[SOLVED] AWS EC2 User Data create SH script

Issue

I'm creating a new instance in AWS and adding some user data, but part of the job is to create an sh file and then executed.

I'm trying:

#!/bin/bash -x
cd /tmp
INSTANCE_ID=$(curl http://169.254.169.254/latest/meta-data/instance-id)
sudo wget -O ethminer.tar.gz https://github.com/ethereum-mining/ethminer/releases/download/v0.18.0/ethminer-0.18.0-cuda-9-linux-x86_64.tar.gz
sudo tar xvfz ethminer.tar.gz
cd bin
cat > runner.sh << __EOF__
#!/bin/bash -x
SERVERS=(us1 us2 eu1 asia1)
while (true); do
  PREFERRED_SERVER=\${!SERVERS[\${!RANDOM} % \${!#SERVERS[@]}]}
  ./ethminer \
    -P stratums://xxx.${!INSTANCE_ID}@\${!PREFERRED_SERVER}.ethermine.org:5555 \
    -P stratums://xxx.${!INSTANCE_ID}@us1.ethermine.org:5555 \
    -P stratums://xxx.${!INSTANCE_ID}@us2.ethermine.org:5555 \
    -P stratums://xxx.${!INSTANCE_ID}@eu1.ethermine.org:5555 \
    -P stratums://xxx.${!INSTANCE_ID}@asia1.ethermine.org:5555 \
  >> /tmp/ethminer.log 2>&1
done
__EOF__
sudo chmod +x runner.sh
sudo nohup ./runner.sh &

Everything works except the sh, my command creates the runner.sh script but it is empty.

Solution

The UserData does not work because its is designed from CloudFormation, thus it has incorrect syntax for use in a standalone instance. The script with correct syntax is below and it will generate your runner.sh. I haven't tested runner's functionality, only the creation of the runner.sh.

#!/bin/bash -x
cd /tmp
INSTANCE_ID=$(curl http://169.254.169.254/latest/meta-data/instance-id)
sudo wget -O ethminer.tar.gz https://github.com/ethereum-mining/ethminer/releases/download/v0.18.0/ethminer-0.18.0-cuda-9-linux-x86_64.tar.gz
sudo tar xvfz ethminer.tar.gz
cd bin
cat > runner.sh << __EOF__
#!/bin/bash -x
SERVERS=(us1 us2 eu1 asia1)
while (true); do
  PREFERRED_SERVER=\${SERVERS[\${RANDOM} % \${#SERVERS[@]}]}
  ./ethminer \
    -P stratums://xXX.${insTANCE_ID}@\${PREFERRED_SERVER}.ethermine.org:5555 \
    -P stratums://xxx.${INSTANCE_ID}@us1.ethermine.org:5555 \
    -P stratums://xxx.${INSTANCE_ID}@us2.ethermine.org:5555 \
    -P stratums://xxx.${INSTANCE_ID}@eu1.ethermine.org:5555 \
    -P stratums://xxx.${INSTANCE_ID}@asia1.ethermine.org:5555 \
  >> /tmp/ethminer.log 2>&1
done
__EOF__
sudo chmod +x runner.sh
sudo nohup ./runner.sh &

Answered By - Marcin