Skip to content
This repository has been archived by the owner on Apr 20, 2020. It is now read-only.

Latest commit

 

History

History
353 lines (244 loc) · 9.96 KB

README.md

File metadata and controls

353 lines (244 loc) · 9.96 KB
Raw

Part 2

My solutions to Devops with Docker - part 2

Exercise 2.1

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

Exercise 2.2

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!!

Exercise 2.3

  • 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
..

Exercise 2.4

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!

Exercise 2.5

  • 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.

Exercise 2.6

  • Add database to backend application too.

We build upon the ex2.3 & ex2.5 solutions to add a postgresql instance

  • ex2.6/docker-compose.yml
    • Obviously this builds upon the solution in ex2.3/
    • Obviously this builds upon the solution in ex2.5/
    • Note I didn't rename the instances, so they still refer to 2.3

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"

Exercise 2.7

  • Configure a machine learning project.

This was the most complicated example so far!

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.

Exercise 2.8

  • Add nginx to example frontend + backend.

We build upon the ex2.3, ex2.5, & ex2.6 solutions to add an nginx instance

  • ex2.8/docker-compose.yml
    • Obviously this builds upon the solution in ex2.3/
    • Obviously this builds upon the solution in ex2.5/
    • Obviously this builds upon the solution in ex2.6/
    • Note I didn't rename the instances, so they still refer to 2.3

The changes here involve:

  • Launching an instance of the nginx container in the docker-compose.yml file
  • Adding the proxy rules in the nginx.conf file, and making it be used.
  • Changing the API_URL and FRONT_URL to 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!

Exercise 2.9

  • 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.

Exercise 2.10

  • 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://127.0.0.1:8000
      • FRONT_URL=http://127.0.0.1:5000
    • Now we're using nginx to proxy to the front-end/back-end containers we can use the public-endpoints:
      • API_URL=http://127.0.0.1/api
      • FRONT_URL=http://127.0.0.1

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.