I have a nginx as proxy, and uWSGI as app server. And I want to add any http headers to uwsgi logs. I can add some var.VAR_NAME to logs.
By docs (http://uwsgi-docs.readthedocs.io/en/latest/LogFormat.html):
%(var.XXX) -> the content of request variable XXX (like var.PATH_INFO, available from
1.9.21)
But this worked only for uwsgi_param from nginx, not for proxy_set_header or smt. like this.
I found answer in uwsgi github issues - https://github.com/unbit/uwsgi/issues/1407#issuecomment-326605267 and updated the docs (http://uwsgi-docs.readthedocs.io/en/latest/LogFormat.html):
%(var.XXX) -> the content of request variable XXX (like var.PATH_INFO
or var.HTTP_X_MY_HEADER for headers from request, available from
1.9.21)
Related
I am running nginx as part of the docker-compose template.
In nginx config I am referring to other services by their docker hostnames (e.g. backend, ui).
That works fine until I do that trick:
docker stop backend
docker stop ui
docker start ui
docker start backend
which makes backend and ui containers to exchange IP addresses (docker provides private network IPs on a basis of giving the next IP available in CIDR to each new requester). This 4 commands executed imitate some rare cases when both upstream containers got restarted at the same time but the nginx container did not. Also, I believe, this should be a very common situation when running pods on Kubernetes-based clusters.
Now nginx resolves backend host to ui's IP and ui to backend's IP.
Reloading nginx' configuration does help (nginx -s reload).
Also, if I do nslookup from within the nginx container - the IPs are always resolved correctly.
So this isolates the problem to be a pure nginx issue around the DNS caching.
The things I tried:
I have the resolver set under the http {} block in nginx config:
resolver 127.0.0.11 ipv6=off valid=10s;
Most common solution proposed by the folks on the internet to use variables in proxy-pass (this helps to prevent nginx to resolve and cache DNS records on start) - that did not make ANY difference at all:
server {
<...>
set $mybackend "backend:3000";
location /backend/ {
proxy_pass http://$mybackend;
}
}
Tried adding resolver line into the location itself
Tried setting the variable on the http{} block level, using map:
http {
map "" $mybackend {
default backend:3000;
}
server {
...
}
}
Tried to use openresty fork of nginx (https://hub.docker.com/r/openresty/openresty/) with resolver local=true
None of the solutions gave any effect at all. The DNS caches are only wiped if I reload nginx configuration inside of the container OR restart the container manually.
My current workaround is to use static docker network declared in docker-compose.yml. But this has its cons too.
Nginx version used: 1.20.0 (latest as of now)
Openresty versions used: 1.13.6.1 and 1.19.3.1 (latest as of now)
Would appreciate any thoughts
UPDATE 2021-09-08: Few months later I am back to solving this same issue and still no luck. Really looks like the bug in nginx - I can not make nginx to re-resolve the dns names. There seems to be no timeout to nginx' dns cache and none of the options listed above to introduce timeouts or trigger dns flush work.
UPDATE 2022-01-11: I think the problem is really in the nginx. I tested my config in many ways a couple months ago and it looks like something else in my nginx.conf prevents the valid parameter of the resolver directive from working properly. It is either the limit_req_zone or the proxy_cache_path directives used for request rate limiting and caching respectively. These just don't play nicely with the valid param for some reason. And I could not find any information about this anywhere in nginx docs.
I will get back to this later to confirm my hypothesis.
Maybe it's because nginx's DNS resolver for upstream servers only works in the commercial version, nginx plus?
https://www.nginx.com/products/nginx/load-balancing/#service-discovery
TLDR: Your Internet Provider may be caching dnses with no respect to tiny TTL values (like 1 second).
I've been trying to retest locally the same thing.
Your docker might be using local resolver (127.0.0.11)
Then Dns might be cached by your OS (which you may clean - that's OS specific)
Then you might have it cached on your WIFI/router (yes!)
