Kubernetes Nginx Ingress file upload returning 502 - nginx

Question

I am trying to upload files from a client through an nginx ingress. I have set the following annotations on the ingress after receiving a 413 response;
Annotations: nginx.ingress.kubernetes.io/body-size: 1024m
nginx.ingress.kubernetes.io/client-body-buffer-size: 50m
nginx.ingress.kubernetes.io/client-max-body-size: 50m
nginx.ingress.kubernetes.io/proxy-body-size: 1024m
nginx.ingress.kubernetes.io/proxy-buffer-size: 32k
nginx.ingress.kubernetes.io/proxy-buffers-number: 8
The client is an Angular application. It sends a base64 string of the file in the request body. I have tried uploading images of a few KB, so I definitely ain't hitting any of these limits. I'm new to Kubernetes. Do I need to restart the ingress for these annotations to take effect?
I have also tried creating a ConfigMap;
apiVersion: v1
kind: ConfigMap
metadata:
name: app-ingress-configuration
namespace: development
labels:
app.kubernetes.io/name: [name of ingress]
app.kubernetes.io/part-of: [name of ingress]
data:
proxy-connect-timeout: "50"
proxy-read-timeout: "120"
proxy-send-timeout: "120"
body-size: "1024m"
client-body-buffer-size: "50m"
client-max-body-size: "50m"
proxy-body-size: "1024m"
proxy-buffers: "8 32k"
proxy-buffer-size: "32k"
Still getting a 502.
Not sure how to access the nginx.conf through kubectl, it seems from the docs if I update this ConfigMap the settings are changed in nginx anyway.
Any help appreciated.
UPDATE
nginx.conf
# Configuration checksum: 1961171210939107273
# setup custom paths that do not require root access
pid /tmp/nginx.pid;
daemon off;
worker_processes 2;
worker_rlimit_nofile 523264;
worker_shutdown_timeout 240s ;
events {
multi_accept on;
worker_connections 16384;
use epoll;
}
http {
client_max_body_size 100M;
lua_package_path "/etc/nginx/lua/?.lua;;";
lua_shared_dict balancer_ewma 10M;
lua_shared_dict balancer_ewma_last_touched_at 10M;
lua_shared_dict balancer_ewma_locks 1M;
lua_shared_dict certificate_data 20M;
lua_shared_dict certificate_servers 5M;
lua_shared_dict configuration_data 20M;
init_by_lua_block {
collectgarbage("collect")
-- init modules
local ok, res
ok, res = pcall(require, "lua_ingress")
if not ok then
error("require failed: " .. tostring(res))
else
lua_ingress = res
lua_ingress.set_config({
use_forwarded_headers = false,
use_proxy_protocol = false,
is_ssl_passthrough_enabled = false,
http_redirect_code = 308,
listen_ports = { ssl_proxy = "442", https = "443" },
hsts = true,
hsts_max_age = 15724800,
hsts_include_subdomains = true,
hsts_preload = false,
})
end
ok, res = pcall(require, "configuration")
if not ok then
error("require failed: " .. tostring(res))
else
configuration = res
end
ok, res = pcall(require, "balancer")
if not ok then
error("require failed: " .. tostring(res))
else
balancer = res
end
ok, res = pcall(require, "monitor")
if not ok then
error("require failed: " .. tostring(res))
else
monitor = res
end
ok, res = pcall(require, "certificate")
if not ok then
error("require failed: " .. tostring(res))
else
certificate = res
end
ok, res = pcall(require, "plugins")
if not ok then
error("require failed: " .. tostring(res))
else
plugins = res
end
-- load all plugins that'll be used here
plugins.init({})
}
init_worker_by_lua_block {
lua_ingress.init_worker()
balancer.init_worker()
monitor.init_worker()
plugins.run()
}
geoip_country /etc/nginx/geoip/GeoIP.dat;
