How to add healthcheck on multiple ports on nginx load balancer? - nginx

We are using nginx for load balancing our application. There are 4 nodes which need to be load-balanced in round-robin fashion.
The load balancing is working fine.
The runtime service is listening at port 9001, which internally redirects to other service on the same node.
So we have defined upstream in nginx.conf, with state file "cluster.state". Following is the excerpt from nginx.conf
upstream cluster {
zone cluster 64k;
state /var/nginx/state/cluster.state;
}
Following is the excerpt in "server" block to route the calls:
location /apipattern {
proxy_set_header Host $host:$server_port;
proxy_read_timeout 300s;
proxy_pass http://cluster/;
}
Following is the excerpt from cluster.state file (changed FQDNs, but port is correct)
server foobar1.com:9001 resolve;
server foobar2.com:9001 resolve;
server foobar3.com:9001 resolve;
server foobar4.com:9001 resolve;
The requirement is to put a healtcheck in place (for nodes mentioned in cluster.state).
The healthcheck services (2 services), on these nodes are available on port 8081 and 8082, with uri=/healthcheck/isup (and NOT on 9001)
How do we configure these healthchecks?

you can add multiple health_check directives under location directive with custom port and uri to have compound/multiple monitors for upstream. This is only possible with NGINX plus, which offers active health checking.
location /juice {
proxy_set_header Host $host;
proxy_pass http://juice/;
health_check port=800 uri=/custom.html;
health_check port=8081 uri=/hello.html;
}

Related

nginx reverse proxy to different applications based on an index in the host name

Previously, I had a single staging environment reachable behind a DNS staging.example.com/. Behind this address is a nginx proxy with the following config. Note that my proxy either redirects
To a (s3 behind) cloudfront distribution (app1)
To a loadbalancer by forwarding the host name (and let's consider my ALB is able to pick the appropriate app based on the host name) (app2)
server {
listen 80;
listen 443 ssl;
server_name
staging.example.com
;
location / {
try_files /maintenance.html #app1;
}
location ~ /(faq|about_us|terms|press|...) {
try_files /maintenance.html #app2;
}
[...] # Lots of similar config than redirects either to app1 or app2
# Application hosted on s3 + CloudFront
location #app1 {
proxy_set_header Host app1-staging.example.com;
proxy_pass http://d2c72vkj8qy1kv.cloudfront.net;
}
# Application hosted behind a load balancer
location #app2 {
proxy_set_header Host app2-staging.example.internal;
proxy_set_header X-ALB-Host $http_host;
proxy_pass https://staging.example.internal;
}
}
Now, my team needs a couple more staging environments. We are not yet ready to transition to docker deployments (the ultimate goal of being able to spawn a complete infra per branch that we need to test... is a bit overkill given our team size) and I'm trying to pull out some tricks instead so we can easily get a couple more staging environments using roughly the same nginx config.
Assume I have a created a few more DNS names with a index_i like staging1.example.com, staging2.example.com. So my nginx proxy will receive requests with a host header that looks like staging#{index_i}.example.com
What I'm thinking of doing :
For my s3 + Cloudfront app, I'm thinking of nesting my files under [bucket_id]/#{index_i}/[app1_files] (previously they were directly in the root folder [bucket_id]/[app1_files])
For my load balancer app, let's assume my load balancer knows where to dispatch https://staging#{iindex_i}.example.com requests.
I'm trying to pull something like this
# incoming host : staging{index_i}.example.com`
server {
listen 80;
listen 443 ssl;
server_name
staging.example.com
staging1.example.com
staging2.example.com # I can list them manually, but is it possible to have something like `staging*.example.com` ?
;
[...]
location #app1 {
proxy_set_header Host app1-staging$index_i.example.com; # Note the extra index_i here
proxy_pass http://d2c72vkj8qy1kv.cloudfront.net/$index_i; # Here proxy_passing to a subfolder named index_i
}
location #app2 {
proxy_set_header Host app2-staging$index_i.example.internal; # Note the extra index_i here
proxy_set_header X-ALB-Host $http_host;
proxy_pass http://staging$index_i.example.internal; # Here I am just forwarding the host header basically
}
So ultimately my questions are
- When my nginx server receives a connexion, can I extract the index_i variable from the request host header (using maybe some regex ?)
- If yes, how can effectively implement the app1 and app2 blocks with index_i ?
After looking at several other questions, I was able to come up with this config that works perfectly: it's possible to extract the said variable using a regex in the host name.
On the downside, for my static single page applications, to make it work with S3, I had to create one bucket per "staging index" (because of the way static hosting on S3 works with website hosting / a single index.html to be used on 404). This made it in turn impossible to work with a single Cloudfront distribution in front of my (previously single) s3.
Here is example of using a proxy with a create-react-app frontend and server-side rendering behind an ALB
server {
listen 80;
listen 443 ssl;
server_name ~^staging(?<staging_index>\d*).myjobglasses.com$
location #create-react-app-frontend {
proxy_pass http://staging$staging_index.example.com.s3-website.eu-central-1.amazonaws.com;
}
location #server-side-rendering-app {
# Now Amazon Application Load Balancer can redirect traffic based on ANY HTTP header
proxy_set_header EXAMPLE-APP old-frontend;
proxy_pass https://staging$staging_index.myjobglasses.com;
}

