Currently I am developing a software which uses Camunda and interacts with a certain Camunda process.
All of this is intended to be delivered as a single 'package'. To do this, I plan on simply using a Camunda Docker container and another container which runs my software. To put it all together I intend to use docker-compose.
For the Camunda container I currently use the 'official' image which you can find here: https://hub.docker.com/r/camunda/camunda-bpm-platform/
I know that it is not for production use yet, but currently it works fine.
To clean it up a little, I derive from the official image and delete certain files and folders. This is my Dockerfile:
FROM camunda/camunda-bpm-platform:7.11.0
RUN rm -r /camunda/webapps/camunda-invoice
RUN rm -r /camunda/webapps/examples
The problem I am encountering right now is that, as far as I know, you have to use the REST Api of Camunda to deploy a process. I did not find any information on deploying it by putting it in a certain directory or something.
For my use case it would be perfect if the Camunda process was deployed while building the Docker image. But I cannot think of a solution of how to do that.
Theoretically, I have to start the Camunda engine during building, deploy the process and stop it afterwards. Did anyone try that already with the official Camunda docker image? Or do you have a better solution for my problem?
An alternative would be to deploy the process via the software I am developing. But I think that is a rather ugly solution and I would like to avoid that.
Thanks in advance,
Timo
Related
I'm new to docker and have been dabbling with it for the past few days. I've managed to successfully use docker-compose for a multi-container deployment involving an app server (flask + gunicorn) and web server (nginx).
Now, I'd like to recreate the deployment on an offline machine. After doing research, it seems that most have mentioned use docker save and docker load to transfer over the base images. However, I'm wondering whether its possible to recreate the deployment from the image created by docker-compose build? Reason being I would like to skip the entire process of wheeling my python package dependencies for offline use, which I would have to do for the method starting from the base images.
I've tried to save that particular image (output of docker-compose build) and load it on the offline machine, and then tried docker run and docker-compose up but both don't seem to work. Would like to check with the community whether this method is even possible, and if so what's the right way to go about it?
Thanks!
To solve my issue, I ended up making an image of each individual container post pip install, then using docker-compose.yml simply to spin them up. As David mentioned, it doesn't seem possible to spin up the container from the single image output by docker-compose build.
I have made a quite simple golang server and I need to deploy it to a digitalocean droplet.
I know that there can be issues with cross-building go apps in case they use cgo, so to not to think about it in future I decided to use docker, so my app will be build and run always in same environment.
The first thing I dont get is about developing an app. When I create a Dockerfile I use commands to add files from my project directory into newly created docker image. Then I run the container created from this image. But what if I edit my code? - as I understood I must stop the container, remove an image and then build it again. This is a bit tricky for such a common situation - or am I doing things wrong?
Second one - I have created a docker droplet on a DO: Whats the way to deploy my app?
I have to push my image to any docker repository and pull it on to the droplet?
Or I can upload it directly?
Or I have to scp my source code to droplet and run same process as on my local machine, building image and then runnjng a container?
But what if I edit my code? - as I understood I must stop the container, remove an image and then build it again. This is a bit tricky for such a common situation - or am I doing things wrong?
Don't delete the image just rebuild it. It will be much faster than the first initial build. Also why is it tricky? It's just one or two commands, you can create a bash or .bat script if it gets annoying.
I have created a docker droplet on a DO: Whats the way to deploy my app?
All three options are a possibility. For the second one you would have to set up your VM as a docker-hub repo which might be more than you need. Using docker hub isn't bad. You could also just build the image on your server. I recommend using docker hub for it's ease and having watchtower set up on your server to restart your web app on new image pushes.
Edit: the above advice was for a VM not a docker droplet. I'm not familiar with DO but this article should help:
https://blog.machinebox.io/deploy-machine-box-in-digital-ocean-385265fbeafd
So, the idea is to dockerize an existing meteor app from 2015. The app is divided into two (backend and frontend). I already made a huge bash script to handle all the older dependencies...software dependencies...etc etc. I just need to run the script and we get the app running. But the idea now is to create a docker image for that project. How should I achieve this? Should I create an empty docker image and run my script there?. Thanks. I'm new to docker.
A bit more info about the stack, the script, the dependencies could be helpful.
Assuming that this app is not in development, you can simply use eg an nginx image, and give it the frontend files to serve.
