add temp env script

temp-env.sh

@@ -0,0 +1,101 @@
+#!/usr/bin/env bash
+#
+# temp-env.sh
+# Spin up a throwaway Debian container, install packages, drop into a shell,
+# and clean up automatically when you exit.
+
+set -euo pipefail
+
+# ---- colors ----
+BOLD='\033[1m'
+CYAN='\033[0;36m'
+GREEN='\033[0;32m'
+YELLOW='\033[0;33m'
+RED='\033[0;31m'
+NC='\033[0m'
+
+info()  { echo -e "${CYAN}==>${NC} $1"; }
+ok()    { echo -e "${GREEN}✔${NC} $1"; }
+warn()  { echo -e "${YELLOW}!${NC} $1"; }
+err()   { echo -e "${RED}✘${NC} $1"; }
+
+# ---- sanity checks ----
+if ! command -v docker &>/dev/null; then
+    err "Docker isn't installed or isn't on PATH."
+    exit 1
+fi
+
+echo -e "${BOLD}Ephemeral Debian Environment${NC}"
+echo "--------------------------------"
+
+# ---- pick a debian tag ----
+read -rp "$(echo -e "${CYAN}?${NC} Debian tag [bookworm]: ")" TAG
+TAG="${TAG:-bookworm}"
+IMAGE="debian:${TAG}"
+
+# ---- packages to install ----
+read -rp "$(echo -e "${CYAN}?${NC} Packages to install (space-separated, blank for none): ")" PACKAGES
+
+# ---- optional extra apt flags ----
+read -rp "$(echo -e "${CYAN}?${NC} Extra apt-get flags (e.g. --no-install-recommends) [none]: ")" APT_FLAGS
+
+# ---- mount a local dir? ----
+read -rp "$(echo -e "${CYAN}?${NC} Mount a local directory into the container? (path or blank): ")" MOUNT_DIR
+MOUNT_ARGS=()
+if [[ -n "$MOUNT_DIR" ]]; then
+    if [[ -d "$MOUNT_DIR" ]]; then
+        MOUNT_ARGS=(-v "$(realpath "$MOUNT_DIR"):/mnt/host")
+        ok "Will mount $(realpath "$MOUNT_DIR") -> /mnt/host"
+    else
+        warn "Directory '$MOUNT_DIR' doesn't exist, skipping mount."
+    fi
+fi
+
+# ---- remove image after exit too? ----
+read -rp "$(echo -e "${CYAN}?${NC} Remove the image (${IMAGE}) after exiting, not just the container? [y/N]: ")" RM_IMAGE
+RM_IMAGE="${RM_IMAGE:-n}"
+
+# ---- build the in-container command ----
+if [[ -n "$PACKAGES" ]]; then
+    INNER_CMD="apt-get update && apt-get install -y ${APT_FLAGS} ${PACKAGES} && bash"
+else
+    INNER_CMD="apt-get update && bash"
+fi
+
+echo
+info "Image:      ${IMAGE}"
+info "Packages:   ${PACKAGES:-<none>}"
+info "Command:    ${INNER_CMD}"
+[[ -n "$MOUNT_DIR" && -d "$MOUNT_DIR" ]] && info "Mount:      $(realpath "$MOUNT_DIR") -> /mnt/host"
+echo
+
+read -rp "$(echo -e "${CYAN}?${NC} Launch now? [Y/n]: ")" CONFIRM
+CONFIRM="${CONFIRM:-y}"
+if [[ ! "$CONFIRM" =~ ^[Yy] ]]; then
+    warn "Aborted."
+    exit 0
+fi
+
+info "Pulling/starting container (this shell disappears on exit, --rm is set)..."
+echo "--------------------------------"
+
+set +e
+docker run --rm -it "${MOUNT_ARGS[@]}" "$IMAGE" bash -c "$INNER_CMD"
+EXIT_CODE=$?
+set -e
+
+echo "--------------------------------"
+ok "Container exited (code ${EXIT_CODE}) and was automatically removed."
+
+if [[ "$RM_IMAGE" =~ ^[Yy] ]]; then
+    info "Checking if any other containers still use ${IMAGE}..."
+    IN_USE=$(docker ps -a --filter ancestor="$IMAGE" -q)
+    if [[ -n "$IN_USE" ]]; then
+        warn "Other containers still reference ${IMAGE}, skipping removal:"
+        docker ps -a --filter ancestor="$IMAGE"
+    else
+        docker rmi "$IMAGE" && ok "Removed image ${IMAGE}."
+    fi
+fi
+
+ok "Done."