cygnus-common docker
Content:
Before starting
Obviously, you will need docker installed and running in you machine. Please, check this official start guide.
Getting an image
Building from sources
Start by cloning the fiware-cygnus
repository:
$ git clone https://github.com/telefonicaid/fiware-cygnus.git
Change directory:
$ cd fiware-cygnus/docker/cygnus-common
And run the following command:
$ docker build -t cygnus-common .
Once finished (it may take a while), you can check the available images at your docker by typing:
$ docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
cygnus-common latest 0d2e537ac922 41 minutes ago 673.8 MB
centos 6 61bf77ab8841 6 weeks ago 228.9 MB
Using docker hub image
Instead of building an image from the scratch, you may download it from hub.docker.com:
$ docker pull fiware/cygnus-common
It can be listed the same way than above:
$ docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
cygnus-common latest 0d2e537ac922 41 minutes ago 673.8 MB
centos 6 61bf77ab8841 6 weeks ago 228.9 MB
Using the image
As it is
The cygnus-common image (either built from the scratch, either downloaded from hub.docker.com) allows running a Cygnus agent in charge of logging messages at INFO level. This is because the default agent configuration runs a logger-sink.
Start a container for this image by typing in a terminal:
$ docker run cygnus-common
Immediately after, you will start seeing cygnus-common logging traces:
+ exec /usr/lib/jvm/java-1.7.0/bin/java -Xmx20m -Dflume.root.logger=INFO,console -cp '/opt/apache-flume/conf:/opt/apache-flume/lib/*:/opt/apache-flume/plugins.d/cygnus/lib/*:/opt/apache-flume/plugins.d/cygnus/libext/*' -Djava.library.path= com.telefonica.iot.cygnus.nodes.CygnusApplication -f /opt/apache-flume/conf/agent.conf -n cygnus-common
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/opt/apache-flume/lib/slf4j-log4j12-1.6.1.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/opt/apache-flume/plugins.d/cygnus/libext/cygnus-common-1.0.0_SNAPSHOT-jar-with-dependencies.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
time=2016-05-17T06:36:23.867UTC | lvl=INFO | corr= | trans= | srv= | subsrv= | function=main | comp= | msg=com.telefonica.iot.cygnus.nodes.CygnusApplication[166] : Starting Cygnus, version 1.0.0_SNAPSHOT.d7cfee4455a59a1854cc53f37e16ff4866b26010
...
...
time=2016-05-17T06:36:25.046UTC | lvl=INFO | corr= | trans= | srv= | subsrv= | function=main | comp=cygnus-common | msg=com.telefonica.iot.cygnus.nodes.CygnusApplication[286] : Starting a Jetty server listening on port 8081 (Management Interface)
You can check the running container (in a second terminal shell):
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
c88bc1b66cdc cygnus-common "/cygnus-entrypoint. 6 seconds ago Up 5 seconds 5050/tcp, 8081/tcp naughty_mayer
You can check the IP address of the container above by doing:
$ docker inspect c88bc1b66cdc | grep \"IPAddress\"
"IPAddress": "172.17.0.8",
Once the IP address of the container is gotten, you may ask for the Cygnus version (in a second terminal shell):
$ curl "http://172.17.0.8:8081/v1/version"
{"success":"true","version":"1.0.0_SNAPSHOT.d7cfee4455a59a1854cc53f37e16ff4866b26010"}
Even you can use API methods to see how to cygnus-common print the logs at INFO level.
$ curl -X POST "http://172.17.0.7:8081/v1/subscriptions?ngsi_version=2" -d '{"subscription":{"description": "title_of_subscription","subject": {"entities": [{"idPattern": ".*","type": "Room"}],"condition": {"attrs": ["attr1"],"expression": {"q": "attr1>40"}}},"notification": {"http": {"url": "http://localhost:1234"},"attrs": ["attr1","attr2"]},"expires": "2016-05-05T14:00:00.00Z","throttling": 5}, "endpoint":{"host":"orion_host", "port":"orion_port", "ssl":"false", "xauthtoken":"your_auth_token"}}'
{"success":"true","result" : { SubscriptionID = 573ac3b6aba73680b1905f5c}
You will be able to see something like the following in the cygnus-common terminal:
time=2016-05-17T07:09:40.956UTC | lvl=INFO | corr= | trans= | srv= | subsrv= | function=handle | comp=cygnus-common | msg=com.telefonica.iot.cygnus.management.ManagementInterface[131] : Management interface request. Method: POST, URI: /v1/subscriptions
time=2016-05-17T07:09:41.343UTC | lvl=INFO | corr=dfca71a9-41f1-4f98-8fa8-4f15612a72db | trans=dfca71a9-41f1-4f98-8fa8-4f15612a72db | srv= | subsrv= | function=<init> | comp=cygnus-common | msg=com.telefonica.iot.cygnus.backends.http.HttpClientFactory[79] : Setting max total connections (500)
time=2016-05-17T07:09:41.343UTC | lvl=INFO | corr=dfca71a9-41f1-4f98-8fa8-4f15612a72db | trans=dfca71a9-41f1-4f98-8fa8-4f15612a72db | srv= | subsrv= | function=<init> | comp=cygnus-common | msg=com.telefonica.iot.cygnus.backends.http.HttpClientFactory[80] : Setting default max connections per route (100)
You can stop the container as:
$ docker stop c88bc1b66cdc
c88bc1b66cdc
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
Using a specific configuration
As seen above, the default configuration distributed with the image is tied to certain values that may not be suitable for you tests. Specifically:
- The logging level is
INFO
. - The logging appender is
console
.
You may need to alter the above values with values of your own.
Editing the docker files
The easiest way is by editing both the Dockerfile
and/or agent.conf
file under docker/cygnus-common
and building the cygnus-common image from the scratch.
This gives you total control on the docker image.
Environment variables
Those parameters associated to an environment variable can be easily overwritten in the command line using the -e
option. For instance, if you want to change the log4j logging level, simply run:
$ docker run -e LOG_LEVEL='DEBUG' cygnus-common
Using volumes
Another possibility is to start a container with a volume (-v
option) and map the entire configuration file within the container with a local version of the file:
$ docker run -v /absolute/path/to/local/agent.conf:/opt/apache-flume/conf/agent.conf cygnus-common-1
Of course, you can combine volumes and environment variables overwriting:
$ docker run -v /absolute/path/to/local/agent.conf:/opt/apache-flume/conf/agent.conf -e LOG_LEVEL='DEBUG' cygnus-common