Colo: Refactor remote command dispatch for create and delete (#7092)

* Colo: Dump escaping mess in remote script templates

* Colo: Rename script templates so shellcheck can get 'em

* shellcheck and nits

* Brace all of the things

* Consistent heredoc tags

* Use bash built-in square bracketing consistently

* simplify logic

net/scripts/colo-node-onacquire.sh

@@ -0,0 +1,50 @@
+#!/usr/bin/env bash
+
+# These variable must be set before the main body is called
+SOLANA_LOCK_FILE="${SOLANA_LOCK_FILE:?}"
+INSTANCE_NAME="${INSTANCE_NAME:?}"
+SSH_AUTHORIZED_KEYS="${SSH_AUTHORIZED_KEYS:?}"
+SSH_PRIVATE_KEY_TEXT="${SSH_PRIVATE_KEY_TEXT:?}"
+SSH_PUBLIC_KEY_TEXT="${SSH_PUBLIC_KEY_TEXT:?}"
+NETWORK_INFO="${NETWORK_INFO:-"Network info unavailable"}"
+CREATION_INFO="${CREATION_INFO:-"Creation info unavailable"}"
+
+if [[ ! -f "${SOLANA_LOCK_FILE}" ]]; then
+  exec 9>>"${SOLANA_LOCK_FILE}"
+  flock -x -n 9 || ( echo "Failed to acquire lock!" 1>&2 && exit 1 )
+  SOLANA_USER="${SOLANA_USER:?"SOLANA_USER undefined"}"
+  {
+    echo "export SOLANA_LOCK_USER=${SOLANA_USER}"
+    echo "export SOLANA_LOCK_INSTANCENAME=${INSTANCE_NAME}"
+    echo "[[ -v SSH_TTY -a -f \"${HOME}/.solana-motd\" ]] && cat \"${HOME}/.solana-motd\" 1>&2"
+  } >&9
+  exec 9>&-
+  cat > /solana-scratch/id_ecdsa <<EOF
+${SSH_PRIVATE_KEY_TEXT}
+EOF
+  cat > /solana-scratch/id_ecdsa.pub <<EOF
+${SSH_PUBLIC_KEY_TEXT}
+EOF
+  chmod 0600 /solana-scratch/id_ecdsa
+  cat > /solana-scratch/authorized_keys <<EOF
+${SSH_AUTHORIZED_KEYS}
+${SSH_PUBLIC_KEY_TEXT}
+EOF
+  cp /solana-scratch/id_ecdsa "${HOME}/.ssh/id_ecdsa"
+  cp /solana-scratch/id_ecdsa.pub "${HOME}/.ssh/id_ecdsa.pub"
+  cp /solana-scratch/authorized_keys "${HOME}/.ssh/authorized_keys"
+  cat > "${HOME}/.solana-motd" <<EOF
+
+
+${NETWORK_INFO}
+${CREATION_INFO}
+EOF
+
+  # Stamp creation MUST be last!
+  touch /solana-scratch/.instance-startup-complete
+else
+  # shellcheck disable=SC1090
+  exec 9<"${SOLANA_LOCK_FILE}" && flock -s 9 && . "${SOLANA_LOCK_FILE}" && exec 9>&-
+  echo "${INSTANCE_NAME} candidate is already ${SOLANA_LOCK_INSTANCENAME}" 1>&2
+  false
+fi