When working with Google Cloud Shell (not "Developers Console" - that's a common misnomer), users often encounter password-related challenges when attempting to modify shell environments. The fundamental issue stems from how Cloud Shell handles user authentication differently from traditional UNIX systems.

Google Cloud Shell implements a unique authentication model:

• No traditional UNIX password exists by default
• Authentication occurs through OAuth2 via your Google account
• The sudo implementation is purposefully limited for security

Instead of using chsh, implement zsh through these alternative methods:

# Method 1: Direct execution
exec zsh

# Method 2: Persistent configuration
echo 'exec zsh' >> ~/.bashrc

# Method 3: Using cloudshell customizations
mkdir -p ~/.cloudshell
echo 'SHELL=/usr/bin/zsh' > ~/.cloudshell/environment

The proper way to install oh-my-zsh in Cloud Shell:

# Clone without sudo
git clone https://github.com/ohmyzsh/ohmyzsh.git ~/.oh-my-zsh

# Copy the template
cp ~/.oh-my-zsh/templates/zshrc.zsh-template ~/.zshrc

# Source it immediately
source ~/.zshrc

Google designed Cloud Shell with these intentional limitations:

• Ephemeral storage (changes may not persist)
• Container-based isolation
• Google-managed user permissions
• No traditional root access

For rare cases requiring elevated permissions:

1. Use Cloud Shell in "Boosted Mode" (upper-right settings)
2. Request temporary permissions through Google Cloud IAM
3. Consider using a Compute Engine instance instead

Many developers encounter a confusing situation when first using Google Cloud Shell (part of Google Developers Console). After launching the shell, attempting to run sudo or passwd commands prompts for a password that doesn't seem to match their Google account credentials.

Google Cloud Shell provides a temporary Linux instance with:

• 5GB of persistent storage ($HOME directory)
• Pre-installed developer tools
• No root access by default

The key thing to understand is that Cloud Shell instances are ephemeral and don't use traditional password authentication.

When you see:

user@cloudshell:~$ passwd
Changing password for user.
(current) UNIX password:
passwd: Authentication token manipulation error
passwd: password unchanged

This occurs because:

1. Cloud Shell uses ephemeral user accounts
2. Password authentication is disabled by design
3. User management is handled through Google's infrastructure

Changing Your Shell (zsh, bash, etc.)

Instead of using chsh which requires sudo, simply modify your .bashrc or create a .zshrc file:

echo 'exec zsh' >> ~/.bashrc
source ~/.bashrc

Installing Packages Without Sudo

For tools you need, use:

mkdir ~/bin
curl -Lo ~/bin/my_tool https://example.com/tool
chmod +x ~/bin/my_tool
export PATH=$PATH:~/bin

Persistent Configuration

Since $HOME persists, add your configurations to:

• ~/.bashrc
• ~/.zshrc
• ~/.profile

For scenarios requiring more control:

1. Use Google Compute Engine for full VM access
2. Consider Cloud Run for containerized environments
3. Use Cloud Build for CI/CD pipelines

The lack of password access is actually a security feature:

• Prevents credential leaks in ephemeral environments
• Reduces attack surface
• Aligns with principle of least privilege