nodeintegration/denv repository overview

⁠denv (docker environment)

⁠Requirements

• Docker installed and running with your intended user in the docker group (ie you can run docker commands as your intended user)

⁠Requirements (optional)

• yq (python yq, basically jq for yaml) If this is not installed in the current path, it will process .denv.yml config using yq within the denv container

⁠How it works?

These images give you a nice wrapper to run arbitrary commands as well as all of the nodeintegration/denv-* image commands inside a container as if it was a local binary

$ source /dev/stdin <<< "$(docker run nodeintegration/denv:latest boot)"
Binding to tag: latest

What this command does is give a denv function in bash:

$ type denv| grep function
denv is a function
$ type denv| grep function
denv-init is a function

If you are curious what this is exactly doing before you load it into your shell:

$ docker run nodeintegration/denv:latest cat /usr/local/bin/boot
$ docker run nodeintegration/denv:latest cat /workspace/bootstrap

What this denv function does is create a wrapper to run the first argument to denv as a container. By default the command will run inside the denv container with your current working directory mounted to /workspace. It is also run as your current uid/gid

$ cat /etc/issue
Ubuntu 18.04.2 LTS \n \l

$ denv cat /etc/issue
Welcome to Alpine Linux 3.9
Kernel \r on an \m (\l)

⁠.denv.yml

This configuration file for denv allows you to commit specific versions of commands you use within a repository perhaps or on your CI/CD system at the commit level It is evaulated per command

⁠Commands run as different docker images/tags

This is where it gets fun. The function denv looks for a file .denv.yml in your current working directory It then looks for a key: commands: and then if there is a sub key called the first argument you supply to denv ie:

cat .denv.yml
commands:
  bash:

denv will then change the docker run image to be bash for the command bash with the tag of latest

Then lets say i want to run an image that doesnt match the command:

commands:
  terraform:
    image: hashicorp/terraform

denv will then for the command terraform use the hashicorp/terraform image with the default tag of latest

...ok...ok but i want a specific tag not latest:

commands:
  terraform:
    image: hashicorp/terraform
    tag: 0.11.11

⁠I want environment variables passed to the commands run time

Easy peasy:

global:
  environment:
    FOO:
    BAR: baz

This will give you FOO and BAR as docker run environment variables It WILL use your current shells environment variables over the .denv.yml value e.g. with the above .denv.yml:

$ denv env | grep -E '^(FOO|BAR)'
BAR="baz"
FOO=""

$ FOO="bar" denv env | grep -E '^(FOO|BAR)'
BAR="baz"
FOO=bar

⁠I want to make sure i have all expected images for commands at the current upstream tag

denv-init

This will scour your .denv.yml for all commands and what images/tags they want and do a docker pull on them