geoip_city /etc/nginx/geoip/GeoLiteCity.dat;
geoip_org /etc/nginx/geoip/GeoIPASNum.dat;
geoip_proxy_recursive on;
aio threads;
aio_write on;
tcp_nopush on;
tcp_nodelay on;
log_subrequest on;
reset_timedout_connection on;
keepalive_timeout 75s;
keepalive_requests 100;
client_body_temp_path /tmp/client-body;
fastcgi_temp_path /tmp/fastcgi-temp;
proxy_temp_path /tmp/proxy-temp;
ajp_temp_path /tmp/ajp-temp;
client_header_buffer_size 1M;
client_header_timeout 60s;
large_client_header_buffers 4 5M;
client_body_buffer_size 1M;
client_body_timeout 60s;
http2_max_field_size 1M;
http2_max_header_size 5M;
http2_max_requests 1000;
http2_max_concurrent_streams 128;
types_hash_max_size 2048;
server_names_hash_max_size 1024;
server_names_hash_bucket_size 64;
map_hash_bucket_size 64;
proxy_headers_hash_max_size 512;
proxy_headers_hash_bucket_size 64;
variables_hash_bucket_size 256;
variables_hash_max_size 2048;
underscores_in_headers off;
ignore_invalid_headers on;
limit_req_status 503;
limit_conn_status 503;
include /etc/nginx/mime.types;
default_type text/html;
gzip on;
gzip_comp_level 5;
gzip_http_version 1.1;
gzip_min_length 256;
gzip_types application/atom+xml application/javascript application/x-javascript application/json application/rss+xml application/vnd.ms-fontobject application/x-font-ttf application/x-web-app-manifest+json application/xhtml+xml application/xml font/opentype image/svg+xml image/x-icon text/css text/javascript text/plain text/x-component;
gzip_proxied any;
gzip_vary on;
# Custom headers for response
server_tokens on;
# disable warnings
uninitialized_variable_warn off;
# Additional available variables:
# $namespace
# $ingress_name
# $service_name
# $service_port
log_format upstreaminfo '$remote_addr - $remote_user [$time_local] "$request" $status $body_bytes_sent "$http_referer" "$http_user_agent" $request_length $request_time [$proxy_upstream_name] [$proxy_alternative_upstream_name] $upstream_addr $upstream_response_length $upstream_response_time $upstream_status $req_id';
map $request_uri $loggable {
default 1;
}
access_log /var/log/nginx/access.log upstreaminfo if=$loggable;
error_log /var/log/nginx/error.log notice;
resolver 10.245.0.10 valid=30s;
# See https://www.nginx.com/blog/websocket-nginx
map $http_upgrade $connection_upgrade {
default upgrade;
# See http://nginx.org/en/docs/http/ngx_http_upstream_module.html#keepalive
'' '';
}
# Reverse proxies can detect if a client provides a X-Request-ID header, and pass it on to the backend server.
# If no such header is provided, it can provide a random value.
map $http_x_request_id $req_id {
default $http_x_request_id;
"" $request_id;
}
# Create a variable that contains the literal $ character.
# This works because the geo module will not resolve variables.
geo $literal_dollar {
default "$";
}
server_name_in_redirect off;
port_in_redirect off;
ssl_protocols TLSv1.2;
ssl_early_data off;
# turn on session caching to drastically improve performance
ssl_session_cache builtin:1000 shared:SSL:10m;
ssl_session_timeout 10m;
# allow configuring ssl session tickets
ssl_session_tickets on;
# slightly reduce the time-to-first-byte
ssl_buffer_size 4k;
# allow configuring custom ssl ciphers
ssl_ciphers '';
ssl_prefer_server_ciphers on;
ssl_ecdh_curve auto;
# PEM sha: ---
ssl_certificate /etc/ingress-controller/ssl/default-fake-certificate.pem;
ssl_certificate_key /etc/ingress-controller/ssl/default-fake-certificate.pem;
proxy_ssl_session_reuse on;
