AWS Task Definition warning when enabled "Auto-configure CloudWatch Logs" - amazon-web-services

when I enable Auto-configure CloudWatch Logs a warning about Network mode appears, it says Your containers in the task will share an ENI using a common network stack. Port mappings can only specify container ports (any existing host port specifications will be removed).
This is the warning that appears, I don't understand what that means

I don't think this has anything to do with the logging configuration. This has to do more with the networking option you picked (awsvpc). When you select that you are basically landing your task right inside the VPC and the task will get a VPC ip address. In other words there is no docker host natting where you expose the port 80 of your nginx container on port 12345 of the host. The warning is just saying that you need to make sure all your containers in the task do not overlap ports because they are reachable as-is on the VPC ip address assigned to the task. Note that awsvpc is the only networking mode supported on Fargate (because with Fargate there is not host anyway). See here for background on ECS networking modes.

Related

AWS: Changing host port in EC2 based ECS task definition using new ECS Console

I am trying to create a new EC2 based ECS task definition using the new ECS console (https://ap-south-1.console.aws.amazon.com/ecs/v2/task-definitions?region=ap-south-1). But in the port mapping section (which is part of Step 1) I only see the option to set Container port. I want this for an nginx container so container port 80 is fine, but I don't see any option to change host port (to 8080 for example).
When I go to the next step I see Fargate is chosen as the default app environment. I change that to EC2 only and go to create the definition. It creates the definition with host port as 80 as well. If I try to create a new revision I see the same options as above and no way to change host port.
Is this just something that's not been implemented in the new console design ? Or am I missing something here ? As I see the proper options to change host port in the classic UI.
Additionally, with this new UI I'm also not able to change things like network (defaults to awsvpc). It seems like this UI is geared completely to a Fargate type of application since all these options I talk about are not required to be configured for Fargate (as per my knowledge).
Thanks!
Unfortunately you cannot set host port, because the new ECS V2 console currently supports only awsvpc for the network mode.
From the console if we click the Info link:
The new Amazon ECS console experience currently only supports the awsvpc network mode, which provides the task with an elastic network interface (ENI).
For the awsvpc network mode, you can set only the container port, since this will be exposed through an ENI to your VPC. You would need bridge mode for being able to configure both the container and host ports.
The V2 console at this point is lacking in functionality compared to the older one. You would want to stick with the older one.
in the new console, Network mode has been moved to the 2nd page. only awsvpc and bridge are supported right now (and it defaults to awsvpc) while we are working to add more features.
The host port field will appear once the network mode is set to bridge - please note Fargate only supports awsvpc network mode.
By the way, please do submit feedback/feature requests/comments about the new console here: https://github.com/aws/containers-roadmap
Thanks!

AWS : VPC Networking mode

I have an ecs architecture, which has an application running as a container and a nginx side car container. So each task has 2 containers(nginx+app). These two containers are linked through bridge network mode. We currently observe increase in response time. We suspected it may be because of docker bridge network.So, we are trying to change to aws vpc mode networking. But when we tried to update to aws vpc network mode, it gave us an error 'Links are not supported when networkMode=awsvpc.'. So how to use aws vpc networking for these kind of side car architectures?
Linking is not supported in AWSVPC network mode.you need to use service discovery.
links
Type: string array
Required: no
The link parameter allows containers to communicate with each other
without the need for port mappings. Only supported if the network mode
of a task definition is set to bridge.
Note
This parameter is not supported for Windows containers or tasks using
the awsvpc network mode.
task_definition_parameters

