Install Debian Stretch 9.8 on HPE Microserver GEN10

microserver, amd, opteron, x3216 x3418 x3421

Pure DEBIAN :)#

The HPE Microserver GEN10 is an impressive piece of rock-solid hardware. Of course… ILO is missing compared to GEN8 but for most use-cases thats not a real issue.

Debian stretch runs nearly out-of-the-box using the netinstall image via USB Stick or network boot. The following tweaks are required to run it flawlessly:

No Graphics after running the installer#

The firmware package firmware-linux-nonfree is required for the AMD APU. Adding “nomodeset” to kernel command line may also work as mentioned on

IOMMU Error#

You may notice a iommu error on boot: the iommu is disabled by default – to enable it add the following parameters to your grub config:

File: /etc/default/grub

GRUB_CMDLINE_LINUX="amd_iommo=on iommu=pt"

Run update-grub to apply the changes and reboot the system – press F2 within the boot menu and to open the BIOS/UEFI menu. The iommu can has to be enabled in Chipset -> GFX Configuration -> IOMMU


Just FYI

 # cat /proc/cpuinfo 
processor	: 0
vendor_id	: AuthenticAMD
cpu family	: 21
model		: 96
model name	: AMD Opteron(tm) X3418 APU
stepping	: 1
microcode	: 0x600611a
cpu MHz		: 1300.000
cache size	: 1024 KB
physical id	: 0
siblings	: 4
core id		: 0
cpu cores	: 2
apicid		: 16
initial apicid	: 0
fpu		: yes
fpu_exception	: yes
cpuid level	: 13
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good acc_power nopl nonstop_tsc extd_apicid aperfmperf pni pclmulqdq monitor ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs xop skinit wdt lwp fma4 tce nodeid_msr tbm topoext perfctr_core perfctr_nb bpext ptsc mwaitx cpb hw_pstate ssbd ibpb vmmcall fsgsbase bmi1 avx2 smep bmi2 xsaveopt amd_ibpb arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold avic overflow_recov
bugs		: fxsave_leak sysret_ss_attrs null_seg spectre_v1 spectre_v2 spec_store_bypass
bogomips	: 3593.06
TLB size	: 1536 4K pages
clflush size	: 64
cache_alignment	: 64
address sizes	: 48 bits physical, 48 bits virtual
power management: ts ttp tm 100mhzsteps hwpstate cpb eff_freq_ro acc_power [13]

Power consumption#

  • IDLE: about 15Watt with a weak powerfactor of ~0.41 (sata boot ssd; no hdd)

Gitea 1.5 on MariaDB 10.1

utf8mb4_general_ci; specified key was too long; max key length is 767 bytes

Error Messages#

In case you’ve tried to upgrade to Gitea 1.4 or 1.5 on Debian 9 with MariaDB 10.1 the following error messages will thrown to your log and the service won’t start:

[...itea/routers/init.go:60 GlobalInit()] [E] Failed to initialize ORM engine: migrate: 
do migrate: Sync2: Error 1071: Specified key was too long; max key length is 767 bytes


The issue is caused by the newly introduced charset utf8mb4_general_ci which is set to default in Gitea >=1.4. This charset requires 4 bytes per character and the indexes on utf8mb4_general_ci fields (varchar 255) won’t fit into the InnoDB scheme.


The only reliable solution is an upgrade to MariaDB 10.2 or 10.3. Just changing settings like innodb_large_prefix=1 or innodb_file_format=Barracuda as mentioned on several sites won’t have any effect to existing tables.


I’ve used a legacy version of Gitea (1.2.3) for a long time which was created initially as utf8_general_ci scheme. Therefore i’ve decided to alter the table + field charsets manually via phpmyadmin and set them to utf8_general_ci.

You have to run the upgrade procedure (start gitea executable) a several time because new tables are not created at once (repeat it 3..5 times).

Finally it works but i’m not sure if there will be any side effects in the future..

Netgear GS108Ev3 Firmware Upgrade failed

switch stocks in bootloader mode, timeout, linux, debian, ubuntu

Upgrading a Netgear switch can be very annoying…i’ve recently bought a second GS108Ev3 and wanted to upgrade the firmware initially but the switch stocks in bootloader mode (still web accessible on By running the upgrade via Firefox or Chromium on Debian the firmware upload stops at ~7% with a timeout error. Same issue with tftp.


Use a Windows Machine (Win 10) + Google Chrome Browser and run the firmware upgrade procedure via web interface on – this will even work in case the Netgear ProSAFE Configuration utility throws a timeout error. VERY WEIRD!

Overall the (first) switch performs very well over the last few years and draws very low power – a great SOHO product with VLAN capabilities (PVID/Tagged/Untagged) but the firmware needs a makeover..

Grandstream VoIP over OpenVPN

asterisk, gxp1625, vpn, settings, config, nat

Grandstream VoIP telephones are very popular because of their high build quality compared to an excellent price. In some cases you want to use an encrypted communication channel between your device and the PBX (e.g. asterisk). The current grandstream firmware includes basic OpenVPN support (client mode, tun) which allows you to tunnel the whole SIP/RTP traffic over an encrypted channel. This is also the best solution to avoid any kind of NAT/routing issues because all devices are directly accessible within the virtual ip subnet.