upstream upstream_balancer {
### Attention!!!
#
# We no longer create "upstream" section for every backend.
# Backends are handled dynamically using Lua. If you would like to debug
# and see what backends ingress-nginx has in its memory you can
# install our kubectl plugin https://kubernetes.github.io/ingress-nginx/kubectl-plugin.
# Once you have the plugin you can use "kubectl ingress-nginx backends" command to
# inspect current backends.
#
###
server 0.0.0.1; # placeholder
balancer_by_lua_block {
balancer.balance()
}
keepalive 32;
keepalive_timeout 60s;
keepalive_requests 100;
}
# Cache for internal auth checks
proxy_cache_path /tmp/nginx-cache-auth levels=1:2 keys_zone=auth_cache:10m max_size=128m inactive=30m use_temp_path=off;
# Global filters
## start server _
server {
server_name _ ;
listen 80 default_server reuseport backlog=511 ;
listen [::]:80 default_server reuseport backlog=511 ;
listen 443 default_server reuseport backlog=511 ssl http2 ;
listen [::]:443 default_server reuseport backlog=511 ssl http2 ;
set $proxy_upstream_name "-";
ssl_certificate_by_lua_block {
certificate.call()
}
location / {
set $namespace "";
set $ingress_name "";
set $service_name "";
set $service_port "";
set $location_path "/";
rewrite_by_lua_block {
lua_ingress.rewrite({
force_ssl_redirect = false,
ssl_redirect = false,
force_no_ssl_redirect = false,
use_port_in_redirects = false,
})
balancer.rewrite()
plugins.run()
}
# be careful with `access_by_lua_block` and `satisfy any` directives as satisfy any
# will always succeed when there's `access_by_lua_block` that does not have any lua code doing `ngx.exit(ngx.DECLINED)`
# other authentication method such as basic auth or external auth useless - all requests will be allowed.
#access_by_lua_block {
#}
header_filter_by_lua_block {
lua_ingress.header()
plugins.run()
}
body_filter_by_lua_block {
}
log_by_lua_block {
balancer.log()
monitor.call()
plugins.run()
}
access_log off;
port_in_redirect off;
set $balancer_ewma_score -1;
set $proxy_upstream_name "upstream-default-backend";
set $proxy_host $proxy_upstream_name;
set $pass_access_scheme $scheme;
set $pass_server_port $server_port;
set $best_http_host $http_host;
set $pass_port $pass_server_port;
set $proxy_alternative_upstream_name "";
client_max_body_size 1m;
proxy_set_header Host $best_http_host;
# Pass the extracted client certificate to the backend
# Allow websocket connections
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection $connection_upgrade;
proxy_set_header X-Request-ID $req_id;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $remote_addr;
proxy_set_header X-Forwarded-Host $best_http_host;
proxy_set_header X-Forwarded-Port $pass_port;
proxy_set_header X-Forwarded-Proto $pass_access_scheme;
proxy_set_header X-Scheme $pass_access_scheme;
# Pass the original X-Forwarded-For
proxy_set_header X-Original-Forwarded-For $http_x_forwarded_for;
# mitigate HTTPoxy Vulnerability
# https://www.nginx.com/blog/mitigating-the-httpoxy-vulnerability-with-nginx/
proxy_set_header Proxy "";
# Custom headers to proxied server
proxy_connect_timeout 5s;
proxy_send_timeout 60s;
proxy_read_timeout 60s;
proxy_buffering off;
proxy_buffer_size 5M;
proxy_buffers 4 5M;
proxy_max_temp_file_size 1024M;
proxy_request_buffering on;
proxy_http_version 1.1;
proxy_cookie_domain off;
proxy_cookie_path off;
# In case of errors try the next upstream server before returning an error
proxy_next_upstream error timeout;
proxy_next_upstream_timeout 0;
proxy_next_upstream_tries 3;
proxy_pass http://upstream_balancer;
proxy_redirect off;
}
# health checks in cloud providers require the use of port 80
location /healthz {
access_log off;
return 200;
}
# this is required to avoid error if nginx is being monitored
# with an external software (like sysdig)
location /nginx_status {
allow 127.0.0.1;
allow ::1;
deny all;
access_log off;
stub_status on;
}
}
## end server _
## start server dev-api
server {
server_name dev-api ;
listen 80 ;
listen [::]:80 ;
listen 443 ssl http2 ;
listen [::]:443 ssl http2 ;
set $proxy_upstream_name "-";
ssl_certificate_by_lua_block {
certificate.call()
}
location / {
set $namespace "development";
set $ingress_name "app-ingress";
set $service_name "app-api-svc";
set $service_port "80";
set $location_path "/";
rewrite_by_lua_block {
lua_ingress.rewrite({
force_ssl_redirect = false,
ssl_redirect = true,
force_no_ssl_redirect = false,
use_port_in_redirects = false,
})
balancer.rewrite()
plugins.run()