AWS ECS error: Task failed ELB health checks in Target group

I am using cloud formation template to build the infrastructure (ECS fargate cluster).
Template executed successfully and stack has been created successfully. However, task has failed with the following error:
Task failed ELB health checks in (target-group arn:aws:elasticloadbalancing:eu-central-1:890543041640:targetgroup/prc-service-devTargetGroup/97e3566c8b307abf)
I am not getting what and where to look for this to troubleshoot the issue.
as it is fargate cluster, I am not getting how to login to container and execute some health check queries to debug further.
Can someone please help me to guide further on this and help me?
Due to this error, I am not even able to access my web app. As ALB won't route the traffic if it is unhealthy.
What I did
After some googling, I found this post:
https://aws.amazon.com/premiumsupport/knowledge-center/troubleshoot-unhealthy-checks-ecs/
However, I guess, this is related to EC2 compatibility in fargate. But in my case, EC2 is not there.
If you feel, I can paste the entire template as well.
please help
This is resolved.
It was the issue with the following points:
Docker container port mapping with host port were incorrect
ALB health check interval time was very short. Due to that, ALB was giving up immediately, not waiting for docker container to up and running properly.
after making these changes, it worked properly
There are quite a few of different possible reasons for this issue, not only the open ports:
Improper IAM permissions for the ecsServiceRole IAM role
Container instance security group Elastic Load Balancing load
balancer not configured for all Availability Zones Elastic Load
Balancing load balancer health check misconfigured
Unable to update the service servicename: Load balancer container name or port changed in task definition
Therefore AWS created an own website in order to address the possibilities of this error:
https://docs.aws.amazon.com/en_en/AmazonECS/latest/developerguide/troubleshoot-service-load-balancers.html
Edit: in my case the health check code of my application was different. The default is 200 but you can also add a range such as 200-499.
Let me share my experience.
In my case everything was correct, except the host on which the server listens, it was localhost which makes the server not reachable from the outside world and respectively the health check didn't work. It should be 0.0.0.0 or empty in some libraries.
I got this error message because the security group between the ECS service and the load balancer target group was only allowing HTTP and HTTPS traffic.
Apparently the health check happens over some other port and or protocol as updating the security group to allow all traffic on all ports (as suggested at https://docs.aws.amazon.com/AmazonECS/latest/userguide/create-application-load-balancer.html) made the health check work.
I had this exact same problem. I was able to get around the issue by:
navigate to EC2 service
then select Target Group in the side panel
select your target group for your load balancer
select the health check tab
make sure the health check for your EC2 instance is the same as the health check in the target group. This will tell your ELB to route its traffic to this endpoint when conducting its health check. In my case my health check path was /health.
In my case, ECS Fargate orchestration of the docker container functionality as a service and not a Web app or API. The service is that is not listening to any port (eg: Schedule corn/ActiveMQ message consumer ...etc).
In order words, it is a client and not a server node. So I made to listen to localhost for health check only...
All I added health check path in Target Group to -
And below code in index.ts -
import express from 'express';
const app = express();
const port = process.env.PORT || 8080;
//Health Check
app.get('/__health', (_, res) => res.send({ ok: 'yes' }));
app.listen(port, () => {
logger.info(`Health Check: Listening at http://localhost:${port}`);
});
As mentioned by tschumann above, check the security group around the ECS cluster. If using Terraform, allow ingress to all docker ephemeral ports with something like below:
resource "aws_security_group" "ecs_sg" {
name = "ecs_security_group"
vpc_id = "${data.aws_vpc.vpc.id}"
}
resource "aws_security_group_rule" "ingress_docker_ports" {
type = "ingress"
from_port = 32768
to_port = 61000
protocol = "-1"
cidr_blocks = ["${data.aws_vpc.vpc.cidr_block}"]
security_group_id = "${aws_security_group.ecs_sg.id}"
}
Possibly helpful for someone.. our target group health check path was set to /, which for our services pointed to Swagger and worked well. After updating to use Springfox instead of manually generating swagger.json, / now performs a 302 redirect to /swagger-ui.html, which caused the health check to fail. Since this was for a Spring Boot service we simply pointed the health check path in the target group to /health instead (OOTB Spring status page).
Solution is partial correct in response 'iravinandan', but in last part of your nodejs router just simple add status(200) and that's it. Or you can set your personal status clicking on advance tab, on end of the page.
app.get('/__health', (request, response) => response.status(200).end(""));
More info here: enter link description here
Regards
My case was a React application running on FARGATE mode.
The first issue was that the Docker image was built over NodeJS "serving" it with:
CMD npm run start # react-scripts start
Besides that's not a good practice at all, it requires a lot of resources (4GB & 2vCPU were not enough), and because of that, the checks were failing. (this article mentions this as a probable cause)
To solve the previous issue, we modify the image as a multistage build with NodeJS for the building phase + NGINX for serving the content. Locally that was working great, but we haven't realized that the default port for NGINX is 80, and you can not use a different host and container port on FARGATE with awsvpc network mode.
To troubleshoot it, I launched an EC2 instance with the right Security Groups to connect with the FARGATE targets on the same port the Load Balancer was failing to perform a Health Check. I was able to execute curl's commands against other targets, but with this unhealthy target (constantly being recycled) I received an instant Connection refused response. It wasn't a timeout, which told me that the target was not able to manage that request because it was not listening to that port. Then I realized that my container was expecting traffic on port 80 and my application was configured to work on a 3xxx port.
The solution here was to modify the default configuration of NGINX to listen to the port we wanted, re-build the image and re-launch the service.
On my case, my ECS Fargate service does not need load balancer so I've removed "Load Balancer" and "Security Group" then it works.
I had the same issue with deploying a java springboot app on ACS running as a fargate. There were 3 issues which I had to address to fix the problem, if this can help others in future.
The container was running on port 8080 (because of tomcat), so the ELB, target group and the two security groups (one with ELB and one with ECS) must allow 8080 in their inbounds rules. Also the task set up had to be revised to change the container to map at 8080.
The port on target group health check section (advance settings) had to be explicitly changed to 8080 instead of 80 as the default.
I had to create a dummy health check path in the application because pinging the root of the app at "/" was resulting in a 302 error code.
Hope this helps.
I have also faced the same issue while using the AWS Fargate.
Here are some possible solutions to try:
First Check the Security group of Service that Attached has outbound and Inbound rules in place.
If you are using the Loadbalancer and pointing out to target group then you must enable the docker container port on security group and attached the inbound traffic only coming from the ALB security group
3)Also check the healthcheck endpoint that we are assigning to target group are there any dependanies it should return only 200 status repsonse / what we have specifed in target group
In my case it was a security group rule which allowed connections only from a certain IP, and this was blocking healthchecks from LB. I added VPC's cidr as another rule to the security group and then it worked.

