docker-socket-proxy/haproxy.cfg

global
    log stdout format raw daemon "${LOG_LEVEL}"

    pidfile /run/haproxy.pid
    maxconn 4000

    # Turn on stats unix socket
    stats socket /var/run/haproxy.sock mode 600 level admin
    server-state-file /var/lib/haproxy/server-state

defaults
    mode http
    log global
    option httplog
    option dontlognull
    option http-keep-alive
    option redispatch
    retries 3
    timeout http-request 10s
    timeout queue 1m
    timeout connect 10s
    timeout client 10m
    timeout server 10m
    timeout http-keep-alive 10s
    timeout check 10s
    maxconn 3000

    # Allow seamless reloads
    load-server-state-from-file global

    # Use provided example error pages
    errorfile 400 /usr/local/etc/haproxy/errors/400.http
    errorfile 403 /usr/local/etc/haproxy/errors/403.http
    errorfile 408 /usr/local/etc/haproxy/errors/408.http
    errorfile 500 /usr/local/etc/haproxy/errors/500.http
    errorfile 502 /usr/local/etc/haproxy/errors/502.http
    errorfile 503 /usr/local/etc/haproxy/errors/503.http
    errorfile 504 /usr/local/etc/haproxy/errors/504.http

backend dockerbackend
    mode http
    option httpchk GET /_ping
    server dockersocket unix@${SOCKET_PATH} no-check

backend docker-events
    mode http
    server dockersocket unix@${SOCKET_PATH} no-check
    timeout server 1s

frontend dockerfrontend
    bind ${BIND_CONFIG}

    # Essential endpoints first
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/_ping } { env(PING) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/version } { env(VERSION) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/info } { env(INFO) -m bool }

    # Method check after essential endpoints
    http-request deny unless METH_GET || METH_HEAD

    # Container operations
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/containers/[a-zA-Z0-9_.-]+/start } { env(ALLOW_START) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/containers/[a-zA-Z0-9_.-]+/stop } { env(ALLOW_STOP) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/auth } { env(AUTH) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/build } { env(BUILD) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/commit } { env(COMMIT) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/configs } { env(CONFIGS) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/containers } { env(CONTAINERS) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/distribution } { env(DISTRIBUTION) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/events } { env(EVENTS) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/exec } { env(EXEC) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/grpc } { env(GRPC) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/images } { env(IMAGES) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/networks } { env(NETWORKS) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/nodes } { env(NODES) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/containers/[a-zA-Z0-9_.-]+/((stop)|(restart)|(kill)) } { env(ALLOW_RESTARTS) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/plugins } { env(PLUGINS) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/secrets } { env(SECRETS) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/services } { env(SERVICES) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/session } { env(SESSION) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/swarm } { env(SWARM) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/system } { env(SYSTEM) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/tasks } { env(TASKS) -m bool }
    http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/volumes } { env(VOLUMES) -m bool }

    default_backend dockerbackend
    http-request deny if ! { path -i -m beg /events }
    use_backend docker-events if { path -i -m beg /events }