Release notes

Review summaries of the main changes in the Gloo 2.5 release.

report

Make sure that you review the breaking changes 🔥 that were introduced in this release and the impact that they have on your current environment.

Introduction

The release notes include important installation changes and known issues. They also highlight ways that you can take advantage of new features or enhancements to improve your product usage.

For more information, see the following related resources:

Upgrade guide: Steps to upgrade from the previous minor version to the current version.
Version reference: Information about Solo’s version support.

🔥 Breaking changes

Review details about the following breaking changes. The severity is intended as a guide to help you assess how much attention to pay to this area during the upgrade, but can vary depending on your environment.

🔔 Medium

Review changes that might have impact to production and require manual intervention, but possibly not until the next version is released.

Prometheus annotations removed: The prometheus.io/port: "<port_number>" annotation was removed from the Gloo management server and agent in 2.5.0. However, the prometheus.io/scrape: true annotation is still present. When you use your own Prometheus instance to scrape metrics, the instance might try to scrape metrics from port numbers that require TLS authentication. This can lead to error messages in the logs. Note that this issue is resolved in 2.5.2.
Gloo UI auth secret: If you set up external authentication for the Gloo UI and you use the glooUi.auth.oidc.clientSecret Helm setting to reference the Kubernetes secret that stores your credentials, the secret might get deleted during the upgrade. To resolve this issue, review the steps in the release note.

ℹ️ Low

Review informational updates that you might want to implement but that are unlikely to materially impact production.

Upstream Prometheus upgrade: The Prometheus Helm chart version is upgraded to a newer version, which requires the Prometheus deployment to be re-created. Gloo Mesh Core uses Helm pre-upgrade hooks to re-create the deployment, which can cause issues in automated environments such as Argo CD.

Gloo UI auth secret

If you set up external authentication for the Gloo UI and you use the glooUi.auth.oidc.clientSecret Helm setting to reference the Kubernetes secret that stores your credentials, the secret might get deleted during the upgrade, due to a bug.

To resolve this issue, you can manually create the secret before the upgrade. Note that during this process, the Gloo UI temporarily cannot be accessed.

Get the client secret from your OIDC provider.
Manually delete the existing Gloo UI OIDC client secret that your installation automatically created for you. You can check the name of the secret in the glooUi.auth.oidc.clientSecret Helm setting. The following example uses dashboard in the gloo-mesh namespace.
```
  kubectl get delete secret -n gloo-mesh dashboard
  
```

Re-create the OIDC client secret without any Helm labels or annotations.

  apiVersion: v1
kind: Secret
metadata:
  name: dashboard
  namespace: gloo-mesh
type: Opaque
stringData:
  oidc-client-secret: $OIDC_CLIENT_SECRET

Update your Helm configuration file to remove the glooUi.auth.oidc.clientSecret setting and to refer to the secret that you just recreated in the glooUi.auth.oidc.clientSecretName setting.

  ...
glooUi:
  enabled: true
  auth:
    enabled: true
    backend: oidc
    oidc:
      appUrl: # The URL that the UI for the OIDC app is available at, from the DNS and other ingress settings that expose the OIDC app UI service.
      clientId: # From the OIDC provider
      clientSecretName: dashboard #The Kubernetes secret with your OIDC client secret that you previously created.
      issuerUrl: # The URL to connect to the OpenID Connect identity provider, often in the format 'https://<domain>.<provider_url>/'.
      appUrl: # The URL that the Gloo UI is exposed at, such as 'https://localhost:8090'.

Continue with the upgrade.

Upstream Prometheus upgrade

Gloo Mesh Core includes a built-in Prometheus server to help monitor the health of your Gloo components. This release of Gloo upgrades the Prometheus community Helm chart from version 19.7.2 to 25.11.0. As part of this upgrade, upstream Prometheus changed the selector labels for the deployment, which requires recreating the deployment. To help with this process, the Gloo Helm chart includes a pre-upgrade hook that automatically recreates the Prometheus deployment during a Helm upgrade. This breaking change impacts upgrades from previous versions to version 2.4.10, 2.5.1, or 2.6.0 and later.

If you do not want the redeployment to happen automatically, you can disable this process by setting the prometheus.skipAutoMigration Helm value to true. For example, you might use Argo CD, which converts Helm pre-upgrade hooks to Argo PreSync hooks and causes issues. To ensure that the Prometheus server is deployed with the right version, follow these steps:

Confirm that you have an existing deployment of Prometheus at the old Helm chart version of chart: prometheus-19.7.2.
```
  kubectl get deploy -n gloo-mesh prometheus-server -o yaml | grep chart
  
```
Delete the Prometheus deployment. Note that while Prometheus is deleted, you cannot observe Gloo performance metrics.
```
  kubectl delete deploy -n gloo-mesh prometheus-server
  
```
In your Helm values file, set the prometheus.skipAutoMigration field to true.
Continue with the Helm upgrade of Gloo Mesh Core. The upgrade recreates the Prometheus server deployment at the new version.