How to deploy continuously using just One EC2 instance with ECS

I want to deploy my nodejs webapp continuously using just One EC2 instance with ECS. I cannot create multiple instances for this app.
My current continuous integration process:
Travis build the code from github, build tag and push docker image and deployed to ECS via ECS Deploy shell script.
Everytime the deployment happen, following error occurs. Because the port 80 is always used by my webapp.
The closest matching container-instance ffa4ec4ccae9
is already using a port required by your task
Is it actually possible to use ECS with one instance? (documentation not clear)
How to get rid of this port issue on ECS? (stop the running container)
What is the way to get this done without using a Load Balancer?
Anything I missed or doing apart from the best practises?
The main issue is the port conflict, which occurs when deploying a second instance of the task on the same node in the cluster. Nothing should stop you from having multiple container instances apart from that (e.g. when not using a load balancer; binding to any ports at all).
To solve this issue, Amazon introduced a dynamic ports feature in a recent update:
Dynamic ports makes it easier to start tasks in your cluster without having to worry about port conflicts. Previously, to use Elastic Load Balancing to route traffic to your applications, you had to define a fixed host port in the ECS task. This added operational complexity, as you had to track the ports each application used, and it reduced cluster efficiency, as only one task could be placed per instance. Now, you can specify a dynamic port in the ECS task definition, which gives the container an unused port when it is scheduled on the EC2 instance. The ECS scheduler automatically adds the task to the application load balancer’s target group using this port. To get started, you can create an application load balancer from the EC2 Console or using the AWS Command Line Interface (CLI). Create a task definition in the ECS console with a container that sets the host port to 0. This container automatically receives a port in the ephemeral port range when it is scheduled.
Here's a way to do it using the green/blue deployment pattern:
Host your containers on port 8080 & 8081 (or whatever port you want). Let's call 8080 green and 8081 blue. (You may have to switch the networking mode from bridge to host to get this to work on a single instance).
Use Elastic Load Balancing to redirect the traffic from 80/443 to green or blue.
When you deploy, use a script to swap the active listener on the ELB to the other color/container.
This also allows you to roll back to a 'last known good' state.
See http://docs.aws.amazon.com/AmazonECS/latest/developerguide/service-load-balancing.html for more information.

How to connect hornetq on AWS VPC from another vm on AWS

I have 2 VMs on AWS. On the first VM I have hornet and application that send messages to hornet. On another VM I have application that is a consumer of hornet.
The consumer fails to pull messages from hornet, and I can't understand why. Hornetq is running, I opened to ports to any IP.
I tried to connect hornet with jconsole (on my local computer) and failed, so I can't see if the hornet has any consumers/ suppliers.
I've tried to change 'bind' configurations to 0.0.0.0 but when I restarted hornet they were automatically changed to what I have as server IP in config.properties.
Any suggestions what might be the problem that I failed to connect my application to the hornetq?
Thanks!
These are the things you need to check for the connectivity between VMs in VPC.
The Security- Group of the instance has both Ingress-Egress Configuration settings unlike the traditional EC2 Security Group [ now Classic EC2 ]. Check the Egress from your Consumer and ingress to the Server
If the instances are in different Subnets you need to check for the ACL as well; however the default setting would be allow.
Check if the iptables / OS level firewall which are blocking.
With respect to the connectivity failed from your local machine to Hornetq - you need to place the Instance in Public sub and configure the Instance's SG accordingly; only the app / VM would accessible to public internet
I have assumed that both the instances are in the Same VPC. However the title of the post sounds slightly misleading - if it is 2 different VPCs altogether, then new concept of VPC Peering also comes in