Quick setup for ssh, and ssh config file

ssh-key-setup.sh

# set the variables
SSH_HOST="gitlab.com"
SSH_USER=`whoami`
SSH_PORT=22

# create folder with the correct permissions
mkdir -p ~/.ssh/;
chmod 700 ~/.ssh/;
touch ~/.ssh/authorized_keys
chmod 600 ~/.ssh/authorized_keys

### --- Create Key Pair --- ###

# generate key with u2f/fido
ssh-keygen -t ecdsa-sk -f ~/.ssh/$SSH_USER@$SSH_HOST -b 4096 -P '' -f ~/.ssh/$SSH_USER@$SSH_HOST

# OR without
ssh-keygen -t rsa -f ~/.ssh/$SSH_USER@$SSH_HOST -b 4096 -P ''

### --- Import Key Pair (Previously Exported) --- ###

# SECRET_NAME was previously set
SECRET_NAME=`echo $SSH_HOST | tr . -`

gcloud secrets versions access latest \
  --secret="$SECRET_NAME" > ~/.ssh/$SSH_USER@$SSH_HOST
  
# set the permissions
chmod 600  ~/.ssh/$SSH_USER@$SSH_HOST

### --- Setup Config for SSH files --- ###

## cat into config
cat >>   ~/.ssh/config << EOF

Host $SSH_HOST
    HostName $SSH_HOST
    User $SSH_USER
    IdentityFile ~/.ssh/$SSH_USER@$SSH_HOST
    Port $SSH_PORT
EOF

# set the permissions
chmod 600 ~/.ssh/config;

### --- Export Key: Copy to HOST --- ###

# copy to instance 
ssh-copy-id -p $SSH_PORT -i ~/.ssh/$SSH_USER@$SSH_HOST.pub $SSH_USER@$SSH_HOST

### --- Export Key: Copy to clipboard --- ###

# ubuntu to clipboard
cat ~/.ssh/$SSH_USER@$SSH_HOST.pub | xclip

# macos to clipboard
cat ~/.ssh/$SSH_USER@$SSH_HOST.pub | pbcopy

### --- Export Key: Copy to GCP Secret --- ###

SECRET_NAME=`echo $SSH_HOST | tr . -`

gcloud secrets create $SECRET_NAME \
 --replication-policy="automatic" \
 --data-file=~/.ssh/$SSH_USER@$SSH_HOST