Add Dockerfile to support running in a container

Dockerfile

@@ -0,0 +1,38 @@
+ARG BASE=debian:bookworm-slim
+
+# Build slinktool in a separate container, so resulting container does not 
+# include compiler tools
+FROM $BASE as buildenv
+RUN apt update \
+    && apt upgrade -y \
+    && apt install -y --no-install-recommends \
+        build-essential \
+    && rm -rf /var/lib/apt/lists/*
+
+# Build executable
+COPY . /build
+RUN cd /build && make
+
+# Build slinktool container
+FROM $BASE
+RUN apt update \
+    && apt upgrade -y \
+    && rm -rf /var/lib/apt/lists/*
+
+# Copy executable and default config from build image
+COPY --from=buildenv /build/slinktool /
+COPY ./entrypoint.sh /
+
+# Add non-root user
+ARG UID=10000
+ARG GID=10001
+ARG USERNAME=containeruser
+RUN \
+    groupadd --gid $GID $USERNAME && \
+    adduser --uid $UID --gid $GID $USERNAME
+
+# Drop to regular user
+USER $USERNAME
+
+# See entrypoint.sh for environment variable support.
+ENTRYPOINT [ "/entrypoint.sh" ]

README.md

@@ -19,6 +19,18 @@ A Makefile.win is included for building for using with Nmake, i.e.
 For further installation simply copy the resulting binary and man page
 (in the 'doc' directory) to appropriate system directories.
 
+Docker:
+A Dockerfile is included for building a container with slinktool compiled.
+To build:
+```
+docker build -t slinktool:latest .
+```
+The entrypoint script will pass though all arguments so usage follows the same syntax as the regular executable:
+```
+docker run slinktool -v -o data.mseed slink.host.com:18000
+```
+Note that if you are connecting to seedlink servers running on your local computer, you will need to add `--network="host"` to the docker command in order to use the host name `localhost`.
+
 ## Licensing
 
