EC2 Userdata Script Fails: nvm Installer Cannot Find .bashrc

When running a cloud‑init user data script, you’re typically working with a non‑interactive, non‑login shell where environment files (like .bashrc) may not exist or be sourced automatically. In your case, the nvm installer is looking for a profile file and falling back to installing in “/.nvm” (note the missing home directory).

Here are two common fixes:

---

1. Explicitly Create and Source nvm’s Environment

Instead of relying on the installer to find your shell profile, manually set up the environment. For example, modify your script to:

BASHCopied
# Ensure a shell profile exists; if running as root, typically /root/.bashrc
touch ~/.bashrc

# Run the nvm installer
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.7/install.sh | bash

# Manually set NVM_DIR and source the nvm script directly
export NVM_DIR="$HOME/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && . "$NVM_DIR/nvm.sh"

# Now install Node.js
nvm install 16

This way, you’re directly loading nvm without waiting for a new interactive shell to pick up profile changes.

---

2. Append the nvm Initialization to a Profile and Source It

Alternatively, you can simulate a login shell by appending the initialization lines to your profile and then sourcing it immediately:

BASHCopied
# Create .bashrc if it doesn't exist, then append nvm config
touch ~/.bashrc
echo 'export NVM_DIR="$HOME/.nvm"' >> ~/.bashrc
echo '[ -s "$NVM_DIR/nvm.sh" ] && . "$NVM_DIR/nvm.sh"' >> ~/.bashrc

# Run the nvm installer
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.7/install.sh | bash

# Source .bashrc to load nvm
source ~/.bashrc

# Install Node.js using nvm
nvm install 16

Ensure that the shell in which your script is executed has the correct HOME variable. In cloud-init, if you’re running as root, HOME should be set to /root (unless you’ve modified it), so the above should work.

---

Why These Changes Work

• Manual Environment Setup: By explicitly setting NVM_DIR and sourcing nvm’s script (nvm.sh), you bypass the installer’s need to search for a profile file.
• Immediate Sourcing: Cloud-init scripts generally run non‑interactively, so changes you expect from a new terminal session are not available. Sourcing the file immediately makes nvm available for subsequent commands.

Choose one approach based on your preference. Both ensure that nvm is properly initialized in the context of your user data script, allowing Node.js installation to proceed.

---

Give one of these adjustments a try in your EC2 user data script, and it should resolve the issue with nvm not being found.