Netdata via HAProxy

HAProxy is a free, very fast and reliable solution offering high availability, load balancing, and proxying for TCP and HTTP-based applications. It is particularly suited for very high traffic web sites and powers quite a number of the world's most visited ones.

If Netdata is running on a host running HAProxy, rather than connecting to Netdata from a port number, a domain name can be pointed at HAProxy, and HAProxy can redirect connections to the Netdata port. This can make it possible to connect to Netdata at https://example.com or https://example.com/netdata/, which is a much nicer experience then http://example.com:19999.

To proxy requests from HAProxy to Netdata, the following configuration can be used:

Default Configuration

For all examples, set the mode to http

defaults
mode http

Simple Configuration

A simple example where the base URL, say http://example.com, is used with no subpath:

Frontend

Create a frontend to receive the request.

frontend http_frontend
## HTTP ipv4 and ipv6 on all ips ##
bind :::80 v4v6
default_backend netdata_backend

Backend

Create the Netdata backend which will send requests to port 19999.

backend netdata_backend
option forwardfor
server netdata_local 127.0.0.1:19999
http-request set-header Host %[src]
http-request set-header X-Forwarded-For %[src]
http-request set-header X-Forwarded-Port %[dst_port]
http-request set-header Connection "keep-alive"

Configuration with subpath

A example where the base URL is used with a subpath /netdata/:

Frontend

To use a subpath, create an ACL, which will set a variable based on the subpath.

frontend http_frontend
## HTTP ipv4 and ipv6 on all ips ##
bind :::80 v4v6
# URL begins with /netdata
acl is_netdata url_beg /netdata
# if trailing slash is missing, redirect to /netdata/
http-request redirect scheme https drop-query append-slash if is_netdata ! { path_beg /netdata/ }
## Backends ##
use_backend netdata_backend if is_netdata
# Other requests go here (optional)
# put netdata_backend here if no others are used
default_backend www_backend

Backend

Same as simple example, except remove /netdata/ with regex.

backend netdata_backend
option forwardfor
server netdata_local 127.0.0.1:19999
http-request set-path %[path,regsub(^/netdata/,/)]
http-request set-header Host %[src]
http-request set-header X-Forwarded-For %[src]
http-request set-header X-Forwarded-Port %[dst_port]
http-request set-header Connection "keep-alive"

Using TLS communication

TLS can be used by adding port 443 and a cert to the frontend. This example will only use Netdata if host matches example.com (replace with your domain).

Frontend

This frontend uses a certificate list.

frontend https_frontend
## HTTP ##
bind :::80 v4v6
# Redirect all HTTP traffic to HTTPS with 301 redirect
redirect scheme https code 301 if !{ ssl_fc }
## HTTPS ##
# Bind to all v4/v6 addresses, use a list of certs in file
bind :::443 v4v6 ssl crt-list /etc/letsencrypt/certslist.txt
## ACL ##
# Optionally check host for Netdata
acl is_example_host hdr_sub(host) -i example.com
## Backends ##
use_backend netdata_backend if is_example_host
# Other requests go here (optional)
default_backend www_backend

In the cert list file place a mapping from a certificate file to the domain used:

/etc/letsencrypt/certslist.txt:

example.com /etc/letsencrypt/live/example.com/example.com.pem

The file /etc/letsencrypt/live/example.com/example.com.pem should contain the key and certificate (in that order) concatenated into a .pem file.:

cat /etc/letsencrypt/live/example.com/fullchain.pem \
/etc/letsencrypt/live/example.com/privkey.pem > \
/etc/letsencrypt/live/example.com/example.com.pem

Backend

Same as simple, except set protocol https.

backend netdata_backend
option forwardfor
server netdata_local 127.0.0.1:19999
http-request add-header X-Forwarded-Proto https
http-request set-header Host %[src]
http-request set-header X-Forwarded-For %[src]
http-request set-header X-Forwarded-Port %[dst_port]
http-request set-header Connection "keep-alive"

