Git Tricks I Keep Having to Look Up

Another trail of breadcrumbs for myself…me being the kind of guy I am, I try to do things the “git” way so I don’t piss off those upstream who might otherwise not have the energy to deal with another PR.

Sync Fork with Upstream
http://stackoverflow.com/questions/3903817/pull-new-updates-from-original-github-repository-into-forked-github-repository?rq=1

Git Squash
https://ariejan.net/2011/07/05/git-squash-your-latests-commits-into-one/

Reverting Git Commits
http://stackoverflow.com/questions/6971717/github-how-to-revert-changes-to-previous-state#6971775

Switching branches
http://stackoverflow.com/questions/1475037/switching-branches-in-git

Push.default warning
http://stackoverflow.com/questions/13148066/warning-push-default-is-unset-its-implicit-value-is-changing-in-git-2-0#13148313

The Git Workflow (according to Atlassian)
https://www.atlassian.com/git/tutorials/comparing-workflows/gitflow-workflow

Switching to SSH for an existing local repo
http://stackoverflow.com/questions/6565357/git-push-requires-username-and-password

The classic…
http://nvie.com/posts/a-successful-git-branching-model/

Occupied Neurons, November edition (late)

Docker In Production: a History of Failure

A cautionary tale to counter some of the newbie hype around the new Infrastructure Jesus that is Docker. I’ve fallen prey to the hype as well, assuming that (a)Docker is ready for prime time, (b) Docker is universally beneficial for all workloads and (c) Docker is measurably superior to the infrastructure design patterns that it intends to replace.

That said, the article is long on complaints, and doesn’t attempt to back its claims with data, third-party verification or unemotional hyperbole. I’m sure we’ll see many counter-articles claiming “it works for me”, “I never saw these kinds of problems” and “what’s this guy’s agenda?”  I’ll still pay attention to commentary like this, because it reads to me like the brain dump of a person exhausted from chasing their tail all year trying to find a tech combo that they can just put in production and not devote unwarranted levels of monitoring and maintenance to. I think their expectations aren’t unreasonable. It sure sounds like the Docker team are more ambitious or cavalier than their position and staffing levels warrant.

Wat

This is one of the most hilarious and horrifying expeditions into the dark corners of (un?)intended consequences in coding languages.  Watching this made me feel like I’m more versed in the lessons of the absurd “stupid pet tricks” with many languages, even if I’d never use 99% of these in real life.  It also made me feel like “did someone deliberately allow these in the language design, or did some nearly-insane persons just end up naturally stumbling on these while trying to make the language do things it should never have done?”

Is Agile dying a slow death?  Or is it being reborn?

This guy captures all my attitudes about “Agile according to the rules” versus “getting an organization tuned to collaborate and learn as fast as possible”.  While extra/unnecessary process makes us feel like we have guard rails to keep people from making mistakes, in my experience what it *actually* does it drive DISengagement and risk aversion in most employees, knowing that unless they have explicit permission to break the rules, their great new idea is likely to attract organizational antibodies.

Stanford’s password policy shuns one-size-fits-all security

This is better than a Bigfoot sighting! An actual organization who’ve thought about security risk vs punishing anti-usability and come up with an approach that should satisfy both campaigns! This UX-in-security bigot can finally die a happy man.

A famed hacker is grading thousands of programs – and may revolutionise software in the process

May not get to the really grotty code security issues that are biting us some days, and probably giving a few CIOs a false sense of security.  Controversial?  Yes.

A necessary next step as software grows up as an engineering discipline? Absolutely.

Let’s see many more security geeks meeting the software developer where they live, and stop expecting em to voluntarily become part-time security experts just because someone came up with another terrific Hollywood Security Theater plot.

A Rebuttal for Python 3

Why are some old-school Pythonistas so damned pissy about Python 3 – to the point of (in at least one egregiously dishonest case) writing long articles trying to dissuade others from using it? Are they still butthurt at Guido for making breaking changes that don’t allow them to run their old Python 2 code on the Python 3 runtime? Do they not like change? Are they aware that humans are imperfect and sometimes have to admit mistakes/try something different? I find it fascinating to watch these kinds of holy wars – it gives the best kinds of insights into what frailties and hot buttons really motivate people.

The best quote’s in the comments: “Wow, I haven’t seen this much bullshit in a “technical” article in a while. A Donald Trump transcript is more honest and informative than that. I seriously doubt Zed Shaw himself believes a single paragraph there; if he actually does, he should stop acting like a Python expert and admit he’s an idiot.”

How The Web Became Unreadable

It’s painful to see some designers slavishly devote their efforts more to the third hand fashion they hear about from other designers, than to the end users of the sites and services to which they deliver their designs. I love a lot of the design work that’s come out the last few years – the jumbled mess that was web design ten years ago was painful – but the practical implications of how that design is consumed in the wild must be paramount.  And it is where I am the final decision maker on shipping software.

Occupied Neurons, October edition

Melinda Gates Asked For Ideas to Help Women in Tech: Here They Are

https://backchannel.com/an-open-letter-to-melinda-gates-7c40d8696b63#
I am psyched that a powerhouse like Gates is taking up the cause, and I sincerely hope she reads this (and many other) articles to get a sense of the breadth of the problem (and how few working solutions there are).  The overlap with race, the attempts to bring more women into classrooms, the tech industry bias towards the elite schools and companies (and not the wealth of other experiences). It’s a target-rich environment to solve.

