adds Dockerfile for proxy and documents its use (#20)

DOCKER.md

@@ -0,0 +1,134 @@
+<!--
+Licensed to the Apache Software Foundation (ASF) under one or more
+contributor license agreements.  See the NOTICE file distributed with
+this work for additional information regarding copyright ownership.
+The ASF licenses this file to You under the Apache License, Version 2.0
+(the "License"); you may not use this file except in compliance with
+the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+-->
+
+# accumulo-proxy-docker
+This documentation covers how to stand up [accumulo-proxy](https://github.com/apache/accumulo-proxy/) within a Docker container.
+
+The guide covers:
+* Building the image
+* Configuring the `proxy.properties` file
+* Selecting an appropriate networking choice
+* Starting and stopping the container
+* Basic troubleshooting tips 
+
+It is not recommended using this guide for a production instance of accumulo-proxy at this time.
+
+## Build the image
+Firstly you will need the tarball of accumulo-proxy, this is documented in the [README.md](README.md) but for simplicity run:
+```commandline
+mvn clean package -Ptarball
+```
+
+Once you have the tarball (should be in ./target/ folder) then invoke the Docker build command to create a container image.
+```commandline
+docker build -t accumulo-proxy:latest .
+```
+
+## Default Configuration and Quickstart
+By default, the container image expects the following to be true:
+1. Your Accumulo instance name is "myinstance"
+2. Your ZooKeeper is available (and reachable from the container) at localhost:2181
+
+You can start the proxy using:
+```commandline
+docker run --rm -d -p 42424:42424 --network="host" --name accumulo-proxy accumulo-proxy:latest;
+```
+
+## Custom proxy.properties
+If you wish to create advanced proxy.properties configuration changes, you should look to volume mount these in when you invoke the `docker run` command, an example is:
+```commandline
+docker run --rm -d -p 42424:42424 -v /path/to/proxy.properties:/opt/accumulo-proxy/conf/proxy.properties --network="host" --name accumulo-proxy accumulo-proxy:latest
+```
+
+## Networking configuration
+Container networking can be a very specialised subject therefore we document two common practices that should cover the majority of use cases for development. 
+
+The proxy container must be able to access both Accumulo and ZooKeeper.
+
+The ZooKeeper location can be configured in the `conf/proxy.properties` file, so you can override this to an acceptable value (see "Custom proxy.properties" section) 
+
+In order to communicate with Accumulo the container will need to be able to resolve the FQDN that the servers have registered in ZooKeeper. If using [fluo-uno](https://github.com/apache/fluo-uno) this is very likely the hostname of your development environment. We'll call this my.host.com and IP 192.168.0.1 for the rest of this document.
+
+### Host networking
+
+Host networking is the simplest mechanism but generally only works for linux hosts where Docker has been installed on 'bare metal' e.g. through an RPM. 
+
+You can test if this will work for you by executing the following steps
+
+Start the accumulo-proxy container and enter it
+```commandline
+docker run -it --rm -p 42424:42424 --network="host" --name accumulo-proxy accumulo-proxy:latest bash;
+```
+
+Once inside the container, execute the curl command to attempt to connect to the monitor webserver:
+```commandline
+curl my.host.com:9995
+```
+
+If the terminal returns an error such as: 
+```
+curl: (7) Failed to connect to my.host.com 9995: Connection refused
+``` 
+then your container cannot see the host, and you will need to look at the next section (Non-Host networking).
+
+If you receive the HTML for the monitor web page then host networking will work for you and you can add `--network="host"` to each Docker command going forward.
+
+An example of using host networking:
+```commandline
+docker run --rm -d -p 42424:42424 --network="host" --name accumulo-proxy accumulo-proxy:latest
+```
+
+Note: You do not need to map your ports (-p) if using host networking, but we include it for clarity.
+
+For more details see the official Docker documentation: [Use host Networking](https://docs.docker.com/network/host)
+
+### Non-Host networking
+If you run outside of a single node linux installation, e.g. Docker for Mac, Docker for Windows or use a VM to isolate your Docker engine then you will likely need to take this path.
+
+Docker allows you to supply additional addresses to be resolved by the container, and these are automatically added by Docker to the /etc/hosts 
+
+For each host add a `--add-host FQDN:IP` entry to your Docker run command, you can add multiple entries if need to, see the official docs covering [network settings](https://docs.docker.com/engine/reference/run/#network-settings).
+
+An example of using this approach:
+
+```commandline
+docker run --rm -d -p 42424:42424 --add-host "my.host.com:192.168.0.1" --name accumulo-proxy accumulo-proxy:latest
+```
+
+## Cleanup
+Once completed you should stop and remove the container.
+```commandline
+docker stop accumulo-proxy;
+docker rm accumulo-proxy;
+```
+
+## Troubleshooting
+It can often be difficult to know where to start with troubleshooting inside containers, if you need to enter the container without starting the proxy we support this:
+```commandline
+docker run -it --rm -p 42424:42424 --network="host" --name accumulo-proxy accumulo-proxy:latest bash
+``` 
+
+The container is very slim so if need be you can add additional tools using `apt`. 
+
+If you wish to manually execute the accumulo-proxy in the container you can:
+```commandline
+/opt/accumulo-proxy/bin/accumulo-proxy -p /opt/accumulo-proxy/conf/proxy.properties
+```
+
+Some resources for additional help:
+* [Main Accumulo Website](https://accumulo.apache.org/)
+* [Contact Us page](https://accumulo.apache.org/contact-us/)

