I have an EC2 instance with a few applications successfully deployed onto it, listening for connections on ports 3000/3001/3002. I can correctly load a web page from it by connecting to its public DNS or public IP on the given port. I.e. curl http://<ec2-ip-address>:3000 works. So I know that the apps are running, and I know that the port bindings/firewall rules/EC2 security groups are all set up correctly to receive connections from the outside world.
I also have an Application Load Balancer, which is supposed to route traffic to the 3 apps depending on the host name, but it always gives me "504 Gateway Time-out". I've checked all the settings but I can't see what's wrong and I'm not really sure how to troubleshoot it from here.
The ALB has a single HTTPS/443 listener, with a cert that's valid for mydomain.com, app1.mydomain.com, app2.mydomain.com, app2.mydomain.com.
The listener has 3 rules, plus the default rule:
Host == app1.mydomain.com => app1-target-group
Host == app2.mydomain.com => app2-target-group
Host == app3.mydomain.com => app3-target-group
Default action (last resort) => default-target-group
Each target group contains only the single EC2 instance, over HTTP, with the following ports:
app1-target-group: 3000
app2-target-group: 3001
app3-target-group: 3002
default-target-group: 3000
Given that I can access the app directly, I'm sure it must be a problem with the way I've configured the ALB/listener/target groups. But the 504 doesn't give me much to go on.
I've tried to turn on access logs to an S3 bucket, but it doesn't seem to be writing anything there. There's a single object called ELBAccessLogTestFile, and no actual logs in the bucket.
EDIT: Some more information... I actually have nginx installed on the EC2 instance, which is where I was previously doing the SSL termination and hostname-to-port mapping/routing. If I change the default-target-group above to point to port 443 over HTTPS, then it works!
So for some reason, routing traffic
- from the ALB to the EC2 instance over HTTPS on port 443 -> OK!
- from the ALB to the EC2 instance over HTTP on port 3000 -> Broken!
But again, I can hit the instance directly on HTTP/3000 from my laptop.
Communication between resources in the same security group is not open by default. Security group membership alone does not provide special access. You still need to open the ports in the security group to allow other resources in the security group to access those ports. You can specify the security group ID in the rule's source field if you don't want to open it up beyond the resources in the security group.
Related
I have deployed a spring boot application in elasticbeanstalk.
In the "application.properties" file, I have set,
server.port=5000
I have added a RDS db and set the following environment properties.
I have also added an inbound rule in the security group of the environment as shown in the image below:
I am still getting the 502 Bad Gateway error when I click on the URL.
Your rule is incorrect.
0.0.0.0/32 means that you accept traffic only from the IP address 0.0.0.0 which basically doesn't exist.
What you want to do is allow traffic from 0.0.0.0/0 which means accept traffic from anywhere in the world.
In case of Elastic Beanstalk, in your instance there is an nginx reverse proxy, which accepts HTTP connections on port 80 and proxies these connections to port 5000.
In your security group inbound rule you should accept HTTP connections on port 80 from everywhere (0.0.0.0/0).
Background
I have followed this tutorial https://docs.aws.amazon.com/AmazonECS/latest/developerguide/ecs-cli-tutorial-ec2.html, composed a docker compose file, made a website A (compose of 4 containers) up and run serving 1 of my client.
However, now I have another client which I need to host another web site website B using similar strategies as above.
Here is the current running service of ECS / EC2
and here are the containers up and running, serving website A now
Questions & concerns
The website A is now situated as 1 of a service in the EC2 under my only cluster, can I use the same EC2 instance and run website B (as another service of the EC2)?
If so, how are the ports / inbound / outbound traffic being managed? Now website A already occupies port 80, 443, 27017 and 3002 of the EC2 instance for inbound traffic, if website B's containers also run in the same EC2 instances, can I still use port 80, 443, 27017 and 3002 for website B. I have read the docs of ALB (Amazon Load Balancer), seems it can fulfill the requirement, am I at the right track?
And the domain name, through route 53, I have registered a domain www.websiteA.com to serve the 1st website, I have also registered another www.websiteB.com preparing to serve website B, in my case, I guess I need to configure the new domain B pointing to the same EC2 IP?
During my deployment of website B, I do not want to affect the availability of website A, can it be maintained during the process of deploying website B's containers?
I want to clear all the concepts before kick-starting to deploy the website B, appreciate for any help, thank you
Follow-up actions
I come up decided to use AWS application load balancer to solve my issue, and have the following configurations setup.