OpenVPN Server Config#

Use the following (minimal) configuration as template. The important options are set to work with the current grandstream firmware ( Certificate based authentication is preferred for security (login/password not needed)!

dev tunX
topology subnet
port 10111
proto udp

# cert based auth
pkcs12 server.p12

# 1024 and 2048 bit dh params are supported
dh dh2048.pem
keepalive 10 120
script-security 2

# bh-cbc as well as aes-128-cbc are supported by the current firmware
cipher aes-256-cbc

# well sha1 is a bit weak but its set within grandstream firmware
auth sha1

# compression has to be enabled

tun-mtu 1500
mtu-disc yes

# custom logging
verb 3

# retain TOS flags (VoIP)

# internal network (VOIP Server)
push "route"


  • Don’t forget to alter your firewall rules. The new OpenVPN subnet needs to be accessible by your VoIP Server (e.g. asterisk) and vice versa
  • Add Quality-of-Service rules to your router which matches the OpenVPN port set above. The traffic should be marked with class EF (realtime, expected forwarding) to avoid package lost. Default VoIP rules will not match because of the encrypted channel!

Using ejs as template-engine within express.js default configuration can be very annoying – you have to pass a dedicated variable set to each response.render() call. But for a lot of tasks it is required to use some kind of global variables in your templates, e.g. page title, resources and much more.

The most reliable solution is a custom template renderer which invokes ejs in the way you want.

Custom Template Engine/Renderer Function#

const _ejs = require('ejs');

// example: global config
const _config = require('../config.json');

// custom ejs render function
module.exports = function render(filename, payload={}, cb){
    // some default page vars = || {}; = || _config.slogan; = || _config.title; = ||;

    // resources
    payload.resources = payload.resources || {};

    // render file
    // you can also pass some ejs lowlevel options
    _ejs.renderFile(filename, payload, {
    }, cb);


const _express = require('express');
const _webapp = _express();
const _path = require('path');
const _tplengine = require('./my-template-engine');

// set the view engine to ejs
_webapp.set('views', _path.join(__dirname, '../views'));
_webapp.engine('ejs', _tplengine);
_webapp.set('view engine', 'ejs');

// your controller
_webapp.get('/', function(req, res){
   // render the view using additional variables
   res.render('myview', {
     x: 1,
     y: 2


Use EnllighterJS with marked

markdown, gfm, javascript, nodejs

marked is one of the most popular markdown parsers written in javascript. It’s quite easy to integrate EnlighterJS within, just pass a custom highlight function as option.

Promised based highlighting#

File: markdown.js

const _marked = require('marked');
const _renderer = new _marked.Renderer();

// escape html specialchars
function escHtml(s){
    return s.replace(/&/g, '&')
            .replace(/"/g, '"')
            .replace(/</g, '&lt;')
            .replace(/>/g, '&gt;');

// EnlighterJS Codeblocks
_renderer.code = function(code, lang){
    return `<pre data-enlighter-language="${lang}">${escHtml(code)}</pre>`;

const _options = {
    // gfm style line breaks
    breaks: true,

    // custom renderer
    renderer: _renderer

// promise proxy
function render(content){
    return new Promise(function(resolve, reject){
        // async rendering
        _marked(content, _options, function(e, html){
            if (e){

module.exports = {
    render: render



const _markdown = require('markdown');

// fetch markdown based content
const rawCode = getMarkdownContent(..);

// render content
const html = await _markdown.render(rawCode);


Comparing the content of two directories binary-safe is a common used feature especially for data synchronization tasks. You can easily implement a simple compare algorithm by generating the sha256 checksums of each file – this is not a high-performance solution but even works on large files!

const _fs = require('fs-magic');

// compare directoy contents based on sha256 hash tables
async function compareDirectories(dir1, dir2){
    // fetch file lists
    const [files1, dirs1] = await _fs.scandir(dir1, true, true);
    const [files2, dirs2] = await _fs.scandir(dir2, true, true);

    // num files, directories equal ?
    if (files1.length != files2.length){
        throw new Error('The directories containing a different number of files ' + files1.length + '/' + files2.length);
    if (dirs1.length != dirs2.length){
        throw new Error('The directories containing a different number of subdirectories ' + dirs1.length + '/' + dirs2.length);

    // generate file checksums
    const hashes1 = await Promise.all( => _fs.sha256file(f)));
    const hashes2 = await Promise.all( => _fs.sha256file(f)));

    // convert arrays to objects filename=>hash
    const lookup = {};
    for (let i=0;i<hashes2.length;i++){
        // normalized filenames
        const f2 = files2[i].substr(dir2.length);
        // assign
        lookup[f2] = hashes2[i];

    // compare dir1 to dir2
    for (let i=0;i<hashes1.length;i++){
        // normalized filenames
        const f1 = files1[i].substr(dir1.length);