For the backend there is a huge variety of options like php, node, etc.
The dockerfile of your backend image should contain the installation and setup of dependencies (except for other services like database. There are images to do those separated).
To keep things simple you should try out docker-compose to configure your containers to act as a service as a whole (and save you some configurations).
Later, to scale things up, you could look for orchestration tools such as kubernetes. But I assume, this service is not there yet (based on your question). :)
Recently I started to practice Dockers. Basically, I am running a C application on Docker container. Now, I want to try cloud foundry, therefore, trying to understand the difference between the two.
I'll describe the application as a novice because I am.
The application I start as a service(from /etc/init.d) and it reads a config file during startup, which specifies what all modules to load and IP of other services and it's own (0.0.0.0 does not work, so I have to give actual IP).
I had to manually update the IP and some details in the config file when the container starts. So, I wrote a startup script which did all the changes when the container starts and then the service start command.
Now, moving on to Cloud Foundry, the first thing I was not able to find is 'How to deploy C application' then I found a C build pack and a binary build pack option. I still have to try those but what I am not able to understand how I can provide a startup script to a cloud foundry container or in brief how to achieve what I was doing with Dockers.
The last option I have is to use docker containers in Cloud foundry, but I want to understand if I can achieve what I described above.
I hope I was clear enough to explain my doubt.
Help appreciated.
An old question, but a lot has changed since this was posted:
Recently I started to practice Dockers. Basically, I am running a C application on Docker container. Now, I want to try cloud foundry, therefore, trying to understand the difference between the two.
...
The last option I have is to use docker containers in Cloud foundry, but I want to understand if I can achieve what I described above.
There's nothing wrong with using Docker containers on CF. If you've already got everything set up to run inside a Docker container, being able to run that on CF give you yet another place you can easily deploy your workload.
While these are pretty minor, there are a couple requirements for your Docker container, so it's worth checking those to make sure it's possible to run on CF.
https://docs.cloudfoundry.org/devguide/deploy-apps/push-docker.html#requirements
Anyways, I am not working on this now as CF is not suitable for the project. It's an SIP application and CF only accepts HTTP/S requests.
OK, the elephant in the room. This is no longer true. CF has support for TCP routes. These allow you to receive TCP traffic directly to your application. This means, it's no longer just HTTP/S apps that are suitable for running on CF.
Instructions to set up your CF environment with TCP routing: https://docs.cloudfoundry.org/adminguide/enabling-tcp-routing.html
Instructions to use TCP routes as a developer: https://docs.cloudfoundry.org/devguide/deploy-apps/routes-domains.html#create-route-with-port
Now, moving on to Cloud Foundry, the first thing I was not able to find is 'How to deploy C application' then I found a C build pack and a binary build pack option.
Picking a buildpack is an important step. The buildpack takes your app and prepares it to run on CF. A C buildpack might sound nice as it would take your source code, build and run it, but it's going to get tricky because your C app likely depends on libraries. Libraries that may or may not be installed.
If you're going to go this route, you'll probably need to use CF's multi-buildpack support. This lets you run multiple buildpacks. If you pair this with the Apt buildpack, you can install the packages that you need so that any required libraries are available for your app as it's compiled.
https://docs.cloudfoundry.org/buildpacks/use-multiple-buildpacks.html
https://github.com/cloudfoundry/apt-buildpack
Using the binary buildpack is another option. In this case, you'd build your app locally. Perhaps in a docker container or on an Ubuntu VM (it needs to match the stack being used by your CF provider, i.e. cf stacks, currently Ubuntu Trusty or Ubuntu Bionic). Once you have a binary or binary + set of libraries, you can simply cf push the compiled artifacts. The binary buildpack will "run" (it actually does nothing) and then your app will be started with the command you specify.
My $0.02 only, but the binary buildpack is probably the easier of the two options.
what I am not able to understand how I can provide a startup script to a cloud foundry container or in brief how to achieve what I was doing with Dockers.
There's a few ways you can do this. The first is to specify a custom start command. You do this with cf push -c 'command'. This would normally be used to just start your app, like './my-app', but you could also use this to do other things.
Ex: cf push -c './prep-my-app.sh && ./my-app'
Or even just call your start script:
Ex: cf push -c './start-my-app.sh'.
