MEC Platform initial implementation (#74)

## MEC Platform
- Mp1 interface following ETSI MEC standard
- Mm5 REST interface
- Mm5 REST python client
- Basic DynDNS using Flask+dnsmasq
- Service registry is based on YAKS
- Script for generate a simple LXD Container with the platform

src/utils/generate_mec.sh

@@ -0,0 +1,60 @@
+#!/usr/bin/env bash
+
+sudo ip link del mecbuildbr
+sudo ip link add mecbuildbr type bridge
+sudo ip link set mecbuildbr up
+
+
+
+lxc profile copy default mecp
+lxc profile device add mecp eth1 nic nictype=bridged parent=mecbuildbr
+lxc launch images:ubuntu/bionic plat -p mecp
+sleep 3;
+lxc file push ./ocaml/mec_platform/etc/10-lxc.yaml plat/etc/netplan/10-lxc.yaml
+lxc exec plat -- netplan apply
+sleep 3;
+lxc exec plat -- sudo apt update -qq
+lxc exec plat -- sudo apt install curl -y
+lxc exec plat -- sudo useradd -m mec
+lxc exec plat -- usermod -aG sudo mec
+lxc exec plat -- echo "mec      ALL=(ALL) NOPASSWD:ALL" | sudo tee -a /etc/sudoers > /dev/null
+lxc exec plat -- mkdir -p /etc/fos/utils/mec
+lxc exec plat -- mkdir -p /etc/fos/utils/
+lxc exec plat -- curl -L -o /tmp/yaks.tar.gz https://www.dropbox.com/s/g4tnzvjwlx3zcr2/yaksd.tar.gz
+lxc exec plat -- tar -xzvf /tmp/yaks.tar.gz -C /etc/fos
+lxc exec plat -- rm -rf /tmp/yaks.tar.gz
+lxc file push ./ocaml/mec_platform/_build/default/me_platform/me_platform.exe plat/etc/fos/utils/platform
+lxc file push -r ./python/dyndns plat/etc/fos/utils
+lxc exec plat -- sudo chown mec:mec -R /etc/fos
+
+lxc file push ../../etc/yaks.service plat/lib/systemd/system/
+lxc file push ../../etc/yaks.target plat/lib/systemd/system/
+lxc file push ./ocaml/mec_platform/etc/mec_platform.service plat/lib/systemd/system/
+lxc file push ./python/dyndns/etc/dyndns.service plat/lib/systemd/system/
+lxc exec plat -- sudo apt install libev-dev libssl-dev nginx dnsmasq python3 python3-pip -y
+lxc exec plat -- sudo pip3 install flask psutil
+
+lxc file push ./ocaml/mec_platform/etc/nginx plat/etc/nginx/sites-available/default
+lxc file push ./ocaml/mec_platform/etc/dnsmasq plat/etc/default/dnsmasq
+lxc file push ./python/dyndns/etc/mec.conf plat/etc/dnsmasq.d/mec.conf
+lxc file push ./ocaml/mec_platform/etc/ip_replace.sh plat/tmp/
+
+lxc exec plat -- touch /tmp/dynhosts
+lxc exec plat -- chmod 0666 /tmp/dynhosts
+lxc exec plat --  /tmp/ip_replace.sh
+
+lxc exec plat -- systemctl stop nginx
+lxc exec plat -- systemctl stop dnsmasq
+
+lxc exec plat -- systemctl daemon-reload
+lxc exec plat -- systemctl enable dnsmasq
+lxc exec plat -- systemctl enable nginx
+lxc exec plat -- systemctl enable yaks
+lxc exec plat -- systemctl enable mec_platform
+lxc exec plat -- systemctl enable dyndns
+
+lxc exec plat -- systemctl start dnsmasq
+lxc exec plat -- systemctl start nginx
+lxc exec plat -- systemctl start yaks
+lxc exec plat -- systemctl start mec_platform
+lxc exec plat -- systemctl start dyndns