Later it goes to your ISP and is beyond your control.
But nslookup is your friend, you can query each dns server between nginx and root DNS server.
Something very easy to reproduce (without setting up local dns server)
Create route 53 'A' entry with TTL of 1 second and try to query AWS dns server in your hosted zone (it will be sth. like ns-239.awsdns-29.com)
Play around with dig / nslookup command
nslookup
set type=a
server ns-239.awsdns-29.com
your.domain.com
It will return IP you have set
Change the Route53 'A' entry to some other ip.
use dig / nslookup and make sure you see changes immediately
Then set resolver in nginx to AWS dns name (for testing purposes only).
If that works it means that DNS is cached elsewere and this is no longer nginx issue!
In my case it was sunrise WIFI router which began to see new IP only after I restarted it (I assume things would resolve after some longer value).
Great help when debugging this is when your nginx is compiled with
--with-debug
Then in nginx logs you see whether given dns was resolved and to what IP.
My whole config looks like this (here with standard docker resolver which has to be set if you are using variables in proxy_pass!)
server {
listen 0.0.0.0:8888;
server_name nginx.my.custom.domain.in.aws;
resolver 127.0.0.11 valid=1s;
location / {
proxy_ssl_server_name on;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-Proto https;
proxy_set_header Host $host;
set $backend_servers my.custom.domain.in.aws;
proxy_pass https://$backend_servers$request_uri;
}
}
Then you can try to test it with
curl -L http://nginx.my.custom.domain.in.aws --resolve nginx.my.custom.domain.in.aws 0.0.0.0:8888
Was struggling on the same thing exactly for the same thing (Docker Swarm) and actually to make it work I required to let the upstream away from my configuration.
Something that works well (tested 5' ago on NGINX 2.22) :
location ~* /api/parameters/(.*)$ {
resolver 127.0.0.11 ipv6=off valid = 1s;
set $bck_parameters parameters:8000;
proxy_pass http://$bck_parameters/api/$1$is_args$args;
}
where $bck_parameters is NOT an upstream but the real server behind.
Doing same thing with upstream will fail.
I am running nginx/1.19.6 on Ubuntu.
I am struggling to get the upstream module to work without returning a 404.
My *.conf files are located in /etc/nginx/conf.d/
FILE factory_upstream.conf:
upstream factoryserver {
server factory.service.corp.com:443;
}
FILE factory_service.conf:
server
{
listen 80;
root /data/www;
proxy_cache factorycache;
proxy_cache_min_uses 1;
proxy_cache_methods GET HEAD POST;
proxy_cache_valid 200 72h;
#proxy_cache_valid any 5m;
location /factory/ {
access_log /var/log/nginx/access-factory.log main;
proxy_set_header x-apikey abcdefgh12345678;
### Works when expressed as a literal.# proxy_pass https://factory.service.corp.com/;
### 404 when using the upstream name.
proxy_pass https://factoryserver/;
}
}
I have error logging set to debug, but after reloading the configuration and attempting a call, there are no new records in the error log.
nginx -t # Scans OK
nginx -s reload # no errors
cat /var/log/nginx/error.log
...
2021/03/16 11:29:52 [notice] 26157#26157: signal process started
2021/03/16 11:38:20 [notice] 27593#27593: signal process started
The access-factory.log does record the request :
127.1.2.3 --;[16/Mar/2021:11:38:50 -0400];";GET /factory/api/manifest/get-full-manifest/PID/904227100052 HTTP/1.1" ";/factory/api/manifest/get-full-manifest/PID/904227100052" ;404; - ;/factory/api/manifest/get-full-manifest/PID/904227100052";-" ";ID="c4cfc014e3faa803c8fe136d6eae347d ";-" ";10.8.9.123:443" ";404" ";-"
To help with debugging, I cached the 404 error, "proxy_cache_valid any 5m;" commented out in the example above:
When I use the upstream name, the cache file contains the followiing:
<##$ non-printable characters $%^>
KEY: https://factoryserver/api/manifest/get-full-manifest/PID/904227100052
HTTP/1.1 404 Not Found
Server: nginx/1.17.8
Date: Tue, 16 Mar 2021 15:38:50 GMT
...