How to configure nginx to expose multiple services on Jelastic?

Through Jelastic's dashboard, I created this:
I just clicked "New environment", then I selected nodejs. I added a docker image (of mailhog).
Now, I would like that port 80 of my environment serves the nodejs application. This is by default so. Therefore nothing to do.
In addition to this, I would like port 8080 (or any other port than 80, like port 5000 for example) of my environment serves mailhog, hosted on the docker image. To do that, I added the following lines to the nginx-jelastic.conf (right after the first server serving the nodejs app):
server {
listen *:8080;
listen [::]:8080;
server_name _;
location / {
proxy_pass http://mailhog_upstream;
}
}
where I have also defined mailhog_upstream like this:
upstream mailhog_upstream{
server 10.102.8.215; ### DEFUPPROTO for common ###
sticky path=/; keepalive 100;
}
If I now browse my environment's 8080 port, then I see ... the nodejs app. If I try any other port than 80 or 8080, I see nothing. Putting another server_name doesn't help. I tried several things but nothing seems to work. Why is that? What am I doing wrong here?
Then I tried to get rid of the above mailhog_upstream and instead write
server {
listen *:5000;
listen [::]:5000;
server_name _;
location / {
proxy_pass http://10.102.8.215;
}
}
Browsing the environment's port 5000 doesn't work either.
If I replace the IP of the nodejs' app with that of my mailhog service, then mailhog runs on port 80. I don't understand how I can make the nodejs app run on port 80 and the mailhog service on port 5000 (or any other port than 80).
Could someone enlighten me please?
After all those failures, I tried another ansatz. Assume the path my env is example.com/. What I've tried above is to get mailhog to work upon calling example.com:5000, which I failed doing. Then I tried to make mailhog available through a call to example.com/mailhog. In order to do that, I got rid of all my modifications above and completed the current server in nginx-jelastic.conf with
location /mailhog {
proxy_pass http://10.102.8.96:8025/;
add_header Set-Cookie "SRVGROUP=$group; path=/";
}
That works in the sense that if I know browse example.com/mailhog, then I get something on the page, but not exactly what I want: it's the mailhog's page without any styling. Also, when I call mailhog's API through example.com/mailhog/api/v2/messages, I get a successful response without body, when I should've received
{"total":0,"count":0,"start":0,"items":[]}
What am I doing wrong this time?
Edit
To be more explicit, I put the following manifest that exhibits the second problem with the nginx location.
Full locations list for your case is a following:
(please pay attention to URIs in upstreams, they are different)
location /mailhog { proxy_pass http://172.25.2.128:8025/; proxy_http_version 1.1; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection " upgrade"; }
location /mailhog/api { proxy_pass http://172.25.2.128:8025/api; proxy_http_version 1.1; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection " upgrade"; }
location /css { proxy_pass http://172.25.2.128:8025; }
location /js { proxy_pass http://172.25.2.128:8025; }
location /images { proxy_pass http://172.25.2.128:8025; }
that works for me with your application
# curl 172.25.2.127/mailhog/api/v2/messages
{"total":0,"count":0,"start":0,"items":[]}
The following ports are opened by default: 80, 8080, 8686, 8443, 4848, 4949, 7979.
Additional ports can be opened using:
endpoints - maps the container internal port to random external
via Jelastic Shared LB
Public IP - provides a direct access to all ports of your
container
Read more in the following article: "Container configuration - Ports". This one may also be useful:"Public IP vs Shared Load Balancer"

Reverse Proxy: HTTPS forwarding to VM (OwnCloud)

