I have created an environment on scale set first instance, now I want to capture an image of that scale set instance (Protected from scale-in) so that I can create another scale set with that image with environment. Any way to capture or backup that instance of scale set in azure?
You can use the Azure CLI command az image create to capture the image from the scale set like this:
az image create -g group_name -n image_name --source instance_os_disk_resourceId --os-type xxxx
And you can use the command az vmss list-instances to get the OS disk resource ID of the instance. For example:
az vmss list-instances -g charlesVMSS -n azurevmss -o table --query "[].[instanceId, storageProfile.osDisk.managedDisk.id]"
Related
For example: upon launching my EC2 instance, I would like to automatically run
docker login
so I can pull a private image from dockerhub and run it. To login to dockerhub I need to input a username and password, and this is what I would like to automate but haven't been able to figure out how.
I do know that you can pass in a script to be ran on launch via User Data. The issue is that my script expects input and I would like to automate entering that input.
Thanks in advance!
If just entering a password for docker login is your problem then I would suggest searching for a manual for docker login. 30 secs on Google gave me this link:
https://docs.docker.com/engine/reference/commandline/login/
It suggests something of the form
docker login --username foo --password-stdin < ~/my_password.txt
Which will read the password from a file my_password.txt in the current users home directory.
Seems like the easiest solution for you here is to modify your script to accept command line parameters, and pass those in with the UserData string.
Keep in mind that this will require you to change your launch configs every time your password changes.
The better solution here is to store your containers in ECS, and let AWS handle the authentication for you (as far as pulling the correct containers from a repo).
Your UserData then turns into something along:
#!/bin/bash
mkdir -p /etc/ecs
rm -f /etc/ecs/ecs.config # cleans up any old files on this instance
echo ECS_LOGFILE=/log/ecs-agent.log >> /etc/ecs/ecs.config
echo ECS_LOGLEVEL=info >> /etc/ecs/ecs.config
echo ECS_DATADIR=/data >> /etc/ecs/ecs.config
echo ECS_CONTAINER_STOP_TIMEOUT=5m >> /etc/ecs/ecs.config
echo ECS_CLUSTER=<your-cluster-goes-here> >> /etc/ecs/ecs.config
docker pull amazon/amazon-ecs-agent
docker run --name ecs-agent --detach=true --restart=on-failure:10 --volume=/var/run/docker.sock:/var/run/docker.sock --volume=/var/log/ecs/:/log --volume=/var/lib/ecs/data:/data --volume=/sys/fs/cgroup:/sys/fs/cgroup:ro --volume=/var/run/docker/execdriver/native:/var/lib/docker/execdriver/native:ro --publish=127.0.0.1:51678:51678 --env-file=/etc/ecs/ecs.config amazon/amazon-ecs-agent:latest
You may or may not need all the volumes specified above.
This setup lets the AWS ecs-agent handle your container orchestration for you.
Below is what I could suggest at this moment -
Create a S3 bucket i.e mybucket.
Put a text file(doc_pass.txt) with your password into that S3 bucket
Create a IAM policy which has GET access to just that particular S3 bucket & add this policy to the EC2 instance role.
Put below script in you user data -
aws s3 cp s3://mybucket/doc_pass.txt doc_pass.txt
cat doc_pass.txt | docker login --username=YOUR_USERNAME --password-stdin
This way you just need to make your S3 bucket secure, no secrets gets displayed in the user data.
I want to fill some tags of the EC2 spot instance, however as it is impossible to do it directly in spot request, I do it via user data script. All is going fine when I specify region statically, but it is not universal approach. When I try to detect current region from instance userdata, the region variable is always empty. I do it in a following way:
#!/bin/bash
region=$(ec2-metadata -z | awk '{print $2}' | sed 's/[a-z]$//')
aws ec2 create-tags \
--region $region \
--resources `wget -q -O - http://169.254.169.254/latest/meta-data/instance-id` \
--tags Key=sometag,Value=somevalue Key=sometag,Value=somevalue
I tried to made a delay before region populating
/bin/sleep 30
but this had no result.
However, when I run this script manually after start, the tags are added fine. What is going on?
