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aws / amazon-ecs-cli

The Amazon ECS CLI enables users to run their applications on ECS/Fargate using the Docker Compose file format, quickly provision resources, push/pull images in ECR, and monitor running applications on ECS/Fargate.
https://docs.aws.amazon.com/AmazonECS/latest/developerguide/ECS_CLI.html
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User-data script has erroneous newline breaking shebang, incompatible with Cloud-init versions on AL2023 #1167

Open AdamMcAdamson opened 3 months ago

AdamMcAdamson commented 3 months ago

Summary

The resulting user-data script from cluster up has an erroneous newline which results in an invalid user-data script being sent to the EC2 instance. Older versions of Cloud-init ignored the issue (19-?, seen in AL2), but newer versions (22.2.2, seen in AL2023) correctly parse shell-scripts, causing the provided script to fail.

Description

Bug is here: https://github.com/aws/amazon-ecs-cli/blob/2791f9b45c3a2cf2788278a0d9eb529650ade8f1/ecs-cli/modules/cli/cluster/userdata/user_data.go#L153-L156

Golang's MIME multipart writer already inserts a newline, leaving the resulting script with an erroneous newline at the start of the file: https://github.com/golang/go/blob/master/src/mime/multipart/writer.go#L120

Expected Behavior

/var/lib/cloud/instance/scripts/part-001:

#!/bin/bash
echo ECS_CLUSTER=cluster-name >> /etc/ecs/ecs.config
...

Observed Behavior

/var/lib/cloud/instance/scripts/part-001:


#!/bin/bash
echo ECS_CLUSTER=cluster-name >> /etc/ecs/ecs.config
...
AdamMcAdamson commented 3 months ago

Fixed with #1168