The key contains the name 'factoryserver' I don't know if that matters or not. Does it?
The server version is different than what I see when I enter the command nginx -v, which is: nginx version: nginx/1.19.6
Does the difference in version in the cache file and the command line indicate anything?
When I switch back to the literal server name in the proxy_pass, I get a 200 response with the requested data. The Key in the cache file then contains the literal upstream server name.
<##$ non-printable characters $%^>
KEY: https://factory.service.corp.com/api/manifest/get-full-manifest/PID/904227100052
HTTP/1.1 200
Server: nginx/1.17.8
Date: Tue, 16 Mar 2021 15:59:30 GMT
...
I will have multiple upstream servers, each providing different services. The configuration will be deployed to multiple factories, each with its own upstream servers.
I would like for the deployment team to only have to update the *_upstream.conf files, and keep the *_service.conf files static from deployment site to deployment site.
factory_upstream.conf
product_upstream.conf
shipping_upstream.conf
abc123_upstream.conf
Why do I get a 404 when using a named upstream server?
Based on the nginx version in the cached response not matching what you see on the command line, it seems that maybe the 404 is coming from the upstream server. I.e, your proxying is working, but the upstream server is returning a 404. To troubleshoot further, I would check the nginx logs for the upstream server and if the incoming request is what you expect.
Note that when using proxy_pass, it makes a big difference whether you have a / at the end or not. With a trailing slash, nginx treats this as the URI it should send the upstream request to and it doesn't include the URI matched by the location block (/factory/) while without, it includes the full URI as-is.
proxy_pass https://factoryserver/ results in https://factory.service.corp.com:443/
proxy_pass https://factoryserver results in https://factory.service.corp.com:443/factory/
Docs: https://docs.nginx.com/nginx/admin-guide/web-server/reverse-proxy/
So maybe when switching between using an upstream and specifying the literal server name, you're inadvertently being inconsistent with the trailing slash. It's a really easy detail to miss, especially when you don't know it's important.
Please provide more information about your server configuration where you proxy pass the requests. Only difference I see now is that you specify the port (443) in your upstream server.
I installed on Ubuntu 16.04, 4 cores, 8Gb RAM. I ran the cerbot command and it returned a congratulatory message that it's successful.
This is my first time installing BigBlueButton. I followed the process and all seemed fine until I tried running it on HTTPS https://live.oltega.com, and it returned
This site can’t be reached
live.oltega.com refused to connect.
Try: Checking the connection
Checking the proxy and the firewall
ERR_CONNECTION_REFUSED
when I served the same on HTTP http://live.oltega.com it worked well but displays a blue screen because it can only work on HTTPS. What can I try next?
After obtaining a Let's Encrypt certificate, you should configure the BBB components like Nginx and Freeswith to use HTTPS.
Follow the instructions mentioned here.
The summary is :
1-Configure FreeSWITCH for using SSL
Edit the file /etc/bigbluebutton/nginx/sip.nginx and change the protocol and port on the proxy_pass line as shown bellow
location /ws {
proxy_pass https://203.0.113.1:7443;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "Upgrade";
proxy_read_timeout 6h;
proxy_send_timeout 6h;
client_body_timeout 6h;
send_timeout 6h;
}
2- Configure BigBlueButton to load session via HTTPS
Edit /usr/share/bbb-web/WEB-INF/classes/bigbluebutton.properties and update the property bigbluebutton.web.serverURL to use HTTPS:
