Add Dockerfile to build and run btcd on Docker.

Dockerfile

@@ -0,0 +1,40 @@
+# This Dockerfile builds btcd from source and creates a small (55 MB) docker container based on alpine linux.
+#
+# Clone this repository and run the following command to build and tag a fresh btcd amd64 container:
+#
+# docker build . -t yourregistry/btcd
+#
+# You can use the following command to buid an arm64v8 container:
+#
+# docker build . -t yourregistry/btcd --build-arg ARCH=arm64v8
+#
+# For more information how to use this docker image visit:
+# https://github.com/btcsuite/btcd/tree/master/docs
+#
+# 8333  Mainnet Bitcoin peer-to-peer port
+# 8334  Mainet RPC port
+
+ARG ARCH=amd64
+
+FROM golang:1.14-alpine3.12 AS build-container
+
+ARG ARCH
+ENV GO111MODULE=on
+
+ADD . /app
+WORKDIR /app
+RUN set -ex \
+  && if [ "${ARCH}" = "amd64" ]; then export GOARCH=amd64; fi \
+  && if [ "${ARCH}" = "arm64v8" ]; then export GOARCH=arm64; fi \
+  && echo "Compiling for $GOARCH" \
+  && go install -v . ./cmd/...
+
+FROM $ARCH/alpine:3.12
+
+COPY --from=build-container /go/bin /bin
+
+VOLUME ["/root/.btcd"]
+
+EXPOSE 8333 8334
+
+ENTRYPOINT ["btcd"]

docs/README.md

@@ -20,6 +20,7 @@
     1. [Code Contribution Guidelines](#ContributionGuidelines)
     2. [JSON-RPC Reference](#JSONRPCReference)
     3. [The btcsuite Bitcoin-related Go Packages](#GoPackages)
+6. [Using Docker](#Docker)
 
 <a name="About" />
 
@@ -294,3 +295,11 @@ information.
       specific hash algorithm to be abstracted.
     * [connmgr](https://github.com/btcsuite/btcd/tree/master/connmgr) -
       Package connmgr implements a generic Bitcoin network connection manager.
+
+<a name="Docker" />
+
+### 6. Using Docker
+
+You can run btcd in a Docker container, without the need to compile the source by yourself. Visit the [Using Docker](https://github.com/btcsuite/btcd/tree/master/docs/using_docker.md) page for more inrormation and examples.
+
+* [Using Docker](https://github.com/btcsuite/btcd/tree/master/docs/using_docker.md) details page