I am running a few Virtual Box'es on my host - one of them is from OwnCloud. This allowed me to set it up really fast, and using PhpVirtualBox, I also have a nice tool for management.
I already know how to forward HTTP traffic to my VMs. They are all set up as NAT with their ports forwarded by scheme:
1VNNN
1: The master-range
V: Virtual Box ID. Basically an ID i choose.
N: Port
That means I have 12080 and 12443 for the OwnCloud box. And now I would like to forward HTTPS traffic. Here is what I did with regular HTTP:
nginx/sites-available/owncloud:
server {
listen (...some ip...):80;
server_name cloud.example.com;
# Proxy
set $REMOTE_PORT 12080;
include basic_proxy;
}
nginx/basic_proxy:
# Proxy
# Really basic, does HTTP stuffles.
# #var $REMOTE_PORT : Remote HTTP port
location / {
proxy_pass http://127.0.0.1:$REMOTE_PORT;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
}
And now I'd like to do it the HTTPS way. What'd be a good way to do so?
I am likely going to share a lot of configs like for proxy, PHP apps and such, which is why I made this into an external file immediately. Modularity is pretty useful.

Config settings for securing Elasticsearch with Nginx

I am running Kibana 1.3 and ElasticSearch 1.4 on the same host and I have installed Nginx in an attempt to keep connections to ES locally. To browse Kibana remotely, I have also registered a dynamic DNS domain name and bind it with the host on which Kibana and ElasticSearch are running on e.g. http://example.no-ip.org.
I think the use of dynamic DNS domain name has caused problems with connectionbetween Kibana and ES and I'm not sure how the configurations should be set so that:
1) only Kibana can communicate with ElasticSearch and on a local-basis
2) ElasticSearch API is not exposed to the world.
The guide I followed is: http://www.elasticsearch.org/blog/playing-http-tricks-nginx/
Here's the config for Nginx:
events {
worker_connections 1024;
}
http {
upstream elasticsearch {
server 127.0.0.1:9200;
server 127.0.0.1:9201;
server 127.0.0.1:9202;
keepalive 15;
}
server {
listen 8080;
location / {
proxy_pass http://elasticsearch;
proxy_http_version 1.1;
proxy_set_header Connection "Keep-Alive";
proxy_set_header Proxy-Connection "Keep-Alive";
}
}
}
And here's the config settings I added in elasticsearch.yml:
network.host: "127.0.0.1"
http.host: "127.0.0.1"
http.cors.allow-origin: "/.*/"
http.cors.enabled: true
As for Kibana, I have changed the default settings to use port 8080:
elasticsearch: "http://" + window.location.hostname + ":8080",
Thank you very much for your help in advance!

How to configure IPython behind nginx in a subpath?

I've got nginx running handling all SSL stuff and already proxying / to a Redmine instance and /ci to a Jenkins instance.
Now I want to serve an IPython instance on /ipython through that very same nginx.
In nginx.conf I've added:
http {
...
upstream ipython_server {
server 127.0.0.1:5001;
}
server {
listen 443 ssl default_server;
... # all SSL related stuff and the other proxy configs (Redmine+Jenkins)
location /ipython {
proxy_pass http://ipython_server;
}
}
}
In my .ipython/profile_nbserver/ipython_notebook_config.py I've got:
c.NotebookApp.base_project_url = '/ipython/'
c.NotebookApp.base_kernel_url = '/ipython/'
c.NotebookApp.port = 5001
c.NotebookApp.trust_xheaders = True
c.NotebookApp.webapp_settings = {'static_url_prefix': '/ipython/static/'}
Pointing my browser to https://myserver/ipython gives me the usual index page of all notebooks in the directory I launched IPython.
However, when I try to open one of the existing notebooks or create a new one, I'm getting the error:
WebSocket connection failed: A WebSocket connection to could not be established. You will NOT be able to run code. Check your network connection or notebook server configuration.
I've tried the same setup with the current stable (1.2.1, via pypi) and development (Git checkout of master) version of IPython.
I also tried adjusting the nginx config according to nginx reverse proxy websockets with no avail.
Due to an enforced policy I'm not able to allow connections to the server on other ports than 443.
Does anybody have IPython running behind an nginx?
I had the same problem. I updated nginx up to the current version (1.6.0). It seems to be working now.
Server config:
location /ipython {
proxy_pass http://ipython_server;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
proxy_set_header Origin "";
}
See: http://nginx.org/en/docs/http/websocket.html

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