Building a Psychologically Safe Workplace: Amy Edmondson at TEDxHGSE

https://m.youtube.com/watch?feature=youtu.be&v=LhoLuui9gX8

I am super-pleased to see that the concept of Psychological Safety is gaining traction in the circles and organizations I’m hanging with these days.  I spend an inordinate amount of time in my work making sure that my teammates and colleagues feel like it’s OK to make a mistake, to own up to dead ends and unknowns, and will sure make the work easier when I’m not the only one fighting the tide of mistrust/worry/fear that creates an environment where learning/risks/mistakes are being discouraged.

Three Books That Influenced CorgiBytes Culture

http://corgibytes.com/blog/2016/09/15/three-influential-books/

Andrea and Scott are two people who have profoundly changed my outlook on what’s possible to bring to the workplace, and how to make a workplace that truly fits what you want (and sometimes need) it to be. Talking about empathy as a first-class citizen, bringing actual balance to the day and the communications, and treating your co-workers better than we treat ourselves – and doing it in a fun line of business with real, deep impact for individual customers.

This is the kind of organization that I could see myself in. And which would draw in the kinds of people I enjoy working with each day.

So after meeting them earlier this year in Portland, I’ve followed their adventures via their blog and twitter accounts. This article is another nuanced look at what has shaped their workplace, and I sincerely hope I can do likewise someday.

Reducing Visual Noise for a Better User Experience

https://medium.com/@alitorbati/reducing-visual-noise-for-a-better-user-experience-ae3407ff9c99

View at Medium.com

These days I find myself apprehensively clicking on Design articles on Medium.  While there’s great design thinking being discussed out there, I seem to be a magnet for finding the ones that complain why users/managers/businesses don’t “get it”.

As I’d hoped, this was an honest and detailed discussion of the inevitable design overload that creeps into most “living products”, and the factors that drove them to improve the impact for non-expert users.

(I am personally most interested in improving the non-expert users’ experience – experts and enthusiasts will always figure out a way to make shit work, even if they don’t like having to beat down a new door; the folks I care to feed are those who don’t have the energy/time/inclination/personality for figuring out something that should be obvious but isn’t.  Give me affordances, not a learning experience e.g. when you’ve got clickable/tappable controls on your page, give me lines/shadows/shading to signify “this isn’t just text”, not just subtle whitespace that cues the well-trained UI designer that there’s a button around that otherwise-identically-styled text.

Scaling the Cliffs of Insanity (aka using Ansible from a Windows controller)

cliffs-of-insanity
Dread Pirate Roberts and Princess Buttercup, out for a morning stroll

This post is just record-keeping for me to remember why I abandoned Ansible on Windows a few months back.

here-there-be-dragons
Seriously, here be dragons

Here’s what I did to enable me to use Ansible for automation

  • Since I’m using a Windows box as my primary desktop for now, I wanted to see if I could avoid running a Linux VM just to manage other *NIX boxes
  • I thought I should be able to get away with using the Git for Windows environment rather than the full Cygwin environment that Jeff Geerling documents here (spoiler alert: I couldn’t, but it’s instructive to document how far I got and where it broke down)

Install and troubleshoot Ansible on Git for Windows

  • I followed installation instructions from step (3) (including using those legacy versions of PyYAML and Jinja2)
  • I skipped step (6) since I already had SSH keys
  • I ran ansible –version, and saw errors like:
     $ ansible --version
     Traceback (most recent call last):
       File "C:/Users/Mike/code/ansible/bin/ansible", line 46, in <module>
        from ansible.utils.display import Display
       File "C:\Users\Mike\code\ansible\lib\ansible\utils\display.py", line 21, in <module>
        import fcntl
     ImportError: No module named 'fcntl'
  • Tried resolving that dependency via http://stackoverflow.com/questions/1422368/fcntl-substitute-on-windows
  • This just led to the following (which seemed a hint that I might encounter many such issues, not worth it):
     $ ansible --version
     Traceback (most recent call last):
       File "C:/Users/Mike/code/ansible/bin/ansible", line 46, in <module>
        from ansible.utils.display import Display
       File "C:\Users\Mike\code\ansible\lib\ansible\utils\display.py", line 33, in <module>
        from termios import TIOCGWINSZ
     ImportError: No module named 'termios'
  • Gave in, uninstalled Python 3.5.1 and jumped back to latest Python 2.x (2.7.1)
  • Still couldn’t get past that error, so I gave up and went to Cygwin

Install and troubleshoot Ansible on Cygwin64

Then I found this article, followed a combo of the top answer:

