My solutions to Devops with Docker - part 2
Create a docker-compose.yml file that starts devopsdockeruh/first_volume_exercise and saves the logs into your filesystem.
i.e. We just need a bind-mount.
Once present:
frodo ~ $ touch logs.txt
frodo ~ $ docker-compose up
Starting ex21_ex2-1_1 ... done
Attaching to ex21_ex2-1_1
ex2-1_1 | (node:1) ExperimentalWarning: The fs.promises API is experimental
ex2-1_1 | Wrote to file /usr/app/logs.txt
ex2-1_1 | Wrote to file /usr/app/logs.txt
^CGracefully stopping... (press Ctrl+C again to force)
Stopping ex21_ex2-1_1 ... done
frodo $ cat logs.txt
Sat, 18 Apr 2020 06:29:15 GMT
Sat, 18 Apr 2020 06:29:18 GMT
Create a docker-compose.yml and use it to start the service so that you can use it with your browser.
i.e. Here we configure port-binding.
Once present:
frodo $ docker-compose up -d
Starting ex22_ex2-2_1 ... done
frodo $ curl http://localhost:8080/
Ports configured correctly!!
- Configure the backend and frontend from part 1 to work in docker-compose.
Here we have to define two containers in the single compose file, the solution is here:
- ex2.3/docker-compose.yml
- This file uses the two images I created for ex1.12
- i.e. An image named "backend" on port 8000
- i.e. An image named "front" on port 5000
Start like so:
frodo $ docker-compose up -d
Creating network "ex23_default" with the default driver
Creating ex23_ex2-3-backend_1 ... done
Creating ex23_ex2-3-front_1 ... done
frodo $
Test like so:
$ curl http://127.0.0.1:5000/
<!DOCTYPE html>
<html lang="en">
..
frodo $ curl 127.0.0.1:8000
Port configured correctly, generated message in logs.txt
..
- Clone https://github.com/docker-hy/scaling-exercise
- Scale so it works
No change required to the docker-compose.yml file, instead I just launched like so:
frodo $ docker-compose up --scale compute=2
Starting load-balancer ... done
Starting scaling-exercise_compute_1 ... done
Starting calculator ... done
Creating scaling-exercise_compute_2 ... done
Attaching to calculator, load-balancer, scaling-exercise_compute_1, scaling-exercise_compute_2
From the terminal I see :
frodo $ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
68945311ff7e compute "docker-entrypoint.s…" About a minute ago Up About a minute 3000/tcp scaling-exercise_compute_2
9b93d9bc6731 compute "docker-entrypoint.s…" 2 minutes ago Up About a minute 3000/tcp scaling-exercise_compute_1
906518e62997 load-balancer "/app/docker-entrypo…" 2 minutes ago Up About a minute 0.0.0.0:80->80/tcp load-balancer
b66682b8a24e calculator "docker-entrypoint.s…" 2 minutes ago Up About a minute 0.0.0.0:3000->3000/tcp calculator
From my browser, http://localhost:3000`, I see:
Your aim is to get the bottom bar to fill before the first depletes!
Congratulations!
- Add redis to the backend-setup
Here we have to do two things:
- Add a redis container.
- Configure the backend container so it can talk to it.
The solution can be found here:
- ex2.5/docker-compose.yml
- Obviously this builds upon the solution in ex2.3/
- Just adds the new redis-image/instance, and the environmental variable.
- Note I didn't rename the instances, so they still refer to 2.3
Start like so:
frodo $ docker-compose up -d
Creating network "ex25_default" with the default driver
Pulling redis (redis:)...
latest: Pulling from library/redis
123275d6e508: Pull complete
f2edbd6a658e: Pull complete
66960bede47c: Pull complete
533694cb3638: Pull complete
1dc100dcb2f1: Pull complete
9ca9ac709269: Pull complete
Creating ex25_ex2-3-front_1 ... done
Creating ex25_ex2-3-backend_1 ... done
Creating ex25_redis_1 ... done
Test via the browser-button on 127.0.0.1:5000:
- Exercise 2.5: Working! It took 0.015 seconds.
- Add database to backend application too.
We build upon the ex2.3 & ex2.5 solutions to add a postgresql instance
Starting launches as expected:
frodo $ docker-compose up -d
Creating ex26_ex2-3-front_1 ... done
Creating ex26_ex2-3-backend_1 ... done
Creating ex26_redis_1 ... done
Creating ex26_psql_1 ... done
Testing via the browser UI shows persistence works:
- Enter "Foo" into Ex 2.6 field, then click "Send Message"
- Reload page, then click "Get All Messages"
- Configure a machine learning project.
