add readme

Author: anthony-nhs

README.md

@@ -0,0 +1,54 @@
+EPS DEV CONTAINERS
+==================
+
+# Introduction
+This repo contains code to build a vscode devcontainer that is used as a base image for all EPS projects.   
+Images are build for amd64 and arm64 and a manifest file created that can be pulled for both architectures.   
+Images are based on mcr.microsoft.com/devcontainers/base:ubuntu-22.04
+Images contain
+ - latest os packages
+ - asdf
+ - aws cli
+ - aws sam cli
+
+ It installs the following dev container features
+ - docker outside of docker
+ - github cli
+
+As the vscode user the following also happens
+
+asdf install and setup for these so they are available globally as vscode user
+ - shellcheck
+ - direnv
+ - actionlint
+ - ruby (for github pages)
+ - trivy
+
+Install asdf plugins for all tools we use
+Install asdf versions of node, python, java, terraform, golang used by all EPS projects to speed up initial build of local dev container
+Install and setup git-secrets
+
+# Project structure
+The dev container is defined in src/base/.devcontainer folder. This folder contains a Dockerfile and a devcontainer.json file which is used to build the container
+
+The dev container is built using https://github.com/devcontainers/cli
+
+The script `scripts/generate_language_version_files.sh` gets the version of node, python, java and terraform from all EPS repositories. It uses the list of repos from https://github.com/NHSDigital/eps-repo-status/blob/main/repos.json to find all EPS repos.
+
+# Build process
+Docker images are built for each pull request, and on merges to main
+
+Docker images are scanned for vulnerabilities using trivy as part of a build step, and the build fails if vulnerabilities are found not in .trivyignore file.
+   
+On merges to main, a new release is created and the images are pushed to github. The images are tagged with `latest` and the version of the release.
+
+# Local testing
+For local testing, you can run
+```
+ARCHITECTURE=amd64 make build-base-image
+``` 
+to build a local image, and then
+```
+make scan-base-image
+```
+to scan for vulnerabilities

src/base/.devcontainer/devcontainer.json

@@ -1,7 +1,7 @@
 // For format details, see https://aka.ms/devcontainer.json. For config options, see the
 // README at: https://github.com/devcontainers/templates/tree/main/src/ubuntu
 {
-    "name": "Ubuntu",
+    "name": "EPS Devcontainer Base",
     // Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
     "build": {
       "dockerfile": "Dockerfile",