  • apt-cyg remove python-cryptography
  • git clone –depth 1 git://github.com/ansible/ansible
  • apt-cyg install git python-{jinja2,six,yaml}
  • wget rawgit.com/transcode-open/apt-cyg/master/apt-cyg && install apt-cyg /bin
  • That results in this output:
     $ ansible --version
     ansible 2.2.0 (devel 37737ca6c1) last updated 2016/05/11 14:27:18 (GMT -700)
       lib/ansible/modules/core:  not found - use git submodule update --init lib/ansible/modules/core
       lib/ansible/modules/extras:  not found - use git submodule update --init lib/ansible/modules/extras
       config file =
       configured module search path = ['/opt/ansible/library']
  • Then running this command from within the local ansible repo (e.g. from /opt/ansible) gets the basic modules you’ll need to get started (e.g. the “ping” module for testing)
    git submodule update –init –recursive
  • Then I decided to test ansible’s ability to connect to the target host based on the command recommended in Ansible’s installation docs:
     $ ansible all -m ping --ask-pass
     SSH password:
     192.168.1.13 | FAILED! => {
        "failed": true,
        "msg": "to use the 'ssh' connection type with passwords, you must install the sshpass program"
     }
  • OK, let’s get sshpass installed on my control device [Windows box] so that we can quickly bootstrap the SSH keys to the target…
  • Since sshpass isn’t an available package in Cygwin package directory, the only way to get sshpass is to install it from source
    •  NOTE: I discovered this the hard way, after trying every trick I could think of to make all this work without having to deal with a C compiler
  • Found this article for OS X users and followed it in my Windows environment (NOTE: I had to install the “make” and “gcccore” packages from Cygwin setup – and then having to re-run apt-cyg remove python-cryptography from the Cygwin terminal again because it gets automatically reinstalled by Cygwin setup)
  • This time when running the command I get a different error – which means I must’ve got sshpass stuffed in the right location:
     $ ansible all -m ping --ask-pass
     SSH password:
     192.168.1.13 | FAILED! => {
        "failed": true,
        "msg": "Using a SSH password instead of a key is not possible because Host Key checking is enabled and sshpass does not support this.  Please add this host's fingerprint to your known_hosts file to manage this host."
     }
  • I’m guessing this means I need to obtain the target host’s SSH public key (and not that the target host refused to connect because it didn’t trust the control host).  So then I had to harvest the target host’s fingerprint
     $ ssh -o StrictHostKeyChecking=ask -l mike 192.168.1.13
     The authenticity of host '192.168.1.13 (192.168.1.13)' can't be established.
     ECDSA key fingerprint is SHA256:RqBcq8aCAgohFeiTlPeYd8hLDfTz1A25ZPlzyxlDrqI.
     Are you sure you want to continue connecting (yes/no)? yes
     Warning: Permanently added '192.168.1.13' (ECDSA) to the list of known hosts.
     mike@192.168.1.13's password:
  • This time around when running the ping command I saw this error:
     $ ansible all -m ping --ask-pass
     SSH password:
     192.168.1.13 | UNREACHABLE! => {
        "changed": false,
        "msg": "Authentication failure.",
        "unreachable": true
     }
  • I finally got the bright idea to poke around the target’s log files and see if there were any clues – sure enough, /var/log/auth.log made it clear enough to me:
     Invalid user Mike from 192.168.1.10
     input_userauth_request: invalid user Mike [preauth]
      pam_unix(sshd:auth): check pass; user unknown
      pam_unix(sshd:auth): authentication failure...
      Failed password for invalid user Mike from 192.168.1.10 port 58665 ssh2
      Connection closed by 192.168.1.10 [preauth]
  • (Boy do I hate *NIX case-sensitivity at times like this – my Windows username on the control device is “Mike” and the Linux username on the target is “mike”)
  • Tried this same command but adding the root user (ansible all -m ping –user root –ask-pass) but kept getting the same error back, and saw /var/log/auth.log reported “Failed password for root from 192.168.1.10”)
  • Re-ran su root in bash on the target just to make sure I wasn’t forgetting the password (I wasn’t)
  • Tried a basic ssh connection with that same password (to eliminate other variables):
     $ ssh root@192.168.1.13
     root@192.168.1.13's password:
     Permission denied, please try again.
     root@192.168.1.13's password:
     Permission denied, please try again.
     root@192.168.1.13's password:
     Permission denied (publickey,password).
  • Tried the same thing with my “mike” user, success:
     $ ssh mike@192.168.1.13
     mike@192.168.1.13's password:
     The programs included with the Debian GNU/Linux system are free software;
     the exact distribution terms for each program are described in the
     individual files in /usr/share/doc/*/copyright.
     Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
     permitted by applicable law.
     Last login: Sat May 14 16:10:05 2016 from 192.168.1.10
     mike@debianbox:~$
  • One more try with the ansible/SSH/password approach:
     $ ansible all -m ping --user mike --ask-pass
     SSH password:
     192.168.1.13 | UNREACHABLE! => {
        "changed": false,
        "msg": "Failed to connect to the host via ssh.",
        "unreachable": true
     }
  • So close!!  Search led to this possibility, so I re-ran with -vvvv param to get this:
     $ ansible all -m ping --user mike --ask-pass -vvvv
     No config file found; using defaults
     SSH password:
     Loaded callback minimal of type stdout, v2.0
     <192.168.1.13> ESTABLISH SSH CONNECTION FOR USER: mike
     <192.168.1.13> SSH: EXEC sshpass -d44 ssh -C -vvv -o ControlMaster=auto -o ControlPersist=60s -o User=mike -o ConnectTimeout=10 -o ControlPath=/home/Mike/.ansible/cp/ansible-ssh-%h-%p-%r 192.168.1.13 '/bin/sh -c '"'"'( umask 77 && mkdir -p "` echo $HOME/.ansible/tmp/ansible-tmp-1463273031.8-128175022355609 `" && echo "` echo $HOME/.ansible/tmp/ansible-tmp-1463273031.8-128175022355609 `" )'"'"''
     <192.168.1.13> PUT /tmp/tmp948_ec TO /home/mike/.ansible/tmp/ansible-tmp-1463273031.8-128175022355609/ping
     <192.168.1.13> SSH: EXEC sshpass -d44 sftp -b - -C -vvv -o ControlMaster=auto -o ControlPersist=60s -o User=mike -o ConnectTimeout=10 -o ControlPath=/home/Mike/.ansible/cp/ansible-ssh-%h-%p-%r '[192.168.1.13]'
     192.168.1.13 | UNREACHABLE! => {
        "changed": false,
        "msg": "SSH Error: data could not be sent to the remote host. Make sure this host can be reached over ssh",
        "unreachable": true
     }
  • I can definitely see the ansible-tmp-1463273031.8-128175022355609 file under ~/.ansible/tmp on the target system, so Ansible is getting authenticated and can run the initial shell commands
  • But I’m not seeing the /ping file under that directory, and I’m wondering if there’s something preventing sftp from connecting to the target host (since that’s the final command being run just before I get back the error). The “sftp” program is available on the controller though.
  • Digging around in Wireshark, I can see the SSHv2 traffic between controller and target, but after the initial key exchange I see exactly 3 encrypted packets sent from the controller (and encrypted responses from the target), and then no further communication between the two thereafter.  The only other activity I see on either system that’s unexplained is the target device ARP’ing for the local router three times, once every second, after the SSH traffic dies off
  • After the first two initial successes in getting the tmp files pushed via ssh, I’ve since only had failures “Failed to connect to the host via ssh.”  Using ProcExp.exe to verify that there is actual network traffic being sent to the target’s IP, and using Wireshark to get some idea what’s getting through and what’s not (but Wireshark is acting up and no longer showing me traffic from controller to target, only target to controller responses, so it’s getting a little nuts at this point)
  • I’ve added “PTR” records to the hosts files on both the controller and the target to resolve the IP address for each other to a defined name, but I’m still getting “failed to connect…” (even though I can confirm that the tools are using the newly-registered name, since I even tried substituting the falsified name in the ansible_hosts file for the previously-used IP address)
  • I tried the advice from here to switch to SCP if SFTP might not be working, but that didn’t help (so I emptied out the .ansible.cfg file again)
  • I don’t know where to look for log files to see exactly what errors are occurring locally, so I’m pretty much stumped at this point
  • !!!!!! I pushed my ssh key to the target host, and the very next run of ansible all -m ping succeeded!!!! 😦
  • CONCLUSION: ssh-pass doesn’t seem compatible with the Windows setup I’ve been using all weekend
  • EPILOGUE: “Failed to connect…” error is back again when running ansible from Windows – I can see successful auth in the target’s /var/log/auth.log, but even -m ping fails (e.g. ansible all -m ping -u root)

