How to know if an instance is running using bash and awscli?

Question

Right now I'm using awscli in my script (bash) to send request checking the instance status after create it. But I'm receiving this message:

/bin/bash: eval: line 130: syntax error: unexpected end of file

I've tried two ways:

This one first:

while INSTANCE_STATE=$(aws ec2 describe-instances \
--instance-ids $INSTANCE_ID --output text  \
--query 'Reservations[*].Instances[*].State.Name');  \
test "$INSTANCE_STATE" = "pending";  \
do sleep 1; echo -n '.' done;  \
echo " $INSTANCE_STATE"

Then, the other one:

until [ test "$INSTANCE_STATE" = "running" ] do \
echo 'Wait for instance.'; \
INSTANCE_STATE=$(aws ec2 describe-instances \
--instance-ids $INSTANCE_ID --output text \
--query 'Reservations[*].Instances[*].State.Name'); \
sleep 2; echo -n '.' done; \
echo " $INSTANCE_STATE"

In both cases the result is almost the same. What I'm doing wrong? Any help please?

Answer 1

Below is one liner command:

while INSTANCE_STATE=$(aws ec2 describe-instances --instance-ids $INSTANCE_ID --output text --query 'Reservations[*].Instances[*].State.Name'); test "$INSTANCE_STATE" = "pending"; do sleep 1; echo -n '.'; done

Below is the shell script:

#!/bin/bash
INSTANCE_ID=
while INSTANCE_STATE=$(aws ec2 describe-instances --instance-ids $INSTANCE_ID --output text --query 'Reservations[*].Instances[*].State.Name');
test "$INSTANCE_STATE" = "running"
do
sleep 1
echo -n '.'
done
echo " $INSTANCE_STATE"

You should stick with the first code as the other one is evaluating the condition first and then assigning the value whereas in the first one it is assigning the value first and then evaluating which will save assigning the variable step.

Other code is throwing below error due to the above reason:

line 3: [: too many arguments

The issue you are seeing with your code is extra \ at some places. Otherwise, your code is working fine.