For simplicity use the included script to do all the steps below
$ ./create-image
FROM alpine:3.3
# Download the Erlang/OTP source
RUN mkdir /buildroot
WORKDIR /buildroot
ADD https://github.com/erlang/otp/archive/OTP-19.2.tar.gz .
RUN tar zxf OTP-19.2.tar.gz
# Install additional packages
RUN apk add --no-cache autoconf && \
apk add --no-cache alpine-sdk && \
apk add --no-cache openssl-dev
# Build Erlang/OTP
WORKDIR otp-OTP-19.2
RUN ./otp_build autoconf && \
CFLAGS="-Os" ./configure --prefix=/buildroot/erlang/19.2 --without-termcap --disable-hipe && \
make -j10
# Install Erlang/OTP
RUN mkdir -p /buildroot/erlang/19.2 && \
make install
# Install Rebar3
RUN mkdir -p /buildroot/rebar3/bin
ADD https://s3.amazonaws.com/rebar3/rebar3 /buildroot/rebar3/bin/rebar3
RUN chmod a+x /buildroot/rebar3/bin/rebar3
# Setup Environment
ENV PATH=/buildroot/erlang/19.2/bin:/buildroot/rebar3/bin:$PATH
# Reset working directory
WORKDIR /buildroot
# Copy our Erlang test application
COPY dockerwatch dockerwatch
WORKDIR dockerwatch
CMD rebar3 as prod release -o /artifacts$ docker build -t build_erlang-dockerwatch --file=alpine/build/Dockerfile .
$ docker run --rm --volume="$PWD/alpine/run/artifacts:/artifacts" build_erlang-dockerwatch
This releases our Erlang application using rebar3 and the following rebar.config.
{deps, [{lager, "3.2.4"}, %% Logging
{jsone, "1.4.2"}, %% JSON Encode/Decode
{cowboy, "1.1.2"}]}. %% HTTP Server
{relx, [{release, {"dockerwatch", "1.0.0"}, [dockerwatch]},
{vm_args, "config/vm.args"},
{sys_config, "config/sys.config"},
{dev_mode, true},
{include_erts, false},
{extended_start_script, true}
]}.
{profiles, [{prod, [{relx, [{dev_mode, false},
{include_erts, true},
{include_src, false}]}]}
]}.The release is stored on our local filesystem under alpine/run/artifacts.
It includes an Erlang runtime as well as our dockerwatch application and all its dependencies.
$ tree -L 3 alpine/run/artifacts/
alpine/run/artifacts/
└── dockerwatch
├── bin
│ ├── dockerwatch
│ ├── dockerwatch-1.0.0
│ ├── install_upgrade.escript
│ ├── nodetool
│ └── start_clean.boot
├── erts-8.2
│ ├── bin
│ ├── doc
│ ├── include
│ ├── lib
│ └── man
├── lib
│ ├── asn1-4.0.4
│ ├── compiler-7.0.3
│ ├── cowboy-1.1.2
│ ├── cowlib-1.0.2
│ ├── crypto-3.7.2
│ ├── dockerwatch-1.0.0
│ ├── goldrush-0.1.9
│ ├── jsone-1.4.2
│ ├── kernel-5.1.1
│ ├── lager-3.2.4
│ ├── public_key-1.3
│ ├── ranch-1.3.2
│ ├── ssl-8.1
│ ├── stdlib-3.2
│ └── syntax_tools-2.1.1
└── releases
├── 1.0.0
├── RELEASES
└── start_erl.data
FROM alpine:3.3
# Install the released application
COPY artifacts/dockerwatch /dockerwatch
# Expose relevant ports
EXPOSE 8080
EXPOSE 8443
CMD ["/dockerwatch/bin/dockerwatch", "foreground"]$ docker build -t erlang-dockerwatch alpine/run/
What happened?
$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
erlang-dockerwatch latest ca683d321e7e 6 minutes ago 21.8 MB
build_erlang-dockerwatch latest 8059ec18fa6e 19 minutes ago 617 MB
Generate certificates in subdirectory ssl.
$ ./create-certs
For some more details of what this command does, see README-CERTS.md
We start the image in docker container by issuing the following command.
$ docker run -d -p 8443:8443 --volume="$PWD/ssl:/etc/ssl/certs" --log-driver=syslog erlang-dockerwatch
870f979c5b4cdb7a1ba930b020043f50fa7457bf787237706fb27eefaf5fe61d
Let's parse some of the input.
-p 8443:8443, exposes port8443from the container to our localhost--volume="$PWD/ssl:/etc/ssl/certs", mounts our local directory with certificates in the container.--log-driver=syslog, will log all data from stdout in the container to our local syslog.
Output in syslog.
$ tail -n10 /var/log/syslog
Feb 21 11:55:17 elxd1168lx9 kernel: [692274.686524] docker0: port 1(vethb1adc6d) entered forwarding state
Feb 21 11:55:17 elxd1168lx9 870f979c5b4c[3837]: Exec: /dockerwatch/erts-8.2/bin/erlexec -noshell -noinput +Bd -boot /dockerwatch/releases/1.0.0/dockerwatch -mode embedded -boot_var ERTS_LIB_DIR /dockerwatch/lib -config /dockerwatch/releases/1.0.0/sys.config -args_file /dockerwatch/releases/1.0.0/vm.args -pa -- foreground
Feb 21 11:55:17 elxd1168lx9 870f979c5b4c[3837]: Root: /dockerwatch
Feb 21 11:55:17 elxd1168lx9 870f979c5b4c[3837]: /dockerwatch
Feb 21 11:55:17 elxd1168lx9 870f979c5b4c[3837]: 10:55:17.463 [info] Application lager started on node dockerwatch@870f979c5b4c#015
Feb 21 11:55:17 elxd1168lx9 870f979c5b4c[3837]: 10:55:17.464 [info] Application ranch started on node dockerwatch@870f979c5b4c#015
Feb 21 11:55:17 elxd1168lx9 870f979c5b4c[3837]: 10:55:17.464 [info] Application cowboy started on node dockerwatch@870f979c5b4c#015
...
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
870f979c5b4c erlang-dockerwatch "/dockerwatch/bin/..." About a minute ago Up About a minute 0.0.0.0:8443->8443/tcp mystifying_thompson
Fetch container IP Address from container id:
$ docker inspect --format='{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' 870f979c5b4c
172.17.0.2
Create a counter called cnt using https with curl:
$ curl --cacert ssl/dockerwatch-ca.pem -i -H "Content-Type: application/json" -X POST -d "" https://localhost:8443/cnt
HTTP/1.1 204 No Content
server: Cowboy
date: Wed, 22 Feb 2017 13:12:54 GMT
content-length: 0
content-type: text/html
vary: accept
Read all counters using https with curl as json:
curl --cacert ssl/dockerwatch-ca.pem -H "Accept: application/json" https://localhost:8443
["cnt"]
Read the counter cnt using https with curl as json:
curl --cacert ssl/dockerwatch-ca.pem -H "Accept: application/json" https://localhost:8443/cnt
{"cnt":0}
Increment the counter cnt using http with curl:
curl -H "Content-Type: application/json" -X POST -d '{}' http://172.17.0.2:8080/cnt
Read the counter cnt using http with curl as text:
curl -H "Accept: text/plain" http://172.17.0.2:8080/cnt
1
Increment the counter cnt by 20 using http with curl:
curl -H "Content-Type: application/json" -X POST -d '{"value":20}' http://172.17.0.2:8080/cnt
Read the counter cnt using http with curl as text:
curl -H "Accept: text/plain" http://172.17.0.2:8080/cnt
21