#----------------------------------------------------
# This URL is where the BBB client is accessible. When a user successfully
# enters a name and password, she is redirected here to load the client.
bigbluebutton.web.serverURL=https://bigbluebutton.example.com
Next, edit the file /usr/share/red5/webapps/screenshare/WEB-INF/screenshare.properties and update the property jnlpUrl and jnlpFile to HTTPS:
streamBaseUrl=rtmp://bigbluebutton.example.com/screenshare
jnlpUrl=https://bigbluebutton.example.com/screenshare
jnlpFile=https://bigbluebutton.example.com/screenshare/screenshare.jnlp
Next, you should do the following command:
$ sudo sed -e 's|http://|https://|g' -i /var/www/bigbluebutton/client/conf/config.xml
Open /usr/share/meteor/bundle/programs/server/assets/app/config/settings.yml editing and change:
kurento:
wsUrl: ws://bbb.example.com/bbb-webrtc-sfu
to
kurento:
wsUrl: wss://bbb.example.com/bbb-webrtc-sfu
and also
note:
enabled: true
url: http://bbb.example.com/pad
to
note:
enabled: true
url: https://bbb.example.com/pad
3- Next, modify the creation of recordings so they are served via HTTPS
Edit /usr/local/bigbluebutton/core/scripts/bigbluebutton.yml and change the value for playback_protocol as follows:
playback_protocol: https
4-If you have installed the API demos, edit /var/lib/tomcat7/webapps/demo/bbb_api_conf.jsp and change the value of BigBlueButtonURL use HTTPS.
// This is the URL for the BigBlueButton server
String BigBlueButtonURL = "https://bigbluebutton.example.com/bigbluebutton/";
5-Finally, to apply all of the configuration changes made, you must restart all components of BigBlueButton:
$ sudo bbb-conf --restart
I use nginx to proxy and hold persistent connections to far away servers for me.
I have configured about 15 blocks similar to this example:
upstream rinu-test {
server test.rinu.test:443;
keepalive 20;
}
server {
listen 80;
server_name test.rinu.test;
location / {
proxy_pass https://rinu-test;
proxy_http_version 1.1;
proxy_set_header Connection "";
proxy_set_header Host $http_host;
}
}
The problem is if the hostname can not be resolved in one or more of the upstream blocks, nginx will not (re)start. I can't use static IPs either, some of these hosts explicitly said not to do that because IPs will change. Every other solution I've seen to this error message says to get rid of upstream and do everything in the location block. That it not possible here because keepalive is only available under upstream.
I can temporarily afford to lose one server but not all 15.
Edit:
Turns out nginx is not suitable for this use case. An alternative backend (upstream) keepalive proxy should be used. A custom Node.js alternative is in my answer. So far I haven't found any other alternatives that actually work.
Earlier versions of nginx (before 1.1.4), which already powered a huge number of the most visited websites worldwide (and some still do even nowdays, if the server headers are to be believed), didn't even support keepalive on the upstream side, because there is very little benefit for doing so in the datacentre setting, unless you have a non-trivial latency between your various hosts; see https://serverfault.com/a/883019/110020 for some explanation.
Basically, unless you know you specifically need keepalive between your upstream and front-end, chances are it's only making your architecture less resilient and worse-off.
(Note that your current solution is also wrong because a change in the IP address will likewise go undetected, because you're doing hostname resolution at config reload only; so, even if nginx does start, it'll basically stop working once IP addresses of the upstream servers do change.)
Potential solutions, pick one:
The best solution would seem to just get rid of upstream keepalive as likely unnecessary in a datacentre environment, and use variables with proxy_pass for up-to-date DNS resolution for each request (nginx is still smart-enough to still do the caching of such resolutions)
Another option would be to get a paid version of nginx through a commercial subscription, which has a resolve parameter for the server directive within the upstream context.
Finally, another thing to try might be to use a set variable and/or a map to specify the servers within upstream; this is neither confirmed nor denied to have been implemented; e.g., it may or may not work.
Your scenario is very similar to the one when using aws ELB as uptreams in where is critical to resolve the proper IP of the defined domain.
