []Metadata{{"foo", "baz.txt"}}}, "../fixtures"}, nil, true},
 		{"Reads file with bad tmpl", args{Params{AppJSON: "app_template_bad.json", Replacements: []Metadata{{"foo", "bar"}}}, "../fixtures"}, nil, true},
 	}
 	for _, tt := range tests {

cmd/marathon-resource/fixtures/foo.txt

@@ -0,0 +1,2 @@
+
+bar