Other References

http://everythingshouldbevirtual.com/ansible-using-ansible-on-windows-via-cygwin

https://help.ubuntu.com/community/SSH/OpenSSH/Keys

Simplifying Vagrant-based testing: unsolved (I’m just calling it out to the universe)

I’m doing some pretty mind-numbing testing using Vagrant (yes, on Windows 10 – I like the challenge, apparently!), to make sure that I’m getting the results from changes I’m making to Ansible scripts.  Currently I’m testing the implementation of Ansible Vault, which means at each step of testing I:

  1. Vagrant destroy whatever box I just worked on
    • Which half the time means Vagrant and Virtualbox get out of sync, and I need to delete files and just vagrant init)
  2. Vagrant up
    • If I just init’d a new box, then I have to go into the Vagrantfile to uncomment then edit the config.vm.synced_folder setting, so that it removes the rsync dependency (setting it to config.vm.synced_folder “.”, “/vagrant”, disabled:true) – otherwise, vagrant up halts when it can’t find an rsync executable
  3. Mount the VM in Virtualbox Manager – Machine, Add…, find the .vbox file), then  launch the VM from VBox Mgr, login as vagrant, and edit the /etc/ssh/sshd_config file to set all instances of PasswordAuthentication to “yes”
  4. Reboot the VM
  5. Vagrant up
  6. Run ssh-keygen -f “/home/mike/.ssh/known_hosts” -R [127.0.0.1]:2222 to clear out the previously-trusted host SSH key
  7. Run ssh-copy-id vagrant@127.0.0.1 -p 2222 to add my user’s SSH public key to the remote system (to enable Ansible to run over SSH)

I haven’t had time yet to start researching how to troubleshoot/automate each of these steps, but which I’ll eventually have to conquer so that I’m not re-learning the manual steps every time I return to volunteering a little spare time to this infrastructure project.

Why doesn’t chmod under Bash on Ubuntu on Windows 10 actually “take”?

I’m continuing to beat my head against a wall, attempting to test a very simple configuration change to an Ansible playbook I wrote, so that I can verify if my understanding of the use of Ansible vault is correct.

The latest problem?  Unix permissions.

Now that I’ve got SSH communications working between by Bash shell (Ubuntu on Windows 10, aka WSL), I’ve implemented changes to the playbook’s files including creating a .vault_pass.txt file under the Bash shell, and encrypting a vault.yml file using the password contained in the .vault_pass.txt.

When I run ansible-playbook role.yml –vault-password-file .vault_pass.txt, it complains of the following:

mike@MIKE-WIN10-SSD:~/code/ansible-role-unattended-upgrades$ ansible-playbook role.yml --vault-password-file .vault_pass.txt
ERROR! Problem running vault password script / m n t / c / U s e r s / M i k e / c o d e / C o p y - a n s i b l e - r o l e - u n a t t e n d e d - u p g r a d e s / . v a u l t _ p a s s . t x t ([Errno 8] Exec format error). If this is not a script, remove the executable bit from the file.

