Tuesday, September 9, 2014

OS X Fuse Input/output error Fix

If you're using OS X Fuse to mount a remote disk on a Mac device, you will occasioanlly receive the following error:

ssh: Input/output error

This has happened to me several times when allowing my Mac to sleep with the disk still mounted. When this happens, any operation on the disk seems to fail. I've managed to fix it with the following steps:

1) Shut down the remote server / disconnect it to prevent corruption (optional)
2) Attempt to unmount the disk cleanly from your Mac: umount /tmp/ssh (where /tmp/ssh is the location of the mounted disk)
3) If that fails, find the process ID of the SSHFS process: ps aux | grep sshfs
4) Kill that process: sudo kill <PID>
5) Remove the old folder: rmdir /tmp/ssh  (rm -rf /tmp/ssh if it fails)
6) Remount everything again:

 mkdir /tmp/ssh
 sshfs user@host:/ /tmp/ssh -ocache=no -onolocalcaches -ovolname=ssh

 This should fix the Input/Output errors and allow you to cleanly remount.

Sunday, September 7, 2014

Monitoring a Scaling Infrastructure at Aviary

I recently wrote a blog post for Aviary, where I am employed as a Server Engineer. It details how we setup monitoring to automatically scale with our infrastructure and covers tools like Nagios, StatsD, CollectD, and Graphite:

Monday, September 1, 2014

Why Security is Important for Developer Operations

After working at my current gig for about a year now (internship plus full-time), I wanted to take some time to outline my experiences transitioning to more of a developer operations role from my existing security background. The transition has been fairly straight-forward, as much of the work I do currently touches security in some aspect. However, the biggest point I've noticed is how much security considerations are involved when developing tools for a traditional developer operations requirement.

While I am a big proponent of at least some security training for everyone in a technical role, it remains to be seen just how much is "enough." Obviously, as the realm of technical fields continues to expand at its current pace, having every member of a technical team fully trained in the security of the applications they are developing is impossible. Yet it is also imperative that they at least understand the risks associated with these applications; doing so should be a requirement of a good developer.

As a "Developer Operations Engineer" (a role whose title is still rather undefined and unstandardized), I generally focus on several categories of projects: infrastructure development, monitoring and incident response, and deployments and the application lifecycle. While this is a highly compressed view of my role, each of these has a dizzying array of security concerns. While some companies offload much of these concerns to a security team, smaller companies need to remain vigilant of their impact.

In most modern startup environments, infrastructure development typically refers to everyone's favorite buzzword: the cloud. Amazon Web Services, Microsoft Azure, Google's App Engine, the list goes on. The security concerns associated with the cloud are not the focus of this post, but I do want to highlight places where security is especially important. Almost every one of these services has security enhancements that are not used as often as they should be. For example, AWS's Virtual Private Cloud is not only free, but can also greatly improve security when used properly. Yet quickly starting instances from EC2 still requires less hassle and so remains the more common choice. Another example is the use of security groups. AWS's security groups are infinitely customizable, yet simply opening a port to the world (0.0.0.0) is a tempting simpler option. While hosted infrastructure providers like Amazon and Google abstract a lot of security work away from the customer, good security practices still require active participation.

Monitoring and incident response is perhaps the area in which a lack of security can have the biggest impact. While many "DevOps" engineers view monitoring in terms of system performance, monitoring must also cover system security. Disk space, CPU utilization, and memory usage are all important indicators of a healthy system, but so too are login attempts, changes to file permissions, and unauthorized outgoing network connections. A good monitoring platform must also monitor for security events that could signal an intrusion or potential breach of security. In the same light, the response to a security event should also contain a viable plan for mitigating the same risk in the future.

Finally, the deployment of applications is a critical component of the security of an infrastructure. Because the main goal of deployments from a developer operation's standpoint is automation, any security bugs introduced once tend to be replicated. For this reason, it is imperative that the deployment process and any actors in it (Jenkins, AWS S3, etc.) are fully secured and audited often. Vulnerabilities that are present here can expand exponentially when deployments are pushed.

The role of developer operations or server engineering is rapidly changing and expanding. While it does, it is important, if not necessary, to include security in the expansion and ensure that those building a company's most critical technological parts are also trained in protecting them.

How to Enable Two-Factor Authentication for iCloud (And Why You Should)

This past weekend was not a good one for at least twenty or so celebrities, as well as Apple's iCloud service. According to a number of reports, a large number of female celebrities had personal photos released from their private iCloud accounts after a hacker was able to gain access to them. While we don't know all the details yet, it is likely that a combination of social engineering, weak passwords, and publicly available security question answers merged to allow the attacker access. In light of these events, it's a great idea to review the security of your account to avoid any accidental exposure of your private information.