Why all in all aws-cli doesn't get default region from profile? I have aws configure properly configured inside the instance, but without --region clause it throws error that region is not specified.
I suspect the ec2-metadata command is not available when your userdata script is executed. Try getting the region from the metadata server directly (which is what ec2-metadata does anyway)
region=$(curl -fsq http://169.254.169.254/latest/meta-data/placement/availability-zone | sed 's/[a-z]$//')
AWS CLI does use the region from default profile.
You can now use this endpoint to get only the instance region (no parsing needed):
http://169.254.169.254/latest/meta-data/placement/region
So in this case:
region=`curl -s http://169.254.169.254/latest/meta-data/placement/region`
I ended up with
region=$(curl -s http://169.254.169.254/latest/dynamic/instance-identity/document | python -c "import json,sys; print"
which worked fine. However, it would be fine if somebody explain the nuts-and-bolts.
I have an EC2 ASG on AWS and I'm interested in storing the shell script that's used to instantiate any given instance in an S3 bucket and have it downloaded and run upon instantiation, but it all feels a little rickety even though I'm using an IAM Instance Role, transferring via HTTPS, and encrypting the script itself while at rest in the S3 bucket using KMS using S3 Server Side Encryption (because the KMS method was throwing an 'Unknown' error).
The Setup
Created an IAM Instance Role that gets assigned to any instance in my ASG upon instantiation, resulting in my AWS creds being baked into the instance as ENV vars
Uploaded and encrypted my Instance-Init.sh script to S3 resulting in a private endpoint like so : https://s3.amazonaws.com/super-secret-bucket/Instance-Init.sh
In The User-Data Field
I input the following into the User Data field when creating the Launch Configuration I want my ASG to use:
#!/bin/bash
apt-get update
apt-get -y install python-pip
apt-get -y install awscli
cd /home/ubuntu
aws s3 cp s3://super-secret-bucket/Instance-Init.sh . --region us-east-1
chmod +x Instance-Init.sh
. Instance-Init.sh
shred -u -z -n 27 Instance-Init.sh
The above does the following:
Updates package lists
Installs Python (required to run aws-cli)
Installs aws-cli
Changes to the /home/ubuntu user directory
Uses the aws-cli to download the Instance-Init.sh file from S3. Due to the IAM Role assigned to my instance, my AWS creds are automagically discovered by aws-cli. The IAM Role also grants my instance the permissions necessary to decrypt the file.
Makes it executable
Runs the script
Deletes the script after it's completed.
The Instance-Init.sh Script
The script itself will do stuff like setting env vars and docker run the containers that I need deployed on my instance. Kinda like so:
#!/bin/bash
export MONGO_USER='MyMongoUserName'
export MONGO_PASS='Top-Secret-Dont-Tell-Anyone'
docker login -u <username> -p <password> -e <email>
docker run - e MONGO_USER=${MONGO_USER} -e MONGO_PASS=${MONGO_PASS} --name MyContainerName quay.io/myQuayNameSpace/MyAppName:latest
Very Handy
This creates a very handy way to update User-Data scripts without the need to create a new Launch Config every time you need to make a minor change. And it does a great job of getting env vars out of your codebase and into a narrow, controllable space (the Instance-Init.sh script itself).
But it all feels a little insecure. The idea of putting my master DB creds into a file on S3 is unsettling to say the least.
The Questions
Is this a common practice or am I dreaming up a bad idea here?
Does the fact that the file is downloaded and stored (albeit briefly) on the fresh instance constitute a vulnerability at all?
Is there a better method for deleting the file in a more secure way?
Does it even matter whether the file is deleted after it's run? Considering the secrets are being transferred to env vars it almost seems redundant to delete the Instance-Init.sh file.
Is there something that I'm missing in my nascent days of ops?
Thanks for any help in advance.
What you are describing is almost exactly what we are using to instantiate Docker containers from our registry (we now use v2 self-hosted/private, s3-backed docker-registry instead of Quay) into production. FWIW, I had the same "this feels rickety" feeling that you describe when first treading this path, but after almost a year now of doing it -- and compared to the alternative of storing this sensitive configuration data in a repo or baked into the image -- I'm confident it's one of the better ways of handling this data. Now, that being said, we are currently looking at using Hashicorp's new Vault software for deploying configuration secrets to replace this "shared" encrypted secret shell script container (say that five times fast). We are thinking that Vault will be the equivalent of outsourcing crypto to the open source community (where it belongs), but for configuration storage.
