Summary:Environment variables are very useful to store sensitive information in Node.js. Here is the tutorial to use environment variables in a secure way.
- Create Env File Nodejs
- Env Files For Appraisal
- Env File Viewer
- Create .env File React
- How To Create An Env File In Aci
- Microsoft Help File Creator
With Replit, you can create an.env file to safely store your secrets. This means you can safely share your code, without sharing your secrets.env Files.env files are used for declaring environment variables. On Replit,.env files are only visible to the owner of the repl. Now we can create.env file in the main directory of the application where package.json and nodemodules resides. The format of environment variables in.env files are name=value per line. PORT = 3000 DBCONNSTRING = someconnection@someuser.somedomain.com SENDGRIDAPI = fgdigydf78gyi5r4fgrf67347.
Environment variables are global variables which are available to use under env object of global process object in Node.js.
The operating system has also a set of environment variables which provides useful information globally.
printenv command shows all Unix OS environment variables.
Many hosting providers have built-in support to set environment variable right from the dashboard. This provides easier application management because we can update any Ports or expired API keys directly without touching the code.
What are Environment variables in Node.js?
Environment variables are pieces of information which are loaded into the process object for further use.
We can directly console.log(process.env) in Node.js REPL or in Node.js file to see all environment variables.
Whenever the Node.js process starts it automatically add environment variables in env object of global process object.
The environment variables are generally stored into .env file in the form of name='value' form.
When the application is initialized, these variables are loaded into process.env for global use into the application. We can access these variables from any application files.
Why use env file or environment variables with Node.js?
Env files store the environment variables. It is NEVER recommended to hard code sensitive information like API keys.
Suppose you created a TODO application which stores data in MongoDB and hardcoded the connection string (they are secure as passwords). Now you publicly shared the code on GitHub. Anyone who views your code can get the database connection string and abuse the resources.
Environment variables come to rescue in this case. We create a .env file and store the connection string in variables and exclude them from public sharing.
Create Env File Nodejs
Environment variables in .env file is a bit more secure (controversial topic) then hard coding. They are destroyed when the application terminates.
They also provide a single source to store sensitive information which we can use globally in our application.
Some peoples prefer to use a config file for this purpose but we need to manually import them in files to use them. It also removes the advantages to manage environment variables from the dashboard.
Node.js Environment Variables Configuration
Env Files For Appraisal
From command line
Prefix the Node.js start command with environment variables in the format name='value' to set environment variables during application start.
For example.
It will store a key PORT value 3000 pair into the env object of global process object in Node.js. To verify this we can console log the PORT variable form app.js file.
The problem with this approach is that we need to manually pass all variables everytime when starting the application. If we forget to pass a specific variable then it will make our application inconsistent.
Using .env file
This is the most common and recommended way of using environment variables in Node.js.
The process is very simple. We need to install dotenv from npm and use it in app.js index file.
In app.js or index.js file.
Now we can create .env file in the main directory of the application where package.json and node_modules resides.
The format of environment variables in .env files are name=value per line.
Note that files starting with . are hidden in UNIX based operation systems. You need to enable 'show hidden files' to view .env files.
Directly (Not Recommended)
It is also possible to set environment variables at runtime, but I don't know why you will do that.
It is never recommended to set environment variables in this way.
Summary
This was the whole thing about environment variables in Node.js. To summarize we can say that environment variables are a better way to store sensitive information in one place.
We can easily exclude them while sharing the application and tell users to create their own .env files with their own specific data like API keys.
Several web hosts provide a way to set environment variables directly from the dashboard.
Here are some common items which we generally store in .env files.
- API keys
- PORT information to run the application
- Database connection strings
- Important usernames and passwords
dump-env takes an .env.template file and some optional environmental variables to create a new .env file from these two sources. No external dependencies are used.
Why?¶
Why do we need such a tool? Well, this tool is very helpful when your CI is building docker (or other) images.Previously we had some complex logic of encrypting and decrypting files, importing secret keys and so on.Now we can just create secret variables for our CI, add some prefix to it, and use dump-env to make our life easier.
Installation¶
Quickstart¶
This quick demo will demonstrate the main and the only purpose of dump-env:
Env File Viewer
This command will:
take
.env.templateparse its keys and values
read all the variables from the environment starting with
SECRET_ENV_remove this prefix
mix it all together, environment vars may override ones from the template
sort keys in alphabetic order
dump all the keys and values into the
.envfile
Advanced Usage¶
Multiple prefixes¶
Create .env File React
This command will do pretty much the same thing as with one prefix. But, it will replace multiple prefixes.Further prefixes always replace previous ones if they are the same.For example:
Strict env variables¶
In case you want to be sure that YOUR_VAR existsin your environment when dumping, you can use --strict flag:
Oups! We forgot to create it! Now this will work:
Any number of --strict flags can be provided.No more forgotten template overrides or missing env vars!
Source templates¶
You can use an env template as a source template by using the -s or --source argument. This will restrict any non-prefixed variables found in the environment to only those already defined in your template.
