install-aws-server: Improve handling of various corner cases.

This script is pretty far from being polished, but it is useful, so we
might as well make it a bit more robust.

tools/setup/install-aws-server

@@ -52,7 +52,7 @@ if [ -z "$branch" ]; then
     branch=$(crudini --get "$zulip_ssh_config_file" repo default_branch)
 fi
 
-VIRTUALENV_NEEDED=$(if $(echo "$type" | grep -q ::app); then echo -n yes; else echo -n no; fi)
+VIRTUALENV_NEEDED=$(if $(echo "$type" | grep -q app_frontend); then echo -n yes; else echo -n no; fi)
 
 # Force RSA keys. We do this because the ECDSA key is not printed on syslog,
 # and our puppet configuration does not use ECDSA. If we don't do this,
@@ -64,7 +64,13 @@ set +e
 ssh "${SSH_OPTS[@]}" "$server" -t -i "$amazon_key_file" -lubuntu -o "ControlMaster=no" <<EOF
 sudo mkdir -p ~root/.ssh && sudo cp .ssh/authorized_keys /root/.ssh/authorized_keys
 sudo sed -i 's/disable_root: true/disable_root: false/' /etc/cloud/cloud.cfg
-mkdir -p /etc/zulip
+sudo mkdir -p /etc/zulip
+EOF
+ssh "${SSH_OPTS[@]}" "$server" -t -i "$amazon_key_file" -lroot <<EOF
+# Set the hostname early
+echo "$hostname" > /etc/hostname
+hostname "$hostname"
+sed -i 's/localhost$/localhost $hostname/' /etc/hosts
 EOF
 
 set -e
@@ -78,25 +84,29 @@ if [ -e "$zulipconf_file" ]; then
 fi
 
 ssh "${SSH_OPTS[@]}" "$server" -t -i "$amazon_key_file" -lroot <<EOF
+set -x
 # Finish setting up the SSH private key
 chmod 600 /root/.ssh/id_rsa
 # Delete the ubuntu user
-userdel ubuntu
+if grep -q '^ubuntu:' /etc/passwd; then
+    userdel ubuntu
+fi
 # Make sure root doesn't have a password
 passwd -d root
 
-# Set the hostname
-echo "$hostname" > /etc/hostname
-sed -i 's/localhost$/localhost $hostname/' /etc/hosts
-
 apt-get update
 apt-get -y upgrade
 
 cd "$(mktemp -d)"
+
+# Get GitHub known_hosts setup
+# TODO: Replace this with hardcoding the actual GitHub keys
+ssh -oStrictHostKeyChecking=no git@github.com </dev/null >/dev/null || true
+
 if ! [ -e "zulip" ]; then
     # need to install git to clone the repo
     apt-get install -y git crudini
-    git clone $zulip_repo
+    git clone "$zulip_repo" zulip
 fi
 cd zulip
 git fetch