I just wanted to know what the specific differentiation is between
environment variables ENV[SOME_VARIABLE]
vs.
Rails 5.2 credentials Rails.application.credentials.some_variable
When should I use one vs. the other? Did the credentials replace the env variables?
Credentials are stored in an encrypted file and are checked into your repository. There is a master key file that acts as the key in development, and you set the value of the master key file as an environment variable in production and both environments have access to the credentials. environment variables, on the other hand, should be used for values which are not secrets. Environment variables are generally not checked into your repository though still.
When should you use env:
When you have fixed no variables in your project
When you don't need environment-specific keys
When should you use credentials:
When you need to update keys frequently and you want to update it locally to test and also wish to maintain it securely ( since every environment has its own credential file and own key to access it
When you want environment-specific key values to isolate environment-wise service access. for example, you wish to maintain different fcm service channel at staging and on production to prevent information leak while testing internally
Related
There are several posts ans Stack Overflow questions about how to manage API tokens on the web, but I see a lot of people repeat what they read somewhere else, often with contradictions...
How do you deal with API Tokens, secrets and the like ?
Here's what I have read so far using 3 different gems
secrets.yml
Introduced with Rails 4.1, then updated to encrypted secrets around rails 5
When initially released on rails 4, they were (or were not ?) meant to be pushed on repositories. However I often saw examples using environment variables for production
# config/secrets.yml
development:
secret_key_base: super_long_secret_key_for_development
...
production:
secret_key_base: <%= ENV["SECRET_KEY_BASE"] %>
...
And at this point someone asked "Why do we use ENV for production ?". A legit question back then, often answered "We don't want production token to be hard coded in the application" (hence how it is not clear anymore if the secrets should have been committed or not).
Later, with Rails 5, secrets became encrypted with a master key, so the encrypted secrets.yml file could be committed to the repository, but then the problem remained the same with the master key used to read the secrets.
PROs:
Rails convention.
Easy deploy with capistrano-secrets gem and cap [stage] setup (and it only deploys stage secrets nice) or similar gems
YML data structure (array/hash ok) + can use Ruby code via ERB
With encrypted secrets since rails 5, easy to collaborate/share the secrets
CONs:
Need to use Rails.application.secrets.xxx
Many services like AWS still read from ENV to automatically setup their gems/services
Is not the 12 factors way (or is it ?)
Quite new, so not really used yet ?
If using encrypted secrets, need to manage the master key
Bkeepers dotenv
Simply defining a .env file at the root that is read by Rails on startup
Plugins like capistrano-env allow to easily inject environment specific ENV on servers, and secrets can still must be managed using .env.staging, .env.production
PROs
ENV is in 12factor rules
3.5k stars... maybe not for nothing ?
the dotenv approach is now available on almost all other languages (JS, Go, etc)
Recent versions allow reusing variables (API_ROOT=X, SOME_ENDPOINT=${X}/endpoint)
CONs
No Ruby interpolation (unless extra code is added to parse the .env with the ERB templating engine for example)
limited to string-string key/val
Figaro
Some sort of hybrid secrets/ENV. With 12factors/Rails/Heroku in mind, but in the end doesn't seem better than the rest...
From the above and the rest I didn't write, it would seem like secrets.yml would be a great winner if those secrets were put in ENV instead (and tbh I feel lazy about writing Rails.Application.secrets each time).
So, suppose I start a quite new Rails app, and also based on your experience. Which one would you choose ?
(My particular stack uses AWS + Capistrano, no Heroku)
I personally think that the "right" approach depends on your environment.
In my case, I have servers which are managed by IT and I don't have access to the vhost or anything else to easily set environment variables. Because of this, I commit a secrets.yml file which doesn't contain the production stanza, then set up Capistrano to add this file to shared_files. On each server, I add the file.
If I had easy access the the vhost, and I was managing the server vhosts with Puppet, Chef, Ansible, or similar, I would use the environment variable approach like the default secrets.yml file.
Your case with AWS appears to be the latter. Ultimately, either option is fine. There is little downside to committing the secrets.yml file without a production stanza.
First, all three methods can be 12-factor compatible. It is compatible if you pass the config value by ENV variable, instead of copying one file to the server first.
