docker/: install rootful Docker; gate kind on it

kind never worked reliably against rootless Docker on Kasm, even with the
cgroup delegation from docker-rootless-cgroup/. So install full Docker
where we can, and flip bin/'s kind gate from "rootless is available" to
"a rootful daemon answers" — kind is simply skipped on Kasm now.

docker/install.sh no-ops when a rootless daemon is already running so it
never fights Kasm's setup. It runs before bin/ in bootstrap so the kind
gate can see the daemon it just started. zsh/zshrc re-execs via newgrp
when the account gained the docker group but the live shell predates it.

docker-rootless-cgroup/ keeps its delegation (still useful for
per-container resource limits); only its kind-centric comments change.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

bin/install.sh

@@ -20,13 +20,15 @@ REPO_ROOT="$(dirname -- "$SCRIPT_DIR")"
 ARCH="$(fetch_arch)"       # x86_64 / aarch64
 DEB="$(fetch_arch_deb)"    # amd64 / arm64
 
-# docker_rootless_available — true only if a rootless Docker daemon is up and
-# reachable. kind needs a container runtime to create clusters; on Kasm we run
-# Docker rootless (never system Docker), so kind is worth installing only when
-# that daemon answers. SecurityOptions lists name=rootless under rootless mode.
-docker_rootless_available() {
+# docker_full_available — true only if a non-rootless (full) Docker daemon is
+# up and reachable. kind needs full Docker: we could not get it working against
+# rootless Docker on Kasm, so it is only worth installing where a rootful
+# daemon answers. SecurityOptions lists name=rootless under rootless mode.
+docker_full_available() {
   command -v docker >/dev/null 2>&1 || return 1
-  docker info -f '{{println .SecurityOptions}}' 2>/dev/null | grep -q 'name=rootless'
+  _secopts="$(docker info -f '{{println .SecurityOptions}}' 2>/dev/null)" || return 1
+  [ -n "$_secopts" ] || return 1
+  ! printf '%s' "$_secopts" | grep -q 'name=rootless'
 }
 
 # jq — command-line JSON processor (single static binary).
@@ -68,9 +70,8 @@ install_k9s() {
 }
 
 # kind — run local Kubernetes clusters in Docker (single static binary). Gated
-# on rootless Docker at the call site since it is useless without a runtime.
-# On systemd-less hosts the rootless daemon also needs cgroup delegation before
-# kind can create clusters; see the docker-rootless-cgroup/ module.
+# on full (non-rootless) Docker at the call site: kind could not be made to
+# work against rootless Docker on Kasm, so it is skipped there.
 install_kind() {
   ver=v0.32.0
   have_version kind "$ver" && { fsay "kind $ver already installed."; return 0; }
@@ -150,10 +151,10 @@ install_jq
 install_kubectl
 install_helm
 install_k9s
-if docker_rootless_available; then
+if docker_full_available; then
   install_kind
 else
-  fsay "Skipping kind: rootless Docker not available."
+  fsay "Skipping kind: full (non-rootless) Docker not available."
 fi
 install_kubectx
 install_kubens

bootstrap.sh

@@ -31,6 +31,8 @@ fi
 
 "$SCRIPT_DIR/zsh/install.sh"
 "$SCRIPT_DIR/git/install.sh"
+# Runs before bin/ so the kind install gate can see the rootful daemon.
+"$SCRIPT_DIR/docker/install.sh"
 "$SCRIPT_DIR/bin/install.sh"
 "$SCRIPT_DIR/ansible/install.sh"
 # Runs last: needs rootless Docker already up (started at boot) so it can

docker-rootless-cgroup/install.sh

@@ -1,7 +1,10 @@
 #!/usr/bin/env sh
 # docker-rootless-cgroup/install.sh — give rootless Docker cgroup v2 controller
-# delegation on a systemd-less host (e.g. Kasm), so per-container cgroups work
-# and `kind` can create clusters.
+# delegation on a systemd-less host (e.g. Kasm), so per-container cgroups work.
+# (This was originally done to support `kind`, but kind never worked reliably
+# against rootless Docker even with delegation — bin/ now only installs kind
+# where full Docker is available. The delegation itself is still useful for
+# per-container resource limits.)
 #
 # Why: rootless Docker only receives delegated cgroup v2 controllers when
 # systemd sets `Delegate=yes` on the user session. Kasm images run no systemd
@@ -117,7 +120,7 @@ cat > "$tmp" <<'SH'
 #!/bin/sh
 # Managed by dotfiles (docker-rootless-cgroup). Shadows /usr/bin/dockerd-rootless.sh
 # on PATH. Places the rootless Docker daemon in a private, delegated cgroup v2
-# leaf so it can enable controllers (needed by `kind`), then execs the real
+# leaf so it can enable controllers (per-container cgroups), then execs the real
 # launcher. No-op if the delegated slice is absent, so it is safe anywhere.
 _cg=/sys/fs/cgroup/rootless/daemon
 if [ -w /sys/fs/cgroup/rootless ] && [ -d "$_cg" ]; then
@@ -156,9 +159,9 @@ done
 driver="$(docker info -f '{{.CgroupDriver}}' 2>/dev/null || true)"
 if [ "$driver" = "none" ] || [ -z "$driver" ]; then
   say "docker-rootless-cgroup: WARNING — CgroupDriver is still '${driver:-unreachable}'."
-  say "  kind will not work yet. Inspect the new dockerd's cgroup:"
+  say "  Per-container cgroups will not work yet. Inspect the new dockerd's cgroup:"
   say "    cat /proc/\$(pgrep -x dockerd | head -1)/cgroup   # expect .../rootless/daemon"
   exit 0
 fi
 say "docker-rootless-cgroup: done. CgroupDriver=$driver — rootless Docker now has"
-say "  delegated cgroups; \`kind create cluster\` can run."
+say "  delegated cgroups; per-container resource limits work."

