feat(stack): refactor stack check & allow ubuntu 20

refs #853,#1265
- refactor system stack check to use systeminformation to check support
- update ubuntu allowed versions to support Ubuntu 20

Author: acburdine

lib/commands/doctor/checks/system-stack.js

@@ -1,65 +1,79 @@
-'use strict';
 const chalk = require('chalk');
-const execa = require('execa');
+const sysinfo = require('systeminformation');
 
-const errors = require('../../../errors');
-
-const taskTitle = 'Checking operating system compatibility';
+const {SystemError} = require('../../../errors');
 
+const taskTitle = 'Checking system compatibility';
 const nginxProgramName = process.env.NGINX_PROGRAM_NAME || 'nginx';
+const versionRegex = /^(?:16|18|20)/;
 
-function systemStack(ctx, task) {
-    let promise;
+async function hasSystemd() {
+    try {
+        const {list} = await sysinfo.processes();
+        const rootProcess = list.find(proc => proc.pid === 1);
 
+        return Boolean(rootProcess) && rootProcess.name === 'systemd';
+    } catch (error) {
+        return false;
+    }
+}
+
+async function hasNginx() {
+    try {
+        const services = await sysinfo.services('*');
+        return services.some(s => s.name === nginxProgramName);
+    } catch (error) {
+        return false;
+    }
+}
+
+async function checkSystem(ctx) {
     if (!ctx.system.platform.linux) {
-        promise = Promise.reject({message: 'Operating system is not Linux'});
-    } else {
-        // TODO: refactor to use ctx.system.operatingSystem
-        promise = execa.shell('lsb_release -a').catch(
-            () => Promise.reject({message: 'Linux version is not Ubuntu 16 or 18'})
-        ).then((result) => {
-            if (!result.stdout || !result.stdout.match(/Ubuntu (?:16|18)/)) {
-                return Promise.reject({message: 'Linux version is not Ubuntu 16 or 18'});
-            }
+        throw new Error('Operating system is not Linux');
+    }
 
-            return ctx.ui.listr([{
-                title: 'Checking systemd is installed',
-                task: () => execa.shell('dpkg -l | grep systemd')
-                    .catch(() => Promise.reject({missing: 'systemd'}))
-            }, {
-                title: `Checking ${nginxProgramName} is installed`,
-                task: () => execa.shell(`dpkg -l | grep ${nginxProgramName}`)
-                    .catch(() => Promise.reject({missing: nginxProgramName}))
-            }], ctx, {
-                concurrent: true,
-                exitOnError: false,
-                renderer: ctx.ui.verbose ? 'verbose' : 'silent'
-            }).catch(error => Promise.reject({
-                message: `Missing package(s): ${error.errors.map(e => e.missing).join(', ')}`
-            }));
-        });
+    const {distro, release} = await sysinfo.osInfo();
+    if (distro !== 'Ubuntu' || !versionRegex.test(release)) {
+        throw new Error('Linux version is not Ubuntu 16, 18, or 20');
     }
 
-    return promise.catch((error) => {
+    const missing = [];
+
+    if (!(await hasSystemd())) {
+        missing.push('systemd');
+    }
+
+    if (!(await hasNginx())) {
+        missing.push('nginx');
+    }
+
+    if (missing.length) {
+        throw new Error(`Missing package(s): ${missing.join(', ')}`);
+    }
+}
+
+async function systemStack(ctx, task) {
+    try {
+        await checkSystem(ctx);
+    } catch (error) {
         ctx.ui.log(
             `System checks failed with message: '${error.message}'
 Some features of Ghost-CLI may not work without additional configuration.
 For local installs we recommend using \`ghost install local\` instead.`,
             'yellow'
         );
 
-        return ctx.ui.confirm(chalk.blue('Continue anyway?'), false).then((confirmed) => {
-            if (confirmed) {
-                task.skip('System stack check skipped');
-                return Promise.resolve();
-            }
+        const skip = await ctx.ui.confirm(chalk.blue('Continue anyway?'), false);
+        if (skip) {
+            task.skip('System stack check skipped');
+            return;
+        }
 
-            return Promise.reject(new errors.SystemError({
-                message: `System stack checks failed with message: '${error.message}'`,
-                task: taskTitle
-            }));
+        throw new SystemError({
+            message: `System stack checks failed with message: '${error.message}'`,
+            task: taskTitle
         });
-    });
+    }
 }
 
 module.exports = {