My thoughts are each of these solutions:
Rails secrets
Developers are forced to go 12-factor, either manually set it on production server, or have another file on local machine and then pass it as ENV every time during deploy. (Didn't know about capistrano-secrets, it probably handles this)
(I think what you said in CON #2 and #3 are the opposite to secret.yml solution)
The accessor is also quite long as you mentioned.
dotenv
It does not encourage 12-factor, and was not originally designed for production env anyways. Either you write code to pass its value as ENV to production during deploy (making it 12 factor compatible), or you copy your .env.production file to the production server.
Also it forces you to use the flat key:value configuration. No nesting.
Figaro
Though it uses YAML, it does not allow nested hash.
It is 12 factor compatible, e.g. it includes code to transfer the config to heroku.
My Solution
I wrote a gem, in which settings are stored in gitignored YAML file. Nesting is allowed. When accessing some value, do Setting.dig(:fb,:api).
It provides mechanism for 12-factor app deploy, by serializing the whole YAML file into a string and pass it to production as ENV.
I no longer have to distinguish between secret config and non-secret config. They are in one place and secret by default. I get benefit of 12-factor app while using easy to namespace YAML files.
What is the best strategy in regards to checking in sensitive information into git? For example, database connection credentials, api keys, etc. For rails app, is it best to add environment files to .gitignore?
Thanks.
Your best bet is to use environment variables.
Check out these two links. The second link will show you how to keep your sensitive information secure by using environment variables to store sensitive data.
Rails Environment Variables
Environment Variables in Ruby on Rails
Nope, you don't need to ignore your env files - just remove all the secrets and use config variables ibstead... you can then refer to them using ENV['varname']
This gist shows one way of doing that using SECRET_KEY_BASE as an example (but you should do it with every sensitive key you have):
https://gist.github.com/cjolly/6265302
I have a url that I am using in one of the controllers. Is there a better place to put this url? The url uses an API key and I was wondering if there is a better place to add this url and/or api key such that its not added in the controller class code and ergo more editable? If i add it as an environment variable or anything else how do i access it from my controller class? thank you. ITS A RUBY AND RAILS PROJECT
Using environment variables might be a good idea if you want to keep things like API keys and passwords out of your source code. Accessing them from within your code is done with the ENV object:
my_api_key = ENV['MY_API_KEY']
To use this technique, you need to set up the variables in your environment before launching your app, and how you do this depends on your local setup, and will likely also vary between development and production.
In development, you can simply set the environment vars in your shell, e.g. with bash:
$ export MY_API_KEY=foobar123abc
$ rails s
Now rails will start and have access to this environment variable. You can also set variables for just a single command:
$ MY_API_KEY=foobar123abc rails s
Depending on what the sevice/api is, you could set some of them to default development/test values in config/environments/development.rb (or test.rb):
ENV['MY_API_KEY'] = 'non_secret_api_key_that_can_be_shared_around'
Setting up environment variables in production will depend on how you're deploying your app. Phusion have an article on using environment variables in Passenger if your using that. There's also a useful article on using environment variables with Heroku which is worth a read even if you're not using them for deployment.
You can add it to application.rb file as
config.service {
:api_key => 'api_key'
}
Or better yet, add it to development.rb and production.rb files so that you can test it better.
You can access this api_key from controller like
Rails.application.config.service[:api_key]
My personal rails project uses a few API's for which I store the API keys/secrets in config/environments/production.yml and development.yml as global variables. I now want to push this project to github for others to use, but I don't want them to have those bits of sensitive data. I also don't want this file in .gitignore because it's required for the app to run. I've considered putting them in the DB somewhere, but am hoping to find a better solution.
TLDR: Use environment variables!
I think #Bryce's comment offers an answer, which I'll just flush out. It seems one approach Heroku recommends is to use environment variables to store sensitive information (API key strings, database passwords). So survey your code and see in which you have sensitive data. Then create environment variables (in your .bashrc file for example) that store the sensivite data values. For example for your database:
export MYAPP_DEV_DB_DATABASE=myapp_dev
export MYAPP_DEV_DB_USER=username
export MYAPP_DEV_DB_PW=secret
Now, in your local box, you just refer to the environment variables whenever you need the sensitive data. For example in database.yml :
development:
adapter: mysql2
encoding: utf8
reconnect: false
database: <%= ENV["MYAPP_DEV_DB_DATABASE"] %>
pool: 5
username: <%= ENV["MYAPP_DEV_DB_USER"] %>
password: <%= ENV["MYAPP_DEV_DB_PW"] %>
socket: /var/run/mysqld/mysqld.sock
I think database.yml gets parsed just at the app's initialization or restart so this shouldn't impact performance. So this would solve it for your local development and for making your repository public. Stripped of sensitive data, you can now use the same repository for the public as you do privately. It also solves the problem if you are on a VPS. Just ssh to it and set up the environment variables on your production host as you did in your development box.