Prometheus annotations removed

In Gloo version 2.5.0, the prometheus.io/port: "<port_number>" annotation was removed from the Gloo management server and agent. However, the prometheus.io/scrape: true annotation is still present. If you have another Prometheus instance that runs in your cluster, and it is not set up with custom scraping jobs for the Gloo management server and agent, the instance automatically scrapes all ports on the management server and agent pods. This can lead to error messages in the management server and agent logs. Note that this issue is resolved in version 2.5.2. To resolve this issue in Gloo version 2.5.0 or 2.5.1, see Run another Prometheus instance alongside the built-in one.

⚒️ Installation changes

In addition to comparing differences across versions in the changelog, review the following installation changes from the previous minor version to version 2.5.

Gloo agent health check port

Because you can now run the Gloo agent as a sidecar container in the management server pod, the default Gloo agent health check port is changed from 8090 to 8091.

Gloo UI

To use the Gloo UI and visualize the network traffic in your environment with the Gloo UI graph, you must set the telemetryCollector.enabled Helm setting to true in each cluster in your environment, including the management cluster.

Portal logs pipeline

The Gloo telemetry pipeline telemetryCollectorCustomization.pipelines.logs/istio_access_logs is renamed to telemetryCollectorCustomization.pipelines.logs/portal. For more information, see Monitor Portal analytics in the Gloo Mesh Gateway docs.

New default values for Gloo UI auth sessions

Some of the default Helm values changed for configuring the Gloo UI auth session storage:

glooUi.auth.oidc.session.backend: The default value changed from "" (empty) to cookie to ensure auth sessions are stored in browser cookies by default.
glooUi.auth.oidc.session.redis.host: The default value changed from "" (empty) to gloo-mesh-redis.gloo-mesh:6379 to ensure a valid Redis host is set when glooUi.auth.oidc.session.backend is changed to redis.

Note that if you previously set values for glooUi.auth.oidc.session.backend and glooUi.auth.oidc.session.redis.host, these values are not overwritten. The new default values are only set if these two fields are currently set to "" (empty).

To learn how to set up Gloo UI auth session storage, see Store UI sessions.

  
glooUi: 
  auth: 
    oidc:
      # Session storage configuration. If omitted, a cookie is used.
      session:
        # Backend to use for auth session storage. 'cookie' and 'redis' are supported.
        backend: "cookie"
        # Redis instance configuration.
        redis:
          # Host at which the Redis instance is accessible. To use the default Redis deployment, specify 'gloo-mesh-redis.gloo-mesh:6379'.
          host: "gloo-mesh-redis.gloo-mesh:6379"

  
glooUi: 
  auth: 
    oidc:
      # Session storage configuration. If omitted, a cookie is used.
      session:
        # Backend to use for auth session storage. 'cookie' and 'redis' are supported.
        backend: ""
        # Redis instance configuration.
        redis:
          # Host at which the Redis instance is accessible. To use the default Redis deployment, specify 'gloo-mesh-redis.gloo-mesh:6379'.
          host: ""

🐞 Bug fixes

Multiple Istio revisions in the same cluster

If you run multiple revisions of Istio in your cluster and use discoverySelectors in each revision to discover the resources in specific namespaces, enable the glooMgmtServer.extraEnvs.IGNORE_REVISIONS_FOR_VIRTUAL_DESTINATION_TRANSLATION environment variable on the Gloo management server. This setting allows virtual destinations to be translated correctly if the east-west gateway and the backing services belong to different namespaces.

notifications

This feature is available in version 2.5.5 and later.

To enable this feature, add the following values to your Helm values file.

  
glooMgmtServer:
  extraEnvs:
  - name: IGNORE_REVISIONS_FOR_VIRTUAL_DESTINATION_TRANSLATION
    value: "true"

To check if you use discoverySelectors in your Istio revision:

Istio lifecycle manager installations:

Get the details of your Istio lifecycle manager resources.
```
  kubectl get istiolifecyclemanagers -A -o yaml
  
```

In your Istio lifecycle manager resource, check if you use discoverySelectors in your spec.installations.istioOperatorSpec.meshConfig

  ...
spec:
 installations:
 - clusters:
   - defaultRevision: true
     name: mycluster
   istioOperatorSpec:
     components:
       pilot:
         k8s:
           env:
           - name: PILOT_SKIP_VALIDATE_TRUST_DOMAIN
             value: "true"
     meshConfig:
       discoverySelectors:
         - matchLabels:
             istio-discovery: enabled

Manual installations:

Get the details of your Istio operator.

  kubectl get istiooperator -A -o yaml

In your Istio operator configuration, check if you use discoverySelectors in your meshConfig settings.