}
# be careful with `access_by_lua_block` and `satisfy any` directives as satisfy any
# will always succeed when there's `access_by_lua_block` that does not have any lua code doing `ngx.exit(ngx.DECLINED)`
# other authentication method such as basic auth or external auth useless - all requests will be allowed.
#access_by_lua_block {
#}
header_filter_by_lua_block {
lua_ingress.header()
plugins.run()
}
body_filter_by_lua_block {
}
log_by_lua_block {
balancer.log()
monitor.call()
plugins.run()
}
port_in_redirect off;
set $balancer_ewma_score -1;
set $proxy_upstream_name "development-app-api-svc-80";
set $proxy_host $proxy_upstream_name;
set $pass_access_scheme $scheme;
set $pass_server_port $server_port;
set $best_http_host $http_host;
set $pass_port $pass_server_port;
set $proxy_alternative_upstream_name "";
client_max_body_size 1024M;
client_body_buffer_size 50M;
proxy_set_header Host $best_http_host;
# Pass the extracted client certificate to the backend
# Allow websocket connections
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection $connection_upgrade;
proxy_set_header X-Request-ID $req_id;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $remote_addr;
proxy_set_header X-Forwarded-Host $best_http_host;
proxy_set_header X-Forwarded-Port $pass_port;
proxy_set_header X-Forwarded-Proto $pass_access_scheme;
proxy_set_header X-Scheme $pass_access_scheme;
# Pass the original X-Forwarded-For
proxy_set_header X-Original-Forwarded-For $http_x_forwarded_for;
# mitigate HTTPoxy Vulnerability
# https://www.nginx.com/blog/mitigating-the-httpoxy-vulnerability-with-nginx/
proxy_set_header Proxy "";
# Custom headers to proxied server
proxy_connect_timeout 50s;
proxy_send_timeout 60s;
proxy_read_timeout 60s;
proxy_buffering off;
proxy_buffer_size 5M;
proxy_buffers 8 5M;
proxy_max_temp_file_size 1024M;
proxy_request_buffering on;
proxy_http_version 1.1;
proxy_cookie_domain off;
proxy_cookie_path off;
# In case of errors try the next upstream server before returning an error
proxy_next_upstream error timeout;
proxy_next_upstream_timeout 0;
proxy_next_upstream_tries 3;
proxy_pass http://upstream_balancer;
proxy_redirect off;
}
}
## end server dev-api
.......
UPDATE 2
Log from kubectl logs -n nginx-ingress-controller-XXX command
127.0.0.1 - - [16/Jul/2020:10:11:14 +0000] "POST [Ingress/Service endpoint] HTTP/2.0" 502 4 "https://[client-host-name]/[client-path]" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.116 Safari/537.36 Edg/83.0.478.58" 9351 0.659 [service-name-80] [] 10.244.1.72:80 14 0.652 502 7b7bdf8a9319e88c80ba3444372daf2d

Answer 1

You need to make sure you have the file size set up on the ingress controller. Nginx will catch up the settings. try this. For more information about the annotations follow this. https://docs.nginx.com/nginx-ingress-controller/configuration/ingress-resources/advanced-configuration-with-annotations/
kind: Ingress
apiVersion: extensions/v1beta1
metadata:
name: service-api-tls-ingress
namespace: production
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/proxy-body-size: 8m

Answer 2

My original issue was nginx, but after I changed the limits it was forwarding the request to the service but I wasn't checking the correct logs. So #mWatney was correct to double check directly to the service/pod.
For anyone else the issue I was seeing was to do with running a .NET core 3.1 application in the Linux alpine container. Within the app I was using a version of System.Drawing.Common which causes exceptions running under Linux, whihc look like this;
System.TypeInitializationException: The type initializer for 'Gdip' threw an exception.
---> System.DllNotFoundException: Unable to load shared library 'libgdiplus'
The solution was to add to the dockerfile;
RUN apk add libgdiplus-dev fontconfig ttf-dejavu --update-cache --repository http://dl-3.alpinelinux.org/alpine/edge/testing/ --allow-untrusted
This allows the use of System.Drawing.Common under Linux by adding the ability to load shared library libgdiplus.
Credit here: https://github.com/dotnet/dotnet-docker/issues/618#issuecomment-467619498
The more permanent solution is to remove the dependency on System.Drawing.Common entirely from the application. Thanks #mWatney for help, you got me on the right track.