Enable authentication

To use basic HTTP Authentication, create an authentication list:

# HTTP Auth
userlist basic-auth-list
group is-admin
# Plaintext password
user admin password passwordhere groups is-admin

You can create a hashed password using the mkpassword utility.

printf "passwordhere" | mkpasswd --stdin --method=sha-256
$5$l7Gk0VPIpKO$f5iEcxvjfdF11khw.utzSKqP7W.0oq8wX9nJwPLwzy1

Replace passwordhere with hash:

user admin password $5$l7Gk0VPIpKO$f5iEcxvjfdF11khw.utzSKqP7W.0oq8wX9nJwPLwzy1 groups is-admin

Now add at the top of the backend:

acl devops-auth http_auth_group(basic-auth-list) is-admin
http-request auth realm netdata_local unless devops-auth

Full Example

Full example configuration with HTTP auth over TLS with subpath:

global
maxconn 20000
log /dev/log local0
log /dev/log local1 notice
user haproxy
group haproxy
pidfile /run/haproxy.pid
stats socket /run/haproxy/admin.sock mode 660 level admin expose-fd listeners
stats timeout 30s
daemon
tune.ssl.default-dh-param 4096 # Max size of DHE key
# Default ciphers to use on SSL-enabled listening sockets.
ssl-default-bind-ciphers ECDH+AESGCM:DH+AESGCM:ECDH+AES256:DH+AES256:ECDH+AES128:DH+AES:RSA+AESGCM:RSA+AES:!aNULL:!MD5:!DSS
ssl-default-bind-options no-sslv3
defaults
log global
mode http
option httplog
option dontlognull
timeout connect 5000
timeout client 50000
timeout server 50000
errorfile 400 /etc/haproxy/errors/400.http
errorfile 403 /etc/haproxy/errors/403.http
errorfile 408 /etc/haproxy/errors/408.http
errorfile 500 /etc/haproxy/errors/500.http
errorfile 502 /etc/haproxy/errors/502.http
errorfile 503 /etc/haproxy/errors/503.http
errorfile 504 /etc/haproxy/errors/504.http
frontend https_frontend
## HTTP ##
bind :::80 v4v6
# Redirect all HTTP traffic to HTTPS with 301 redirect
redirect scheme https code 301 if !{ ssl_fc }
## HTTPS ##
# Bind to all v4/v6 addresses, use a list of certs in file
bind :::443 v4v6 ssl crt-list /etc/letsencrypt/certslist.txt
## ACL ##
# Optionally check host for Netdata
acl is_example_host hdr_sub(host) -i example.com
acl is_netdata url_beg /netdata
http-request redirect scheme https drop-query append-slash if is_netdata ! { path_beg /netdata/ }
## Backends ##
use_backend netdata_backend if is_example_host is_netdata
default_backend www_backend
# HTTP Auth
userlist basic-auth-list
group is-admin
# Hashed password
user admin password $5$l7Gk0VPIpKO$f5iEcxvjfdF11khw.utzSKqP7W.0oq8wX9nJwPLwzy1 groups is-admin
## Default server(s) (optional)##
backend www_backend
mode http
balance roundrobin
timeout connect 5s
timeout server 30s
timeout queue 30s
http-request add-header 'X-Forwarded-Proto: https'
server other_server 111.111.111.111:80 check
backend netdata_backend
acl devops-auth http_auth_group(basic-auth-list) is-admin
http-request auth realm netdata_local unless devops-auth
option forwardfor
server netdata_local 127.0.0.1:19999
http-request set-path %[path,regsub(^/netdata/,/)]
http-request add-header X-Forwarded-Proto https
http-request set-header Host %[src]
http-request set-header X-Forwarded-For %[src]
http-request set-header X-Forwarded-Port %[dst_port]
http-request set-header Connection "keep-alive"
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