The first thing you need to do and ensure is that the DNS servers you are using can resolve to your domains, then you could create your config like this:
resolver 10.0.0.2 valid=300s;
resolver_timeout 10s;
location /foo {
set $foo_backend_servers foo_backends.example.com;
proxy_pass http://$foo_backend_servers;
}
location /bar {
set $bar_backend_servers bar_backends.example.com;
proxy_pass http://$bar_backend_servers;
}
Notice the resolver 10.0.0.2 it should be IP of the DNS server that works and answer your queries, depending on your setup this could be a local cache service like unbound. and then just use resolve 127.0.0.1
Now, is very important to use a variable to specify the domain name, from the docs:
When you use a variable to specify the domain name in the proxy_pass directive, NGINX re‑resolves the domain name when its TTL expires.
You could check your resolver by using tools like dig for example:
$ dig +short stackoverflow.com
In case is a must to use keepalive in the upstreams, and if is not an option to use Nginx +, then you could give a try to openresty balancer, you will need to use/implement lua-resty-dns
A one possible solution is to involve a local DNS cache. It can be a local DNS server like Bind or Dnsmasq (with some crafty configuration, note that nginx can also use specified dns server in place of the system default), or just maintaining the cache in hosts file.
It seems that using hosts file with some scripting is quite straightforward way. The hosts file should be spitted into the static and dynamic parts (i.e. cat hosts.static hosts.dynamic > hosts), and the dynamic part should be generated (and updated) automatically by a script.
Perhaps it make sense to check from time to time the hostnames for changing IPs, and update hosts file and reload configuration in nginx on changes. In case of some hostname cannot be resolved the old IP or some default IP (like 127.0.1.9) should be used.
If you don't need the hostnames in the nginx config file (i.e., IPs are enough), the upstream section with IPs (resolved hostnames) can be generated by a script and included into nginx config — and no need to touch the hosts file in such case.
I put the resolve parameter on server and you need to set the Nginx Resolver in nginx.conf as below:
/etc/nginx/nginx.conf:
http {
resolver 192.168.0.2 ipv6=off valid=40s; # The DNS IP server
}
Site.conf:
upstream rinu-test {
server test.rinu.test:443;
keepalive 20;
}
My problem was container related. I'm using docker compose to create the nginx container, plus the app container. When setting network_mode: host in the app container config in docker-compose.yml, nginx was unable to find the upstream app container. Removing this fixed the problem.
we can resolve it temporarily
cd /etc
sudo vim resolv.conf
i
nameserver 8.8.8.8
:wq
then do sudo nginx -t
restart nginx it will work for the momment
An alternative is to write a new service that only does what I want. The following replaces nginx for proxying https connections using Node.js
const http = require('http');
const https = require('https');
const httpsKeepAliveAgent = new https.Agent({ keepAlive: true });
http.createServer(onRequest).listen(3000);
function onRequest(client_req, client_res) {
https.pipe(
protocol.request({
host: client_req.headers.host,
port: 443,
path: client_req.url,
method: client_req.method,
headers: client_req.headers,
agent: httpsKeepAliveAgent
}, (res) => {
res.pipe(client_res);
}).on('error', (e) => {
client_res.end();
})
);
}
Example usage:
curl http://localhost:3000/request_uri -H "Host: test.rinu.test"
which is equivalent to:
curl https://test.rinu.test/request_uri
I want to remove Nginx from http response header. I can Hide my Nginx version but I want to hide Nginx too.
Thanks
Use the ngx_headers_more module - see http://wiki.nginx.org/NginxHttpHeadersMoreModule.
It allows you to configure any arbitrary headers you'd like - both request and response headers. Once you've installed it (and thus recompiled your version of Nginx), use the following configuration:
more_set_headers 'Server: my-server';
Alternatively, if you don't want a Server header at all, then clear it using:
more_clear_headers 'Server';