  ...
meshConfig:
  discoverySelectors:
    - matchLabels:
        istio-discovery: enabled

Indefinite reconciliation of IssuedCertificates

If you install the gloo-mesh-mgmt-server management plane or gloo-mesh-agent data plane in a custom namespace other than gloo-mesh, skip upgrades to 2.5.7 and 2.5.8. These patch versions have a bug that causes IssuedCertificates to reconcile indefinitely. Instead, upgrade directly to patch version 2.5.9 or later, in which the issue is resolved.

🌟 New features

Review the following new features that are introduced in version 2.5 and that you can enable in your environment.

Delimiters in JWT token claims

As of version 2.5.12, you can configure custom delimiters when you extract claims from JWT tokens. This way, you can append the claim information in a header in a different format than the default comma-delimited format. For example steps, see Extract claims to headers.

Failover priority

You can use the new priorityLabels field in the FailoverPolicy to prioritize destinations that get traffic in case of failure. Previously, you could only use localityMappings to set up basic failover from one location to another, not a prioritized order of multiple locations. For more information, see the Failover guide.

Redis safe mode

In versions 2.5.3 and lower, a race condition was identified that can be triggered during simultaneous restarts of the management plane and Redis, including an upgrade to a newer Gloo version. If hit, this failure mode can lead to partial translations on the Gloo management server which can result in Istio resources being temporarily deleted from the output snapshots that are sent to the Gloo agents. For more information about this failure scenario, see Redis and Gloo management server restart. To resolve this issue, a new safe mode feature was added that you can enable by setting glooMgmtServer.safeMode Helm chart option to true.

If safe mode is enabled, translation of input snapshots halts until the input snapshots of all registered Gloo agents are present in the Redis cache. This feature improves management plane stability during disaster scenarios and upgrades. For more information, see Safe mode. The safe mode feature is disabled by default.

To enable safe mode, follow these general steps:

Scale down the number of Gloo management server pods to 0.

  kubectl scale deployment gloo-mesh-mgmt-server --replicas=0 -n gloo-mesh

Upgrade your Gloo Mesh Core installation. Add the following settings in the Helm values file for the Gloo management plane.
```
  
glooMgmtServer:
  safeMode: true
  
```
Scale the Gloo management server back up to the number of desired replicas. The following example uses 1 replica.
```
  kubectl scale deployment gloo-mesh-mgmt-server --replicas=1 -n gloo-mesh
  
```

Redis safe start window

With safe mode, the Gloo management server halts translation until the input snapshots of all workload clusters are present in the Redis cache. However, if clusters have connectivity issues, translation might be halted for a long time, even for healthy clusters. You might want translation to resume after a certain period of time, even if some input snapshots are missing in the Redis cache. To do so, you must use the glooMgmtServer.safeStartWindow field in your Gloo management server Helm values file to specify the time in seconds to halt translation. Note that this setting is ignored if glooMgmtServer.safeMode is set to true. The default value is 180 seconds. You can disable the wait time by setting this field to 0 (zero). For more information, see Option 2: Safe start window.

To set a safe start window, follow these general steps:

Scale down the number of Gloo management server pods to 0.

  kubectl scale deployment gloo-mesh-mgmt-server --replicas=0 -n gloo-mesh

Upgrade your Gloo Mesh Core installation. Add the following settings in the Helm values file for the Gloo management plane.
```
  
glooMgmtServer:
  safeMode: false
  safeStartWindow: 90
  
```
Scale the Gloo management server back up to the number of desired replicas. The following example uses 1 replica.
```
  kubectl scale deployment gloo-mesh-mgmt-server --replicas=1 -n gloo-mesh
  
```

I/O threads for Redis in 2.5.6

A new Helm value redis.deployment.ioThreads was introduced to specify the number of I/O threads to use for the built-in Redis instance. Redis is mostly single threaded, however some operations, such as UNLINK or slow I/O accesses can be performed on side threads. Increasing the number of side threads can help improve and maximize the performance of Redis as these operations can run in parallel.

report

The default and minimum valid value for this setting is 1. If you plan to increase the number of I/O side threads, make sure that you also change the CPU requests and CPU limits for the Redis pod. Set the CPU requests and limits to the same number that you use for the I/O side threads plus 1. That way, you can ensure that each side thread has an available CPU core, and that an additional CPU core is left for the main Redis thread. For example, if you want to set I/O threads to 2, make sure to add 3 CPU cores to the resource requests and limits for the Redis pod. You can find further recommendations regarding I/O threads in this Redis configuration example.

