Tide is a Prow component for managing a pool of GitHub PRs that match a given set of criteria. It will automatically retest PRs that meet the criteria ("tide comes in") and automatically merge them when they have up-to-date passing test results ("tide goes out").
- Automatically runs batch tests and merges multiple PRs together whenever possible.
- Ensures that PRs are tested against the most recent base branch commit before they are allowed to merge.
- Maintains a GitHub status context that indicates if each PR is in a pool or what requirements are missing.
- Supports blocking merge to individual branches or whole repos using specifically labelled GitHub issues.
- Exposes Prometheus metrics.
- Supports repos that have 'optional' status contexts that shouldn't be required for merge.
- Serves live data about current pools and a history of actions which can be consumed by Deck to populate the Tide dashboard, the PR dashboard, and the Tide history page.
- Scales efficiently so that a single instance with a single bot token can provide merge automation to dozens of orgs and repos with unique merge criteria. Every distinct 'org/repo:branch' combination defines a disjoint merge pool so that merges only affect other PRs in the same branch.
- Provides configurable merge modes ('merge', 'squash', or 'rebase').
Tide was created in 2017 by @spxtr to replace mungegithub's Submit Queue. It was designed to manage a large number of repositories across organizations without using many API rate limit tokens by identifying mergeable PRs with GitHub search queries fulfilled by GitHub's v4 GraphQL API.
graph TD;
subgraph github[GitHub]
subgraph org/repo/branch
head-ref[HEAD ref];
pullrequest[Pull Request];
status-context[Status Context];
end
end
subgraph prow-cluster
prowjobs[Prowjobs];
config.yaml;
end
subgraph tide-workflow
Tide;
pools;
divided-pools;
pools-->|dividePool|divided-pools;
filtered-pools;
subgraph syncSubpool
pool-i;
pool-n;
pool-n1;
accumulated-batch-prowjobs-->|filter out <br> incorrect refs <br> no longer meet merge requirement|valid-batches;
valid-batches-->accumulated-batch-success;
valid-batches-->accumulated-batch-pending;
status-context-->|fake prowjob from context|filtered-prowjobs;
filtered-prowjobs-->|accumulate|map_context_best-result;
map_context_best-result-->map_pr_overall-results;
map_pr_overall-results-->accumulated-success;
map_pr_overall-results-->accumulated-pending;
map_pr_overall-results-->accumulated-stale;
subgraph all-accumulated-pools
accumulated-batch-success;
accumulated-batch-pending;
accumulated-success;
accumulated-pending;
accumulated-stale;
end
accumulated-batch-success-..->accumulated-batch-success-exist{Exist};
accumulated-batch-pending-..->accumulated-batch-pending-exist{Exist};
accumulated-success-..->accumulated-success-exist{Exist};
accumulated-pending-..->accumulated-pending-exist{Exist};
accumulated-stale-..->accumulated-stale-exist{Exist};
pool-i-..->require-presubmits{Require Presubmits};
accumulated-batch-success-exist-->|yes|merge-batch[Merge batch];
merge-batch-->|Merge Pullrequests|pullrequest;
accumulated-batch-success-exist-->|no|accumulated-batch-pending-exist;
accumulated-batch-pending-exist-->|no|accumulated-success-exist;
accumulated-success-exist-->|yes|merge-single[Merge Single];
merge-single-->|Merge Pullrequests|pullrequest;
require-presubmits-->|no|wait;
accumulated-success-exist-->|no|require-presubmits;
require-presubmits-->|yes|accumulated-pending-exist;
accumulated-pending-exist-->|no|can-trigger-batch{Can Trigger New Batch};
can-trigger-batch-->|yes|trigger-batch[Trigger new batch];
can-trigger-batch-->|no|accumulated-stale-exist;
accumulated-stale-exist-->|yes|trigger-highest-pr[Trigger Jobs on Highest Priority PR];
accumulated-stale-exist-->|no|wait;
end
end
Tide-->pools[Pools - grouped PRs, prow jobs by org/repo/branch];
pullrequest-->pools;
divided-pools-->|filter out prs <br> failed prow jobs <br> pending non prow checks <br> merge conflict <br> invalid merge method|filtered-pools;
head-ref-->divided-pools;
prowjobs-->divided-pools;
config.yaml-->divided-pools;
filtered-pools-->pool-i;
filtered-pools-->pool-n;
filtered-pools-->pool-n1[pool ...];
pool-i-->|report tide status|status-context;
pool-i-->|accumulateBatch|accumulated-batch-prowjobs;
pool-i-->|accumulateSerial|filtered-prowjobs;
classDef plain fill:#ddd,stroke:#fff,stroke-width:4px,color:#000;
classDef k8s fill:#326ce5,stroke:#fff,stroke-width:4px,color:#fff;
classDef github fill:#fff,stroke:#bbb,stroke-width:2px,color:#326ce5;
classDef pools-def fill:#00ffff,stroke:#bbb,stroke-width:2px,color:#326ce5;
classDef decision fill:#ffff00,stroke:#bbb,stroke-width:2px,color:#326ce5;
classDef outcome fill:#00cc66,stroke:#bbb,stroke-width:2px,color:#326ce5;
class prowjobs,config.yaml k8s;
class Tide plain;
class status-context,head-ref,pullrequest github;
class accumulated-batch-success,accumulated-batch-pending,accumulated-success,accumulated-pending,accumulated-stale pools-def;
class accumulated-batch-success-exist,accumulated-batch-pending-exist,accumulated-success-exist,accumulated-pending-exist,accumulated-stale-exist,can-trigger-batch,require-presubmits decision;
class trigger-highest-pr,trigger-batch,merge-single,merge-batch,wait outcome;