switch to installing fpm via ruby via apt

src/action.js

@@ -1,7 +1,7 @@
 import * as core from '@actions/core';
 import * as github from '@actions/github';
 import * as action_information from 'information';
-import {executeFpmBuild, isTrueString, prepareFpmArgs} from './lib';
+import {executeFpmBuild, installFpmViaRuby, isTrueString, prepareFpmArgs} from './lib';
 
 
 try {
@@ -14,6 +14,8 @@ try {
 
   const fpmArgs = prepareFpmArgs();
 
+  await installFpmViaRuby();
+
   executeFpmBuild(fpmArgs, debug);
 }
 catch (error) {

src/lib.js

@@ -1,37 +1,34 @@
 import * as core from '@actions/core';
-import child_process from 'child_process';
+
+const exec = require('@actions/exec');
 
 export function prepareFpmArgs() {
   return '';
 }
 
-export function executeFpmBuild(computedFpmArgs, debug) {
+export async function installFpmViaRuby(debug) {
+  const aptCmd = 'sudo apt-get install ruby';
+  const gemCmd = 'sudo gem install fpm';
+  if (debug) {
+    console.log('ruby install command: ', rubyCmd);
+  }
+
+  await exec.exec(aptCmd);
+  await exec.exec(gemCmd);
+}
+
+export async function executeFpmBuild(computedFpmArgs, debug) {
 
   const userFpmArgs = core.getInput('fpm_args');
-  const dockerCmd   = 'docker run --rm -i'
-    + ` -v "${process.cwd()}:/workspace/source"`
-    + ' -w /workspace/source'
-    + ' gitea.dhswt.de/actions/fpm:master'
+  const fpmCmd      = 'fpm'
     + ' ' + computedFpmArgs
     + ' ' + userFpmArgs;
 
   if (debug) {
-    console.log('docker command: ', dockerCmd);
+    console.log('fpm command: ', fpmCmd);
   }
 
-  const proc = child_process.spawnSync(dockerCmd, {
-    shell: true,
-    stdio: 'inherit',
-    cwd  : process.cwd()
-  });
-
-  if (proc.status != null && proc.status > 0) {
-    throw new Error('fpm build failed');
-  }
-
-  if (proc.error != null) {
-    throw proc.error;
-  }
+  await exec.exec(fpmCmd);
 }
 
 function isNonEmptyStr(str) {