The answer to your question is not very simple. I am still figuring this out myself, but you can look at certain projects such as mesos-dns which publish SRV records for running docker containers, allowing you to programmatically find services you have started up. For example, here I have started up a container that publishes an HTTP interface. Mesos starts it up on a random node, and assigns it a random high TCP port. All I know is that it is called "tomsflask" and that it has a TCP port. With this information, I ask the mesos-dns system where is it running, as you can see in the NSLOOKUP command below, requesting the SRV record which mesos-dns automatically created when the container started. In the next command, I use CURL to show what content is being produced on the port (31427) and hostname I had received from the SRV command.
june@cluster:~$ nslookup -type=SRV _tomsflask._tcp.marathon.mesos _tomsflask._tcp.marathon.mesos service = 0 0 31427 tomsflask-5p8ho-s83. marathon.slave.mesos. june@cluster:~$ curl http://tomsflask-5p8ho-s83.marathon.slave.mesos:31427 Hello World from Flask (default) Thanks, June Taylor System Administrator, Minnesota Population Center University of Minnesota On Tue, Apr 26, 2016 at 11:52 AM, Stefano Bianchi <[email protected]> wrote: > Yes i guess i understood, so when i star a socker container like wordpress > this app could have the need to contact another container as mysql, here > project calico should be an efficient way to make this. > Ok i will try, just to understand, first i run the mysql, then mesos will > allocate it on a certain slave, then i need to run wordpress. How can i > specify where is the mysql container in marathon UI? > > 2016-04-26 17:48 GMT+02:00 June Taylor <[email protected]>: > >> Stefano, >> >> You would want to search for an appropriate image on Docker Hub. Here is >> one I have NO experience with: https://hub.docker.com/_/mysql/ >> >> You would then need to learn about how the image is expecting to be >> configured, so you can set it up appropriately. >> >> This is not really a fully thought out solution. I assume you're trying >> to do this for more of a proof-of-concept, though. So it may be fine for >> your needs. >> >> >> Thanks, >> June Taylor >> System Administrator, Minnesota Population Center >> University of Minnesota >> >> On Tue, Apr 26, 2016 at 10:43 AM, Stefano Bianchi <[email protected]> >> wrote: >> >>> My problem is this, where can i find the mysql container? I have just >>> said to marathon to rim a wordpress docker container, without specify mysql >>> one. >>> Il 26/apr/2016 17:39, "Aaron Carey" <[email protected]> ha scritto: >>> >>>> If you run the wordpress container on a different host to the mysql >>>> container and use --link on the command line, does that work? >>>> >>>> -- >>>> >>>> Aaron Carey >>>> Production Engineer - Cloud Pipeline >>>> Industrial Light & Magic >>>> London >>>> 020 3751 9150 >>>> >>>> ------------------------------ >>>> *From:* Stefano Bianchi [[email protected]] >>>> *Sent:* 26 April 2016 16:23 >>>> *To:* [email protected] >>>> *Subject:* RE: Launch docker container from Marathon UI >>>> >>>> Hi Aaron >>>> Actually both mesos-dns and calico are running even though these >>>> containers im running are not, yet, using the calico ipaddr specific in >>>> json description. >>>> So i guess it is a problem of bridging, i guess simply specify HOST >>>> option on container field in Marathon UI >>>> Il 26/apr/2016 16:59, "Aaron Carey" <[email protected]> ha scritto: >>>> >>>>> --link in docker should really be avoided when using marathon/mesos as >>>>> it implies the containers are on the same host, but this will not always >>>>> be >>>>> the case when mesos schedules your containers (also I think it's being >>>>> deprecated in docker anyway.. not sure though?). >>>>> >>>>> This problem looks like one of service discovery