CF also has support for a .profile script. This can be pushed with your app (at the root of the files you push), and it will be executed by the platform prior to your application starting up.
https://docs.cloudfoundry.org/devguide/deploy-apps/deploy-app.html#profile
Normally, you'd want to use a .profile script as you'd want to let the buildpack decide how to start your app (setting -c will override the buildpack), but in your case with the C or binary buildpack's, it's unlikely the buildpack will be able to do that, so you'll end up having to set a custom start command anyway.
For this specific case, I'd suggest using cf push -c as it's slightly easier, but for all other cases and apps deployed with other buildpacks, I'd suggest a .profile script.
Hope that helps!
I have a hunch that docker could greatly improve my webdev workflow - but I haven't quite managed to wrap my head around how to approach a project adding docker to the stack.
The basic software stack would look like this:
Software
Docker image(s) providing custom LAMP stack
Apache with several modules
MYSQL
PHP
Some CMS, e.g. Silverstripe
GIT
Workflow
I could imagine the workflow to look somewhat like the following:
Development
Write a Dockerfile that defines a LAMP-container meeting the requirements stated above
REQ: The machine should start apache/mysql right after booting
Build the docker image
Copy the files required to run the CMS into e.g. ~/dev/cmsdir
Put ~/dev/cmsdir/ under version control
Run the docker container, and somehow mount ~/dev/cmsdir to /var/www/ on the container
Populate the database
Do work in /dev/cmsdir/
Commit & shut down docker container
Deployment
Set up remote host (e.g. with ansible)
Push container image to remote host
Fetch cmsdir-project via git
Run the docker container, pull in the database and mount cmsdir into /var/www
Now, this looks all quite nice on paper, BUT I am not quite sure whether this would be the right approach at all.
Questions:
While developing locally, how would I get the database to persist between reboots of the container instance? Or would I need to run sql-dump every time before spinning down the container?
Should I have separate container instances for the db and the apache server? Or would it be sufficient to have a single container for above use case?
If using separate containers for database and server, how could I automate spinning them up and down at the same time?
How would I actually mount /dev/cmsdir/ into the containers /var/www/-directory? Should I utilize data-volumes for this?
Did I miss any pitfalls? Anything that could be simplified?
If you need database persistance indepent of your CMS container, you can use one container for MySQL and one container for your CMS. In such case, you can have your MySQL container still running and your can redeploy your CMS as often as you want independently.
For development - the another option is to map mysql data directories from your host/development machine using data volumes. This way you can manage data files for mysql (in docker) using git (on host) and "reload" initial state anytime you want (before starting mysql container).
Yes, I think you should have a separate container for db.
I am using just basic script:
#!/bin/bash
$JOB1 = (docker run ... /usr/sbin/mysqld)
$JOB2 = (docker run ... /usr/sbin/apache2)
echo MySql=$JOB1, Apache=$JOB2
Yes, you can use data-volumes -v switch. I would use this for development. You can use read-only mounting, so no changes will be made to this directory if you want (your app should store data somewhere else anyway).
docker run -v=/home/user/dev/cmsdir:/var/www/cmsdir:ro image /usr/sbin/apache2
Anyway, for final deployment, I would build and image using dockerfile with ADD /home/user/dev/cmsdir /var/www/cmsdir
I don't know :-)
You want to use docker-compose. Follow the tutorial here. Very simple. Seems to tick all your boxes.
https://docs.docker.com/compose/
I understand this post is over a year old at this time, but I have recently asked myself very similar questions and have several great answers to your questions.
You can setup a MySQL docker instance and have data persist on a stateless data container, aka the data container does not need to be actively running
Yes I would recommend having a separate instance for your web server and database. This is the power of Docker.
Check out this repo I have been building. Basically it is as simple as make build & make run and you can have a web server and database container running locally.
You use the -v argument when running the container for the first time, this will link a specific folder on the container to the host running the container.
I think your ideas are great and it is currently possible to achieve all that you are asking.
Here is a turn key solution achieving all of the needs you have listed.
I've put together an easy to use docker compose setup that should match your development workflow requirements.
https://github.com/ehyland/docker-silverstripe-dev
Main Features
Persistent DB
Your choice of HHVM + NGINX or Apache2 + PHP5
Debug and set breakpoints with xDebug
The README.md should be clear enough to get you started.