In fewer words, we haven't run across many problems with a very similar situation we've been using for about a year, but we are now looking at using an external open source project (Hashicorp's Vault) to replace our homegrown method. Good luck!
An alternative to Vault is to use credstash, which leverages AWS KMS and DynamoDB to achieve a similar goal.
I actually use credstash to dynamically import sensitive configuration data at container startup via a simple entrypoint script - this way the sensitive data is not exposed via docker inspect or in docker logs etc.
Here's a sample entrypoint script (for a Python application) - the beauty here is you can still pass in credentials via environment variables for non-AWS/dev environments.
#!/bin/bash
set -e
# Activate virtual environment
. /app/venv/bin/activate
# Pull sensitive credentials from AWS credstash if CREDENTIAL_STORE is set with a little help from jq
# AWS_DEFAULT_REGION must also be set
# Note values are Base64 encoded in this example
if [[ -n $CREDENTIAL_STORE ]]; then
items=$(credstash -t $CREDENTIAL_STORE getall -f json | jq 'to_entries | .[]' -r)
keys=$(echo $items | jq .key -r)
for key in $keys
do
export $key=$(echo $items | jq 'select(.key=="'$key'") | .value' -r | base64 --decode)
done
fi
exec $#
I'm trying to set up a means to register an instance in route53 automatically when the instance is created, using salt and this article.
The article uses ec2-metadata to get the instance-id and and the hostname. I'm wondering if there is a way, using bash within the instance, to get the instance Name instead. ec2-metadata only seems to show the instance-id. Thanks in advance.
First, you need to get the instance-id.
AWS_INSTANCE_ID=`curl -s http://169.254.169.254/latest/meta-data/instance-id`
Than you can get the ec2 instance name using below command.
EC2_NAME=$(aws ec2 describe-tags --region $REGION --filters "Name=resource-id,Values=$AWS_INSTANCE_ID" "Name=key,Values=Name" --output text | cut -f5)
Please ensure that you have AWS Cli Installed.
I hope this helps.
Thanks!
First and foremost, the Amazon EC2 Instance Metadata Service also provides quite some other Names besides the instance-id, if these might be what you are looking for - see Instance Metadata Categories:
hostname - The private hostname of the instance. In cases where multiple network interfaces are present, this refers to the eth0 device (the device for which the device number is 0).
local-hostname - The private DNS hostname of the instance. In cases where multiple network interfaces are present, this refers to the eth0 device (the device for which the device number is 0).
public-hostname - The instance's public DNS. If the instance is in a VPC, this category is only returned if the enableDnsHostnames attribute is set to true.
If you are looking for the Name as exposed in the AWS Management Console though, you would indeed need to resort to using one of the Tools for Amazon Web Services to retrieve it - that Name is in fact just a regular tag with the key Name (see Tagging Your Amazon EC2 Resources), which happens to be used across most AWS services for the obvious purpose.
Here's how to get it with the AWS Command Line Interface for example (skipping region and credentials):
aws ec2 describe-tags \
--filters Name=resource-id,Values=i-abcd1234 Name=key,Values=Name \
--query Tags[].Value --output text
For more advanced CLI JSON output processing than what's possible with the built in --query option, you could resort to jq (a lightweight and flexible command-line JSON processor).
Overthink's answer provides an example based on the now legacy Amazon EC2 API Tools (please note the comments, which correctly point out that you'd nowadays deal with credentials differently, see Tell the CLI Tools Who You Are and IAM Roles for EC2 instances for details).