src/utils/ocaml/mec_platform/Makefile

@@ -5,9 +5,13 @@ atd:
 	atdgen -t me_platform/rest_types.atd
 	atdgen -j-std me_platform/rest_types.atd
 	atdgen -v me_platform/rest_types.atd
+	atdgen -t me_platform/dns_types.atd
+	atdgen -j-std me_platform/dns_types.atd
+	atdgen -v me_platform/dns_types.atd
 
 clean:
 	rm -rf me_platform/rest_types*.ml me_platform/rest_types*.mli
+	rm -rf me_platform/dns_types*.ml me_platform/dns_types*.mli
 	dune clean
 	rm -rf ./_build
 

src/utils/ocaml/mec_platform/etc/10-lxc.yaml

@@ -0,0 +1,8 @@
+network:
+  version: 2
+  ethernets:
+    eth0: {dhcp4: true}
+
+    eth1:
+          addresses : [192.168.11.254/24]
+          dhcp4: no

src/utils/ocaml/mec_platform/etc/dnsmasq

@@ -0,0 +1,33 @@
+# This file has five functions:
+# 1) to completely disable starting dnsmasq,
+# 2) to set DOMAIN_SUFFIX by running `dnsdomainname`
+# 3) to select an alternative config file
+#    by setting DNSMASQ_OPTS to --conf-file=<file>
+# 4) to tell dnsmasq to read the files in /etc/dnsmasq.d for
+#    more configuration variables.
+# 5) to stop the resolvconf package from controlling dnsmasq's
+#    idea of which upstream nameservers to use.
+# For upgraders from very old versions, all the shell variables set
+# here in previous versions are still honored by the init script
+# so if you just keep your old version of this file nothing will break.
+DNSMASQ_USER='mec'
+#DOMAIN_SUFFIX=`dnsdomainname`
+#DNSMASQ_OPTS="--conf-file=/etc/dnsmasq.alt"
+
+# Whether or not to run the dnsmasq daemon; set to 0 to disable.
+ENABLED=1
+
+# By default search this drop directory for configuration options.
+# Libvirt leaves a file here to make the system dnsmasq play nice.
+# Comment out this line if you don't want this. The dpkg-* are file
+# endings which cause dnsmasq to skip that file. This avoids pulling
+# in backups made by dpkg.
+CONFIG_DIR=/etc/dnsmasq.d,.dpkg-dist,.dpkg-old,.dpkg-new
+
+# If the resolvconf package is installed, dnsmasq will use its output
+# rather than the contents of /etc/resolv.conf to find upstream
+# nameservers. Uncommenting this line inhibits this behaviour.
+# Note that including a "resolv-file=<filename>" line in
+# /etc/dnsmasq.conf is not enough to override resolvconf if it is
+# installed: the line below must be uncommented.
+#IGNORE_RESOLVCONF=yes

src/utils/ocaml/mec_platform/etc/ip_replace.sh

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+
+ip -4 -o addr show dev eth0 | awk '{split($4,a,"/");print a[1]}' | xargs -i sed -i -e "s/ip/{}/g" /etc/nginx/sites-available/default

src/utils/ocaml/mec_platform/etc/mec_platform.service

@@ -0,0 +1,14 @@
+[unit]
+Description = Eclipse fog05 MEC DynDNS service
+After=yaks.target
+
+
+[Service]
+Type=simple
+PIDFile=/var/fos/platform.pid
+ExecStart = /etc/fos/utils/platform
+KillMode=process
+Restart=on-failure
+User=mec
+[Install]
+WantedBy=multi-user.target

src/utils/ocaml/mec_platform/etc/nginx

@@ -0,0 +1,24 @@
+server {
+	listen 192.168.11.254:8081;
+	#server_name mp1.platfrom.mec;
+	location / {
+		proxy_pass http://127.0.0.1:8081;
+	}
+}
+
+server {
+	listen ip:8091;
+	#server_name mm5.platform.mec;
+	location / {
+
+		proxy_pass http://127.0.0.1:8091;
+	}
+}
+
+server {
+	listen ip:9999;
+	#server_name dyndns.platfrom.mec;
+	location / {
+		proxy_pass http://127.0.0.1:9999;
+	}
+}

