Destination Template¶

destination_template is a rule-level field that controls exactly where data lands in each sink — the collection name, key prefix, znode path, file path, or release name — using placeholders resolved at sync time.

Placeholders¶

Placeholder	Resolved from
`{env}`	Resolved environment (e.g. `production`, `staging`, `pr-42`)
`{tenant}`	Tenant ID from the `X-Tenant-ID` request header

Per-sink behavior¶

Sink	What it controls	Template	Resolved value
MongoDB	Collection name	`"{env}-config"`	`production-config`
ZooKeeper	znode root path	`"/{tenant}/{env}"`	`/acme/pr-42`
Redis	Key prefix	`"{env}:cfg"`	`production:cfg`
S3	Key prefix	`"{tenant}/{env}/"`	`acme/production/`
Linux server	Full remote file path	`"/etc/app/{env}.env"`	`/etc/app/production.env`
Helm	Release name	`"app-{env}"`	`app-production`
ConfigMap	ConfigMap name	`"myapp-{env}"`	`myapp-production`
Vercel	Environment variable prefix	`"{env}_"`	`production_`

Examples¶

One template, three environments¶

rules: [{
  platform:             "github"
  datasource:           "mongo"
  file_name:            "configs/app.yaml"
  repositories:         ["my-org/*"]
  destination_template: "{env}-config"
  branch_map: {
    main:    "production"
    develop: "staging"
    test:    "test"
  }
}]

Push branch	Resolved env	Collection written to
`main`	`production`	`production-config`
`develop`	`staging`	`staging-config`
`test`	`test`	`test-config`

Per-tenant isolation¶

destination_template: "{tenant}/{env}-config"

A push from tenant acme to main writes to acme/production-config. A push from tenant globex to main writes to globex/production-config.

PR preview environments¶

rules: [{
  platform:             "github"
  datasource:           "mongo"
  file_name:            "configs/app.yaml"
  repositories:         ["my-org/app"]
  destination_template: "{env}-config"
  env_as_pr:            true    // PR #42 → env = "pr-42"
}]

Each pull request gets its own isolated collection: pr-42-config, pr-103-config, etc.

ZooKeeper path per tenant and environment¶

rules: [{
  platform:             "github"
  datasource:           "zookeeper"
  destination_template: "/{tenant}/{env}"
}]

Writes znodes under /acme/production/, /acme/staging/, etc.

Validation¶

If {env} appears in the template, at least one environment resolution strategy must be enabled:

env_as_branch: true
env_as_pr: true
env_as_tags: true
branch_map: { ... }
file_path_map: { ... }

varTrack will reject the bundle at startup if {env} is used with no resolution strategy configured.

Fallback behavior¶

If destination_template is not set, each sink falls back to its own sink-specific configuration key (e.g. collection for MongoDB, key_prefix for Redis).