Two-Factor Authentication

One of the easiest ways to secure your iCloud account is to use two-factor authentication. With this feature enabled, an attacker will not be able to log into your account unless he or she also has access to your phone. To set it up, first head over to your Apple ID security page here: https://appleid.apple.com/account/manage/security

Make sure that two-factor authentication is setup. If it is not, begin the process by clicking the link. You will be asked for several pieces of information, including a phone number and answers to your security questions. You will also be asked to provide the code texted to you as well as given a very long reset code which should be treated as if it is your password (in other words, don't write it down some place that will be lost, and don't save it on your desktop).

Once you enter all this information, two-factor authentication will be setup. Congratulations, you've just made your iCloud account ten thousand times more secure!

iCloud Two-Factor Authentication


Security Questions

For most accounts, the only thing that stands between a hacker resetting your password and maintaining your security is a strong set of password security questions. What good are these questions if an attacker can find the answers on Facebook? This is a good time to check your questions and make sure they are hacker-proof. Here are some tips:

  1. Security questions should be simple for you to remember but complex for anyone else
  2. The answers to your questions should not be something an attacker can find on Facebook, Twitter, your blog, or on your abandoned MySpace page.
  3. Be very specific in your answers. If the question asks where you met your significant other (a common question), don't use "Los Angeles" as the answer. Instead, provide a specific street name, a friend's name who introduced you, etc.).
  4. Don't choose simple questions. "What is your favorite color?" and "Where were you born?" are ridiculously simple questions for attackers. Choose more complex questions that ask for information not found in your online profiles.
Securing iCloud is relatively simple and doing so can go a long way in securing your personal photos and documents. Unfortunately, leaks like the one that happened this weekend are going to occur. But by following these guidelines, at least you can make the hacker's efforts less rewarding, and in most cases, stop them entirely.

Friday, July 11, 2014

Changing Releases and Tags on GitHub to a Different Commit

I recently came across a situation where I accidentally created a release on GitHub, pointed at a specific tag which was tagged to a commit. I fixed the changes, committed, but wanted the release to point to the new commit instead of the old one with the error. Unfortunately, GitHub doesn't have a way to do this online, but it can be done through a combination of command line git and the GitHub website.

First, make sure your repo is up-to-date with "git fetch." This will pull down the tag you made, including the wrong one.

git fetch

Next, delete the old tag by running:

git tag -d [tag-name-here]

So, for example, I did:

git tag -d v1.1.0

Next, commit and push your latest changes including the change you want the release to point to:

git add folder/file
git commit -m "message here"
git push -u origin master

Finally, push your tag changes as well:

git push origin :[tag-name-here]

If your tag has the same name as a branch, run:

git push origin :refs/tags/[tag-name-here]

Now, open GitHub in your browser and navigate to the "releases" page. Your release should now be listed as a "Draft" because its tag has been deleted.

You can now discard this release and create a new one with the same name pointed at the most recent commit.

Wednesday, July 2, 2014

Use google-passport Authentication in Node.js Projects without Google+

NPM passport-google and 400 Error "OpenID auth request contains an unregistered domain"

If you've been using the Node.js module "passport-google" for authentication in your projects you will now notice that new projects are receiving an error stating:

"400 That's an error. OpenID auth request contains an unregistered domain."

This issue is due to the fact that Google has deprecated their OpenID API for new domains beginning in May 2014. Old projects which had previously been used should not have an issue (although you should upgrade at some point), but new projects will not be allowed to authenticate.

There are two fixes for this:

1) Convert your application to using the new, Google+ sign-in. This will require users to have a Google+ profile and approve your application to access it. The passport-google-plus module located on GitHub can do just that: https://github.com/sqrrrl/passport-google-plus

2) Convert your application to use OAuth2.0 signin. Your users will not need to have a Google+ profile and this new method is the closest match to the old. The passport-google-oauth module can help with this: https://github.com/jaredhanson/passport-google-oauth

If you choose the second option, be sure to only provide the userinfo scope (and not the google.plus scope):

passport.authenticate('google', { scope: ['https://www.googleapis.com/auth/userinfo.email'] })

One additional note is that you will now be required to register your application at https://console.developers.google.com and create a client ID and secret (which are used in the passport module).

Friday, June 27, 2014

JavaScript Print Date in YYYY-MM-DD HH:mm:ss Format With Leading Zeros

Printing out a JavaScript date with leading zeros is a bit more complex than it should be.

var now = new Date();
var dateToPrint = now.getFullYear() + '-' + ('0' + (now.getMonth() + 1)).slice(-2) + '-' + ('0' + now.getDate()).slice(-2) + ' ' + ('0' + (now.getHours() + 1)).slice(-2) + ':' + ('0' + now.getMinutes()).slice(-2) + ':' + ('0' + now.getSeconds()).slice(-2);

The .slice(-2) method allows us to add a leading "0" to every date (including those already containing two characters) and then slice out the last two.

For example, if it is 1PM, the time is 13 (getHours() + 1), but then written as 013, then sliced to 13.