Nova is a file-based environment variable manager. A logical group of variables is referred to as a profile which can be evaluated by Nova to eventually land in your [program's] environment.
A profile is a regular directory containing a file for each environment variable it provides:
test/profiles/default
├── 10-CONSUL_HTTP_ADDR
├── 10-CONSUL_HTTP_DATACENTER
└── 20-CONSUL_PATH
Unlike .env files, the values of these variables are computed by scripts so
they are not limited to static values. Additionally, the order in which Nova
evaluates the scripts can be controlled to compute dependent values.
Because profiles are directories of files, syncing them between multiple machines and sharing them with others is easy.
Download the bin/nova script to somewhere in your $PATH, or use Git:
git clone https://github.com/amireh/nova ~/.nova &&
echo 'export PATH="$HOME/.nova/bin:$PATH"' >> ~/.profileRemember to restart your shell to reflect the change to PATH.
nova [-p|--profile DIR]
[--no-rc] [--debug] [--export]
[--]
[program...]
A profile must be specified either on the command-line with -p or in the file
.novarc. When it is not specified, or does not exist, Nova exits with 1.
The name of the profile to use or a full path to it. Profiles are available in
$NOVA_DIR/profiles.
Load values from a file like .env (dotenv) if it's present. This will load
values only for the variables listed in the profile.
Precedence goes to:
- variables in the current environment
- variables in an evaluated file
- variables in the profile
Do not look for and use the .novarc file.
Do not bail if an environment variable is already set, but instead override it with the profile value.
Stop parsing Nova command-line parameters and forward to the program. Use this if an Nova parameter conflicts with a parameter of the program you want to run.
The program to execute with the loaded profile. When omitted, Nova will print the current profile values and exit with 0.
program can be your shell program (like bash) if you want to drop into a
shell with the profile loaded.
A profile is a directory under $NOVA_DIR/profiles containing a shell script
for each environment variable. The script must print the value to the special
file descriptor 3:
echo my_value >&3
Files are evaluated by lexicographical order -- you can control their evaluation
order by prefixing their names with digits followed by a dash (-) and Nova
will strip that prefix from the variable name.
In the following example profile, the scripts for VAULT_TOKEN and
CONSUL_HTTP_TOKEN will have access to the values of the variables before them:
.nova
└── profiles
└── default
├── 10-CONSUL_HTTP_ADDR
├── 10-CONSUL_HTTP_DATACENTER
├── 10-VAULT_ADDR
├── 10-VAULT_USER
├── 20-VAULT_TOKEN
└── 30-CONSUL_HTTP_TOKEN
To disable a variable without removing its file, suffix its filename with tilde
(~).
Nova will look for a file named .novarc starting from the current directory
($PWD) all the way up to the root folder. When present, that file may contain
command-line options for Nova such as --profile.
You can disable this behavior by passing --no-rc.
Since profiles are regular directories and files, you can use any archiver such
as tar to share them with others.
For example, to share the profile abc with someone, I would first archive it:
tar -C ~/.nova -cf ~/nova-abc.tar ./profiles/abc
Then upload it somewhere, ask the person to download it and to install it as such:
tar -C "${NOVA_DIR:-$HOME/.nova}" -xf nova-abc.tar
- Added option to override variables already present in the environment
- Fixed a bug that was causing the env tempfile to behave as a pipe on Bash 5.1. Temporary env file is now explicitly created as a file, as Bash 5.1+ may now create here-docs as pipes instead of files. See note "c." in http://git.savannah.gnu.org/cgit/bash.git/plain/NEWS?h=bash-5.1.
- Nova version is now displayed in the help listing.