MXS-1300: Send requests to multiple hosts

The host and port options were replace with one hosts option which
combines the two. This allows a single command to be executed on multiple
maxscale instances. Added accompanying code for checking responsiveness of
all maxscale instances and handling synchronization of the check
results. The code uses ECMAScript 2016 native promises to do this.

Added a configurable timeout to all requests. This should allow users to
interact with MaxScale over slow and laggy networks.

Before each executed command, all hosts given as parameters are pinged to
make sure they are alive. This should reduce the possibility of partial
execution of commands due to failed MaxScales.

The results of requests are grouped by the values of the hosts
option. This allows users to compare results of multiple servers with
relative ease.

Fixed reversion of the default credentials from mariadb:admin to
admin:mariadb.

client/maxctrl/common.js

@@ -114,44 +114,52 @@ module.exports = function() {
     }
 
     // Helper for converting endpoints to acutal URLs
-    this.getUri = function(endpoint, options) {
-        var base = 'http://';
+    this.getUri = function(host, endpoint) {
+        var base = 'http://'
         var argv = this.program.argv
 
         if (argv.secure) {
-            base = 'https://';
+            base = 'https://'
         }
 
-        return base + argv.user + ':' + argv.password + '@' +
-            argv.host + ':' + argv.port + '/v1/' + endpoint;
+        return base + argv.user + ':' + argv.password + '@' + host + '/v1/' + endpoint
     }
 
     // Helper for executing requests and handling their responses
     this.doRequest = function(resource, cb, obj) {
+        pingCluster()
+            .then(function() {
+                var argv = this.program.argv
+                argv.hosts.forEach(function(host) {
+                    args = obj || {}
+                    args.uri = getUri(host, resource)
+                    args.json = true
+                    args.timeout = argv.timeout
 
-        args = obj || {}
-        args.uri = getUri(resource),
-        args.json = true
-
-        request(args, function(err, resp, res) {
-            if (err) {
-                // Failed to request
-                logError(JSON.stringify(err, null, 4))
-            } else if (resp.statusCode == 200 && cb) {
-                // Request OK, returns data
-                cb(res)
-            } else if (resp.statusCode == 204) {
-                // Request OK, no data
-                console.log(colors.green('OK'))
-            } else {
-                // Unexpected return code, probably an error
-                var errstr = resp.statusCode + ' ' + resp.statusMessage
-                if (res) {
-                    errstr += ' ' + JSON.stringify(res, null, 4)
-                }
-                logError(errstr)
-            }
-        })
+                    request(args, function(err, resp, res) {
+                        if (err) {
+                            // Failed to request
+                            console.log(colors.yellow(host) + ':')
+                            logError(JSON.stringify(err, null, 4))
+                        } else if (resp.statusCode == 200 && cb) {
+                            // Request OK, returns data
+                            console.log(colors.yellow(host) + ':')
+                            cb(res)
+                        } else if (resp.statusCode == 204) {
+                            // Request OK, no data
+                            console.log(colors.yellow(host) + ': ' + colors.green('OK'))
+                        } else {
+                            // Unexpected return code, probably an error
+                            var errstr = resp.statusCode + ' ' + resp.statusMessage
+                            if (res) {
+                                errstr += ' ' + JSON.stringify(res, null, 4)
+                            }
+                            console.log(colors.yellow(host) + ':')
+                            logError(errstr)
+                        }
+                    })
+                })
+            })
     }
 
     this.updateValue = function(resource, key, value) {
@@ -180,3 +188,27 @@ function getTable(headobj) {
         head: headobj
     })
 }
+
+function pingMaxScale(host) {
+    return new Promise(function(resolve, reject) {
+        request('http://' + host + '/v1', function(err, resp, res) {
+            if (err) {
+                reject(err)
+            } else if (resp.statusCode != 200) {
+                reject(resp.statusCode + ' ' + resp.statusMessage)
+            } else {
+                resolve()
+            }
+        })
+    })
+}
+
+function pingCluster() {
+    var promises = []
+
+    this.program.argv.hosts.forEach(function(i) {
+        promises.push(pingMaxScale(i))
+    })
+
+    return Promise.all(promises)
+}

client/maxctrl/maxctrl.js

@@ -18,31 +18,26 @@ const maxctrl_version = '1.0.0';
 
 program
     .version(maxctrl_version)
-    .group(['u', 'p', 'h', 'p', 'P', 's'], 'Global Options:')
+    .group(['u', 'p', 'h', 's', 't'], 'Global Options:')
     .option('u', {
         alias:'user',
         global: true,
-        default: 'mariadb',
+        default: 'admin',
         describe: 'Username to use',
         type: 'string'
     })
     .option('p', {
         alias: 'password',
         describe: 'Password for the user',
-        default: 'admin',
+        default: 'mariadb',
         type: 'string'
     })
     .option('h', {
-        alias: 'host',
-        describe: 'MaxScale hostname',
-        default: 'localhost',
-        type: 'string'
-    })
-    .option('P', {
-        alias: 'port',
-        describe: 'MaxScale REST API port',
-        default: 8989,
-        type: 'number'
+        alias: 'hosts',
+        describe: 'List of MaxScale hosts. The hosts must be in ' +
+            '<hostname>:<port> format and each host must be separated by spaces.',
+        default: 'localhost:8989',
+        type: 'array'
     })
     .option('s', {
         alias: 'secure',
@@ -50,6 +45,13 @@ program
         default: 'false',
         type: 'boolean'
     })
+    .option('t', {
+        alias: 'timeout',
+        describe: 'Request timeout in milliseconds',
+        default: '10000',
+        type: 'number'
+    })
+
     .command(require('./lib/list.js'))
     .command(require('./lib/show.js'))
     .command(require('./lib/set.js'))