Not sure what it would look like with bash, but you could use an SDK from the instance itself if you can get the instance id. You would query the ec2 recourse and pass in the ec2 instance id. Using the ruby sdk it would look like:
i = ec2.instances["i-12345678"]
puts i.dns_name
Found that describe-tags not working in my config, failed with 'UnauthorizedOperation' error. Got this working with describe-instances:
aws ec2 describe-instances --filters Name=instance-id,Values=$(wget -qO- http://instance-data/latest/meta-data/instance-id) --query Reservations[].Instances[].Tags[].Value --output text
Command using region and access keys from current user's aws config file's [default] section: ~/.aws/config . If need to use another user's region/keys (can be found at AWS console's IAM dashboard), you can add them to another section in that file, for example [user2] and use in command like this:
aws --profile user2 ec2 describe-instances --filters Name=instance-id,Values=$(wget -qO- http://instance-data/latest/meta-data/instance-id) --query Reservations[].Instances[].Tags[].Value --output text
Use this command to show which metadata is available
TOKEN=`curl -X PUT "http://169.254.169.254/latest/api/token" -H "X-aws-ec2-metadata-token-ttl-seconds: 21600"` \
&& curl -H "X-aws-ec2-metadata-token: $TOKEN" -v http://169.254.169.254/latest/meta-data/
You can chain any one of the below file/folders to display the required info
ami-id
ami-launch-index
ami-manifest-path
block-device-mapping/
events/
hostname
iam/
identity-credentials/
instance-action
instance-id
instance-life-cycle
instance-type
local-hostname
local-ipv4
mac
metrics/
network/
placement/
profile
public-keys/
reservation-id
For eg. instance-type can be chained this to the above command as follows:
TOKEN=`curl -X PUT "http://169.254.169.254/latest/api/token" -H "X-aws-ec2-metadata-token-ttl-seconds: 21600"` \
&& curl -H "X-aws-ec2-metadata-token: $TOKEN" -v http://169.254.169.254/latest/meta-data/instance-type
Reference from AWS
ec2metadata tool is useful to get information about the EC2 server.
You can use the following;
ec2metadata --instance-id
in bash;
INSTANCE_ID=$(ec2metadata --instance-id)
You can also access other useful information like the following;
--ami-id
--ami-launch-index
--ami-manifest-path
--ancestor-ami-ids
--availability-zone
--block-device-mapping
--instance-action
--instance-id
--instance-type
--local-hostname
--local-ipv4
--kernel-id
--mac
--profile
--product-codes
--public-hostname
--public-ipv4
--public-keys
--ramdisk-id
--reserveration-id
--security-groups
I see that you can convert an instance stored instance to be EBS backed as this question shows. However, I want to do the opposite, take an EBS backed instance and convert it to be Instance Store backed.
Is this possible? How do I do this?
Launch an instance-store instance from an AMI that uses the same kernel used by your EBS-backed AMI.
Create an EBS volume from the snapshot underlying the EBS AMI. (Alternatively, launch an instance of the EBS AMI and Stop the instance when it begins booting. Detach the root volume from the instance - this is usually the volume attached to /dev/sda1.)
Attach the EBS volume to the instance-store instance.
rsync the contents of the EBS volume to the root volume.
Create an instance-store AMI using the standard methods.
Detach the EBS volume and delete it. If you launched an EBS instance in step 2, terminate it.
You can try this:
# Install ec2-tools (http://s3.amazonaws.com/ec2-downloads/ec2-api-tools.zip)
$ export EC2_PRIVATE_KEY=/path/to/your/key.pem
$ export EC2_CERT=/path/to/your/sert.pem
$ export AWS_ACCOUNT_ID=XXXX-XXXX-XXXX
$ export AWS_KEY=YOURAWSKEY
$ export AWS_SECRET_KEY=YOURAWSSECRETKEY
$ ec2-bundle-vol -d /tmp -k $EC2_PRIVATE_KEY -c $EC2_CERT -u $AWS_ACCOUNT_ID
$ ec2-upload-bundle -b s3-bucket-name -m /tmp/image.manifest.xml -a $AWS_KEY -s $AWS_SECRET_KEY
$ ec2-register s3-bucket-name/image.manifest.xml -K $EC2_PRIVATE_KEY -C $EC2_CERT --region eu-west-1
# In command above you can choose another region (e.g us-west-1)
# By running command above you will see on your screen something like this: IMAGE ami-3cc1a4a
# Now you can create new instance based on your just registered ami-3cc1a4a using ec2-tools or Amazon Console
Good luck!