Make install script more robust (#1255)

* Add checks for download and file

* Edit docs

Author: theletterf

docs/contribute/locally.md

@@ -40,6 +40,8 @@ This guide uses the first option. If you'd like to clone the repository and buil
 
    This downloads the latest binary, makes it executable, and installs it to your user PATH.
 
+   To download and install the binary file manually, refer to [Releases](https://github.com/elastic/docs-builder/releases) on GitHub.
+
 2. **Run docs-builder from a docs folder**
 
    Use the `serve` command from any docs folder to start serving the documentation at http://localhost:3000. The path to the `docset.yml` file that you want to build can be specified with `-p`:
@@ -66,16 +68,16 @@ If you get a `Permission denied` error, make sure that you aren't trying to run
 
    This downloads the latest binary, makes it executable, and installs it to your user PATH.
 
+   To download and install the binary file manually, refer to [Releases](https://github.com/elastic/docs-builder/releases) on GitHub.
+
 2. **Run docs-builder from a docs folder**
 
    Use the `serve` command from any docs folder to start serving the documentation at http://localhost:3000. The path to the `docset.yml` file that you want to build can be specified with `-p`:
 
    ```sh
    docs-builder serve
    ```
-
-To download and install the binary file manually, refer to [Releases](https://github.com/elastic/docs-builder/releases) on GitHub.
-
+   
 :::
 ::::
 

install.sh

@@ -1,5 +1,5 @@
 #!/bin/sh
-set -e
+set -euo pipefail
 
 # Determine OS type and architecture
 OS=$(uname -s | tr '[:upper:]' '[:lower:]')
@@ -56,11 +56,22 @@ fi
 echo "Downloading docs-builder for $OS/$ARCH..."
 
 # Download the appropriate binary
-curl -LO "https://github.com/elastic/docs-builder/releases/latest/download/$BINARY"
+if ! curl -LO "https://github.com/elastic/docs-builder/releases/latest/download/$BINARY"; then
+  echo "Error: Failed to download $BINARY. Please check your internet connection."
+  exit 1
+fi
+
+# Validate the downloaded file
+if [ ! -s "$BINARY" ]; then
+  echo "Error: Downloaded file $BINARY is missing or empty."
+  exit 1
+fi
 
 # Extract only the docs-builder file to /tmp directory
-# Use -o flag to always overwrite files without prompting
-unzip -j -o "$BINARY" docs-builder -d /tmp
+if ! unzip -j -o "$BINARY" docs-builder -d /tmp; then
+  echo "Error: Failed to extract docs-builder from $BINARY."
+  exit 1
+fi
 
 # Ensure the binary is executable
 chmod +x /tmp/docs-builder