install: add fallback where yaml creation failed

In some rare case, .deb installer fails to create /etc/dhtnet/dnc.yaml
config. In theses case, dnc service fail to start, so post-install
script now check if /etc/dhtnet/dnc.yaml exists and create it if not.
dnc.service now rely entirely on /etc/dhtnet/dnc.yaml for configuration,
removing hardcoded flags in service file.

Change-Id: Ia827dd92532a6b17584e15b1af34cc236980202e

extras/packaging/gnu-linux/debian/postinst

@@ -9,8 +9,18 @@ create_server_keys() {
         echo "Generating server keys..."
         dhtnet-crtmgr --setup -o /etc/dhtnet/
         dhtnet-crtmgr -a -c /etc/dhtnet/id/id-server.crt -p /etc/dhtnet/id/id-server.pem
+        configure_yaml
         disable_dnc_service
     fi
+    echo "===================="
+    echo "dnc server installed and configured."
+    echo "To configure it, edit /etc/dhtnet/dnc.yaml"
+    echo "To enable and start server, run:"
+    echo "  systemctl enable dnc.service"
+    echo "  systemctl start dnc.service"
+    echo "To configure your dnc client, run:"
+    echo "  dhtnet-crtmgr --interactive"
+    echo "===================="
 }
 
 # reload_dnc_service() {
@@ -26,4 +36,23 @@ disable_dnc_service() {
     systemctl disable dnc.service
 }
 
+configure_yaml() {
+    if [ -f /etc/dhtnet/dnc.yaml ]; then
+        sed -i 's/^#certificate:.*$/certificate: \"\/etc\/dhtnet\/id\/id-server.crt\"/' /etc/dhtnet/dnc.yaml
+        sed -i 's/^#privateKey:.*$/privateKey: \"\/etc\/dhtnet\/id\/id-server.pem\"/' /etc/dhtnet/dnc.yaml
+    else
+        echo "bootstrap: \"bootstrap.jami.net\"" > /etc/dhtnet/dnc.yaml
+        echo "turn_host: \"turn.jami.net\"" > /etc/dhtnet/dnc.yaml
+        echo "turn_user: \"ring\"" > /etc/dhtnet/dnc.yaml
+        echo "turn_pass: \"ring\"" > /etc/dhtnet/dnc.yaml
+        echo "turn_realm: \"ring\"" > /etc/dhtnet/dnc.yaml
+        echo "port: 22" > /etc/dhtnet/dnc.yaml
+        echo "ip: \"127.0.0.1\"" > /etc/dhtnet/dnc.yaml
+        echo "certificate: \"/etc/dhtnet/id/id-server.crt\"" > /etc/dhtnet/dnc.yaml
+        echo "privateKey: \"/etc/dhtnet/id/id-server.pem\"" > /etc/dhtnet/dnc.yaml
+        echo "anonymous: false" > /etc/dhtnet/dnc.yaml
+        echo "verbose: false" > /etc/dhtnet/dnc.yaml
+    fi
+}
+
 create_server_keys

tools/dnc/systemd/dnc.service.in

@@ -8,7 +8,7 @@ Documentation=https://git.jami.net/savoirfairelinux/dhtnet/blob/master/tools/dvp
 [Service]
 Type=exec
 Environment="DHTNET_CACHE_DIR=/var/run/dhtnet"
-ExecStart=@bindir@/dnc -l -d @sysconfdir@/dhtnet/dnc.yaml -c @sysconfdir@/dhtnet/id/id-server.crt -p @sysconfdir@/dhtnet/id/id-server.pem
+ExecStart=@bindir@/dnc -l -d @sysconfdir@/dhtnet/dnc.yaml
 Restart=on-failure
 ProtectSystem=strict
 ProtectKernelTunables=yes