        // exists ?
        if (!lookup[f1]){
            throw new Error('File <' + files1[i] + '> does not exist in <' + dir2 + '>');

        // hash valid ?
        if (lookup[f1] !== hashes1[i]){
            throw new Error('File Checksum of <' + files1[i] + '> does not match <' + files2[i] + '>');

    return true;

await compareDirectories('/tmp/data0', '/tmp/data1');


TravisCI: Use custom Node.js version within container based builds

nodejs binary, custom version, second language

Sometime you may need a special version of Node.js or a recent version within a foreign build environment. But in the modern container-based infrastructure it is not possible to use apt to install custom packets which are not whitelisted. As an workaround, you can download pre-build binaries via wget into your build directory and add the bin/ dir to your PATH. This allows you to use any pre-build third party software without installation.

Example: PERL with javascript testcases#

os: linux

language: perl

  - "5.24"
  - "5.14"

# skip perl (cpanm) dependency management
# install nodejs into home folder
  # fetch latest nodejs archive
  - wget -O /tmp/nodejs.tgz
  # unzip
  - tar -xzf /tmp/nodejs.tgz
  # add nodejs binaries to path - this has to be done here!
  - export PATH=$PWD/node-v8.8.1-linux-x64/bin:$PATH
  # show node version
  - node -v
  - npm -v
  # install node dependencies
  - npm install

  # syntax check
  - perl -Mstrict -Mdiagnostics -cw rsnapshot
  # run javascript based tests
  - npm test



TravisCI: Setup MySQL Tables+Data before running Tests

test, mysql, mariadb, travis, continuous integration, before_install

In case your projects make use of external databases like MySQL/MariaDB you need to setup your continuous integration tests with dedicated testcases including application specific database structures. This requires some initial steps to load the database dump before starting the tests. Thanks to you do’t need to do this kind of stuff within your application – just use the test configuration!

Travis+MySQL Server#

First of all, we add MySQL Server as service within our .travis.yml file. This initializes a dedicated database instance for testing. Additionally we hook into the before_install action to initialize our database structure. In this example all SQL commands are loaded from an external file located in our test directory.

language: node_js
  - "7"
  - "7.6"
  - "8"
  - mysql
  - mysql -u root --password="" < test/travis.sql

Initial Database Setup#

Our Test Database structure is definied within a dedicated SQL file in test/travis.sql. It contains all necessary commands to add a new user, create demo database, create demo tables and finally add some test-data.

# Create Testuser
CREATE USER 'dev'@'localhost' IDENTIFIED BY 'dev';

# Create DB
USE `demo`;

# Create Table
  `user_id` int(11) NOT NULL,
  `created_on` timestamp NULL DEFAULT NULL,
  `username` varchar(50) DEFAULT NULL,
  `salt` varchar(20) DEFAULT NULL,
  `password` varchar(50) DEFAULT NULL,
  `email` varchar(150) DEFAULT NULL,
  `firstname` varchar(50) DEFAULT NULL,
  `lastname` varchar(50) DEFAULT NULL,
  `dob` date DEFAULT NULL

  ADD PRIMARY KEY (`user_id`);


# Add Data

pfSense: Persistent OpenVPN Connection to Strato-HiDrive

openvpn, tls-auth, key-direction, smb, encryption

You may use Strato HiDrive as an external storage for team collaboration, internal file-sharing or remote backups. In such cases it can be very useful to establish the secure connection via your corporate UTM Gateway instead on each client. This only requires an additional HiDrive Account which has the ability to connect via VPN (Login allowed via OpenVPN).

This solution requires the HiDrive business plans with advanved protocol featureset!

Step 1 – Download the OpenVPN Config Package#

First of all, you have to download the official openvpn config package directly from the Strato Website. It contains the CA, TLS-Auth Key as well as a poor OpenVPN Config.

Step 2 – Upload the CA#

Go into the pfSense Webinterface and add a new CA – paste the content of the file into the textarea and save it. The CA is now available within the OpenVPN Client config.

Step 3 – Create a new VPN Client Instance#

Finally goto VPN -> OpenVPN -> Clients and create a new instance.

Connection Settings#


You should use a dedicated HiDrive User-Account which has the ability to connect via VPN. Use this account credentials for the OpenVPN User Authentication.


By default, OpenVPN uses BF-CBC as cipher with SHA1 auth – not AES as set in pfSense GUI.


This is the most tricky/weak part..Strato is using the TLS-Auth Key in bidirectional mode, which is not recommended. Normally the key-direction 0 will be used for servers, 1 for clients and pfSense is not offering an option to change this via the GUI.

But its possible to add the TLS-Auth Key as inline statement under “Advanced Configuration -> Custom Options” without a key-direction (bidirectional by default). Just paste the following code. It contains the TLS-Auth key as of Mai 2017.

Manual TLS-Auth Config

tls-auth [inline]<tls-auth>-----BEGIN OpenVPN Static key V1-----
-----END OpenVPN Static key V1-----</tls-auth>