This was the most complicated example so far!
- Build the images via ex2.7/build-images.sh
- End result is three Docker images
ml-kurkkumopo-frontendml-kurkkumopo-backendml-kurkkumopo-training
- End result is three Docker images
- Then created a ex2.7/docker-compose.yml
- This launches them.
Launch like so:
frodo $ docker-compose up -d
Creating ex27_ml-kurkkumopo-frontend_1 ... done
Creating ex27_ml-kurkkumopo-training_1 ... done
Creating ex27_ml-kurkkumopo-backend_1 ... done
Waiting forever I slowly see things being populated:
frodo $ watch ls images/ model/
images/:
cucumber_4f1827ba-994c-4ff2-b645-c91ce60c412d.jpg
cucumber_bf055234-92b6-44e2-a948-89584162c1dc.jpg
model/:
kurkkumopotin.sav
..
Opening http://127.0.0.1:3000/ I see the React App which does the comparison. Cute.
- Add nginx to example frontend + backend.
We build upon the ex2.3, ex2.5, & ex2.6 solutions to add an nginx instance
The changes here involve:
- Launching an instance of the
nginxcontainer in thedocker-compose.ymlfile - Adding the proxy rules in the
nginx.conffile, and making it be used. - Changing the
API_URLandFRONT_URLto use the public-URLs
NOTE: I continue to refer to the ex2.3-front and ex2.3-backend hosts, since they've not been changed.
Launch like so:
frodo ~/x/part2/ex2.8 $ docker-compose up -d
Starting ex28_nginx_1 ... done
Starting ex28_psql_1 ... done
Starting ex28_redis_1 ... done
Starting ex28_ex2-3-backend_1 ... done
Starting ex28_ex2-3-front_1 ... done
Test by clicking all the buttons; they work!
- Configure bind-mount/volumes for psql & redis
We build upon the ex2.3, ex2.5, ex2.6, & ex2.8 solutions to add volumes
The changes here were to add volumes for psql & redis:
..
volumes:
- redis.state:/data
volumes:
- psql.state:/var/lib/postgresql/data
Bring it up like so:
frodo $ mkdir psql.state/ redis.state/
frodo $ docker-compose up -d
Starting ex29_psql_1 ... done
Starting ex29_ex2-3-backend_1 ... done
Starting ex29_ex2-3-front_1 ... done
Starting ex29_redis_1 ... done
Starting ex29_nginx_1 ... done
Confirm data is stored on the host, beneath psql.state & redis.state
frodo $ docker-compose down
Stopping ex29_ex2-3-front_1 ... done
Stopping ex29_nginx_1 ... done
Stopping ex29_redis_1 ... done
Stopping ex29_psql_1 ... done
Stopping ex29_ex2-3-backend_1 ... done
Removing ex29_ex2-3-front_1 ... done
Removing ex29_nginx_1 ... done
Removing ex29_redis_1 ... done
Removing ex29_psql_1 ... done
Removing ex29_ex2-3-backend_1 ... done
Removing network ex29_default
frodo $ ls redis.state/
dump.rdb
frodo $ ls psql.state/
ls: cannot open directory 'psql.state/': Permission denied
frodo $ sudo ls psql.state/
base pg_dynshmem pg_logical pg_replslot pg_stat pg_tblspc pg_wal postgresql.conf
global pg_hba.conf pg_multixact pg_serial pg_stat_tmp pg_twophase pg_xact postmaster.opts
pg_commit_ts pg_ident.conf pg_notify pg_snapshots pg_subtrans PG_VERSION postgresql.auto.conf
frodo ~/x/part2/ex2.9 $
NOTE: Permissions on the psql.state/ directory were broken; sudo to the rescue.
- Some buttons may have stopped working in the frontend + backend project.
- Make sure that every button for exercises works.
I'd already fixed this!, in exercise 2.8. Regardless please find the solution files beneath ex2.10/.
The files there are based upon those in the previous exercise.
- The specific change I made was to refer to the external URI for the front & backend.
- In the beginning we used public URLs:
API_URL=http://127.0.0.1:8000FRONT_URL=http://127.0.0.1:5000
- Now we're using
nginxto proxy to the front-end/back-end containers we can use the public-endpoints:API_URL=http://127.0.0.1/apiFRONT_URL=http://127.0.0.1
- In the beginning we used public URLs:
nginx.conf file, etc, is the same as before. This submission is 100% identical to my solution to ex2.8, with the addition of the volumes from ex2.9.