New subject: Manipulating SDP IP for Inbound Calls

26 Jul 2020

Hi,

I am working on a project involving Kamailio dockerezation, which is meant to run
alongside Freeswitch and RTPEngine containers, on the basis of a Docker-Compose file which
is launched on top of a CentOS 7.7 host system.
I was able to create and run the containers successfully, they are starting and listening
to the correct ports, but for some unexplained reason - the incoming SIP traffic is not
getting picked up by Kamailio. I can easily trace the traffic from the host, but when
SSHing the container and running a test from within, no traffic goes by.
I've used netcat to generate plain UDP traffic to the container, and it was logged
into the Kamailio log files, but real-life traffic doesn't seem to work.
I've tried moving to host mode (from bridge), but it didn't make any difference.
All required firewall rules were opened obviously, I've also tried shutting the
firewall off completely but it didn't help.

Does anyone experienced anything similar while running Kamailio in Dockers, and could
provide me a go-through on what steps did he take to fix it?

EXCERPT FROM MY DOCKERFILE

# Getting Kamailio source code from GIT
RUN mkdir -p /usr/local/src/kamailio-5.3
WORKDIR /usr/local/src/kamailio-5.3
RUN git clone --depth 1 --no-single-branch https://github.com/kamailio/kamailio
WORKDIR /usr/local/src/kamailio-5.3/kamailio
RUN git checkout -b 5.3.2

# Compile the source code and install Kamailio
RUN make include_modules="phonenum db_mysql xmlrpc http_async_client jansson auth_db
nathelper websocket tls outbound topoh http_client" cfg && \
    make all && make install

# Default setting is to run Kamailio as user “kamailio” and group “kamailio”
RUN adduser --quiet --system --group --disabled-password \
        --shell /bin/false --gecos "Kamailio" \
        --home /var/run/kamailio kamailio

# To use init.d script for starting/stopping the Kamailio server
COPY Init/kamailio /etc/init.d/
RUN chmod 755 /etc/init.d/kamailio
COPY Default/kamailio /etc/default/
COPY kamailio.service /etc/systemd/system/
RUN mkdir -p /var/run/kamailio
RUN chown kamailio:kamailio /var/run/kamailio

COMPOSE (BRIDGE NETWORK VERSION)

kamailioegress:
  build: kamailio_egress
  image: kamailioegress:latest
  container_name: kamailioegress
  restart: always
  environment:
    - DATABASE=kamailioe
    - SIP_DOMAIN=XXX
    - DBHOST=kamailiodb
    - DBROOTUSER=root
    - DBROOTPASS=XXX
    - PUBLIC_IPV4=XXX
  depends_on:
    - Kamailio-Base
    - kmdb
    - freeswitch
    - rtpengine
  expose:
    - "5060/udp"
    - "5060/tcp"
  ports:
    - "XXX:5060:5060/udp"
  networks:
    private-net:
      ipv4_address: "172.18.0.30"
  deploy:
    mode: replicated
    replicas: 1
    restart_policy:
      condition: always
      delay: 5s
      max_attempts: 3
      window: 120s

networks:
  private-net:
    driver: bridge
    ipam:
      config:
        - subnet: 172.18.0.0/16
    driver_opts:
      com.docker.network.bridge.name: wrtcpriv
  public-net:
    external:
      name: host

COMPOSE (HOST MODE VERSION)

kamailioegress:
  build: kamailio_egress
  image: kamailioegress:latest
  container_name: kamailioegress
  network_mode: host
  restart: always
  environment:
    - DATABASE=kamailioe
    - SIP_DOMAIN=XXX
    - DBHOST=172.18.0.10
    - DBROOTUSER=root
    - DBROOTPASS=XXX
    - PUBLIC_IPV4=XXX
    - EGPORT=5060
    - LINTE=ens224
    - LINTI=ens192
    - RTPENGINE=localhost
  depends_on:
    - Kamailio-Base
    - kmdb
    - freeswitch
    - rtpengine
  expose:
    - "5060/udp"
  ports:
    - "213.8.76.13:5060:5060/udp"
  deploy:
    mode: replicated
    replicas: 1
    restart_policy:
      condition: always
      delay: 5s
      max_attempts: 3
      window: 120s

CONFIG FILE

/* uncomment and configure the following line if you want Kamailio to
 * bind on a specific interface/port/proto (default bind on all available) */
listen=udp:0.0.0.0:LPORT advertise PUBLIC_IP:LPORT

KAMAILIO-LOCALE

#!define DBURL "mysql://root:XXX@DBHOST/kamailioe"
#!substdef "!MY_DBURL!mysql://root:XXX@DBHOST/kamailioe!g"
#!substdef "!RTPENGINE!MY_RTPENGINE!g"
#!substdef "!SIP_DOMAIN!MY_SIP_DOMAIN!g"
#!substdef "!PUBLIC_IP!MY_PUBLIC_IP!g"
#!substdef "!PRIVATE_IP!MY_PRIVATE_IP!g"
#!substdef "!LPORT!MY_LPORT!g"
#!substdef "!LINT!MY_LINT!g"
#!substdef "!HOMER_IP!10.1.0.100!g"
#!substdef "!API_URL!http://localhost:3000/v1/mock!g"
#!substdef "/CCODES/972|380/"
#!substdef "/NUM_TRANSLATE_OUT_RE/\\\\+?(CCODES)([0-9]+)/"
#!substdef "/NUM_TRANSLATE_IN_RE/0([0-9]+)/"

FIREWALL RULES

-bash-4.2# firewall-cmd --list-all
public (active)
  target: default
  icmp-block-inversion: no
  interfaces: ens192 ens224
  sources: 192.168.1.39
  services: dhcpv6-client http https sip ssh
  ports: 9323/tcp 9323/udp
  protocols:
  masquerade: no
  forward-ports:
  source-ports:
  icmp-blocks:
  rich rules:
        rule family="ipv4" destination address="XXX" port
port="5060" protocol="udp" accept
        rule family="ipv4" destination address="XXX" port
port="5060" protocol="tcp" accept

NETSTAT OUTPUT
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State      
PID/Program name
udp        0      0 XXX:5060        0.0.0.0:*                           22479/kamailio

Edward

Kamailio Dockerization