docs/using_docker.md

@@ -0,0 +1,160 @@
+# Using Docker
+
+- [Using Docker](#using-docker)
+  - [Introduction](#introduction)
+  - [Docker volumes](#docker-volumes)
+  - [Known error messages when starting the btcd container](#known-error-messages-when-starting-the-btcd-container)
+  - [Examples](#examples)
+    - [Preamble](#preamble)
+    - [Full node without RPC port](#full-node-without-rpc-port)
+    - [Full node with RPC port](#full-node-with-rpc-port)
+    - [Full node with RPC port running on TESTNET](#full-node-with-rpc-port-running-on-testnet)
+
+## Introduction
+
+With Docker you can easily set up *btcd* to run your Bitcoin full node. You can find the official *btcd* Docker images on Docker Hub [btcsuite/btcd](https://hub.docker.com/r/btcsuite/btcd). The Docker source file of this image is located at [Dockerfile](https://github.com/btcsuite/btcd/blob/master/Dockerfile).
+
+This documentation focuses on running Docker container with *docker-compose.yml* files. These files are better to read and you can use them as a template for your own use. For more information about Docker and Docker compose visit the official [Docker documentation](https://docs.docker.com/).
+
+## Docker volumes
+
+**Special diskspace hint**: The following examples are using a Docker managed volume. The volume is named *btcd-data* This will use a lot of disk space, because it contains the full Bitcoin blockchain. Please make yourself familiar with [Docker volumes](https://docs.docker.com/storage/volumes/).
+
+The *btcd-data* volume will be reused, if you upgrade your *docker-compose.yml* file. Keep in mind, that it is not automatically removed by Docker, if you delete the btcd container. If you don't need the volume anymore, please delete it manually with the command:
+
+```bash
+docker volume ls
+docker volume rm btcd-data
+```
+
+For binding a local folder to your *btcd* container please read the [Docker documentation](https://docs.docker.com/). The preferred way is to use a Docker managed volume.
+
+## Known error messages when starting the btcd container
+
+We pass all needed arguments to *btcd* as command line parameters in our *docker-compose.yml* file. It doesn't make sense to create a *btcd.conf* file. This would make things too complicated. Anyhow *btcd* will complain with following log messages when starting. These messages can be ignored:
+
+```bash
+Error creating a default config file: open /sample-btcd.conf: no such file or directory
+...
+[WRN] BTCD: open /root/.btcd/btcd.conf: no such file or directory
+```
+
+## Examples
+
+### Preamble
+
+All following examples uses some defaults:
+
+- container_name: btcd
+  Name of the docker container that is be shown by e.g. ```docker ps -a```
+
+- hostname: btcd **(very important to set a fixed name before first start)**
+  The internal hostname in the docker container. By default, docker is recreating the hostname every time you change the *docker-compose.yml* file. The default hostnames look like *ef00548d4fa5*. This is a problem when using the *btcd* RPC port. The RPC port is using a certificate to validate the hostname. If the hostname changes you need to recreate the certificate. To avoid this, you should set a fixed hostname before the first start. This ensures, that the docker volume is created with a certificate with this hostname.
+
+- restart: unless-stopped
+  Starts the *btcd* container when Docker starts, except that when the container is stopped (manually or otherwise), it is not restarted even after Docker restarts.
+
+To use the following examples create an empty directory. In this directory create a file named *docker-compose.yml*, copy and paste the example into the *docker-compose.yml* file and run it.
+
+```bash
+mkdir ~/btcd-docker
+cd ~/btcd-docker
+touch docker-compose.yaml
+nano docker-compose.yaml (use your favourite editor to edit the compose file)
+docker-compose up (creates and starts a new btcd container)
+```
+
+With the following commands you can control *docker-compose*:
+
+```docker-compose up -d``` (creates and starts the container in background)
+
+```docker-compose down``` (stops and delete the container. **The docker volume btcd-data will not be deleted**)
+
+```docker-compose stop``` (stops the container)
+
+```docker-compose start``` (starts the container)
+
+```docker ps -a``` (list all running and stopped container)
+
+```docker volume ls``` (lists all docker volumes)
+
+```docker logs btcd``` (shows the log )
+
+```docker-compose help``` (brings up some helpful information)
+
+### Full node without RPC port
+
+Let's start with an easy example. If you just want to create a full node without the need of using the RPC port, you can use the following example. This example will launch *btcd* and exposes only the default p2p port 8333 to the outside world:
+
+```yaml
+version: "2"
+
+services:
+  btcd:
+    container_name: btcd
+    hostname: btcd
+    image: btcsuite/btcd:latest
+    restart: unless-stopped
+    volumes:
+      - btcd-data:/root/.btcd
+    ports:
+      - 8333:8333
+
+volumes:
+  btcd-data:
+```
+
+### Full node with RPC port
+
+To use the RPC port of *btcd* you need to specify a *username* and a very strong *password*. If you want to connect to the RPC port from the internet, you need to expose port 8334(RPC) as well.
+
+```yaml
+version: "2"
+
+services:
+  btcd:
+    container_name: btcd
+    hostname: btcd
+    image: btcsuite/btcd:latest
+    restart: unless-stopped
+    volumes:
+      - btcd-data:/root/.btcd
+    ports:
+      - 8333:8333
+      - 8334:8334
+    command: [
+        "--rpcuser=[CHOOSE_A_USERNAME]",
+        "--rpcpass=[CREATE_A_VERY_HARD_PASSWORD]"
+    ]
+
+volumes:
+  btcd-data:
+```
+
+### Full node with RPC port running on TESTNET
+
+To run a node on testnet, you need to provide the *--testnet* argument. The ports for testnet are 18333 (p2p) and 18334 (RPC):
+
+```yaml
+version: "2"
+
+services:
+  btcd:
+    container_name: btcd
+    hostname: btcd
+    image: btcsuite/btcd:latest
+    restart: unless-stopped
+    volumes:
+      - btcd-data:/root/.btcd
+    ports:
+      - 18333:18333
+      - 18334:18334
+    command: [
+        "--testnet",
+        "--rpcuser=[CHOOSE_A_USERNAME]",
+        "--rpcpass=[CREATE_A_VERY_HARD_PASSWORD]"
+    ]
+
+volumes:
+  btcd-data:
+```