17 KiB
AWS Systems Manager
TL;DR
Usage
# Get connection statuses.
aws ssm get-connection-status --target 'instance-id'
# Start sessions.
aws ssm start-session --target 'instance-id'
# Run commands.
aws ssm start-session \
--target 'instance-id' \
--document-name 'CustomCommandSessionDocument' \
--parameters '{"logpath":["/var/log/amazon/ssm/amazon-ssm-agent.log"]}'
aws ssm send-command \
--instance-ids 'i-0123456789abcdef0' \
--document-name 'AWS-RunShellScript' \
--parameters "commands="echo 'hallo'"
# Wait for commands execution.
aws ssm wait command-executed --instance-id 'i-0123456789abcdef0' --command-id 'abcdef01-2345-abcd-6789-abcdef012345'
# Get commands results.
aws ssm get-command-invocation --instance-id 'i-0123456789abcdef0' --command-id 'abcdef01-2345-abcd-6789-abcdef012345'
aws ssm get-command-invocation \
--instance-id 'i-0123456789abcdef0' --command-id 'abcdef01-2345-abcd-6789-abcdef012345' \
--query '{"status": Status, "rc": ResponseCode, "stdout": StandardOutputContent, "stderr": StandardErrorContent}'
Real world use cases
Also check out the snippets.
# Connect to instances if they are available.
instance_id='i-08fc83ad07487d72f' \
&& eval $(aws ssm get-connection-status --target "$instance_id" --query "Status=='connected'" --output 'text') \
&& aws ssm start-session --target "$instance_id" \
|| (echo "instance ${instance_id} not available" >&2 && false)
# Run commands and get their output.
instance_id='i-0915612f182914822' \
&& command_id=$(aws ssm send-command --instance-ids "$instance_id" \
--document-name 'AWS-RunShellScript' --parameters 'commands="echo hallo"' \
--query 'Command.CommandId' --output 'text') \
&& aws ssm wait command-executed --command-id "$command_id" --instance-id "$instance_id" \
&& aws ssm get-command-invocation --command-id "$command_id" --instance-id "$instance_id" \
--query '{"status": Status, "rc": ResponseCode, "stdout": StandardOutputContent, "stderr": StandardErrorContent}'
Requirements
For instances to be managed by Systems Manager and be available in lists of managed nodes, it must:
-
Run a supported operating system.
-
Have the SSM Agent installed and running.
sudo dnf -y install 'amazon-ssm-agent' sudo systemctl enable --now 'amazon-ssm-agent.service' -
Have an AWS IAM instance profile attached with the correct permissions.
The instance profile enables the instance to communicate with the Systems Manager service. Alternatively, the instance must be registered to Systems Manager using hybrid activation.The minimum permissions required are given by the Amazon-provided
AmazonSSMManagedInstanceCorepolicy (arn:aws:iam::aws:policy/AmazonSSMManagedInstanceCore). -
Be able to to connect to a Systems Manager endpoint through the SSM Agent in order to register with the service.
From there, the instance must be available to the service. This is confirmed by the service by sending a signal every five minutes to check the instance's health.After the status of a managed node has been
Connection Lostfor at least 30 days, the node could be removed from the Fleet Manager console.
To restore it to the list, resolve the issues that caused the lost connection.
Check whether SSM Agent successfully registered with the Systems Manager service by executing the aws ssm describe-instance-associations-status command.
It won't return results until a successful registration has taken place.
aws ssm describe-instance-associations-status --instance-id 'instance-id'
Failed invocation
{
"InstanceAssociationStatusInfos": []
}
Successful invocation
{
"InstanceAssociationStatusInfos": [
{
"AssociationId": "51f0ed7e-c236-4c34-829d-e8f2a7a3bb4a",
"Name": "AWS-GatherSoftwareInventory",
"DocumentVersion": "1",
"AssociationVersion": "2",
"InstanceId": "i-0123456789abcdef0",
"ExecutionDate": "2024-04-22T14:41:37.313000+02:00",
"Status": "Success",
"ExecutionSummary": "1 out of 1 plugin processed, 1 success, 0 failed, 0 timedout, 0 skipped. ",
"AssociationName": "InspectorInventoryCollection-do-not-delete"
},
…
]
}
Gotchas
-
SSM starts shell sessions under
/usr/bin(source):Other shell profile configuration options
By default, Session Manager starts in the "/usr/bin" directory.
Integrate with Ansible
Create a dynamic inventory which name ends with aws_ec2.yml (e.g. test.aws_ec2.yml or simply aws_ec2.yml).
Refer the amazon.aws.aws_ec2 inventory for more information about the file specifications.
It needs to be named like that to be found by the
'community.aws.aws_ssm' connection plugin.