No problem, I’ve got this.  Just gotta run chmod 600 (or similarly, to remove the execute bit for my user) on the .vault_pass.txt file.  [For comparison, I just tried this on the same configuration under Ubuntu – which is having a different blocking issue at present, but not related to file permissions – and the command took immedateily.]  Hah, you should be so lucky:

mike@MIKE-WIN10-SSD:~/code/ansible-role-unattended-upgrades$ ls -la .vault_pass.txt
-rwxrwxrwx 1 root root 25 Sep 26 18:38 .vault_pass.txt
mike@MIKE-WIN10-SSD:~/code/ansible-role-unattended-upgrades$ chmod 600 .vault_pass.txt
mike@MIKE-WIN10-SSD:~/code/ansible-role-unattended-upgrades$ ls -la .vault_pass.txt
-rwxrwxrwx 1 root root 25 Sep 26 18:38 .vault_pass.txt
mike@MIKE-WIN10-SSD:~/code/ansible-role-unattended-upgrades$ whoami
mike
mike@MIKE-WIN10-SSD:~/code/ansible-role-unattended-upgrades$ sudo chmod 600 .vault_pass.txt
[sudo] password for mike:
mike@MIKE-WIN10-SSD:~/code/ansible-role-unattended-upgrades$ ls -la .vault_pass.txt
-rwxrwxrwx 1 root root 25 Sep 26 18:38 .vault_pass.txt

Yes, I get that the file is owned by root, and I’m running as mike – so why doesn’t it make a difference when I run sudo chmod?  Is this a problem with files owned by root?  Is this a problem with chmod?  Is this a problem with WSL/Bash?

Lightbulb moment

I went hunting for such issues in the Microsoft repo for the Bash On Windows project, and found this issue & comment:

https://github.com/Microsoft/BashOnWindows/issues/81#issuecomment-207553514

So I figured I re-examine the situation.  All my files under the ~/code folder are owned by root – even . and .., which is odd…

mike@MIKE-WIN10-SSD:~/code$ ls -la
total 68
drwxrwxrwx 2 root root 0 Sep 26 10:51 .
drwxrwxrwx 2 root root 0 Aug 16 17:00 ..
drwxrwxrwx 2 root root 0 Aug 16 16:28 ansible-role-unattended-upgrades

Then I looked at my home folder and – d’oh!

mike@MIKE-WIN10-SSD:~$ ls -la
total 24
drwxr-xr-x 2 mike mike 0 Sep 26 18:37 .
drwxr-xr-x 2 root root 0 Dec 31 1969 ..
-rw------- 1 mike mike 2452 Aug 16 22:48 .bash_history
-rw-r--r-- 1 mike mike 220 Aug 5 10:06 .bash_logout
-rw-r--r-- 1 mike mike 3637 Aug 5 10:06 .bashrc
lrwxrwxrwx 1 mike mike 22 Aug 16 12:58 code -> /mnt/c/Users/Mike/code

Idiot.

Now I remember: when I first sat down with this Bash On Ubuntu on Windows setup, I figured I’d save myself some trouble by using the exact same files in all my local repos – why bother duplicating the repos between Windows and Bash on Ubuntu?  So I symlinked a mount of the /code folder from my Windows user profile…and left myself a nice little landmine, it seems.

Rather than struggle with cacls.exe and try to find some magic combination that results in non-executable permissions on that file through the WSL translation layer (if at all), I just cloned the repo to a different folder (local to the Bash/Ubuntu/Win10 environment) and retried, with trivial success.

Simple troubleshooting the usual SSH error from Ansible

After the struggles I’ve had over the last couple of days, it’s strangely reassuring to stumble on a problem I’ve actually *seen* before, and recently.  Firsthand even.

I’ve fresh-built a Debian 8.5.2 VM in Virtualbox via Vagrant.  Then I setup an Ansible inventory file to point to the box’s current vagrant ssh-config settings.  Then fired off the tried-and-true ansible connectivity test, ansible all -u vagrant -m ping.  Here’s the response:

127.0.0.1 | UNREACHABLE! => {
    "changed": false,
    "msg": "ERROR!  SSH encountered an unknown error during the connection.  We recommend you re-run the command using -vvvv, which will enable SSH debugging output to help diagnose the issue",
    "unreachable": true
}

Running the same command with -vvvv parameter results in a garbage heap of unformatted/concatenated debug screed, which ends with:

debug1: No more authentication methods to try.\r\nPermission denied (publickey,password).\r\n"

Simple Solution

As I’ve documented to myself already elsewhere, I need to run the following two commands:

ssh-keygen -t rsa

ssh-copy-id -p 2222 vagrant@127.0.0.1

Bingo!  Nice to get an easy win.

Troubleshooting another SSH blocker (networking?) in debian/jessie64

Since I ran into another wall with trying to use Ansible Vault under Bash on Ubuntu on Windows10 (this time, chmod wouldn’t change the permissions on the .vault_pass.txt file from 755 to 600 – or any other permissions set for that matter), I went back to my Linux-based setup to try out the Ansible Vault solution I’d devised.

Here, I ended up unable to communicate with the VM using Ansible because SSH from Ubuntu to the Debian8 box had an incompatibility – to wit, when I ran ssh vagrant@127.0.0.1 -p 2222, the command eventually timed out with the error “ssh_exchange_identification: read: Connection reset by peer”.

This is yet another piece of evidence that someone very recently (I believe between the 8.5.2 and the 8.6.0 versions of the box on Atlas) made breaking changes to the OpenSSH and/or OpenSSL configuration of the box.  One change I’ve figured out is they disabled PasswordAuthentication in the /etc/ssh/sshd_config file.

