Remapping Apps

Araali uses convention to discovers apps in your k8s environment. As best practice, apps are deployed in their own namespace. There is no good reason to actually not do so.

However, due to team isolation, sometimes namespaces are pre-created by the infrastructure team and kept small by design (to prevent proliferation and also to keep the privileges for namespace management limited to a smaller team).

For e.g. some people could have static namespaces that denote environments instead of apps (prod, staging, dev). In other cases, namespaces could be created per team for isolation (team1, team2). If teams map to features/apps, then there is not much of an issue. However, a single team could be responsible for multiple logical apps and the namespace itself ends up becoming a container for these apps.

For such scenarios Araali allows you to customize apps the way you understand it, regardless of which namespace they will show up in.

Remapping Using Pod Label Key

If your pods already have a label that represents your desired app remap structure, then App Remapping can be easily accomplished via the UI.

Click and select “App Remap” and then click on the “+” icon on the top right corner.

This will open “Add Pod Label” where you can select the zone/cluster, app/namespace that you want to remap. Pass the Pod Label Key for Araali to pull the information from the Pod metadata and remap your app.

Or, do it using code:

// List existing App-Mapping Based on Pod-Label
$ ./araalictl app-mapping -op list
- zone: nightly-k8s
app: nightly-bend
label: app

// Create Yaml file with zone, app that needs to be remapped and the label to be used for remapping.
Create a new file: app_remap.yaml

- zone: test-zone
  app: test-app
  label: app

// Add new pod label based app remapping
$ cat app_remap.yaml | ./araalictl app-mapping -op add
{"success":true}
$ ./araalictl app-mapping -op list
- zone: nightly-k8s
  app: nightly-bend
  label: name
- zone: test-zone
  app: test-app
  label: app

// Delete existing pod label based app remapping
$ cat app_remap.yaml | ./araalictl app-mapping -op del
{"success":true}
$ ./araalictl app-mapping -op list
- zone: nightly-k8s
  app: nightly-bend
  label: app

App (Re)mapping Using podName

This is a sample google shop application where all the pods show up under a single app - gshop. We’ll walk through the process of splitting this up into three different apps.

List all the apps to pod mapping as a yaml file

$ ./araalictl api -list-pod-mappings > pod_mapping.yaml

Update the mapping yaml file

1. We delete the pods we don’t want to remap.

2. As we can see we have the app and namespace set to the same value.

3. Now we reset the app to the name we would like to see it as.

This can be done programmatically as well. Here we show a manual way of editing the yaml files.

Below is a sample yaml file generated. Now we would like to re-map the pods as below.

frontend → gshop-frontend

redis-cart → gshop-db

rest of the services → gshop-service

Here is the code:

$ vi pod_mapping.yaml
- zone: prod
  namespace: gshop
  pod: checkoutservice
  app: gshop
- zone: prod
  namespace: gshop
  pod: frontend
  app: gshop
- zone: prod
  namespace: gshop
  pod: cartservice
  app: gshop
- zone: prod
  namespace: gshop
  pod: recommendationservice
  app: gshop
- zone: prod
  namespace: gshop
  pod: currencyservice
  app: gshop
- zone: prod
  namespace: gshop
  pod: shippingservice
  app: gshop
- zone: prod
  namespace: gshop
  pod: adservice
  app: gshop
- zone: prod
  namespace: gshop
  pod: redis-cart
  app: gshop
- zone: prod
  namespace: gshop
  pod: productcatalogservice
  app: gshop
- zone: prod
  namespace: gshop
  pod: emailservice
  app: gshop
- zone: prod
  namespace: gshop
  pod: paymentservice
  app: gshop

Edited yaml file (with changed app):

$ vi pod_mapping.yaml
- zone: prod
  namespace: gshop
  pod: checkoutservice
  app: gshop-service
- zone: prod
  namespace: gshop
  pod: frontend
  app: gshop-frontend
- zone: prod
  namespace: gshop
  pod: cartservice
  app: gshop-service
- zone: prod
  namespace: gshop
  pod: recommendationservice
  app: gshop-service
- zone: prod
  namespace: gshop
  pod: currencyservice
  app: gshop-service
- zone: prod
  namespace: gshop
  pod: shippingservice
  app: gshop-service
- zone: prod
  namespace: gshop
  pod: adservice
  app: gshop-service
- zone: prod
  namespace: gshop
  pod: redis-cart
  app: gshop-db
- zone: prod
  namespace: gshop
  pod: productcatalogservice
  app: gshop-service
- zone: prod
  namespace: gshop
  pod: emailservice
  app: gshop-service
- zone: prod
  namespace: gshop
  pod: paymentservice
  app: gshop-service

Update the pod to app mapping in araali

$ cat pod_mapping.yaml | ./araalictl api -update-pod-mappings

Once the above exercise is complete we can see that a single app before got split into three different apps as below.

Programmatic Mapping by Example

This can also be programmatically achieved using our python APIs. The transformations should ideally be idempotent so they can be rerun without issues:

mapping = araalictl.get_pod_apps()

if (obj["zone"] == "nightly-k8s" and
    obj["namespace"] == "nightly-bend" and
    "pod" in obj):

    if obj["pod"] in ["flowstitcher", "flowprocessor",
                      "assetinfo-processor",
                      'applens-generator',
                      "applens-compactor",
                      "vulnscanner"]:

        obj["app"] = "nightly-bend-pipeline"

araalictl.push_pod_apps(mapping)

Functions

Get

Get all Mapping content.

Command LinePython

./araalictl app-mapping -op list

Add

Add to mapping content.

Command LinePython

# "i" to insert at cursor, "a" for after cursor, and "o" for line above cursor
vi add_mapping.txt
# Insert zone, app, label in yaml format
# Esc to exit edit mode in vi
# “:wq” to quit once in control mode
cat add_mapping.txt | ./araalictl app-mapping -op add

Remove

Remove from mapping content.

Command LinePython

# "i" to insert at cursor, "a" for after cursor, and "o" for line above cursor
vi add_mapping.txt
# Insert zone, app, label in yaml format
# Esc to exit edit mode in vi
# “:wq” to quit once in control mode
cat add_mapping.txt | ./araalictl app-mapping -op del