install: Move PUPPET_CLASSES env var to --puppet-classes argument.

`--no-init-db` is used to silence the need for `--hostname` and
`--email` arguments; it is a proxy for "this is not a frontend host."
We would ideally like to use `has_class` to know if the user's
provided puppet classes are include an `app_frontend`, and thus
`--hostname` and `--email` are required -- but doing that requires
several other steps, and we would like this feedback to be immediate.

We make the presence of `--puppet-classes` equivalent to
`--no-init-db`, since nearly every configuration with
`--puppet-classes` does not install both a database and a frontend,
which is what is required to initialize a database.

docs/production/deployment.md

@@ -199,7 +199,7 @@ For example, to install a Zulip Redis server on a machine, you can run
 the following after unpacking a Zulip production release tarball:
 
 ```bash
-env PUPPET_CLASSES=zulip::profile::redis ./scripts/setup/install
+./scripts/setup/install --puppet-classes zulip::profile::redis
 ```
 
 All puppet modules under `zulip::profile` are allowed to be configured
@@ -234,10 +234,10 @@ Follow the [standard instructions](install.md), with modified `install`
 arguments:
 
 ```bash
-export PUPPET_CLASSES=zulip::profile::standalone_nodb
 ./zulip-server-*/scripts/setup/install --certbot \
     --email=YOUR_EMAIL --hostname=YOUR_HOSTNAME \
-    --no-init-db --postgresql-missing-dictionaries
+    --puppet-classes=zulip::profile::standalone_nodb \
+    --postgresql-missing-dictionaries
 ```
 
 #### Step 2: Create the PostgreSQL database

scripts/lib/install

@@ -10,12 +10,14 @@ Usage:
 
 Options:
   --hostname=zulip.example.com
-      The user-accessible domain name for this Zulip server, i.e., what users will type
-      in their web browser.  Required, unless --no-init-db is set and --certbot is not.
+      The user-accessible domain name for this Zulip server, i.e.,
+      what users will type in their web browser.  Required, unless
+      --no-init-db or --puppet-classes is set, and --certbot is not.
+
   --email=zulip-admin@example.com
-      The email address of the person or team who should get support and error emails
-      from this Zulip server.  Required, unless --no-init-db is set and --certbot is
-      not.
+      The email address of the person or team who should get support
+      and error emails from this Zulip server.  Required, unless
+      --no-init-db or --puppet-classes is set and --certbot is not.
 
   --certbot
       Obtains a free SSL certificate for the server using Certbot,
@@ -37,9 +39,13 @@ Options:
   --postgresql-missing-dictionaries
       Set postgresql.missing_dictionaries, which alters the initial database.  Use with
       cloud managed databases like RDS.  Conflicts with --no-overwrite-settings.
+
   --no-init-db
       Does not do any database initialization; use when you already have a Zulip
       database.
+  --puppet-classes
+      Comma-separated list of Puppet classes to install; defaults to
+      'zulip:::profile::standalone'.  Implies --no-init-db.
 
   --no-overwrite-settings
       Preserve existing `/etc/zulip` configuration files.
@@ -119,6 +125,12 @@ while true; do
             NO_INIT_DB=1
             shift
             ;;
+        --puppet-classes)
+            PUPPET_CLASSES="$2"
+            NO_INIT_DB=1
+            shift
+            shift
+            ;;
 
         --no-overwrite-settings)
             NO_OVERWRITE_SETTINGS=1

tools/setup/bootstrap-aws-installer

@@ -71,11 +71,8 @@ git clone "$REPO_URL" zulip -b "$BRANCH"
 git -C zulip checkout "$BRANCH"
 
 (
-    export PUPPET_CLASSES="$FULL_ROLES"
     export APT_OPTIONS="-o Dpkg::Options::=--force-confnew"
-    /root/zulip/scripts/setup/install \
-        --self-signed-cert \
-        --no-init-db
+    /root/zulip/scripts/setup/install --puppet-classes "$FULL_ROLES"
 )
 
 # Delete the ubuntu user