This problem?  Looks like (based on my read of articles like this one) the ssh client and server can’t agree on some cryptographic parameter.  Fun.  Cause there’s only about a million combinations of these parameters to play with.

[I also pursued ideas like the solution to this report, but currently the Debian8 box’s /etc/hosts.deny is still empty of uncommented entries.  Or the “is sshd running” idea from this report, but /var/log/auth.log definitely includes “[date] jessie sshd[366]: Server listening on 0.0.0.0 port 22”.]

OK, so what’s the fastest way to isolate the set of parameters  that are being offered and demanded between the client and server?

Running the ssh client with -vvv parameter doesn’t help much – it enumerates the “key_load_public” attempts (rsa, rsa-cert, dsa, dsa-cert, ecdsa, ecdsa-cert, ed25519, ed25519-cert), then “Enabling compatibility mode for protocol 2.0” and the SSH version “Local version string SSH-2.0-OpenSSH_7.2ps Ubuntu-4ubuntu2.1”, then fires off the “connection reset by peer” error again.  Dpkg -l reports that openssh-client is “1:7.2ps-4ubuntu2.1”.

What’s the server’s version of OpenSSH?  According to dpkg -l, it’s “1;6.7p1-5+deb8u3.  Is that right – 1.6.7?  And if so, how do I find out if there’s a cryptographic configuration incompatibility between 1.7.2 and 1.6.7?  [Certainly I can see that we have no such “connection reset by peer” issue between my Win10 Bash on Ubuntu shell, running 1.6.6p1 of openssh-client and the Debian8 box’s 1.6.7p1, so cryptographic compatibility between 1.6.6 and 1.6.7 is a reasonable assumption.]  Or better, is it possible to upgrade the Debian8 box’s openssh-server to something later than 1.6.7 – preferably (but not exclusively) 1.7.2?

On the server, I can crawl through the /etc/ssh/sshd_config” file to look for configured parameters (RSAAuthentication yes for example), but that doesn’t tell me what the OpenSSH defaults are, and doesn’t tell me what’s necessarily being asked of OpenSSL either (which might be swallowing the actual error).

Aside/Weirdness: networking

I started to pursue the idea of upgrading OpenSSH, so I ran sudo apt-get update to prepare for updating everything in the VM.  That’s when I noticed I wasn’t getting any network connectivity, as it spat back “Could not resolve ‘security.debian.org'” and “Could not resolve ‘httpredir.debian.org'”.

Vbox Mgr indicates I’m using NAT networking (the default), which has worked for me in the past – and works fine for the same Vagrant box running on my Win10 VirtualBox/Vagrant instance (sudo apt-get update “Fetched 529 kB in 3s (142kB/s)”).  Further, the Ubuntu host for this VM has no problem reaching the network.

So I tried changing to Bridged Adapter in Vbox Manager.  Nope, no difference.  Why does the same Vagrant box work fine under Windows but not under Ubuntu?  Am I cursed?

Back to the root problem

Let me review: I’m having a problem getting Ansible to communicate with the VM over SSH.  So let’s get creative:

  • Can Ansible be coerced into talking to the target without SSH?
  • Can Ansible use password authentication instead of public key authentication for SSH?
  • Can the Ubuntu client be downgraded from 1.7.2 to 1.6.7 openssh-client?

Lightbulb moment

Of course!  The “connection reset by peer” issue isn’t a matter of deep crypto at all – unless I’m misreading this, the fact that the Ubuntu SSH client takes nearly a minute to return the “connection reset” error and the fact that the Debian VM doesn’t seem to have any IP networking ability off the host…adds up to SSH client not even connecting to the VM’s sshd?

Boy do I feel dumb.  This has nothing to do with crypto – it’s simple layer 3 issues.

Reminds me of a lesson I learned 20 years ago, and seem to re-learn every year or three: “When you hear hooves, think horses not zebras.”

Then how do we establish where the problem is – Virtualbox, Ubuntu, Debian or something else?

  • If it’s a problem in the Debian VM, then download a different Vagrant box
  • If it’s a problem in the Virtualbox setting, keep trying different network settings until one breaks through
  • If it’s a problem in the Ubuntu host, look for reasons why there’d be a block between 127.0.0.1 (host to VM or vice-versa)

What other evidence do we have?  Well, when I run vagrant up from the Ubuntu host, it gets to “default: SSH auth method: private key” then eventually reports “Timed out while waiting for the machine to boot.  This means that Vagrant was unable to communicate with the guest machine within the configured (“config.vm.boot_timeout” value) time period.”  Makes me more suspicious of the VM.

Searching the Vagrant boxes registry, mosaicpro/html looks like it’s desktop (not locked-down server) oriented, so I tried that one.  Watched it boot, then report “default: Warning: Remote connection disconnect. Retrying…” over and over for a few minutes.  The console via Vbox Mgr looked like the Ubuntu VM was trying to configure networking (even though DHCP had offered it an address of 10.2.0.15 – which must’ve been the NAT adapter, since my home network runs on 192.168.1/24).  But oddly, networking from within the client was working fine after that – ping out to my home router (192.168.1.1) returned fine.  OK, then I’m *definitely* suspecting that Debian/jessie64 (8.6.0) box.

Vagrant/Debian downgrade anyone?

So, after all this, can I download a previous version of the Debian/jessie64 box (e.g. 8.5.2, not this troublesome 8.6.0)?  Let’s try it, using this article as basis.

