Dokku Environment Variables - ruby-on-rails

In one of the dokku plugin's (specifically the dokku-shoreman plugin), I see references to variables like $APP, $1. Where are these variable stored?
I accidentally deleted all of the docker containers and images on my server and after re-deploying, dokku-shoreman is no longer working, instead exiting with status code 1. I think these variables may be the key.
Any help appreciated!

To see all environment variables, dokku config APP_NAME
https://dokku.com/docs~v0.4.11/configuration-management/

Related

Node-config custom-environment-variables not Picking Docker environment Variables

Working on Windows OS.
My node app using node-config isn't using docker environment variables. It's always using the default config.
I am using node-config custom environment variables as described here: https://github.com/lorenwest/node-config/wiki/Environment-Variables#custom-environment-variables
Everything is working well when running the app locally. The config by passes the default ones and takes the ones defined in my User variables when set.
Problem
I start a docker instance with all required Environment variables
set.
I verify the env variables by running docker exec container_name env
However, the node app still uses the default config, instead of the environment variables.
I am not sure what setup I may be missing.
I'm a maintainer of node-config. I don't test with Docker or Heroku, but this most be an ordering problem. As long as the environment variables are set before require('config') happens, they will work-- at that point Docker or Heroku doesn't matter. The activity is happening inside the Node.js JavaScript engine at that point.
Try this simple test: Just before your line where you require('config'), use console.log or an equivalent to print out the environment variables that you care about. I expect you'll find that when it's not working it's because the environment variables are not set before node-config is loaded.

Rails: Use environment variables defined with Figaro in Docker

If I'm not wrong, it seems like defined with Figaro variables are not available in Docker container.
I have env files to configure Postgresq DB:
POSTGRES_USER=ENV['db_user']
POSTGRES_PASSWORD=ENV['db_password]
POSTGRES_DB=ENV['db_name']
I have application.yml file copied with all the other Rails app files to the container (I could check it with ls in the container shell).
Is it a normal behaviour ?
I also faced this issue when working on a Rails application.
The thing to note here is that for Docker, environment variables are placed in a .env file or an env_file (my_variables.env). Environment files placed in .yml or .yaml files (application.yml) are not often recognized by Docker during runtime. Here's a link to Docker's official documentation that further explains it: The “.env” file
An example of such environment variables are Database connection strings which are required during the application startup process like:
database_name
database_username
database_password
However, you can still use the Figaro gem for defining variables that are not required during application startup, like:
RAILS_MASTER_KEY
That's all.
I hope this helps

Load environment variables in rails app without restarting server

How can I make my rails app aware of the new environment variables after I have edited my /etc/environment file on my remote EC2 instance?
I frequently add new (minor) things in my secrets.yml but I don't want to restart my server for it, nor do I want to use an existing secret.
In linux every process inherits envvars from its parent process and the values are passed by value, not by reference. Also, they don't behave like closures. So, child process (your rails/ruby app process) will not get any new environment variables of its parent (the shell process where you started your rails/ruby app).
That's why it is not possible. However, you can use gems like dotenv and figaro to watch some file with your environment variables and reload them when they are changed.
You should be able to add a line to your config/spring.rb:
Spring.watch "config/secrets.yml"
This will allow Spring to detect when changes have occurred in your secrets.yml file.
However, if you're actually asking about how to make your app aware that you've changed environment variables in a file, then it's not possible. Config values may be detected in files, but environment variables are detected in the shell environment. You have to load those into your shell for them to take any effect, and this would require stopping your server, sourcing the new changes into the environment, and starting the server again.
Understanding the difference between a config value in a file (.yml, .xml, .ini, etc) versus an environment variable in a shell script is important, because how it's applied and made usable is entirely different.

How to set up and use Rails environment variables in production server?

I need to set up an environment variable for my rails app. Both in my local machine and in the production server. I read some tutorials on the internet but NONE has given the complete instruction on how to set and use these variable in the actual production server. I use digital ocean and linux server to host my rails app.
I have spent days trying to figure this out, but still haven't found a clear and complete instruction from setting the variables on my local machine -> push it to git repo -> set and use the variables in production server. So, hope somebody can help me here, thanks!
UPDATE:
This is how I currently setup the environment variables in my rails app by using figoro gem:
You can set system-wide environment variables in the /etc/rc.local file (which is executed when the system boots). If your Rails app is the sole user of the Linux system, that is a good place to store credentials such as API keys because there is no risk of including this file in a public Git repository, as it is outside the application directory. The secrets will only be vulnerable if the attacker gains shell access to your Linux server.
Set the environment variables within /etc/rc.local (do not include the <> characters):
export SOME_LOGIN=<username>
export SOME_PASS=<password>
To see the value of an environment variable, use one of the following commands in the Linux shell:
printenv MY_VAR
echo $MY_VAR
To access those environment variables within Rails, use the following syntax:
Inside .rb files or at the rails console
ENV['MY_VAR']
Inside .yml files:
<%= ENV['MY_VAR'] %>
For anyone still having this issue, figaro now has an easy method in setting the production variables in heroku. Just run:
$ figaro heroku:set -e production
ryzalyusoff.
For Unix
You can use LINUX ENV in rails application.
# .env
GITHUB_SECRET_KEY=SECRET
TWITTER_ACCESS_KEY=XXXXXXXXXXXX
# in rails code
puts ENV["TWITTER_ACCESS_KEY"] # => SECRET
Create .env files for local machine and your production server. Export environment variables like this(on server with ssh):
export GITHUB_SECRET_KEY="XXXXXXXXXXXXXXXXXX"
Anyway, storing keys in config - bad idea. Just add .env.example, others keys configs add to .gitignore. Goodluck.
Example with Rails
For Windows
Syntax
SET variable
SET variable=string
SET /A "variable=expression"
SET "variable="
SET /P variable=[promptString]
SET "
Key
variable : A new or existing environment variable name e.g. _num
string : A text string to assign to the variable.
expression : Arithmetic expression
Windows CMD
I believe we should not push a secret file on git.
To ignore such file use gitignore file and push other code on the git.
On the server side just copy the secret file and create a symlink for that file.
You can find demo here http://www.elabs.se/blog/57-handle-secret-credentials-in-ruby-on-rails
You can set your environment variables in production in the same way, you do it for local system. However, there are couple of gems, which make it easier to track and push to production. Have a look at figaro. This will help you in setting up and deployment of env vars.
You can do this with figaro gem
or in rails 4 there is a file named secret.yml in config folder where you can define your environment variables this file is by default in .gitignore file.For production you need to manually copy that file to server for security reason so that your sensitive information is not available to any one
First create your variable like:
MY_ENV_VAR="this is my var"
And then make it global:
export MY_ENV_VAR
You can check if the process succeeded with:
printenv
Or:
echo MY_ENV_VAR

How to see the value of rails environment variables on production server

I'm currently trying to troubleshoot an issue on a production server for a rails app and have realised I don't know how to view the values of certain environment variables being used by the application.
I'm using figaro to store things such as the devise secret key but need to make sure that the value is correct for the instance of my app that is running.
I'm looking for something along the lines of
echo $MY_DEVISE_KEY
I understand that I can access figaro's variables from inside the rails console but would that be a different instance?
Also, I'm using ubuntu server and nginx to serve my app.
Thanks in advance
Have you tried
printenv
and you can search for a specific env variable like
printenv | grep foo

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