envi

envi

A CLI for managing application configuration backed by DynamoDB

Installation

With a working Golang installation run the following command:

go get github.com/tskinn/envi

Also, make sure that $GOPATH/bin is in your $PATH so that your shell can find the go binaries.

Configuration

Since envi is backed by a DynamoDB table, the DynamoDB table must exist before using envi. By default envi will try to use a table named "envi" located in the "us-east-1" region.

The only other thing required before using envi is valid credentials and permissions to the DynamodDB table. You can provide an AWS Access Key ID and Access Key Secret via environment variables but the most convenient way is to have AWS configigured locally through the AWS CLI.

Environment variables ENVI_TABLE and ENVI_REGION can be used to change the default DynamoDB table and AWS region or they can be set with a flag.

Usage

NAME:
   envi

USAGE:
   envi set --application myapp --environment dev --variables=one=eno,two=owt,three=eerht
   envi s -a myapp -e dev -v one=eno,two=owt,three=eerht
   envi s -i myapp__dev -f path/to/file/with/exported/vars
   envi g -a myapp -e dev -o json

VERSION:
   0.0.0

DESCRIPTION:
   A simple application configuration store cli backed by dynamodb

COMMANDS:
     set, s     save application configuraton in dynamodb
     get, g     get the application configuration for a particular application
     update, u  update an applications configuration by inserting new vars and updating old vars if specified
     delete, d  delete the application configuration for a particular application
     help, h    Shows a list of commands or help for one command

GLOBAL OPTIONS:
   --help, -h     show help
   --version, -v  print the version

Commands

get

The get command is self expalatory. Besides the default output format (simple key=value) there are two other options: json and sh. The json option prints an array of objects containg and name and value (this is the format used in AWS ECS Task Definition templates). The sh option is the same as the regulare output but export is added to the beginning of each line so as to more convenient in using the env vars in a cli.

NAME:
   envi get - get the application configuration for a particular application

USAGE:
   envi get [command options] [arguments...]

OPTIONS:
   --output value, -o value       format of the output of the variables (default: "text")
   --table value, -t value        name of the dynamodb to store values (default: "envi") [$ENVI_TABLE]
   --region value, -r value       name of the aws region in which dynamodb table resides (default: "us-east-1") [$ENVI_REGION]
   --id value, -i value           id of the application environment combo; if id is not provided then application__environment is used as the id
   --application value, -a value  name of the application
   --environment value, -e value  name of the environment

set

Use with CAUTION.

Use set to create new configurations. Set overrides all variables so if one attempts to set a config with only one variable, all current variables will be deleted and replaced with the single new variable.

If not creating a new config, it is better to use the update command.

NAME:
   envi set - save application configuraton in dynamodb

USAGE:
   envi set [command options] [arguments...]

OPTIONS:
   --variables value, -v value    env variables to store in the form of key=value,key2=value2,key3=value3
   --file value, -f value         path to a shell file that exports env vars
   --table value, -t value        name of the dynamodb to store values (default: "envi") [$ENVI_TABLE]
   --region value, -r value       name of the aws region in which dynamodb table resides (default: "us-east-1") [$ENVI_REGION]
   --id value, -i value           id of the application environment combo; if id is not provided then application__environment is used as the id
   --application value, -a value  name of the application
   --environment value, -e value  name of the environment

update

The update command will override provided variables while leaving current variables untouched.

Here is an example of how to update a single variable:

envi u -i omega__staging -v OLD_VAR=new-value

The above command will replace the OLD_VAR value with "new-value" and leave all other unmentioned variables untouched.

NAME:
   envi update - update an applications configuration by inserting new vars and updating old vars if specified

USAGE:
   envi update [command options] [arguments...]

OPTIONS:
   --variables value, -v value    env variables to store in the form of key=value,key2=value2,key3=value3
   --file value, -f value         path to a shell file that exports env vars
   --table value, -t value        name of the dynamodb to store values (default: "envi") [$ENVI_TABLE]
   --region value, -r value       name of the aws region in which dynamodb table resides (default: "us-east-1") [$ENVI_REGION]
   --id value, -i value           id of the application environment combo; if id is not provided then application__environment is used as the id
   --application value, -a value  name of the application
   --environment value, -e value  name of the environment

delete

The delete command will delete variables from a config if variables are provided. If no variables are provided the entire config will be deleted.

When deleting variables provide only the names of the variables to be deleted. The same goes for files containing the env vars. The file should only have the names of the vars to be deleted.

NAME:
   envi delete - delete the application configuration for a particular application

USAGE:
   envi delete [command options] [arguments...]

OPTIONS:
   --variables value, -v value    env variables to delete in the form of key=value,key2=value2,key3=value3
   --file value, -f value         path to a shell file that contains env vars
   --table value, -t value        name of the dynamodb to store values (default: "envi") [$ENVI_TABLE]
   --region value, -r value       name of the aws region in which dynamodb table resides (default: "us-east-1") [$ENVI_REGION]
   --id value, -i value           id of the application environment combo; if id is not provided then application__environment is used as the id
   --application value, -a value  name of the application
   --environment value, -e value  name of the environment

Testing

There is a script to run the go tests and to test the basic functionality of envi called run_tests.sh. This script assumes privileged AWS credentials are setup in the environment. From the root of the project simply run:

bash run_tests.sh

To just run go tests:

cd store
go test