docker/install.sh

@@ -0,0 +1,62 @@
+#!/usr/bin/env sh
+# docker/install.sh — install full (rootful) Docker Engine and let the
+# invoking user talk to it without sudo.
+#
+# What it does:
+#   1. Installs Docker Engine via Docker's official convenience script
+#      (get.docker.com — supports both RHEL- and Debian-family distros and
+#      sets up the upstream package repo). Skipped when `docker` is already
+#      installed.
+#   2. Enables and starts the service (systemd hosts only).
+#   3. Adds the invoking user to the `docker` group so the daemon socket is
+#      usable without sudo. Takes effect at next login.
+#
+# Deliberately no-ops when a rootless Docker daemon is detected (e.g. Kasm
+# ships its own rootless setup) — installing rootful Docker there would fight
+# the existing runtime. See docker-rootless-cgroup/ for the Kasm-side config.
+#
+# Idempotent and safe to re-run. Uses sudo.
+set -eu
+
+say() { printf '%s\n' "$*" >&2; }
+
+# --- skip on rootless-Docker hosts -------------------------------------------
+if command -v docker >/dev/null 2>&1 &&
+   docker info -f '{{println .SecurityOptions}}' 2>/dev/null | grep -q 'name=rootless'; then
+  say "docker: rootless Docker daemon detected; leaving it alone."
+  exit 0
+fi
+
+# --- 1. install engine -------------------------------------------------------
+if command -v docker >/dev/null 2>&1; then
+  say "docker: engine already installed ($(docker --version 2>/dev/null || echo 'version unknown'))."
+else
+  say "docker: installing Docker Engine via get.docker.com..."
+  tmp="$(mktemp)"
+  if command -v curl >/dev/null 2>&1; then
+    curl -fsSL https://get.docker.com -o "$tmp"
+  elif command -v wget >/dev/null 2>&1; then
+    wget -qO "$tmp" https://get.docker.com
+  else
+    say "docker: need curl or wget"; exit 1
+  fi
+  sudo sh "$tmp"
+  rm -f "$tmp"
+fi
+
+# --- 2. enable + start the service (systemd only) ----------------------------
+if [ -d /run/systemd/system ] && command -v systemctl >/dev/null 2>&1; then
+  sudo systemctl enable --now docker
+else
+  say "docker: no systemd; not managing the service (start dockerd yourself)."
+fi
+
+# --- 3. group membership for the invoking user -------------------------------
+user="$(id -un)"
+if id -nG "$user" | tr ' ' '\n' | grep -qx docker; then
+  say "docker: $user already in the docker group."
+else
+  sudo usermod -aG docker "$user"
+  say "docker: added $user to the docker group."
+  say "  Log out and back in (or run 'newgrp docker') for it to take effect."
+fi

zsh/zshrc

@@ -2,6 +2,19 @@
 # overwritten on the next bootstrap run. Edit zsh/zshrc in the dotfiles repo
 # instead.
 
+# If this account was added to the docker group (dotfiles/docker/install.sh)
+# but this shell's session predates that, re-exec via newgrp so docker works
+# without a full logout. Guarded: fires only when the group is on the account
+# yet missing from the running shell's groups, so the newgrp'd shell (which
+# has the group) cannot loop.
+# Only for real terminals ([ -t 0 ]): newgrp replaces the shell and would
+# swallow the command in scripted `zsh -i -c ...` invocations.
+if [ -t 0 ] && [ -S /var/run/docker.sock ] \
+   && id -nG "${USER:-$(id -un)}" 2>/dev/null | grep -qw docker \
+   && ! id -Gn 2>/dev/null | grep -qw docker; then
+  exec newgrp docker
+fi
+
 # Userland tools installed by dotfiles/bin/install.sh live here.
 case ":$PATH:" in
   *":$HOME/.local/bin:"*) ;;