Upgrade Kong Gateway

Upgrade to major, minor, and patch Kong Gateway releases using the kong migrations commands.

You can also use the commands to migrate all Kong Gateway (OSS) entities to Kong Gateway. See Migrating from Kong Gateway (OSS) to Kong Gateway.

If you experience any issues when running migrations, contact Kong Support for assistance.

Upgrade path for Kong Gateway releases

Kong adheres to semantic versioning, which makes a distinction between major, minor, and patch versions. The upgrade path for major and minor versions differs depending on the previous version from which you are migrating:

  • Upgrading from 2.5.x to 2.6.x is a minor upgrade; however, read below for important instructions on database migration, especially for Cassandra users.

  • Upgrading from from 1.x is a major upgrade. Follow the Version Prerequisites. Be aware of any noted breaking changes as documented in the version to which you are upgrading.

Version prerequisites for migrating to Kong Gateway 2.6.x

If you are not on Kong Gateway 2.5.x, you must first incrementally upgrade to 2.5.x before upgrading to 2.6.x. Zero downtime is possible but not guaranteed if you are upgrading incrementally between versions, from 0.36.x to 1.3.x to 1.5.x to 2.1.x to 2.2.x to 2.3.x to 2.4.x to 2.5.x to 2.6.x., plan accordingly.

  • If running a version of Kong Gateway earlier than 1.5, migrate to 1.5 first.
  • If running a version of Kong Gateway earlier than 2.1, migrate to 2.1 first.
  • If running a version of Kong Gateway earlier than 2.2, migrate to 2.2 first.
  • If running a version of Kong Gateway earlier than 2.3, migrate to 2.3 first.
  • If running a version of Kong Gateway earlier than 2.4, migrate to 2.4 first.
  • If running a version of Kong Gateway earlier than 2.5, migrate to 2.5 first.

Dev Portal migrations

There are no migrations necessary for the Dev Portal when upgrading from 2.5.x to 2.6.x.

If you are currently using the Developer Portal in 1.5.x, it will no longer work without manually migrating files to version 2.1.x.

Upgrade considerations

Before upgrading, review this list for any configuration or breaking changes that affect your current installation.

  • If you are adding a new plugin to your installation, you need to run kong migrations up with the plugin name specified. For example, KONG_PLUGINS=oauth2.

Hybrid mode considerations

  • If you are currently running 2.6.x in classic (traditional) mode and want to run in hybrid mode instead, follow the hybrid mode installation instructions after running the migration.
  • Custom plugins (either your own plugins or third-party plugins that are not shipped with Kong) need to be installed on both the Control Plane and the Data Planes in Hybrid mode. Install the plugins on the Control Plane first, and then the Data Planes.
  • The Rate Limiting Advanced plugin does not support the cluster strategy in hybrid mode. The redis strategy must be used instead.

Kong for Kubernetes considerations

The Helm chart automates the upgrade migration process. When running helm upgrade, the chart spawns an initial job to run kong migrations up and then spawns new Kong pods with the updated version. Once these pods become ready, they begin processing traffic and old pods are terminated. Once this is complete, the chart spawns another job to run kong migrations finish.

While the migrations themselves are automated, the chart does not automatically ensure that you follow the recommended upgrade path. If you are upgrading from more than one minor Kong version back, check the upgrade path recommendations for Kong open source or Kong Gateway.

Although not required, users should upgrade their chart version and Kong version independently. In the event of any issues, this will help clarify whether the issue stems from changes in Kubernetes resources or changes in Kong.

For specific Kong for Kubernetes version upgrade considerations, see Upgrade considerations

Kong deployment split across multiple releases

The standard chart upgrade automation process assumes that there is only a single Kong release in the Kong cluster, and runs both migrations up and migrations finish jobs.

If you split your Kong deployment across multiple Helm releases (to create proxy-only and admin-only nodes, for example), you must set which migration jobs run based on your upgrade order.

