feat(chezmoi): add env_vars option for setting fixed environment variables

Adds a semicolon-separated KEY=VALUE option that appends export statements
to /etc/bash.bashrc and /etc/zsh/zshenv at build time, following the same
pattern as persist-shell-history.

Author: ckagerer

src/chezmoi/README.md

@@ -17,6 +17,8 @@ This feature does not install Atuin, Starship, or shell themes. Those tools must
 
 To persist Atuin history across rebuilds, combine this feature with [persist-shell-history](../persist-shell-history/).
 
+If `env_vars` is set, the key-value pairs are exported as environment variables in every shell session (bash and zsh) via the system-wide shell config files.
+
 ## Example Usage
 
 ```json
@@ -27,6 +29,17 @@ To persist Atuin history across rebuilds, combine this feature with [persist-she
 }
 ```
 
+## Example With Environment Variables
+
+```json
+"features": {
+    "ghcr.io/ckagerer/devcontainer-features/chezmoi:1": {
+        "dotfiles_repo": "twpayne/dotfiles",
+        "env_vars": "MY_VAR=hello;OTHER_VAR=world"
+    }
+}
+```
+
 ## Example With Atuin
 
 ```json

src/chezmoi/devcontainer-feature.json

@@ -34,6 +34,11 @@
             "type": "boolean",
             "default": false,
             "description": "Ignore errors during setup and continue execution."
+        },
+        "env_vars": {
+            "type": "string",
+            "default": "",
+            "description": "Semicolon-separated KEY=VALUE pairs to export as environment variables (e.g. MY_VAR=hello;OTHER=world)."
         }
     },
     "postCreateCommand": "/usr/local/share/chezmoi-atuin-init.sh",

src/chezmoi/install.sh

@@ -165,4 +165,24 @@ sed -i \
 
 chmod 755 "$INIT_ATUIN_SCRIPT_PATH"
 
+apply_env_vars() {
+  [ -z "${ENV_VARS:-}" ] && return 0
+
+  if [ -f /etc/bash.bashrc ] && ! grep -q "# chezmoi-env-vars" /etc/bash.bashrc; then
+    printf "\n# chezmoi-env-vars\n" >>/etc/bash.bashrc
+    printf '%s' "${ENV_VARS}" | tr ';' '\n' | while IFS= read -r pair; do
+      [ -n "${pair}" ] && printf 'export %s\n' "${pair}" >>/etc/bash.bashrc
+    done
+  fi
+
+  if [ -d /etc/zsh ] && ! grep -q "# chezmoi-env-vars" /etc/zsh/zshenv 2>/dev/null; then
+    printf "\n# chezmoi-env-vars\n" >>/etc/zsh/zshenv
+    printf '%s' "${ENV_VARS}" | tr ';' '\n' | while IFS= read -r pair; do
+      [ -n "${pair}" ] && printf 'export %s\n' "${pair}" >>/etc/zsh/zshenv
+    done
+  fi
+}
+
+apply_env_vars
+
 echo "Done"

test/chezmoi/env_vars.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+set -e
+
+source dev-container-features-test-lib
+
+check "CHEZMOI_TEST_VAR exported in bash" bash -c 'source /etc/bash.bashrc && [ "${CHEZMOI_TEST_VAR}" = "hello" ]'
+check "CHEZMOI_OTHER_VAR exported in bash" bash -c 'source /etc/bash.bashrc && [ "${CHEZMOI_OTHER_VAR}" = "world" ]'
+
+reportResults

test/chezmoi/scenarios.json

@@ -1,4 +1,20 @@
 {
+    "env_vars": {
+        "image": "ubuntu:jammy",
+        "features": {
+            "ghcr.io/devcontainers/features/common-utils:1": {
+                "installZsh": false,
+                "installOhMyZsh": false,
+                "upgradePackages": false,
+                "username": "octocat"
+            },
+            "chezmoi": {
+                "dotfiles_repo": "twpayne/dotfiles",
+                "env_vars": "CHEZMOI_TEST_VAR=hello;CHEZMOI_OTHER_VAR=world"
+            }
+        },
+        "remoteUser": "octocat"
+    },
     "test": {
         "image": "ubuntu:jammy",
         "features": {