I first look into load balancer
And configured as follows
I setup a load balancer which listens for requests using HTTP protocol with incoming port 80, whenever there are users access the web server (i.e.: the frontend container), listener will forward that request to the target group (i.e.: http-port-80-access)
And here is the target group (http-port-80-access) which contains a registered target (currently my ec2 instance running the containers), the host port of the container is 32849 which in turn made used by the associated load balancer (web-access-load-balancer) for dynamic port mapping.
I have also configured 1 more rule on top of the default rule, whenever user access url of websiteA, load balancer will forward the request to the target group (http-port-80-access).
All things set, and the healthy test also passed. I then used the following ecs-cli compose service up command to wire up the load balancer with the service
ecs-cli compose --file ./docker-compose-aws-prod.yml --cluster my-ecs-cluster-name --ecs-profile my-ecs-profile --cluster-config my-cluster --project-name my-project --ecs-params ./ecs-params.yml service up --target-group-arn arn:aws:elasticloadbalancing:us-east-2:xxxxxxxxx:targetgroup/http-port-80-access/xxxxxxxx --container-name frontend --container-port 80
where frontend is the service name of the frontend container of website A
However, turn out when I access www.websiteA.com through browser, nothing but ERR_CONNECTION_REFUSED, accessing www.websiteA.com:32849 did accessible, but is not what I desired.
I am wondering which part I configured wrongly
If you are sending traffic directly to the instance then you would have to host on a different port. You should consider using an ALB, which would allow you to use dynamic ports in ECS. The ALB can accept traffic from ports 80 and 443 for different domains and route the traffic to different containers based on things like the domain.
The website A is now situated as 1 of a service in the EC2 under my only cluster, can I use the same EC2 instance and run website B (as another service of the EC2)?
Indeed. However - as you already found out, you have to split the traffic based on something (hostname, path,..). That's where the reverse-proxy comes in play (either managed - ALB, NLB or your own - nginx, haproxy,.. ) .
It's simple for the http traffic (based on the host)
If so, how are the ports / inbound / outbound traffic being managed? Now website A already occupies port 80, 443, 27017 and 3002 of the EC2 instance for inbound traffic, if website B's containers also run in the same EC2 instances, can I still use port 80, 443, 27017 and 3002 for website B.
assuming the ports 27017 and the 3002 are using own binary protocol (not http). You will have handle that.
You can in theory define the port mapping (map different public listening port to these custom ports), but then you need to either use NLB (network load balancer) or expose the ports on hosts public IP. In the latter case I'm not sure with ECS you can guarantee which IP is used (e.g. having multiple worker nodes)
I have read the docs of ALB (Amazon Load Balancer), seems it can fulfill the requirement, am I at the right track?
ALB is layer 7 reverse proxy (http), it is imho the best option for the web access, not for binary protocols.
, I guess I need to configure the new domain B pointing to the same EC2 IP?
that's the plan
During my deployment of website B, I do not want to affect the availability of website A, can it be maintained during the process of deploying website B's containers?
shouldn't be a problem
Run website B on different ports. To allow end users to interact with website B without specify port numbers use a reverse-proxy. See AWS CloudFront.
I am confused about configuring the EC2 security group settings.
There are three options (TCP, SSH, HTTPS) and each of them requires you to add an IP/port number.
For context, in my work I'm usually running Flask apps over EC2 and I only want particular people to view them. My question is understanding the difference between TCP, SSH, and HTTPs but more importantly which of these are important for me to configure.
Within the EC2 Console, under Security Groups:
SSH and HTTPS in the Type dropdown, are presets which set the port to 22 and 443 respectively.
TCP is the protocol. Both SSH and HTTPS are TCP.
If you're running a server which you want to expose on a non standard port, you can select Custom TCP Rule, then set the port acordingly.
You should probably have one security group that allows SSH traffic, then assign this security group to the EC2 instances you wish to shell into:
Then have a separate security group that allows the webserver traffic, in this case I also have one for port 80, aswell as 443:
Of course you will then need a server running on that EC2 instance to receive the traffic. This might be a reverse proxy like nginx, which then proxies traffic to the correct port for your app server (run your flask app with something like gunicorn in production).
If nginx and gunicorn are running on the same box, and say gunicorn serves on port 8000, then you wouldn't need a security group for this as it's loopback traffic. Your nginx configuration points to port 8000.