To handle clusters split across multiple releases, you should:

  1. Upgrade one of the releases with:

    1. helm upgrade RELEASENAME -f values.yaml \
    2. --set migrations.preUpgrade=true \
    3. --set migrations.postUpgrade=false

  2. Upgrade all but one of the remaining releases with:

    1. helm upgrade RELEASENAME -f values.yaml \
    2. --set migrations.preUpgrade=false \
    3. --set migrations.postUpgrade=false

  3. Upgrade the final release with:

    1. helm upgrade RELEASENAME -f values.yaml \
    2. --set migrations.preUpgrade=false \
    3. --set migrations.postUpgrade=true

This ensures that all instances are using the new Kong package before running kong migrations finish.

Migrating databases for Upgrades

Kong Gateway supports the zero downtime migration model. This means that while the migration is in process, you have two Kong clusters with different versions running that are sharing the same database. This is sometimes referred to as the blue-green migration model.

The migrations are designed so that there is no need to fully copy the data. The new version of Kong Gateway is able to use the data as it is migrated, and the old Kong cluster keeps working until it is finally time to decommission it. For this reason, the full migration is split into two commands:

  • kong migrations up: performs only non-destructive operations
  • kong migrations finish: puts the database in the final expected state (DB-less mode is not supported in Kong Gateway)

Postgres

  1. Download 2.6.x, and configure it to point to the same datastore as your old 2.5.x (or 2.6.x-beta) cluster.
  2. Run kong migrations up.

  3. After that finishes running, both the old (2.5.x) and new (2.6.x) clusters can now run simultaneously on the same datastore. Start provisioning 2.6.x nodes, but do not use their Admin API yet.

  4. Gradually divert traffic away from your old nodes, and redirect traffic to your 2.6.x cluster. Monitor your traffic to make sure everything is going smoothly.

  5. When your traffic is fully migrated to the 2.6.x cluster, decommission your old 2.5.x (or 2.6.x-beta) nodes.
  6. From your 2.6.x cluster, run kong migrations finish. From this point onward, it is no longer possible to start nodes in the old 2.5.x (or 2.6.x-beta) cluster that still points to the same datastore. Run this command only when you are confident that your migration was successful. From now on, you can safely make Admin API requests to your 2.6.x nodes.

Cassandra

Due to internal changes, the table schemas used by Kong Gateway 2.6.x on Cassandra are incompatible with those used by Kong Gateway 2.0.x. Migrating using the usual commands kong migrations up and kong migrations finish will require a small window of downtime, since the old and new versions cannot use the database at the same time. Alternatively, to keep your previous version fully operational while the new one initializes, you will need to transfer the data to a new keyspace using a database dump, as described below:

  1. Download 2.6.x, and configure it to point to a new keyspace.

  2. Run kong migrations bootstrap.

    Once that finishes running, both the old (2.5.x) and new (2.6.x) clusters can now run simultaneously, but the new cluster does not have any data yet.

  3. On the old cluster, run kong config db_export. This will create a file named kong.yml with a database dump.

  4. Transfer the file to the new cluster and run kong config db_import kong.yml. This will load the data into the new cluster.
  5. Gradually divert traffic away from your old nodes, and into your 2.5.x cluster. Monitor your traffic to make sure everything is going smoothly.
  6. When your traffic is fully migrated to the 2.6.x cluster, decommission your old nodes.

Installing 2.6.x on a fresh datastore

For installing on a fresh datastore, Kong Gateway 2.6.x has the kong migrations bootstrap command. Run the following commands to prepare a new 2.6.x cluster from a fresh datastore. By default, the kong CLI tool loads the configuration from /etc/kong/kong.conf, but you can optionally use the -c flag to indicate the path to your configuration file:

  1. $ kong migrations bootstrap [-c /path/to/kong.conf]
  2. $ kong start [-c /path/to/kong.conf]