app-migration-cli

This tool migrates apps from one MC to another. It's coupled to the vintage -> capi migration tool.

Running this script dumps apps.application.giantswarm.io Objects and their related config (configmap and/or secrets) to disk. Mentioned config will be renamed and put in a different namespace (capi way).

In a second stage, these objects are reapplied to a new MC.

✈️ Rundown

Parts of the script must run in advance of the CAPI Migration, others are scheduled after a successfull infrastructure migration.

1. preflight - readonly checks if a migration is possible; not neccessary to run

   • validate access to both mcs
   • check WC condition/health (only "Created" is allowed)
   • ...

2. prepare - writing all resources to disk

   • filtering certain default/non-migratable apps
   • writing all apps to disk
   • writing all dependend cm/secrets to disk
   • converting vintage apps,cm/secrets locations to capi org-namespace

• ⏳ Infrastructure migration should happen here...*

3. apply - applying the resources to the new MC
   • checking if certain default resources are available
   • applying the dumped resources to the new MC

Recomendation to run the tool

• To ensure there are no interference with kubeconfigs that the tool uses, create a new temporary file for kubeconfig.

❯❯❯ export KUBECONFIG=$(mktemp)
                                <sourceMC>  <destMC> <WC Name> <Org Namespace>
❯❯❯ ./app-migration-cli prepare -s gaia     -d golem -n ulli30 -o org-ulli
Connected to gs-gaia, k8s server version v1.24.17
Connected to gs-golem, k8s server version v1.24.16
Finalizer set on NS: gaia-ulli30
Scheduled 1 non-default apps for migration

# apps, cm, secrets written to disk in yaml; Namespace reorganization already included
❯❯❯ ll ulli30-apps.yaml
.rw-r-----  5.0k ull  16 Jan 10:53  ulli30-apps.yaml

❯❯❯ ./capi-migration-cli --mc-capi golem --mc-vintage gaia --cluster-namespace org-ulli --cluster-name ulli30
[...]
Deleted vintage ulli30 node pool ASG.
Finished migrating cluster ulli30 to CAPI infrastructure

❯❯❯ ./app-migration-cli apply -s gaia -d golem -n ulli30 -f ulli30-apps.yaml -o org-ulli
Connected to gs-gaia, k8s server version v1.24.17
Connected to gs-golem, k8s server version v1.24.16

All prerequistes are found on the new MC for app migration
Applying all non-default APP CRs to MC
All non-default apps applied successfully.

Notes

• currently only working for vintage
• currently only working for aws based clusters