From 8705d1b81f2c56bd0c0010d848bbded2a3284337 Mon Sep 17 00:00:00 2001
From: Marco Dinis <marco.dinis@goteleport.com>
Date: Mon, 22 Aug 2022 10:21:54 +0100
Subject: [PATCH] NodeJoin script: fix when no labels are provided

Recently we added a way to add labels on newly added nodes based on the
token.
Each token now has a list of SuggestedLabels, which are used to feed
that list.

However, if that list is empty, the generated script would trigger the
following error:
`teleport: error: unexpected`

This happens when running the `teleport node configure ...` command.

This happens because the command is generating an empty argument `""`
when running the `teleport node configure ...` command.
So it looks like this:
```bash
${TELEPORT_BINARY_DIR}/teleport node configure \
      --token token \
      joinmethod \
      --ca-pin pin \
      --auth-server host:port \
      "" \
      --output someport
```
That empty argument breaks things.

So, in order to fix it, we are going to change the default value when no
labels are provided.
Instead of an empty string, we'll use an empty array.

Demo (teleport node configure message removed for brev
No label
```bash
$ LABELS_FLAG=(); f=$(mktemp -d)/node.yaml; teleport node configure --auth-server w:1 "${LABELS_FLAG[@]}" --output $f && yq .s
sh_service.labels $f

enabled: "yes"
commands:
  - name: hostname
    command: [hostname]
    period: 1m0s

```

Single label
```bash
$ LABELS_FLAG=(--labels x=y); f=$(mktemp -d)/node.yaml; teleport node configure --auth-server w:1 "${LABELS_FLAG[@]}" --output $f && yq .ssh_service $f

enabled: "yes"
labels:
  x: "y"
commands:
  - name: hostname
    command: [hostname]
    period: 1m0s

```

Multiple labels
```bash
$ LABELS_FLAG=(--labels x=y,dev=prod); f=$(mktemp -d)/node.yaml; teleport node configure --auth-server w:1 "${LABELS_FLAG[@]}" --output $f && yq .ssh_service $f

enabled: "yes"
labels:
  dev: prod
  x: "y"
commands:
  - name: hostname
    command: [hostname]
    period: 1m0s
```
---
 lib/web/scripts/node-join/install.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/web/scripts/node-join/install.sh b/lib/web/scripts/node-join/install.sh
index 32a02ff0624df..66cbfdc19dc99 100755
--- a/lib/web/scripts/node-join/install.sh
+++ b/lib/web/scripts/node-join/install.sh
@@ -45,7 +45,7 @@ JOIN_METHOD_FLAG=""
 
 # inject labels into the configuration
 LABELS='{{.labels}}'
-LABELS_FLAG=""
+LABELS_FLAG=()
 [ -n "$LABELS" ] && LABELS_FLAG=(--labels "${LABELS}")
 
 # When all stanza generators have been updated to use the new