(I went one step further and ran the initial command as vagrant add debian-8.5.2 https://atlas.hashicorp.com/debian/boxes/jessie64/versions/8.5.2/providers.virtualbox.box – and amazingly, this variation seemed to work!)

And here’s some promising results:

  • lsb_release -a reports the 8.5.2 box as “Debian GNU/Linux 8.5 (jessie)”, vs the 8.6.0 box as “Debian GNU/Linux 8.6 (jessie)”
  • A quick look at the /etc/ssh/sshd_config from the 8.5.2 box shows there is *no* insertion of the PasswordAuthentication configuration parameter (let alone setting it to “no” like in the 8.6.0 box)
  • Network connectivity from the 8.5.2 box to my home router is awesome (vs the 8.6.0 box that can’t seem to ping out of a wet paper bag)

Final Lesson

If you’re a Vagrant + Virtualbox user, stay FAR away from the 8.6.0 version of the debian/jessie64 box (unless you’re prepared to fight with these same issues I have, and probably other ‘security lockdown’ ideas that I haven’t even uncovered yet, but are almost surely there).

Troubleshooting SSH blocker in the Debian/jessie64 Vagrant box

After getting Vagrant and Virtualbox to play nice together, I turned my attention back to testing my Ansible Vault configuration ideas on a Debian8 VM.

Because I’d been having continued problems connecting to the damned box, I init’d a new VM based on debian/jessie64.  Once again, however, I noticed two issues:

  1. Vagrant is no longer registering new VMs in the VirtualBox Manager (when did Vagrant stop doing this?)
  2. I’m unable to copy SSH keys to freshly-booted Debian VM – ssh-copy-id results in this response:
    mike@MIKE-WIN10-SSD:~/$ ssh-copy-id vagrant@127.0.0.1 -p 2200
    /usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
    /usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
    Permission denied (publickey).

This article purports to have the answer to this, but even after fixing and re-checking the /etc/ssh/sshd_config multiple times, I’m still getting the same “Permission denied (publickey)” response.

After a couple of hours of tail-chasing, I finally remembered the debug flags in the ssh command (-v and -vvv).  That results in this output:

mike@MIKE-WIN10-SSD:~/code/Copy-ansible-role-unattended-upgrades$ ssh -p 2200 vagrant@127.0.0.1 -v
OpenSSH_6.6.1, OpenSSL 1.0.1f 6 Jan 2014
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to 127.0.0.1 [127.0.0.1] port 2200.
debug1: Connection established.
debug1: identity file /home/mike/.ssh/id_rsa type 1
debug1: identity file /home/mike/.ssh/id_rsa-cert type -1
debug1: identity file /home/mike/.ssh/id_dsa type -1
debug1: identity file /home/mike/.ssh/id_dsa-cert type -1
debug1: identity file /home/mike/.ssh/id_ecdsa type -1
debug1: identity file /home/mike/.ssh/id_ecdsa-cert type -1
debug1: identity file /home/mike/.ssh/id_ed25519 type -1
mike@MIKE-WIN10-SSD:~/code/Copy-ansible-role-unattended-upgrades$ ssh -p 2200 vagrant@127.0.0.1 -v
OpenSSH_6.6.1, OpenSSL 1.0.1f 6 Jan 2014
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to 127.0.0.1 [127.0.0.1] port 2200.
debug1: Connection established.
debug1: identity file /home/mike/.ssh/id_rsa type 1
debug1: identity file /home/mike/.ssh/id_rsa-cert type -1
debug1: identity file /home/mike/.ssh/id_dsa type -1
debug1: identity file /home/mike/.ssh/id_dsa-cert type -1
debug1: identity file /home/mike/.ssh/id_ecdsa type -1
debug1: identity file /home/mike/.ssh/id_ecdsa-cert type -1
debug1: identity file /home/mike/.ssh/id_ed25519 type -1
debug1: identity file /home/mike/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.8
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.7p1 Debian-5+deb8u3
debug1: match: OpenSSH_6.7p1 Debian-5+deb8u3 pat OpenSSH* compat 0x04000000
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-sha1-etm@openssh.com none
debug1: kex: client->server aes128-ctr hmac-sha1-etm@openssh.com none
debug1: sending SSH2_MSG_KEX_ECDH_INIT
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ECDSA b0:b7:27:f4:0a:91:a4:37:8c:ce:35:a3:e3:fe:db:2d
debug1: Host '[127.0.0.1]:2200' is known and matches the ECDSA host key.
debug1: Found key in /home/mike/.ssh/known_hosts:4
debug1: ssh_ecdsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /home/mike/.ssh/id_rsa
debug1: Authentications that can continue: publickey
debug1: Trying private key: /home/mike/.ssh/id_dsa
debug1: Trying private key: /home/mike/.ssh/id_ecdsa
debug1: Trying private key: /home/mike/.ssh/id_ed25519
debug1: No more authentication methods to try.
Permission denied (publickey).

I tried regenerating keys, but that still ends with the same “Permission denied (publickey)” message.

Is it possible that the Debian box’s sshd isn’t accepting RSA keys for SSH auth?  If that were true, wouldn’t the sshd_config include “RSAAuthentication no” instead of the “RSAAuthentication yes” I’m seeing?

