2022-03-11: Issues authenticating via SAML SSO

Incident DRI

Current Status

It was determined that a software change resulted in failures in single sign on group authentication for people with expired sessions. As we weren't able to roll back, we are reverting this change and will investigate corrective actions.

Workaround

This issue appears to only affect users with expired SAML SSO sessions. To get those users back into GitLab before we deploy a fix for the issue, please have them clear their GitLab cookies (or all cookies) in their browser before trying to authenticate via SAML SSO again.

Summary for CMOC notice / Exec summary:

1. Customer Impact: Limited impact (< 20 cases reported)
2. Service Impact: ServiceWeb
3. Impact Duration: 13:47 UTC - end time UTC ( duration in minutes )
4. Root cause: RootCauseSoftware-Change [gitlab-org/gitlab!82512 (merged)]

Timeline

Recent Events (available internally only):

• Deployments
• Feature Flag Changes
• Infrastructure Configurations
• GCP Events (e.g. host failure)
• Gitlab.com Latest Updates

All times UTC.

2022-03-10

• 15:09 - Instigating MR merged

2022-03-11

• 13:47 - Deployment containing the affected MR was deployed in GPRD.
• 16:40 - @tristan declares incident in Slack.
• 16:40 - @mchacon3 (EOC) and @dcroft (Incident Manager) paged
• 17:03 - @cat Identifies this was caused by a change: gitlab-org/gitlab!82512 (merged)
• 17:07 - @dblessing @cynthia Identifies a workaround for customers: #6567 (comment 872090847)
• 17:12 - @cat creates a revert MR gitlab-org/gitlab!82727 (merged)
• 17:36 - Revert MR pipeline is re-started
• 18:39 - Revert MR is merged

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• Corrective action
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Takeaways

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Corrective Actions

Corrective actions should be put here as soon as an incident is mitigated, ensure that all corrective actions mentioned in the notes below are included.

• corrective action Consider implementing an expedited revert pipeline (related feature request: gitlab-org/gitlab#355504)
• corrective action Investigate the QA failure's relationship to the instigating MR
• corrective action Consider adding logging for pipeline cancellation

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Incident Review

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Customer Impact

1. Who was impacted by this incident? (i.e. external customers, internal customers)
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2. What was the customer experience during the incident? (i.e. preventing them from doing X, incorrect display of Y, ...)
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3. How many customers were affected?
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4. If a precise customer impact number is unknown, what is the estimated impact (number and ratio of failed requests, amount of traffic drop, ...)?
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What were the root causes?

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Incident Response Analysis

1. How was the incident detected?
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2. How could detection time be improved?
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3. How was the root cause diagnosed?
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4. How could time to diagnosis be improved?
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5. How did we reach the point where we knew how to mitigate the impact?
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6. How could time to mitigation be improved?
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7. What went well?
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Post Incident Analysis

1. Did we have other events in the past with the same root cause?
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2. Do we have existing backlog items that would've prevented or greatly reduced the impact of this incident?
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3. Was this incident triggered by a change (deployment of code or change to infrastructure)? If yes, link the issue.
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What went well?

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Guidelines

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Resources

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