However if you have a separate EC2 instance running gunicorn, you might wish to set up a secuirty group for this to allow internal traffic from your VPC CIDR range:
I only want particular people to view them
This is probably a job for authentication on the app, as oppose to security groups, unless your certain of the public IPs from which you wish people to connect.
In the above examples above a Source of 0.0.0.0/0 is allowing traffic from anywhere to reach that port. The console has a convenient dropdown which lets you set My IP if you only want to allow traffic from the IP you're using to connect to the console. Otherwise you'd need to manually calculate the CIDR blocks.
Hope this helps. It probably raises more questions.
Https/Http are important for you. Both are used with websites. Https is http over SSL, meaning more secure than http. You just need these.
Http/https uses TCP port 80 and 443 by default.
SSH is used to securely access a Unix based server.
I'm getting gateway time-outs when trying to use a port specifically for websockets using an Application Load Balancer inside an Elastic Beanstalk environment.
The web application and websocket server is held within a Docker container, the application runs fine however wss://domain.com:8080 will just time out.
Here is the Load balancer listeners, using the SSL cert for wss.
The target group it points to is accepting 'Protocol' of HTTP (I've tried HTTPS) and forwards to 8080 onto an EC2 instance. Or.. It should be. (Doesn't appear to be an option for TCP on Application Load Balancers).
I've had a look over the Application Load Balancer logs and it looks like the it reaches the target group, but times out between it's connection to the EC2 instance, and I'm stumped on why.
All AWS Security Groups have been opened on all traffic for the time being, I've checked the host and found that the port is open and being listened to by Nginx which will route to the correct port to the docker container:
docker ps also shows me:
And once inside the container I can see that the port is being listened to by the Websocket server:
So it can't be the EC2 instance itself, can it? Is there an issue routing websockets via ports in an ALB?
-- Edit --
Current SG of the ALB:
The EC2 instance SG:
Accepted answer here seems to be "open Security Groups for EC2 (web server) and ALB inbound & outbound communication on required ports since websockets need two way communication."
This is incorrect and the reason why it solved the problem is coincidental.
Let me explain:
"Websockets needs two way communication..." - Sure but the TCP sessions is only ever opened from one way - from the client.
You don't have to allow any outbound connections from the EC2 instance (web server) in order to use web sockets.
Of course the ALB needs to be able to do TCP connections to the EC2 instance. But not to the client. Why? Well the ALB is accepting TCP connections (usually on port 80 and 443). It is setting up a TCP session that was initiated by the client. It is then trying to set up a new TCP session to the web server behind the ALB. This should be done on the port that you decided to have the web server listening on. The Security Group around the ALB needs to be able to do outbound connections on this port to the web server. This is the reason why "open up everything" worked. It has nothing to do with "two way communication".
You could use any ports of course but you don't need to use any other ports than 80 & 443 (such as 8080) on both the Load Balancer or the EC2.
Websockets need two way communication, make sure security groups attached to all resources (EC2 & ALB) allow both inbound & outbound communication on required ports.
I've registered domain with bigrock.in
Created ec2 instance in aws
created elastic ip
registered with route53 and gave my domain name
changed the name servers in bigrock with the provided names in bigrock
ssh to the ec2 instance with elastic ip
ran node.js app with forever
with the following environemnt variables
export ROOT_URL="www.domain.com"
at the time of route53 process, I created A record with www sub-domain to elasticIp
But, I'm not seeing anything at domain.com or at elasticIp xxx.xxx.xxx.xxx
Did I miss any steps, Is there anything wrong I did or do I need to do anything to make this works
EDIT
I haven't added any A or CNAME records to bigrock just changed the name server to the servers provided by ROuter53
Edit 2
that is my security group outbound details, My app is running on port 80.
Are those settings correct?
EDIT 3
My INbound rules
You've got a rule to allow all traffic from anywhere on the INBOUND security groups so its not that (make sure you fix this later when you get it working - as it is, its a bit of a security hole).
Next thing I would normally say is its a dns problem, but as you say you've tried going to the eip as well as the domain name its not that either.
Next likely candidates are:
The server isnt listening - it may be that it hasnt started properly try checking the logs,The machine's firewall is blocking connections. (try turning it off - keep this at VERY short time length though - its a huge risk in combination with your security group settings)
Or your server is not listening on port 80, e.g. it might be listening on 8080 or 443. Check the server config - by default browsers assume port 80 for http, if its not listening on that you will have to specify the port in the address bar as well e.g. http://example.com:8080