add internal rtl_tcp

Dockerfile

@@ -1,4 +1,4 @@
-FROM ghcr.io/sdr-enthusiasts/docker-baseimage:base
+FROM ghcr.io/sdr-enthusiasts/docker-baseimage:rtlsdr
 
 SHELL ["/bin/bash", "-o", "pipefail", "-c"]
 
@@ -28,8 +28,12 @@ RUN set -x && \
 
 COPY rootfs/ /
 
-ENV SRC_ADDR="" \
+ENV SRC_ADDR="127.0.0.1" \
     SRC_PORT="1234" \
     SINK_ADDR="0.0.0.0" \
     RW_SINK_PORT="7373" \
-    RO_SINK_PORT="7374"
+    RO_SINK_PORT="7374" \
+    GAIN="0" \
+    FREQ="1545600550" \
+    RATE="1536000" \
+    SERIAL="00001542"

README.md

@@ -25,8 +25,13 @@ This container is a thin wrapper around [rpatel3001/rtlmuxer](https://github.com
 
 | Variable | Description | Default |
 |----------|-------------|---------|
-| `SRC_ADDR` | Address of the rtl_tcp source we are proxying. | Unset |
-| `SRC_PORT` | Port of the rtl_tcp source we are proxying. | 1234 |
-| `SINK_ADDR` | Address to bind for the proxied connections. | 0.0.0.0 |
-| `RW_SINK_PORT` | Port to bind for the read/write proxy connection. | 7373 |
-| `RO_SINK_PORT` | Port to bind for the read-only proxy connection. | 7374 |
+| `SRC_ADDR` | Address of the rtl_tcp source we are proxying. | 127.0.0.1 |
+| `SRC_PORT` | Port of the rtl_tcp source we are proxying.    | 1234 |
+| `SINK_ADDR` | Address to bind for the proxied connections.  | 0.0.0.0 |
+| `RW_SINK_PORT` | Port to bind for the read/write proxy connection.   | 7373  |
+| `RO_SINK_PORT` | Port to bind for the read-only proxy connection.    | 7374  |
+| `RTL_TCP` | Set to any value to run RTL_TCP inside the container.    | Unset |
+| `GAIN`    | Initial gain when using RTL_TCP.        | 0 |
+| `FREQ`    | Initial frequency when using RTL_TCP.   | 1545600550 |
+| `RATE`    | Initial sample rate when using RTL_TCP. | 1536000    |
+| `SERIAL`  | Serial or device index for RTL_TCP.     | 00001542   |

rootfs/etc/s6-overlay/s6-rc.d/rtl_tcp/run

@@ -0,0 +1,8 @@
+#!/command/with-contenv bash
+#shellcheck shell=bash
+
+if [[ -n "${RTL_TCP}" ]]; then
+  exec rtl_tcp -a 0.0.0.0 -p $SRC_PORT -f $FREQ -g $GAIN -s $RATE -d $SERIAL 2>&1 | stdbuf -o0 awk '{print "[rtlmuxer] " strftime("%Y/%m/%d %H:%M:%S", systime()) " " $0}'
+else
+  exec sleep 86400
+fi

rootfs/etc/s6-overlay/s6-rc.d/rtl_tcp/type

@@ -0,0 +1 @@
+longrun

rootfs/etc/s6-overlay/s6-rc.d/rtlmuxer/run

@@ -0,0 +1,4 @@
+#!/command/with-contenv bash
+#shellcheck shell=bash
+
+exec rtlmuxer --src-address=$SRC_ADDR --src-port=$SRC_PORT --sink-bind-address=$SINK_ADDR --sink-bind-port-a=$RW_SINK_PORT --sink-bind-port-b=$RO_SINK_PORT 2>&1 | stdbuf -o0 awk '{print "[rtlmuxer] " strftime("%Y/%m/%d %H:%M:%S", systime()) " " $0}'

rootfs/etc/s6-overlay/s6-rc.d/rtlmuxer/type

@@ -0,0 +1 @@
+longrun