within the mesos >>>>> cluster: how does one service contact the other when it doesn't know which >>>>> host the other service may have landed on? >>>>> >>>>> There are several different solutions for service discovery, you can >>>>> look into some like Project Calico to offer a network layer to docker or >>>>> try dns based solutions like Mesos-dns or Consul (along with >>>>> mesos-consul). >>>>> I think marathon also has some concept of service discovery built in too >>>>> if >>>>> you use something like haproxy. >>>>> >>>>> I hope this helps! >>>>> >>>>> Aaron >>>>> >>>>> -- >>>>> >>>>> Aaron Carey >>>>> Production Engineer - Cloud Pipeline >>>>> Industrial Light & Magic >>>>> London >>>>> 020 3751 9150 >>>>> >>>>> ------------------------------ >>>>> *From:* June Taylor [[email protected]] >>>>> *Sent:* 26 April 2016 15:22 >>>>> *To:* [email protected] >>>>> *Subject:* Re: Launch docker container from Marathon UI >>>>> >>>>> Stefano, >>>>> >>>>> The docker run flag --link is intended to connect the container to >>>>> another running container. I do not know how this would operate in >>>>> marathon. Perhaps it would be an application group which starts up the >>>>> mysql docker image first, then the Wordpress docker image after it. >>>>> >>>>> >>>>> Thanks, >>>>> June Taylor >>>>> System Administrator, Minnesota Population Center >>>>> University of Minnesota >>>>> >>>>> On Tue, Apr 26, 2016 at 9:20 AM, Stefano Bianchi <[email protected] >>>>> > wrote: >>>>> >>>>>> Thanks *Rad* Gruchalski, actually i'm trying to make a json file >>>>>> that "translate" this command in marathon: >>>>>> >>>>>> docker run --name some-wordpress --link some-mysql:mysql -d wordpress >>>>>> >>>>>> i guess the error is relate to the fact that i'm not specifying --link >>>>>> some-mysql:mysql >>>>>> My problem is that i don't know how to do that, i tried to fill >>>>>> environment variable fields: >>>>>> >>>>>> Key = link >>>>>> Value = some-mysql:mysql >>>>>> >>>>>> But in this way the app does not work as well. How can i configure >>>>>> these env variables? >>>>>> >>>>>> 2016-04-26 16:01 GMT+02:00 Rad Gruchalski <[email protected]>: >>>>>> >>>>>>> It says exactly what the problem is. >>>>>>> >>>>>>> Start a marathon task with correct environment variables in env and >>>>>>> you will be fine. >>>>>>> >>>>>>> Best regards, >>>>>>> Radek Gruchalski >>>>>>> [email protected] <[email protected]> >>>>>>> de.linkedin.com/in/radgruchalski/ >>>>>>> >>>>>>> >>>>>>> *Confidentiality: *This communication is intended for the >>>>>>> above-named person and may be confidential and/or legally privileged. >>>>>>> If it has come to you in error you must take no action based on it, >>>>>>> nor must you copy or show it to anyone; please delete/destroy and inform >>>>>>> the sender immediately. >>>>>>> >>>>>>> On Tuesday, 26 April 2016 at 15:56, Stefano Bianchi wrote: >>>>>>> >>>>>>> jupyter is working fine. >>>>>>> i tried to run wordpress and i get this error in stderr of mesos: >>>>>>> >>>>>>> error: missing WORDPRESS_DB_HOST and MYSQL_PORT_3306_TCP environment >>>>>>> variables >>>>>>> >>>>>>> Did you forget to --link some_mysql_container:mysql or set an >>>>>>> external db >>>>>>> >>>>>>> with -e WORDPRESS_DB_HOST=hostname:port? >>>>>>> >>>>>>> >>>>>>> >>>>>>> Some one of you know this issue? >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> 2016-04-26 15:51 GMT+02:00 Stefano Bianchi <[email protected]>: >>>>>>> >>>>>>> However thank you so much to all! >>>>>>> >>>>>>> 2016-04-26 15:22 GMT+02:00 Stefano Bianchi <[email protected]>: >>>>>>> >>>>>>> i found the answer by my self sorry if i disturbed you. >>>>>>> >>>>>>> 2016-04-26 15:19 GMT+02:00 Stefano Bianchi <[email protected]>: >>>>>>> >>>>>>> Now that it is running, how can i check the User Interface? >>>>>>> >>>>>>> >>>>>>> 2016-04-26 15:18 GMT+02:00 Stefano Bianchi <[email protected]>: >>>>>>> >>>>>>> Yes, now it's running!!! June you are awesome!!! >>>>>>> >>>>>>> 2016-04-26 15:16 GMT+02:00 Stefano Bianchi <[email protected]>: >>>>>>> >>>>>>> i have done these 2 commands, now jupyter is in deploying in >>>>>>> marathon, staging in mesos. >>>>>>> Is there some additional configuration needed? >>>>>>> >>>>>>> 2016-04-26 15:13 GMT+02:00 Stefano Bianchi <[email protected]>: >>>>>>> >>>>>>> June i tried to run your json, but the task is waiting, and if >>>>>>> starts it failed immediately. >>>>>>> >>>>>>> I guess because i did not type this commands: >>>>>>> >>>>>>> >>>>>>> 1. >>>>>>> >>>>>>> echo 'docker,mesos' > /etc/mesos-slave/containerizers >>>>>>> >>>>>>> 2. >>>>>>> >>>>>>> $ echo '5mins' > /etc/mesos-slave/executor_registration_timeout >>>>>>> >>>>>>> >>>>>>> Could it be the problem? >>>>>>> >>>>>>> 2016-04-26 15:02 GMT+02:00 Stefano Bianchi <[email protected]>: >>>>>>> >>>>>>> Thank you June taylor, it is axactly what i was intending. >>>>>>> if it is not disturbing you, i try jupyter notebook as well, just to >>>>>>> make some tests on how to launch marathon. >>>>>>> stay tuned :) >>>>>>> >>>>>>> 2016-04-26 14:58 GMT+02:00 Stefano Bianchi <[email protected]>: >>>>>>> >>>>>>> thanks haosdent. >>>>>>> actually i have run this kind of apps through rest api. >>>>>>> Now i want learn how to laung docker files. I found this exaple: >>>>>>> >>>>>>> { >>>>>>> "container": { >>>>>>> "type": "DOCKER", >>>>>>> "docker": { >>>>>>> "network": "HOST", >>>>>>> "image": "group/image" >>>>>>> }, >>>>>>> "volumes": [ >>>>>>> { >>>>>>> "containerPath": "/etc/a", >>>>>>> "hostPath": "/var/data/a", >>>>>>> "mode": "RO" >>>>>>> }, >>>>>>> { >>>>>>> "containerPath": "/etc/b", >>>>>>> "hostPath": "/var/data/b", >>>>>>> "mode": "RW" >>>>>>> } >>>>>>> ] >>>>>>> }} >>>>>>> >>>>>>> >>>>>>> I am able to link the correspondent field in the marathon UI with >>>>>>> what is written in this json. >>>>>>> What i need to understand is, what i should write in: >>>>>>> >>>>>>> "image": "group/image" >>>>>>> >>>>>>> i mean, with what i have to replace group and image? >>>>>>> For instance, if i would run wordpress container on docker hub what >>>>>>> i should put replacing "group/image" ? >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> 2016-04-26 14:30 GMT+02:00 haosdent <[email protected]>: >>>>>>> >>>>>>> This is marathon REST API document: >>>>>>> https://mesosphere.github.io/marathon/docs/rest-api.html#post-v2-apps >>>>>>> . Usually we define a task json file and call the rest api. >>>>>>> >>>>>>> For example, create tasks.json which content is >>>>>>> >>>>>>> ``` >>>>>>> { >>>>>>> "id": "/test-sleep", >>>>>>> "cmd": "sleep 200" >>>>>>> } >>>>>>> ``` >>>>>>> >>>>>>> And >>>>>>> >>>>>>> ``` >>>>>>> curl -X POST -H "Content-type: application/json" >>>>>>> http://${YOUR_MARATHON_ADDR}:8080/v2/apps >>>>>>> -d @tasks.json >>>>>>> ``` >>>>>>> >>>>>>> You could find more field definitions in their document. >>>>>>> >>>>>>> On Tue, Apr 26, 2016 at 8:24 PM, Stefano Bianchi < >>>>>>> [email protected]> wrote: >>>>>>> >>>>>>> Hi guys >>>>>>> >>>>>>> i'm trying to follow the instructions on mesosphere documentation, >>>>>>> but it is a little bit unlear for me that i am new to this world. >>>>>>> i' would like to launch a wordpress container, present on docker hub >>>>>>> here https://hub.docker.com/_/wordpress/ , from marathon UI but i >>>>>>> don't understand the mechanism. >>>>>>> I understood that i don't have to specify a command in "Command" >>>>>>> field, but i don't know how to fill the dockers fields in marathon UI to >>>>>>> launch wordpress container. >>>>>>> Could you please help me or tell me where i can find a clearer >>>>>>> documentation? >>>>>>> >>>>>>> Thanks. >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> -- >>>>>>> Best Regards, >>>>>>> Haosdent Huang >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>> >> >