It’s odd – when I attempt to ssh directly, I’m getting this kind of output – this implies that the remote sshd is attempting to accept password for authentication, even though it’s acting like I haven’t typed in the correct password (I am):

mike@MIKE-WIN10-SSD:~/code/Copy-ansible-role-unattended-upgrades$ ssh vagrant@127.0.0.1 2200
vagrant@127.0.0.1's password:
Permission denied, please try again.
vagrant@127.0.0.1's password:
Permission denied, please try again.
vagrant@127.0.0.1's password:
Received disconnect from 127.0.0.1: 14:

Time for a reset.

Solution (?)

Ripped out every VM on my system.  Re-inited.  Edited Vagrantfile.  Tried/failed.  Mounted the machine in the VirtualBox Manager app (because, Vagrant’s still not registering the machine with the Manager UI). Launched the Debian box interactively from VBox Mgr.

Edited the /etc/ssh/sshd_config file to change the PasswordAuthentication setting TWICE.

Yes, TWICE.

Something, somewhere, is inserting two entries (one commented out, the other uncommented at the very end of the file) that are both set to “no”.

What.  The.  Heck.

Set them *both* to yes (left them both uncommented, just for show) and rebooted the box.

Now?

ssh-copy-id is easily able to authenticate with the vagrant password *and* copy the current RSA public key to the appropriate file:

mike@MIKE-WIN10-SSD:~/$ ssh-copy-id vagrant@127.0.0.1 -p 2222
The authenticity of host '[127.0.0.1]:2222 ([127.0.0.1]:2222)' can't be established.
ECDSA key fingerprint is b0:b7:27:f4:0a:91:a4:37:8c:ce:35:a3:e3:fe:db:2d.
Are you sure you want to continue connecting (yes/no)? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
Permission denied (publickey).
mike@MIKE-WIN10-SSD:~/code/Copy-ansible-role-unattended-upgrades$ ssh-copy-id vagrant@127.0.0.1 -p 2222
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
vagrant@127.0.0.1's password:

Number of key(s) added: 1

Now try logging into the machine, with: "ssh -p '2222' 'vagrant@127.0.0.1'"
and check to make sure that only the key(s) you wanted were added.

Boy, *that’s* going to be fun to remember to do every time I destroy and recreate this VM.

[Oh, and keep this article in your back pocket in case you run into a different SSH troubleshooting issue: http://askubuntu.com/questions/311558/ssh-permission-denied-publickey]

Troubleshooting E_FAIL SessionMachine between Virtualbox and Vagrant

Today I wanted to dive back into my research on Ansible, so I fired up one of my Debian VMs under Vagrant/Virtualbox.  The VM was an older image (8.5.3) so I updated to the latest (8.6.0), and then found myself troubleshooting weird connectivity issues for hours.

Eventually I got myself to this point, where the VirtualBox Manager wouldn’t even start up the VM:

debian-virtualbox-startup-issue

This error leads to the following article:

http://superuser.com/questions/785072/e-fail-0x80004005-when-running-linux-through-windows-8-virtualbox

The AppCompatFlags entry doesn’t exist, but as for another user, even though VirtualBox Manager reports it’s running the latest version (5.0.26), looking at the Downloads page tells a different story (5.1.6).  Installed that, then of course Vagrant howled loudly:

C:\Users\Mike\VirtualBox VMs\BaseDebianServer>vagrant destroy
The provider 'virtualbox' that was requested to back the machine
'default' is reporting that it isn't usable on this system. The
reason is shown below:

Vagrant has detected that you have a version of VirtualBox installed
that is not supported by this version of Vagrant. Please install one of
the supported versions listed below to use Vagrant:

4.0, 4.1, 4.2, 4.3, 5.0

A Vagrant update may also be available that adds support for the version
you specified. Please check www.vagrantup.com/downloads.html to download
the latest version.

C:\Users\Mike\VirtualBox VMs\BaseDebianServer>vagrant -v
Vagrant 1.8.1

There’s a 1.8.5 Vagrant version available, so I installed that too.

There, once again the master and the servant are back in sync:

C:\Users\Mike\VirtualBox VMs\BaseDebianServer>vagrant up
Bringing machine 'default' up with 'virtualbox' provider...
==> default: Importing base box 'debian/jessie64'...
==> default: Matching MAC address for NAT networking...
==> default: Checking if box 'debian/jessie64' is up to date...
==> default: Setting the name of the VM: BaseDebianServer_default_1474924390887_22621
==> default: Clearing any previously set network interfaces...
==> default: Preparing network interfaces based on configuration...
 default: Adapter 1: nat
==> default: Forwarding ports...
 default: 22 (guest) => 2222 (host) (adapter 1)
==> default: Booting VM...
==> default: Waiting for machine to boot. This may take a few minutes...
 default: SSH address: 127.0.0.1:2222
 default: SSH username: vagrant
 default: SSH auth method: private key
 default:
 default: Vagrant insecure key detected. Vagrant will automatically replace
 default: this with a newly generated keypair for better security.
 default:
 default: Inserting generated public key within guest...
 default: Removing insecure key from the guest if it's present...
 default: Key inserted! Disconnecting and reconnecting using new SSH key...
==> default: Machine booted and ready!
==> default: Checking for guest additions in VM...
 default: No guest additions were detected on the base box for this VM! Guest
 default: additions are required for forwarded ports, shared folders, host only
 default: networking, and more. If SSH fails on this machine, please install
 default: the guest additions and repackage the box to continue.
 default:
 default: This is not an error message; everything may continue to work properly,
 default: in which case you may ignore this message.

<editorial understatement=”on”>Based on the SuperUser question above, I’m guessing this isn’t an uncommon problem as Vagrant and Virtualbox rev their engines.</editorial>