You can still also use prefixes to add extra variables from the environment
Strict Source¶
Using the --strict-source flag has the same effect as defining a --strict flag for every variable defined in the source template.
Creating secret variables in some CIs¶
Real-world usages¶
Projects that use this tool in production:
Related¶
You might also be interested in:
License¶
API Reference¶
dump(template:str=', prefixes:Optional[List[str]]=None, strict_keys:Optional[Set[str]]=None, source:str=', strict_source:bool=False) → Dict[str, str][source]¶This function is used to dump .env files.
As a source you can use both:1. env.template file (' by default)2. env vars prefixed with some prefix (' by default)
Env Files For Appraisal
From command line
Prefix the Node.js start command with environment variables in the format name='value' to set environment variables during application start.
For example.
It will store a key PORT value 3000 pair into the env object of global process object in Node.js. To verify this we can console log the PORT variable form app.js file.
The problem with this approach is that we need to manually pass all variables everytime when starting the application. If we forget to pass a specific variable then it will make our application inconsistent.
Using .env file
This is the most common and recommended way of using environment variables in Node.js.
The process is very simple. We need to install dotenv from npm and use it in app.js index file.
In app.js or index.js file.
Now we can create .env file in the main directory of the application where package.json and node_modules resides.
The format of environment variables in .env files are name=value per line.
Note that files starting with . are hidden in UNIX based operation systems. You need to enable 'show hidden files' to view .env files.
Directly (Not Recommended)
It is also possible to set environment variables at runtime, but I don't know why you will do that.
It is never recommended to set environment variables in this way.
Summary
This was the whole thing about environment variables in Node.js. To summarize we can say that environment variables are a better way to store sensitive information in one place.
We can easily exclude them while sharing the application and tell users to create their own .env files with their own specific data like API keys.
Several web hosts provide a way to set environment variables directly from the dashboard.
Here are some common items which we generally store in .env files.
- API keys
- PORT information to run the application
- Database connection strings
- Important usernames and passwords
dump-env takes an .env.template file and some optional environmental variables to create a new .env file from these two sources. No external dependencies are used.
Why?¶
Why do we need such a tool? Well, this tool is very helpful when your CI is building docker (or other) images.Previously we had some complex logic of encrypting and decrypting files, importing secret keys and so on.Now we can just create secret variables for our CI, add some prefix to it, and use dump-env to make our life easier.
Installation¶
Quickstart¶
This quick demo will demonstrate the main and the only purpose of dump-env:
Env File Viewer
This command will:
take
.env.templateparse its keys and values
read all the variables from the environment starting with
SECRET_ENV_remove this prefix
mix it all together, environment vars may override ones from the template
sort keys in alphabetic order
dump all the keys and values into the
.envfile
Advanced Usage¶
Multiple prefixes¶
Create .env File React
This command will do pretty much the same thing as with one prefix. But, it will replace multiple prefixes.Further prefixes always replace previous ones if they are the same.For example:
Strict env variables¶
In case you want to be sure that YOUR_VAR existsin your environment when dumping, you can use --strict flag:
Oups! We forgot to create it! Now this will work:
Any number of --strict flags can be provided.No more forgotten template overrides or missing env vars!
Source templates¶
You can use an env template as a source template by using the -s or --source argument. This will restrict any non-prefixed variables found in the environment to only those already defined in your template.
You can still also use prefixes to add extra variables from the environment
Strict Source¶
Using the --strict-source flag has the same effect as defining a --strict flag for every variable defined in the source template.
Creating secret variables in some CIs¶
Real-world usages¶
Projects that use this tool in production:
Related¶
You might also be interested in:
License¶
API Reference¶
dump(template:str=', prefixes:Optional[List[str]]=None, strict_keys:Optional[Set[str]]=None, source:str=', strict_source:bool=False) → Dict[str, str][source]¶This function is used to dump .env files.
As a source you can use both:1. env.template file (' by default)2. env vars prefixed with some prefix (' by default)
template – The path of the
.envtemplate file,use an empty string when there is no template file.prefixes – List of string prefixes to use only certain envvariables, could be an empty string to use all available variables.
strict_keys – List of keys that must be presented in env vars.
source – The path of the
.envtemplate file,defines the base list of env vars that should be checked,disables the fetching of non-prefixed env vars,use an empty string when there is no source file.strict_source – Whether all keys in source template must also bepresented in env vars.
Ordered key-value pairs of dumped env and template variables.
StrictEnvException – when some variable from template is missing.
main() → NoReturn[source]¶Runs dump-env script.
How To Create An Env File In Aci
Example
This example will dump all environ variables:
This example will dump all environ variables starting with PIP_:
This example will dump all environ variables starting with PIP_and update them with variables starting with SECRET_:
Microsoft Help File Creator
This example will dump everything from .env.template fileand all env variables with SECRET_ prefix into a .env file:
This example will fail if REQUIRED does not exist in environ:
This example will dump everything from a source .env.template filewith only env variables that are defined in the file:
This example will fail if any keys in the source template do not existin the environment:
