sre-checklist: A repository from Tettehisrael

🎯 Repository Purpose: Provide teams and individuals an idea on what to take into consideration and what to aspire for in the SRE field and work

Note: these checklists are opinionated. They are based on my own opinion and experience and are not universal truth (duh! 😄). So you should definitely doubt anything you read here and you are more than welcome to add your own opinion on the matter, by starting a discussion or proposing a change to the project

🚧 You may say this repository is still in progress. I wouldn't treat it as complete source at this point or anything close to that. Contributions are more than welcome!

Team - Responsibilities - Skills	Production - Requirements - Provisioning
Git - CI	Cloud - Provisioning	Kubernetes - Scaling

Team 👫
Production
Technologies 💻

Team

Responsibilities

Decide on responsibilities
- Common
  - Infrastructure management
  - Monitoring
  - Incident Management
  - Infra and Reliability related automation
- Arguable
  - App Performance - Arguable because some organizations treat it as dev responsibility
Documented/Written
- Make sure to write down the responsibilities of the team somewhere. That will be useful for many things like new members joining, recruiting, clarity for the organization and more.

Skills

Must

Coding
- It doesn't matter what language! it seems market right now leaning towards Go mostly, for SRE and Devops, but Python is also quite common and eventually whatever works best for the team is what matters
Monitoring
- To achieve good reliability and improve it, monitoring should be performed continuously. This makes it to quite critical skill to own
CI/CD
- CI/CD today is integrated in every development process, whether it's of the application itself or the automation and infra managed by SRE and DevOps teams
IaC, CM
- IaC and CM is how you manage infra and operations through code. If you do your work as SRE manually and using ad-hoc commands or UI, you probably want to reconsider your approach and obtain some IaC (Infrastructure as Code) and CM (configuration management) skills and knowledge

Optional

Some will argue that the following skills and topics shouldn't be optional and are 100% must, but in my personal view they very much depend on your responsibilities as SRE and your work environment. If your environment consists mostly of bare metal (physical) servers for example and there are no containers, then why containers is a must for you?

Containers
Kubernetes
Cloud
Virtualization

Processes

Incident Management
- There must be a well defined process to how incidents are managed. Some thoughts:
  - Where incidents are reported/raised?
  - Who monitors the alerts at any given point of time?
  - Do you need 100% time coverage?
  - Is there any team that gets the alerts before the SRE team and tries to handle the issue?
- Is the process automated?
  - Do you need to manually open a ticket?
  - Do you need to go to incidents platform/page or do you get an alert?
  - Do you schedule a meeting to talk about

SRE Team Goals

Set goals
- Define SLO (Service Level Objective)
- 100% reliability is not a good goal! (not sustainable + not feasible. One example: maybe you can drive 100% reliability for the service you own, but most of the time not for its dependencies)

SRE Lead

Is there an onboarding page for SREs joining the team?
Schedule 1:1 meeting with team (probably...manager or lead? TBD)
Identify Possible Gaps. Few things to watch our for:
- Does development team waits on SRE for infra related operations?
- Basically going over other check lists in this page :)
Identify SRE team maturity and work on improving it
- Step 1: Operations: SRE is focused on resolving issues, dealing with requests
  - At this step you'll be mainly focused on making sure you and the team are able to respond to any issue raised
  - Slowly you'll automated processes, fixes and move towards step 2
- Step 2: Automation: SRE is moving towards automation and self-service. Providing tooling, documentation, etc.
  - In this step you focus on building the mindset of automating fixes, documenting what the team and others parties in the organization should be aware of
  - This step is probably the most long one. Don't expect to achieve it in short time, just make sure you have consistent progress towards next step
- Step 3: Product: SRE is focused on improving the product itself - reliability, performances, etc.
  - Congratulations. Processes are automated, you respond quickly to issue, .., you are living the dream. Now you can go deeper and focus on the product itself
  - This not for everyone but definitely a feasible step and one to aspire for
Keep learning ALL THE TIME
- Learn how others are doing it!
  - https://github.com/upgundecha/howtheysre - so many good examples!

New SRE Team Member

Welcome :)
Have a mentor? Great. If not, ask for one
Do the onboarding
- No onboarding? maybe you can be the first to add one
Learn about the product
- What it does?
- Is it SaaS? On-Premise? ...
- How it's delivered and deployed?
Time to deep dive into operations
- TODO: add some items :)

Production

Requirements

What are the requirements for going to production?

Provisioning

How do you provision the infrastructure required for deploying the application? (Terraform, Pulumi, CloudFormation, ...)

Installation

How to install the application and its dependencies? (Container, Bash Script, Ansible, ...)

Deployment

How to deploy the application or the application service? (k8s, cloud instances)

Configuration

How to configure the application? (k8s, Ansible, ...)

Resiliency

Your app is able to withstand outages (usually by implement multi-region or multi-cloud architectures)
Your app will scale up and down in response to load change

Technologies 💻

Git Repositories

CI

Is there CI for every project?
- Linting and Styling
- Unit tests
- E2E testing

Security

Least Privilege and Zero Trust
- Make sure only people from team/company have access to the repositories

Automation

This is quite advanced but still, you may want to consider automating repositories creation and access control (using technologies like Terraform or programming languages, you can automate fully the process of repositories management)

Cloud

Provisioning

Resources managed through IaC technologies such as Terrform, Pulumi, etc.
- If at any point you need restore you entire infrastructure you have the code to do so and can perform it quite quickly

Tracking and Monitoring

Resources are tagged, labeled
- Env (e.g. staging, prod, dev)
- Owner (e.g. team)

Accounts

Separate accounts for dev, staging, production, ...
- Why? better isolation, granular and accurate authentication and authorization, reporting per env, ...

Resources

Resources Quotas are set (no one wants to hit high bills)
Important resources are protected from being removed - whether directly, using internal cleanup tooling or any other method
- One option: Prevent allowing to delete a resource if there is no label called 'can_be_deleted' on it
- Another option: Enforce users to write the resource name when removing it (this is something that is already implemented by some cloud providers, but you can implement in your tooling as well)

Reliability

No single point of failure
- Resources deployed across availability zones, regions, etc.

Kubernetes

Resource Management

Apply/Add labels for every type of resources. You may use this page as a suggestion to which labels you should be adding
Every workload has requests defined for CPU and memory (this ensures the workload gets the resources it requires and it's scheduled on the right node)
Every workload has limits defined for memory (but NOT CPU)

CI/CD

CI/CD for Cluster bootstraping
CD process for manifests/configurations (using something like Flux, ArgoCD)
- Make sure cluster bootstraping (the process of preparing the cluster) is managed fully using GitOps

Cluster Management

Cluster for each environment? Dev, QA, Staging, Production
- Per region? Per cloud? How distributed your environment should be?
Cluster Policy Management
- Networking Policies
- Storage Policies

Scaling

Cluster Scaling
- Choose between manually managing scaling or completely managed scaling
- For different reasons, you might want to consider setting minimum node and max nodes for your node pool
Application/Pod Scaling
- VPA (Vertical Pod Autoscaler)
- HPA (Horizontal)

Chaos Engineering

Choose Chaos Engineering framework that is compatible with Kubernetes
- Chaos-Mesh
- Litmus Experiments

GitOps - ArgoCD

Git Repositories

Infra code (Manifests, Configurations, etc.) is in a separate repository (and not in application repository)

GitOps Management

Sync Strategy

Auto Prune (resources deleted when files/content deleted)
Self-heal (cluster state corrected based on Git state and when manual changes done to the cluster)

Monitoring

Choose monitoring solution
- If you can afford it, consider going for ready monitoring solutions like DataDog, NewRelic, ...
- Be aware of maintenance and how much time you are willing to invest in developing and maintaining monitoring solution
Alerts/Monitors
- Critical alerts defined
- Team gets notifications on critical alerts (Slack, Phone, Email, ... perhaps all. whatever works best for the team)
Incident Management
Dashboards

Chaos Engineering

The interesting topic of ensuring your environment can withstand unexpected disruptions

TODO: insert a list of steps to go towards the process of establishing and integrating chaos engineering in your environments

IaC

The Chosen One

Things to consider when choosing IaC technology:
- Maturity (new vs. well established and known)
- Community and support
- Number of integrations, plugins, providers, modules, ...

Implementation

Follow DRY (Don't Repeat Yourself) principle as in make sure there are no code duplication so when you change parameter's value for example, you don't need to change it in two different place
Readable code - use naming conventions, formatting, ... make sure anyone can read the code and doesn't suffer much in doing so :)

Terraform

Development and CI/CD

CI pipeline to test Terraform changes (syntax, lint, ...)
- Consider inserting cost considerations (e.g. test whether a change will raise the bill significantly if you are using a public cloud)
CD pipeline to deploy/apply Terraform changes after the change is merged
To apply changes as part of a pull request (without merging a change) you can use something like Atlantis
- This way you can avoid using local configurations and credentials
Needless to say, but once you started to use Terraform in your org, you should use only that and not allow users to make changes manually in the providers you are using (that will lead to errors when running terraform apply)

State

Stored in a private secured location
- Encrypted
- Public access blocked
Stored in a shared location as it may be updated by different team members
Backed up (e.g. by having versioning)
Never edited directly/manually (as it should be managed and updated by Terraform itself as part of the Terraform lifecycle)

Terraform Projects File Structure

Separate directory for each environment (staging, production, ...)
Separate backend for each environment (as you don't want share the same authentication and access controls for all environments)

Separate directory in each environment for each component and application

staging/
  networking/
  applications/
  databases/

production/
  networking/
  applications/
    web-app-1/
    web-app-2/
  databases/
    mongo/
    mysql/

global/
  user_access_management/

modules/
  applications/
    web-app-1/...

