Add logrotate support for *.log files in /run mounts of apps

logrotate config files may contain arbitrary commands which are
exectued as root, thus the config files have to be owned by root.
This is the reason we need the sudo scripts :-/

To test the generated scripts, just run:
$ logrotate /etc/logrotate.conf -v

Fixes #396

src/apptask.js

@@ -42,6 +42,7 @@ var addons = require('./addons.js'),
     manifestFormat = require('cloudron-manifestformat'),
     net = require('net'),
     nginx = require('./nginx.js'),
+    os = require('os'),
     path = require('path'),
     paths = require('./paths.js'),
     safe = require('safetydance'),
@@ -56,6 +57,9 @@ var addons = require('./addons.js'),
 
 var COLLECTD_CONFIG_EJS = fs.readFileSync(__dirname + '/collectd.config.ejs', { encoding: 'utf8' }),
     RELOAD_COLLECTD_CMD = path.join(__dirname, 'scripts/reloadcollectd.sh'),
+    LOGROTATE_CONFIG_EJS = fs.readFileSync(__dirname + '/logrotate.ejs', { encoding: 'utf8' }),
+    MV_LOGROTATE_CONFIG_CMD = path.join(__dirname, 'scripts/mvlogrotateconfig.sh'),
+    RM_LOGROTATE_CONFIG_CMD = path.join(__dirname, 'scripts/rmlogrotateconfig.sh'),
     RMAPPDIR_CMD = path.join(__dirname, 'scripts/rmappdir.sh'),
     CREATEAPPDIR_CMD = path.join(__dirname, 'scripts/createappdir.sh');
 
@@ -171,6 +175,32 @@ function removeCollectdProfile(app, callback) {
     });
 }
 
+function addLogrotateConfig(app, callback) {
+    assert.strictEqual(typeof app, 'object');
+    assert.strictEqual(typeof callback, 'function');
+
+    docker.inspect(app.containerId, function (error, result) {
+        if (error) return callback(error);
+
+        var runVolume = result.Mounts.find(function (mount) { return mount.Destination === '/run'; });
+        if (!runVolume) return callback(new Error('App does not have /run mounted'));
+
+        var logrotateConf = ejs.render(LOGROTATE_CONFIG_EJS, { volumePath: runVolume.Source });
+        var tmpFilePath = path.join(os.tmpdir(), app.id + '.logrotate');
+        fs.writeFile(tmpFilePath, logrotateConf, function (error) {
+            if (error) return callback(error);
+            shell.sudo('addLogrotateConfig', [ MV_LOGROTATE_CONFIG_CMD, tmpFilePath, app.id ], callback);
+        });
+    });
+}
+
+function removeLogrotateConfig(app, callback) {
+    assert.strictEqual(typeof app, 'object');
+    assert.strictEqual(typeof callback, 'function');
+
+    shell.sudo('removeLogrotateConfig', [ RM_LOGROTATE_CONFIG_CMD, app.id ], callback);
+}
+
 function verifyManifest(app, callback) {
     assert.strictEqual(typeof app, 'object');
     assert.strictEqual(typeof callback, 'function');
@@ -362,6 +392,7 @@ function install(app, callback) {
         updateApp.bind(null, app, { installationProgress: '10, Cleaning up old install' }),
         unconfigureNginx.bind(null, app),
         removeCollectdProfile.bind(null, app),
+        removeLogrotateConfig.bind(null, app),
         stopApp.bind(null, app),
         deleteContainers.bind(null, app),
         // oldConfig can be null during upgrades
@@ -406,6 +437,9 @@ function install(app, callback) {
         updateApp.bind(null, app, { installationProgress: '70, Creating container' }),
         createContainer.bind(null, app),
 
+        updateApp.bind(null, app, { installationProgress: '75, Setting up logrotate config' }),
+        addLogrotateConfig.bind(null, app),
+
         updateApp.bind(null, app, { installationProgress: '80, Setting up collectd profile' }),
         addCollectdProfile.bind(null, app),
 
@@ -467,6 +501,7 @@ function configure(app, callback) {
         updateApp.bind(null, app, { installationProgress: '10, Cleaning up old install' }),
         unconfigureNginx.bind(null, app),
         removeCollectdProfile.bind(null, app),
+        removeLogrotateConfig.bind(null, app),
         stopApp.bind(null, app),
         deleteContainers.bind(null, app),
         function (next) {
@@ -496,6 +531,9 @@ function configure(app, callback) {
         updateApp.bind(null, app, { installationProgress: '60, Creating container' }),
         createContainer.bind(null, app),
 
+        updateApp.bind(null, app, { installationProgress: '65, Setting up logrotate config' }),
+        addLogrotateConfig.bind(null, app),
+
         updateApp.bind(null, app, { installationProgress: '70, Add collectd profile' }),
         addCollectdProfile.bind(null, app),
 
@@ -548,6 +586,7 @@ function update(app, callback) {
         // we cannot easily 'recover' from backup failures because we have to revert manfest and portBindings
         updateApp.bind(null, app, { installationProgress: '25, Cleaning up old install' }),
         removeCollectdProfile.bind(null, app),
+        removeLogrotateConfig.bind(null, app),
         stopApp.bind(null, app),
         deleteContainers.bind(null, app),
         function deleteImageIfChanged(done) {
@@ -579,6 +618,9 @@ function update(app, callback) {
         updateApp.bind(null, app, { installationProgress: '80, Creating container' }),
         createContainer.bind(null, app),
 
+        updateApp.bind(null, app, { installationProgress: '85, Setting up logrotate config' }),
+        addLogrotateConfig.bind(null, app),
+
         updateApp.bind(null, app, { installationProgress: '90, Add collectd profile' }),
         addCollectdProfile.bind(null, app),
 
@@ -608,6 +650,9 @@ function uninstall(app, callback) {
         updateApp.bind(null, app, { installationProgress: '0, Remove collectd profile' }),
         removeCollectdProfile.bind(null, app),
 
+        updateApp.bind(null, app, { installationProgress: '5, Remove logrotate config' }),
+        removeLogrotateConfig.bind(null, app),
+
         updateApp.bind(null, app, { installationProgress: '10, Stopping app' }),
         stopApp.bind(null, app),