 Copyright (C) 2016 Chad Trabant, IRIS Data Management Center

entrypoint.sh

@@ -0,0 +1,155 @@
+#!/bin/bash
+#
+# Entrypoint script to map environment variables into command line arguments.
+#
+# Three kinds of arguments are supported:
+#
+# 1. Option and value EG "--port 8888"
+#
+# Configure these by adding keys to the ARG_MAPPING dictionary in the code. See
+# the comments there for details.
+# 
+# Arguments and values will be space separated and values will be single quoted
+# in the resulting command EG "--port '8888'". Any unset or empty string 
+# environment varables do not result in any command line argument being 
+# specified. 
+#
+# 2. Flags EG "--verbose"
+#
+# Configure these by adding keys to the ARG_MAPPING dictionary in the code the
+# same as above. But use them by setting the environment variable's value to the
+# magic Python-inspired value "ACTION_STORE_TRUE".
+#
+# 3. Subcommands or bare values EG "docker run"
+#
+# Configure one environment variable name in the ARG_MAPPING dictionary in the
+# code the same as above by specifying it with the command line argument magic 
+# value of "&". This environment variable's value will be added to the very
+# end of the command with no quotes.
+#
+# Any additional arguments passed to this script, except "--debug", will be 
+# passed to the command. Passing "--debug" will cause this script to enter
+# debugging mode and print out information without running the final command.
+#
+# This requires BASH VERSION 4 OR GREATER. Beware Alpine and other busybox or
+# ash based distros.
+#
+# Example usage in a Dockerfile:
+#
+#   COPY ./entrypoint.sh .
+#   # Set any default values here, if it's appropriate to build them into the
+#   # container.
+#   ENV SAMPLE_VARIABLE=foo
+#   ENV LESS_USED_OPTION=bar
+#
+#   # Uncomment to build container in debugging entrypoint.sh mode.
+#   #CMD = ["--debug"]
+#   ENTRYPOINT ["./entrypoint.sh"]
+#
+# Example usage in a compose.yml file that runs the above Dockerfile:
+#
+#   services:
+#     my_service_name:
+#       image: dockerimagename
+#       environment:
+#         SAMPLE_VARIABLE: foo_override
+#         SOME_OTHER_VARIABLE: not_foo
+#         LESS_USED_OPTION: '' # value is set to empty string which entrypoint.sh
+#                              # will interpret as unset
+#
+# Examples running the container from the command line:
+#
+#  # Run container in debugging mode, outputing the command that would be run
+#  docker run dockerimagename --debug
+#
+#  # Run container overriding SAMPLE_VARIABLE to a new value
+#  docker run -e SAMPLE_VARIABLE='foo_override' dockerimagename
+#
+#  # Run container with any built-in default variables, but additional command
+#  # line arguments
+#  docker run dockerimagename -v --rarely-used-option bar
+#
+
+set -euo pipefail
+
+declare -A ARG_MAPPING
+
+# Set program name to run here.
+COMMAND_LINE="/slinktool"
+
+# Add arguments specific to your program here in the form:
+# ARGMAPPING["command line arg including dashes"]="environment variable name"
+ARG_MAPPING["-V"]="VERSION"
+ARG_MAPPING["-h"]="HELP"
+ARG_MAPPING["-H"]="EXTENDED_HELP"
+ARG_MAPPING["-vv"]="VERBOSE"
+ARG_MAPPING["-P"]="PING"
+ARG_MAPPING["-pp"]="PRINT_RECORD_DETAILS"
+ARG_MAPPING["-u"]="PRINT_RECORD_DATA"
+ARG_MAPPING["-nd"]="NETWORK_RECONNECT_DELAY"
+ARG_MAPPING["-nt"]="NETWORK_TIMEOUT"
+ARG_MAPPING["-k"]="KEEPALIVE"
+ARG_MAPPING["-x"]="STATEFILE"
+ARG_MAPPING["-d"]="DIALUP"
+ARG_MAPPING["-b"]="BATCH"
+ARG_MAPPING["-o"]="DUMPFILE"
+ARG_MAPPING["-A"]="DIRECTORY_FORMAT"
+ARG_MAPPING["-SDS"]="SDS_DIRECTORY"
+ARG_MAPPING["-BUD"]="BUD_DIRECTORY"
+ARG_MAPPING["-s"]="SELECTORS"
+ARG_MAPPING["-I"]="STREAM_LIST_FILE"
+ARG_MAPPING["-S"]="STREAM_LIST"
+ARG_MAPPING["-tw"]="TIME_WINDOW"
+ARG_MAPPING["-i"]="INFO_REQUEST"
+ARG_MAPPING["-I"]="INFO_ID"
+ARG_MAPPING["-L"]="INFO_STATION_LIST"
+ARG_MAPPING["-Q"]="INFO_STREAM_LIST"
+ARG_MAPPING["-G"]="INFO_GAP_LIST"
+ARG_MAPPING["-C"]="INFO_CONNECTION_LIST"
+ARG_MAPPING["&"]="HOST_AND_PORT"
+
+# Process any additional command line args, eating "--debug" as an argument to
+# this script.
+DEBUGGING=
+for arg
+do
+    shift
+    if [[ "$arg" == "--debug" ]] ; then
+        DEBUGGING='true'
+    else
+        set -- "$@" "$arg"
+    fi
+done
+
+if [[ $DEBUGGING ]] ; then
+    echo "Argument --debug detected, entrypoint.sh entering debugging mode. No command will be run."
+fi
+
+# Build command line arguments from environment variables
+SUFFIX_ARGUMENT=
+for cl_arg in "${!ARG_MAPPING[@]}";
+do
+    env_var="${ARG_MAPPING[$cl_arg]}"
+    if [[ ! -z ${!env_var+x} ]] ; then
+        if [[ "${!env_var}" == "ACTION_STORE_TRUE" ]] ; then
+            # Flag option
+            COMMAND_LINE="${COMMAND_LINE} ${cl_arg}"
+        elif [[ "${cl_arg}" == "&" ]] ; then
+            # Subcommand option
+            SUFFIX_ARGUMENT=${!env_var}
+        else
+            # Option and value
+            COMMAND_LINE="${COMMAND_LINE} ${cl_arg} ${!env_var}"
+        fi
+    elif [[ $DEBUGGING ]] ; then
+        echo "Argument $cl_arg not passed because variable $env_var is unset"
+    fi
+done
+
+# Run command
+if [[ $DEBUGGING ]] ; then
+    echo "Additional arguments passed to entrypoint.sh: $@"
+    echo "Final command to be run: $COMMAND_LINE $@ $SUFFIX_ARGUMENT"
+else
+    exec $COMMAND_LINE $@ $SUFFIX_ARGUMENT
+fi