You don't put everything in main.tf
- Terraform configuration files themselves can be organized in many ways
- Possible files:
  - main.tf
  - outputs.tf
  - variables.tf
  - providers.tf
  - dependencies.tf
- Files can be further divided (avoid managing very long files)

Terraform Code

Variables have description (to document what they are used for)
Set lifecycle "prevent_destroy" on resources that should never be deleted (e.g. Terraform state source like S3 bucket)
Try not including shell scripts inline (some tend to grow quite a lot over time). Use instead templatefile function to render a script from a file
No hardcoded repeated values (common examples are ports, CIDR blocks, etc.). Instead use the concept of locals
Prefer using for_each instead of count. count is very limited in modifying lists as it uses list position/index to rely on while for_each is map, set based so it based on specific keys
Consistent naming, code style conventions and formatting
Set tagging standards
- Decide on which tags to use. Some ideas:
  - owner (team, department, ...)
  - generted_by/managed_by/... = "terraform"
- Rather than specifying tags for each resources, consider setting them at provder level with default_tags. This will help you manage tags at scale

Modules

Avoid duplication of Terraform code/configuration by using modules
Try to make modules reusable as much as possible
- Don't include provider code in a reusable module. Different teams and organizations can use different provider versions and constraints (e.g. different default tags)
Avoid hardcoding values, especially in the case reusable modules. To make them reusable, values will have to come from input variables
Consider using only separate resources in a module and not inline blocks as they may limit you at some point or another when reusing the module
Don't use relative paths! use path references (e.g. path.module, path.root)
Try avoiding using latest version of a module. Instead stick for example to tags.
- Branches can be also used, but since anyone can introduce a change to them, they considered less stable than tags

Git

Recommended repositories layout:
- Separate Repository for modules
- Separate Repository for environments (this repository makes use of the modules repository mentioned above)
Consider using Git tags
- They can be used for specifying specific versions of modules

Cloud

Don't hardcode image IDs (it's hard to maintain long term). Instead use filters


data "cloud_image" "image_data" {
  provider = ...
  filter {
    name = "name"
    values = ["some-image-you-would-like-to-use"]
}

resource "some_instance" "instance" {
  image = data.cloud_image.image_data.id
}

Secrets

Basics!
- DON'T store credentials in Terraform configuration as it's highly insecure
- Eventually sensitive data will end up in your state file, for this reason make sure it's encrypted and only visible to those who should be able to access it
  - Same applies for plan files
Provider Credentials
- For local Terraform work/development, you can use generic secret-management tools/CLIs like 1Password or provider-specific options like aws-vault
- For CI/CD that's highly depends on the CI/CD solution/service you are using:
  - GitHub Actions: Use Open ID Connect (OIDC) to establish connection with your provider. You then can specify in your GitHub Actions workflow the following:
```
- uses: aws-actions/configure-aws-credentials@v1
  with:
    role-to-assume: arn:aws:iam::someIamRole
    aws-region: ...
```
- Jenkins: If Jenkins runs on the provider, you can use the provider access entities (like roles, policies, ...) to grant the instance, on which Jenkins is running, access control
- CircleCI: you can use CircleCI Context and then specify it in your CircleCI config file
```
context:
  - some-context
```
Secrets in Terraform Configuration
- Consider how you would like to manage secrets inside Terraform configuration files
  - Environment Variables - you define Terraform variables (with sensitive = true) and pass values with environment variables
    - pros: simple to use, no need to store sensitive data inside Terraform code
    - cons: managed outside of Terraform so tracking, enforcing, managing for different environments, ... is challenging or not feasible
  - Encrypted Files - encrypting the secret and storing the encrypted secrets in Terraform configurations
    - pros: secrets are encrypted and are of Terraform code and part of the version control system
    - cons: working this way can be cumbersome (to modify, you first have to decrypt, makes the changes and then encrypt it again). Still holds security risk if someone gets their hands on the decryption key
  - Secret Store - centralized secret store
    - pros: no plain text secrets in Terraform configurations. Easy to standardize practices and policies around secrets if they are all in the same place
    - cons: not managed as part of the repository, version control, ... makes it easier to makes mistakes in regards to different environments. Costs

Credits

Logos credits can be found here

Tettehisrael/sre-checklist

Team

Responsibilities

Skills

Must

Optional

Processes

SRE Team Goals

SRE Lead

New SRE Team Member

Production

Requirements

Provisioning

Installation

Deployment

Configuration

Resiliency

Technologies 💻

Git Repositories

CI

Security

Automation

Cloud

Provisioning

Tracking and Monitoring

Accounts

Resources

Reliability

Kubernetes

Resource Management

CI/CD

Cluster Management

Scaling

Chaos Engineering

GitOps - ArgoCD

Git Repositories

GitOps Management

Sync Strategy

Monitoring

Chaos Engineering

IaC

The Chosen One

Implementation

Terraform

Development and CI/CD

State

Terraform Projects File Structure

Terraform Code

Modules

Git

Cloud

Secrets

Credits