Dockerfile

@@ -0,0 +1,78 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+FROM openjdk:8
+
+EXPOSE 42424
+
+WORKDIR /opt/accumulo-proxy
+
+ARG HADOOP_VERSION=3.2.1
+ARG ZOOKEEPER_VERSION=3.5.7
+ARG ACCUMULO_VERSION=2.0.0
+ARG ACCUMULO_PROXY_VERSION=2.0.0-SNAPSHOT
+
+ARG HADOOP_HASH=a57962a24d178193349917730bf95cdc99bde9df
+ARG ZOOKEEPER_HASH=619928c8553b62775119e3d7d143a4714a160365
+ARG ACCUMULO_HASH=b72bf5c3dcaa25387933a032925046234f30e17a
+
+# Download from Apache mirrors instead of archive #9
+ENV APACHE_DIST_URLS \
+  https://www.apache.org/dyn/closer.cgi?action=download&filename= \
+# if the version is outdated (or we're grabbing the .asc file), we might have to pull from the dist/archive :/
+  https://www-us.apache.org/dist/ \
+  https://www.apache.org/dist/ \
+  https://archive.apache.org/dist/
+
+RUN set -eux; \
+  download_bin() { \
+    local f="$1"; shift; \
+    local hash="$1"; shift; \
+    local distFile="$1"; shift; \
+    local success=; \
+    local distUrl=; \
+    for distUrl in ${APACHE_DIST_URLS}; do \
+      if wget -nv -O "/tmp/${f}" "${distUrl}${distFile}"; then \
+        success=1; \
+        # Checksum the download
+        echo "${hash}" "/tmp/${f}" | sha1sum -c -; \
+        break; \
+      fi; \
+    done; \
+    [ -n "${success}" ]; \
+  };\
+   \
+   download_bin "apache-zookeeper.tar.gz" "${ZOOKEEPER_HASH}" "zookeeper/zookeeper-${ZOOKEEPER_VERSION}/apache-zookeeper-${ZOOKEEPER_VERSION}-bin.tar.gz"; \
+   download_bin "hadoop.tar.gz" "$HADOOP_HASH" "hadoop/core/hadoop-${HADOOP_VERSION}/hadoop-$HADOOP_VERSION.tar.gz"; \
+   download_bin "accumulo.tar.gz" "${ACCUMULO_HASH}" "accumulo/${ACCUMULO_VERSION}/accumulo-${ACCUMULO_VERSION}-bin.tar.gz";
+
+# Install the dependencies into /opt/
+RUN tar xzf /tmp/hadoop.tar.gz -C /opt/ && ln -s /opt/hadoop-${HADOOP_VERSION} /opt/hadoop
+RUN tar xzf /tmp/apache-zookeeper.tar.gz -C /opt/ && ln -s /opt/apache-zookeeper-${ZOOKEEPER_VERSION}-bin /opt/apache-zookeeper
+RUN tar xzf /tmp/accumulo.tar.gz -C /opt/ && ln -s /opt/accumulo-${ACCUMULO_VERSION} /opt/accumulo && sed -i 's/\${ZOOKEEPER_HOME}\/\*/\${ZOOKEEPER_HOME}\/\*\:\${ZOOKEEPER_HOME}\/lib\/\*/g' /opt/accumulo/conf/accumulo-env.sh
+
+ENV HADOOP_HOME /opt/hadoop
+ENV ZOOKEEPER_HOME /opt/apache-zookeeper
+ENV ACCUMULO_HOME /opt/accumulo
+
+# Add the proxy binary
+COPY target/accumulo-proxy-${ACCUMULO_PROXY_VERSION}-bin.tar.gz /tmp/
+RUN tar xzf /tmp/accumulo-proxy-${ACCUMULO_PROXY_VERSION}-bin.tar.gz -C /opt/accumulo-proxy --strip 1
+ENV ACCUMULO_PROXY_HOME /opt/accumulo-proxy
+
+# Ensure Accumulo is on the path.
+ENV PATH "${PATH}:${ACCUMULO_HOME}/bin"
+
+CMD ["/opt/accumulo-proxy/bin/accumulo-proxy", "-p", "/opt/accumulo-proxy/conf/proxy.properties"]

README.md

@@ -41,6 +41,10 @@ Thrift language binding).
     ./bin/accumulo-proxy -p conf/proxy.properties
     ```
 
+# Docker Environment
+
+The Accumulo Proxy can also now be packaged and started in a Docker container, see the [DOCKER.md](DOCKER.md) for full details.
+
 # Build language specific bindings
 
 Bindings have been built in `src/main/` for Java, Python, and Ruby.