Tag: cloud

Cheap and Secure Cloud Backups

I’ve wanted to find a good provider of cheap and secure cloud backups for a while. I’ve compared some cloud drive providers, but didn’t quite like those. They usually have very limited free plans, somewhat pricey paid plans (e.g. 50GB for about 24$ a year for OneDrive), or like in the case of Google no information available at all. By the way, “Google one is coming soon” isn’t an announcement that I want to look at for more than a few days when looking for pricing info.

Then, I’ve looked at pricing of cloud storage providers, such as AWS, Azure and Google Cloud. Those offer storage around 1 cent ($0.01) per GB per month. That’s a quarter of the OneDrive cost! It’s even less if you consider their archive offerings (AWS Glacier, Archive in Azure, Coldline Storage for Google). The cheapest offering here is from Microsoft at 0.2 cents ($0.002) per GB per month, but with some usage caveats. Since the point of backups is to keep them for a long time, this quickly adds up though.

Now I’ve written a line or two of code before, so I figured I could as well write my own tool for this. So here is bart, the backup and restore tool. Note that at this point I do not offer bart as a ready-to-use executable, but only as MIT-licensed source code. In addition, bart currently works only with Azure Blob Storage – or with storage mounted into the machine’s file system. However, adding other cloud providers/archive destinations should be relatively easy, given the interfaces used in the tool.

Security

In terms of security, bart encrypts every file before storing it in the archive destination. A user-provided password is used together with a randomly generated salt to derive a key for encryption with AES. On first use of any archive destination, bart generates a random salt, and each archive has its own password and salt. To avoid anybody with access to the archive destination from even snooping the names of your files, the names are hashed (SHA1) and the hashes used to store the encrypted files. This has the disadvantage that renaming/moving a file results in another file in the destination archive, though.

Usage

Once you compiled bart, you can use it as follows.

./bart [-name string] [-path string] [-m noop|restore|delete] -acct string -key string
  -name string
        The name of the backup archive. (default "backup")
  -path string
        The path to the directory to backup and/or restore. (default ".")
  -m string
        A behavior for files missing locally: 'noop' to do nothing, 'restore' to restore them from the backup, 'delete' to delete them in the backup archive. (default "noop")
  -acct string
        The Azure Storage Account name.
  -key string
        The Azure Storage Account Key.

Sources

The sources are on GitHub @ https://github.com/rokeller/bart.

Conclusion

I’ve used bart for backup of some photos/videos for a while now. For the about 42GB I have uploaded so far my monthly bill from Microsoft is about 42 cents ($0.42). Those months where I upload new files the cost is a little higher (a few cents usually) because of the extra transactions. My backed up files are encrypted. If this isn’t cheap and secure cloud backups, what is?

Using Cloud-Init to Auto-Deploy New EC2 Instances

So you have a machine role that you’re auto-scaling in AWS and you want new EC2 instances to initialize automatically after their creation? Cloud-init is here to help; it let’s you manage and configure many aspects of the machine (like installing the latest updates or missing packages). It also let’s you run any commands you want. So what else would you need to get your own bits installed? That’s right, nothing!

#cloud-config
# Update existing packages
apt_update: true

# Install more packages
packages:
- tomcat7
- jq

# Download the latest bits from S3, extract and setup.
runcmd:
- aws s3api get-object --bucket my-bits --key latest/mybits.tar.gz mybits.tar.gz
- mkdir mybits
- tar xvzf mybits.tar.gz -C mybits
- bash mybits/my-own-setup-script.sh

In this case, the script my-own-setup-script.sh is run at the end of initialization and can make sure to deploy everything as required. All you need to do, is push a package with the latest bits onto S3 and all new instances for this role will automatically get the latest bits installed when they are created. Of course you’ll need to make sure that the machine’s IAM role is allowed access to the corresponding S3 bucket and file.