If you set I/O threads, the Redis pod must be restarted during the upgrade so that the changes can be applied. During the restart, the input snapshots from all connected Gloo agents are removed from the Redis cache. If you also update settings in the Gloo management server that require the management server pod to restart, the management server’s local memory is cleared and all Gloo agents are disconnected. Although the Gloo agents attempt to reconnect to send their input snapshots and re-populate the Redis cache, some agents might take longer to connect or fail to connect at all. To ensure that the Gloo management server halts translation until the input snapshots of all workload cluster agents are present in Redis, it is recommended to enable safe mode on the management server alongside updating the I/O threads for the Redis pod. For more information, see Safe mode. Note that in version 2.6.0 and later, safe mode is enabled by default.

To update I/O side threads in Redis as part of your Gloo Mesh Core upgrade:

Scale down the number of Gloo management server pods to 0.

  kubectl scale deployment gloo-mesh-mgmt-server --replicas=0 -n gloo-mesh

Upgrade Gloo Mesh Core and use the following settings in your Helm values file for the management server. Make sure to also increase the number of CPU cores to one core per thread, and add an additional CPU core for the main Redis thread. The following example also enables safe mode on the Gloo management server to ensure translation is done with the complete context of all workload clusters.
```
  
glooMgmtServer:
  safeMode: true
redis: 
  deployment: 
    ioThreads: 2
    resources: 
      requests: 
        cpu: 3
      limits: 
        cpu: 3
  
```
Scale the Gloo management server back up to the number of desired replicas. The following example uses 1 replica.
```
  kubectl scale deployment gloo-mesh-mgmt-server --replicas=1 -n gloo-mesh
  
```

🚧 Known issues

The Solo team fixes bugs, delivers new features, and makes changes on a regular basis as described in the changelog. Some issues, however, might impact many users for common use cases. These known issues are as follows:

Cluster names: Do not use underscores (_) in the names of your clusters or in the kubeconfig context for your clusters.
Istio:
- Due to a lack of support for the Istio CNI and iptables for the Istio proxy, you cannot run Istio (and therefore Gloo Mesh Core) on AWS Fargate. For more information, see the Amazon EKS issue.
- Istio 1.21 is not supported in Gloo Mesh Core version 2.5.
- Istio 1.20 is supported only as patch version 1.20.1-patch1 and later. Do not use patch versions 1.20.0 and 1.20.1, which contain bugs that impact several Gloo Mesh Core features that rely on Istio ServiceEntries.
- For FIPS-compliant Solo distributions of Istio 1.17.2 and 1.16.4, you must use the -patch1 versions of the latest Istio builds published by Solo, such as 1.17.2-patch1-solo-fips for Solo distribution of Istio 1.17. These patch versions fix a FIPS-related issue introduced in the upstream Envoy code. In 1.17.3 and later, FIPS compliance is available in the -fips tags of regular Solo distributions of Istio, such as 1.17.3-solo-fips.
OTel pipeline: FIPS-compliant builds are not currently supported for the OTel collector agent image.

Release notes

Introduction link

🔥 Breaking changes link

🔔 Medium link

ℹ️ Low link

Gloo UI auth secret link

Upstream Prometheus upgrade link

Prometheus annotations removed link

⚒️ Installation changes link

Gloo agent health check port link

Gloo UI link

Portal logs pipeline link

New default values for Gloo UI auth sessions link

🐞 Bug fixes link

Multiple Istio revisions in the same cluster link

Indefinite reconciliation of IssuedCertificates link

🌟 New features link

Delimiters in JWT token claims link

Failover priority link

Redis safe mode link

Redis safe start window link

I/O threads for Redis in 2.5.6 link

🚧 Known issues link

Introduction

🔥 Breaking changes

🔔 Medium

ℹ️ Low

Gloo UI auth secret

Upstream Prometheus upgrade

Prometheus annotations removed

⚒️ Installation changes

Gloo agent health check port

Gloo UI

Portal logs pipeline

New default values for Gloo UI auth sessions

🐞 Bug fixes

Multiple Istio revisions in the same cluster

Indefinite reconciliation of IssuedCertificates

🌟 New features

Delimiters in JWT token claims

Failover priority

Redis safe mode

Redis safe start window

I/O threads for Redis in 2.5.6

🚧 Known issues