Meanwhile, if your production setup involves a hands off deployment where you can't ssh to the production server, like Heroku's does, you need to look at how to remotely set up environment variables. For Heroku this is done with heroku config:add. So, per the same article, if you had S3 integrated into your app and you had the sensitive data coming in from the environment variables:
AWS::S3::Base.establish_connection!(
:access_key_id => ENV['S3_KEY'],
:secret_access_key => ENV['S3_SECRET']
)
Just have Heroku create environment variables for it:
heroku config:add S3_KEY=8N022N81 S3_SECRET=9s83159d3+583493190
Another pro of this solution is that it's language neutral, not just Rails. Works for any app since they can all acquire the environment variables.
How about this...
Create a new project and check it into GitHub with placeholder values in the production.yml and development.yml files.
Update .gitignore to include production.yml and development.yml.
Replace the placeholder values with your secrets.
Now you can check your code into GitHub without compromising your secrets.
And anyone can clone your repo without any extra steps to create missing files (they'll just replace the placeholder values as you did).
Does that meet your goals?
They're probably best put in initializers (config/initializers/api.yaml) though I think what you've got cooked up is fine. Add the actual keys to your .gitignore file and run git rm config/environments/production.yml to remove that sensitive data from your repo. Fair warning, it will remove that file too so back it up first.
Then, just create a config/environments/production.yml.example file next to your actual file with the pertinent details but with the sensitive data left out. When you pull it out to production, just copy the file without the .example and substitute the appropriate data.
Use environment variables.
In Ruby, they're accessible like so:
ENV['S3_SECRET']
Two reasons:
The values will not make it into source control.
"sensitive data" aka passwords tend to change on a per-environment basis anyways. e.g. you should be using different S3 credentials for development vs production.
Is this a best practice?
Yes: http://12factor.net/config
How do I use them locally?
foreman and dotenv are both easy. Or, edit your shell.
How do I use them in production?
Largely, it depends. But for Rails, dotenv is an easy win.
What about platform-as-a-service?
Any PaaS should give you a way to set them. Heroku for example: https://devcenter.heroku.com/articles/config-vars
Doesn't this make it more complicated to set up a new developer for the project?
Perhaps, but it's worth it. You can always check a .env.sample file into source control with some example data in it. Add a note about it to your project's readme.
Rails 4.1 has now a convention for it. You store this stuff in secrets.yml. So you don't end up with some global ENV calls scattered across Your app.
This yaml file is like database.yml erb parsed, so you are still able to use ENV calls here. In that case you can put it under version control, it would then serve just as a documentation which ENV vars has to be used. But you also can exlcude it from version control and store the actual secrets there. In that case you would put some secrets.yml.default or the like into the public repo for documentation purposes.
development:
s3_secret: 'foo'
production:
s3_secret: <%= ENV['S3_SECRET']%>
Than you can access this stuff under
Rails.application.secrets.s3_secret
Its discussed in detail at the beginning of this Episode
I need to store an encryption key that is going to be accessed through the application globally. Is there a storage place for settings and configs? I tried searching but couldn't come up with anything.
There's several ways to do something like this.
The simplest way to make something like that globally available to your app is to define a constant within config/environment.rb (or config/environments/production.rb.
However, with sensitive data it's important that they're decoupled from your primary SCM and only available within the production environment - at least this way, if your code is compromised, your encryption key is safe.
There's a couple of methods of doing this that I know of - one would be to set they key in an environment variable, which can then be accessed in Ruby through ENV['variable_name].
Another option is to store it in an external file that's de-coupled from your code repository, then have that read in with an initializer.
Whichever way you do it, you can combine this approach with a constant declaration in config/environment.rb:
# config/environment.rb
ENCRYPTION_KEY = ENV['encryption_key']
This way, should you change the storage location of your key, you only need to change one line of code.
You can set all your secret constants in a config/initializers/01_secrets.rb file. Here are a few things to think about:
The 01 prefix is to make sure that
the secret constants are set before other
initializers that make use of these
constants are loaded.
The 01_secrets.rb file should not be
checked in to your SCM.
The server(s) that store this file
must be properly secured and the file
itself should have maximum security.
E.g.
# config/initilizers/01_secret.rb
ENV['ENCRYPTION_KEY'] = "your_key"