# File: 'aws_ec2.yml'.
plugin: aws_ec2
regions:
- eu-east-2
exclude_filters:
- tag-key:
- aws:eks:cluster-name # EKS nodes do not use SSM-capable images
include_filters:
- instance-state-name: running
keyed_groups:
- key: tags.Name
# add hosts to 'tag_Name_<tag_value>' groups for each aws_ec2 host's 'Tags.Name' attribute
prefix: tag_Name_
separator: ""
- key: tags.application
# add hosts to 'tag_application_<tag_value>' groups for each aws_ec2 host's 'Tags.application' attribute
prefix: tag_application_
separator: ""
hostnames:
- instance-id
# acts as keyword to use the instances' 'InstanceId' attribute
# use 'private-ip-address' to use the instances' 'PrivateIpAddress' attribute instead
# or any option in <https://docs.aws.amazon.com/cli/latest/reference/ec2/describe-instances.html#options> really
Pitfalls:
-
One shall not use the
remote_userconnection option, as it is not supported by the plugin.
From the plugin notes:The
community.aws.aws_ssmconnection plugin does not support using theremote_userandansible_uservariables to configure the remote user. Thebecome_userparameter should be used to configure which user to run commands as. Remote commands will often default to running as thessm-agentuser, however this will also depend on how SSM has been configured. -
Since SSM starts shell sessions under
/usr/bin, one must explicitly set Ansible's temporary directory to a folder the remote user can write to (source):ANSIBLE_REMOTE_TMP='/tmp' ansible…# file: ansible.cfg remote_tmp=/tmp- hosts: all + vars: + ansible_remote_tmp: /tmp tasks: …This, or use the shell profiles in SSM's preferences to change the directory when logged in.
Troubleshooting
Refer Troubleshooting managed node availability.
- Check the Requirements are satisfied.
- Check node availability using
ssm-cli.
Check node availability using ssm-cli
Refer
Troubleshooting managed node availability using ssm-cli.
From the managed instance:
$ sudo dnf -y install 'amazon-ssm-agent'
$ sudo systemctl enable --now 'amazon-ssm-agent.service'
$ sudo ssm-cli get-diagnostics --output 'table'
┌──────────────────────────────────────┬─────────┬─────────────────────────────────────────────────────────────────────┐
│ Check │ Status │ Note │
├──────────────────────────────────────┼─────────┼─────────────────────────────────────────────────────────────────────┤
│ EC2 IMDS │ Success │ IMDS is accessible and has instance id i-0123456789abcdef0 in │
│ │ │ region eu-west-1 │
├──────────────────────────────────────┼─────────┼─────────────────────────────────────────────────────────────────────┤
│ Hybrid instance registration │ Skipped │ Instance does not have hybrid registration │
├──────────────────────────────────────┼─────────┼─────────────────────────────────────────────────────────────────────┤
│ Connectivity to ssm endpoint │ Success │ ssm.eu-west-1.amazonaws.com is reachable │
├──────────────────────────────────────┼─────────┼─────────────────────────────────────────────────────────────────────┤
│ Connectivity to ec2messages endpoint │ Success │ ec2messages.eu-west-1.amazonaws.com is reachable │
├──────────────────────────────────────┼─────────┼─────────────────────────────────────────────────────────────────────┤
│ Connectivity to ssmmessages endpoint │ Success │ ssmmessages.eu-west-1.amazonaws.com is reachable │
├──────────────────────────────────────┼─────────┼─────────────────────────────────────────────────────────────────────┤
│ Connectivity to s3 endpoint │ Success │ s3.eu-west-1.amazonaws.com is reachable │
├──────────────────────────────────────┼─────────┼─────────────────────────────────────────────────────────────────────┤
│ Connectivity to kms endpoint │ Success │ kms.eu-west-1.amazonaws.com is reachable │
├──────────────────────────────────────┼─────────┼─────────────────────────────────────────────────────────────────────┤
│ Connectivity to logs endpoint │ Success │ logs.eu-west-1.amazonaws.com is reachable │
├──────────────────────────────────────┼─────────┼─────────────────────────────────────────────────────────────────────┤
│ Connectivity to monitoring endpoint │ Success │ monitoring.eu-west-1.amazonaws.com is reachable │
├──────────────────────────────────────┼─────────┼─────────────────────────────────────────────────────────────────────┤
│ AWS Credentials │ Success │ Credentials are for │
│ │ │ arn:aws:sts::012345678901:assumed-role/managed/i-0123456789abcdef0 │
│ │ │ and will expire at 2024-04-22 18:19:48 +0000 UTC │
├──────────────────────────────────────┼─────────┼─────────────────────────────────────────────────────────────────────┤
│ Agent service │ Success │ Agent service is running and is running as expected user │
├──────────────────────────────────────┼─────────┼─────────────────────────────────────────────────────────────────────┤
│ Proxy configuration │ Skipped │ No proxy configuration detected │
├──────────────────────────────────────┼─────────┼─────────────────────────────────────────────────────────────────────┤
│ SSM Agent version │ Success │ SSM Agent version is 3.3.131.0 which is the latest version │
└──────────────────────────────────────┴─────────┴─────────────────────────────────────────────────────────────────────┘
Further readings
- Amazon Web Services
- AWS' CLI
- Ansible
- EC2