Ansible README update and small fixes

DOCKER/Dockerfile

@@ -1,18 +1,35 @@
 FROM alpine:3.7
 MAINTAINER Greg Szabo <greg@tendermint.com>
 
-#Default home for tendermint. The node command will look for $TMHOME/config/genesis.json at initialization.
+# Tendermint will be looking for the genesis file in /tendermint/config/genesis.json
+# (unless you change `genesis_file` in config.toml). You can put your config.toml and
+# private validator file into /tendermint/config.
+#
+# The /tendermint/data dir is used by tendermint to store state.
 ENV TMHOME /tendermint
+
+# OS environment setup
+# Set user right away for determinism, create directory for persistence and give our user ownership
+# jq and curl used for extracting `pub_key` from private validator while
+# deploying tendermint with Kubernetes. It is nice to have bash so the users
+# could execute bash commands.
 RUN apk update && \
     apk upgrade && \
-    apk --no-cache add curl jq && \
+    apk --no-cache add curl jq bash && \
     addgroup tmuser && \
     adduser -S -G tmuser tmuser -h "$TMHOME"
 
+# Run the container with tmuser by default. (UID=100, GID=1000)
 USER tmuser
+
+# Expose the data directory as a volume since there's mutable state in there
 VOLUME [ $TMHOME ]
+
 WORKDIR $TMHOME
+
+# p2p and rpc port
 EXPOSE 46656 46657
+
 ENTRYPOINT ["/usr/bin/tendermint"]
 CMD ["node", "--moniker=`hostname`"]
 STOPSIGNAL SIGTERM