hello-sre

Please read these instructions carefully.

There are 2 applications in this project:

• hello-python is a web page that contains a form; when the form is submitted, hello-python enqueues the message on a RabbitMQ queue.

• hello-node is a worker that consumes the RabbitMQ queue and stores any message on a MySQL database.

There's also a create_database.sql script, to help you prepare the MySQL database.

Each application contains a short README file with more information.

Problem

Deploy this entire stack in a way that any message entered on the hello-python form is stored on a MySQL database by hello-node.

• There are a few bugs in the code, and you'll need to fix them to solve this exercise; you should not require any specific knowledge of either Python or NodeJS to solve these issues.

• If you need to make any changes to help you debugging (such as adding logs or catching exceptions) we suggest you keep them so we can understand your thought process.

• If you have some knowledge of Python or NodeJS development, feel free to implement or suggest simple improvements to the applications to make them production-ready.

Solutions

We'll accept any of the following types of solution:

• A script using a CLI, SDK, API or library that deploys the stack on a host running a modern Linux distribution or on the GCP cloud.

• A Docker Compose file or another similar container orchestration solution that deploys the stack on a host running a modern Linux distribution or on the GCP cloud.

• A recipe using one or more configuration management tools (e.g. Terraform, Ansible, Chef, Puppet, CloudFormation, Vagrant, Packer, etc.) that deploys the stack on a host running a modern Linux distribution or on the GCP cloud. Plus for GKE.

Important: please edit this README file with step-by-step instructions on how to deploy using your solution. Feel free to also include a short paragraph and/or a diagram explaining your solution.

Expectations

When assessing this exercise, we will take the following points into consideration:

• Whether the solution works or not
• How easy it is to deploy the solution
• How resilient it is (e.g. if the database takes a few more seconds to start than usual, does the system stop working and never recovers? What happens if the application are stress tested? Do the solution works on preemptible VMs?)

Suppose that a junior developer (who has access to most common Linux distributions and an GCP account) will try to run your solution. Would they be able to install all requirements and run it easily? Would they be able to verify that it works? Should any problems arise (e.g. a package is missing), would they be able to identify and fix it?

We don't expect a production-grade solution, but we expect you to show that you'd be able to deploy a production-grade distributed system given enough tools and time.

Submissions

You should send us a git patch file with your solution. To do so follow these steps:

1. Clone (do NOT fork) this repository to your machine:

   $ git clone https://github.com/resultadosdigitais/hello-sre.git

2. Implement your solution

3. Take a look at your changes:

   $ git status
   
   On branch master
   Your branch is up to date with 'origin/master'.
   
   Changes not staged for commit:
   (use "git add/rm <file>..." to update what will be committed)
   (use "git checkout -- <file>..." to discard changes in working directory)
   
       modified:   README.md
       deleted:    create_database.sql
   
   Untracked files:
   (use "git add <file>..." to include in what will be committed)
   
       anyfile.exe
       importantfile.yaml
       mysql/
   
   no changes added to commit (use "git add" and/or "git commit -a")

4. If necessary, add new files and folders (don't include unnecessary files such as anyfile.exe):

   $ git add -N importantfile.yaml mysql

5. Take a new look at your changes and check the diff:

   $ git status
   
   On branch master
   Your branch is up to date with 'origin/master'.
   
   Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
   (use "git checkout -- <file>..." to discard changes in working directory)
   
       modified:   README.md
       new file:   importantfile.yaml
       renamed:    create_database.sql -> mysql/create_database.sql
   
   Untracked files:
   (use "git add <file>..." to include in what will be committed)
   
       anyfile.exe
   
   no changes added to commit (use "git add" and/or "git commit -a")

   $ git diff

   diff --git a/README.md b/README.md
   index e723eca..de696b1 100644
   --- a/README.md
   +++ b/README.md
   @@ -69,3 +69,7 @@ Please do **not** fork this repository and do **not** publish your solution onli
   ## Contact
   
   Feel free to reach out if you have any questions! Also, we expect this problem to take some hours at most, but please do get in touch if you need more time to provide a good solution! It is far better than delivering something that does not work :)
   +
   +## How to run it
   +
   +Instructions
   diff --git a/importantfile.yaml b/importantfile.yaml
   new file mode 100644
   index 0000000..ab061ed
   --- /dev/null
   +++ b/importantfile.yaml
   @@ -0,0 +1,2 @@
   +i:
   +  am: important
   diff --git a/create_database.sql b/mysql/create_database.sql
   similarity index 100%
   rename from create_database.sql
   rename to mysql/create_database.sql

6. Make sure that it looks like your solution, otherwise repeat the steps above. If everything looks ok, move to the next step.

7. Commit your changes locally:

   $ git commit -am "My solution"
   
   [master a5e1d83] My solution
   3 files changed, 6 insertions(+)
   create mode 100644 importantfile.yaml
   rename create_database.sql => mysql/create_database.sql (100%)

8. Create a patch file containing your changes:

   $ git format-patch origin/master --stdout > result.patch

9. Check result.patch, it should look like git diff output. To check the diff after committing, use git diff origin/master HEAD.

   1. If something looks wrong, run git reset origin/master and go to step 2.

   2. If everything looks right Email us the result.patch file.

Please do not fork this repository and do not publish your solution online!

Contact

Feel free to reach out if you have any questions! Also, we expect this problem to take some hours at most, but please do get in touch if you need more time to provide a good solution! It is far better than delivering something that does not work :)