nickjacob
/ systemd-prblm.service
Last active
March 17, 2023 16:11
execute arbitrary bash code/variable substitution in systemd units
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| [Unit] | |
| Description=Demonstrate Bash | |
| [Service] | |
| ExecStartPre=/usr/bin/bash -c "/usr/bin/systemctl set-environment MYVAR=$(( 2 + 2 ))" | |
| ExecStart=/usr/bin/echo "2 + 2 = ${MYVAR}" |
mbrannigan
/ CentOS 7 - attach ENI and have it actually work
Created
February 16, 2017 04:10
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| ############################################ | |
| # Instance info | |
| ############################################ | |
| INSTANCE_ID=$(/usr/bin/curl -s http://169.254.169.254/latest/meta-data/instance-id) | |
| EC2_AVAIL_ZONE=`/usr/bin/curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone` | |
| REGION="`echo \"$EC2_AVAIL_ZONE\" | /bin/sed -e 's:\([0-9][0-9]*\)[a-z]*\$:\\1:'`" | |
| ENI_ID="${ENI_ID}" # have terraform or whatever you're using provide this | |
| ENI_IP=$(/usr/bin/aws ec2 describe-network-interfaces --region=${REGION} | \ | |
| /usr/bin/jq -cr --arg i "${ENI_ID}" '.NetworkInterfaces[]|select(.NetworkInterfaceId==$i).PrivateIpAddress') | |
| NETCIDR="${ENI_IP%.*}.0/24" # yeah, it's defaults for my network, put in whatever it is for you |