src/utils/ocaml/mec_platform/me_platform/DNS.ml

@@ -0,0 +1,92 @@
+open Httpaf
+open Httpaf_lwt_unix
+open Lwt.Infix
+
+
+
+module DynDNS = struct
+
+  type t = {
+    address : string;
+    port : int;
+    base_uri : string;
+    (* sock : Lwt_unix.file_descr; *)
+    addr_info : Unix.addr_info;
+  }
+
+
+
+  let read_body body =
+    let p,c = Lwt.wait () in
+    let fullb = Faraday.create 65535 in
+    let rec on_read buffer ~off ~len =
+      if len > 0 then
+        begin
+          Faraday.write_bigstring ~off ~len fullb buffer;
+          Body.schedule_read body ~on_eof ~on_read;
+        end
+      else
+        on_eof ();
+    and on_eof () =
+      Faraday.close fullb;
+      Lwt.wakeup_later c (Faraday.serialize_to_string fullb);
+    in
+    Body.schedule_read body ~on_eof ~on_read;
+    p
+
+
+  let do_request uri meth header body self =
+    let sock = Lwt_unix.socket Unix.PF_INET Unix.SOCK_STREAM 0 in
+    let p,c = Lwt.wait () in
+    let error_handler _ =
+      Logs.err (fun m ->  m "This is a DNS client error");
+      Lwt.wakeup c ""
+    in
+    let response_handler _ resp_body =
+      let _ = (read_body resp_body >>= fun body ->
+               Logs.debug (fun m -> m "Body is %s" body);
+               Lwt.wakeup_later c (body);
+               Lwt_unix.close sock)
+      in ()
+      (* Create only one sck *)
+    in
+    let%lwt _ = Lwt_unix.connect sock self.addr_info.Unix.ai_addr in
+    let headers = Headers.of_list ([
+        "Content-Length", (string_of_int (String.length body));
+        "Connection", "keep-alive";
+      ] @ header)
+    in
+    let request_body = Client.request ~error_handler ~response_handler sock (Request.create ~headers meth uri) in
+    Body.write_string request_body body;
+    Body.close_writer request_body;
+    let%lwt res = p in
+    Lwt.return res
+
+  let get_dns_rules self =
+    let uri = self.base_uri ^ "/record" in
+    let%lwt resp = do_request uri `GET [] "" self in
+    let r = Dns_types.get_response_of_string resp in
+    Lwt.return r.result
+
+  let add_dns_rule self ip name =
+    let uri = self.base_uri ^ "/record" in
+    let body =  (Dns_types.string_of_dns_record {ip; name}) ^ "\n" in
+    let%lwt resp = do_request uri `PUT [] body self in
+    let _ = Dns_types.add_remove_response_of_string resp in
+    Lwt.return_unit
+
+  let remove_dns_rule self ip name =
+    let uri = self.base_uri ^ "/record" in
+    let body =  Dns_types.string_of_dns_record {ip; name} in
+    let%lwt resp = do_request uri `DELETE [] body self in
+    let _ = Dns_types.add_remove_response_of_string resp in
+    Lwt.return_unit
+
+  let create address port base_uri =
+    let%lwt addr_info = Lwt_unix.getaddrinfo address (string_of_int port) [Unix.(AI_FAMILY PF_INET)] >>= fun al -> Lwt.return @@ List.hd al in
+    Lwt.return {address; port; base_uri; addr_info}
+
+  let destroy  _ =
+    Lwt.return_unit
+
+end

src/utils/ocaml/mec_platform/me_platform/DNS.mli

@@ -0,0 +1,18 @@
+
+
+
+module DynDNS : sig
+
+  type t
+
+  val create : string -> int -> string -> t Lwt.t
+
+  val get_dns_rules : t -> Dns_types.dns_record list Lwt.t
+
+  val add_dns_rule: t -> string -> string -> unit Lwt.t
+
+  val remove_dns_rule: t -> string -> string -> unit Lwt.t
+
+  val destroy : t -> unit Lwt.t
+
+end