The Why

• Have you ever spent more than 5 minutes building a sed command to manipulate a simple configuration file?

  For example, you have this yaml configuration:

  services:
    elasticsearch:
      cluster: avengers
      addresses:
        - 192.168.2.3:9200
        - 192.158.2.4:9200

  How would you add an elasticsearch address using sed? Or any other command line programmatic way for that matter?

  If you have to google the answer, its not worth it. Just use dictfile:

  Add your configuration file to the dictfile repository: (just once)

  dictfile repository add --alias services --file-path services.yaml --fmt yaml

  Then run the following command from anywhere you like:

  dictfile configure services add --key services:elasticsearch:addresses --value 192.168.2.5:9200

  Your file will be as expected: (order and indentation is not currently preserved)

  services:
    elasticsearch:
      addresses:
      - 192.168.2.3:9200
      - 192.158.2.4:9200
      - 192.168.2.5:9200
      cluster: avengers

  In addition, all standard dictionary operations are supported as well (put, delete, get)

• Have you ever introduced a syntax error when changing a config file?

  I think we have all been there: You make a small change to the configuration file, only to later realize you made a typo or some other stupid thing.

  With dictfile, this wont happen. Given you manipulate the file only with dictfile, it simply wont allow you to make any change that breaks the format of the file.

• Have you ever wondered what changes were made to a configuration file on your production server?

  Your system is acting up, though no code changes were pushed to it for a while. What else can affect it? Well, configuration obviously.

  If multiple changes were made to the configuration file manually, you have no way of knowing what changed and when. However, dictfile saves the entire history of changes for you:

  dictfile repository revisions --alias services

  +----------+-------------------------+----------------------------+---------+---------------------------------------------------------------+
  |  alias   |           path          |         timestamp          | version |                            message                            |
  +----------+-------------------------+----------------------------+---------+---------------------------------------------------------------+
  | services | /Users/elip/config.yaml | 2018-06-12T17:53:15.886623 |    0    | original version committed automatically upon adding the file |
  | services | /Users/elip/config.yaml | 2018-06-12T17:53:31.213890 |    1    |                  Added an elasticsearch host                  |
  | services | /Users/elip/config.yaml | 2018-06-12T17:54:56.851202 |    2    |               Changed elasticsearch cluster name              |
  +----------+-------------------------+----------------------------+---------+---------------------------------------------------------------+    
  

• Have you ever needed to reset a configuration file to a specific point in time?

  Now that you have the history, you can very simple reset to any point in time:

  dictfile repository reset --alias services --version 1

  You can also have a look at each version using:

  dictfile repository show --alias services --version 0

  services:
    elasticsearch:
      cluster: avengers
      addresses:
        - 192.168.2.3:9200
        - 192.158.2.4:9200

The when

When your configuration files are in one of the following dict based formats:

• YAML
• INI
• PROPERTIES
• JSON

Building the tool, I saw two main use cases in front of me:

Build Time

Basically, every time I had to manipulate a configuration file from inside a docker file, it made me sad, and I was sad a lot. I found dictfile very useful for programmatic editing of these configuration files during build time.

Runtime

Even if you dont edit files at build time, you probably SSH'd into a server to edit a configuration file more than once in your life. (If not, bravo on the CM setup, I envy you --> you probably never worked in a startup)

So, gone are the days of manually editing configuration files on production servers, dictfile is a much safer and controlled way of doing it.

The who

Anyone. I dont really have anything to say here, it just seemed fitting to have a The who section as well.

The how

pip install dictfile

Also, since dictfile uses PyCI for releases, you can just download a binary executable:

Linux/MacOS:

sudo curl -L https://github.com/iliapolo/dictfile/releases/download/{version}/dictfile-$(uname -m)-$(uname -s) -o /usr/local/bin/dictfile

Windows (PowerShell):

[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
Invoke-WebRequest "https://github.com/iliapolo/dictfile/releases/download/{version}/dictfile-x86-Windows.exe" -UseBasicParsing -OutFile $Env:ProgramFiles\dictfile.exe