feat(configuration): add git repo as configuration store

.build-tools/go.mod

@@ -1,6 +1,6 @@
 module github.com/dapr/components-contrib/build-tools
 
-go 1.24.13
+go 1.25.0
 
 require (
 	github.com/dapr/components-contrib v0.0.0

.github/scripts/components-scripts/conformance-configuration.git-setup.sh

@@ -0,0 +1,23 @@
+#!/bin/sh
+# Set up a local bare git upstream used by the configuration.git conformance
+# and certification tests. Exports GIT_UPSTREAM_URL pointing at a file:// URL
+# so the tests don't need any network access.
+
+set -e
+
+ROOT=/tmp/dapr-conf-git
+rm -rf "$ROOT"
+mkdir -p "$ROOT"
+
+git init --bare "$ROOT/upstream.git"
+
+SEED="$ROOT/seed"
+git clone "$ROOT/upstream.git" "$SEED"
+git -C "$SEED" config user.email "ci@dapr.io"
+git -C "$SEED" config user.name "ci"
+git -C "$SEED" config commit.gpgsign false
+git -C "$SEED" commit --allow-empty -m "initial"
+git -C "$SEED" branch -M main
+git -C "$SEED" push origin main
+
+echo "GIT_UPSTREAM_URL=file://$ROOT/upstream.git" >> "$GITHUB_ENV"

.github/scripts/test-info.mjs

@@ -279,6 +279,16 @@ const components = {
         conformanceSetup: 'conformance-configuration.kubernetes-setup.sh',
         sourcePkg: ['configuration/kubernetes'],
     },
+    'configuration.git': {
+        certification: true,
+        certificationSetup: 'conformance-configuration.git-setup.sh',
+        sourcePkg: ['configuration/git'],
+    },
+    'configuration.git.local': {
+        conformance: true,
+        conformanceSetup: 'conformance-configuration.git-setup.sh',
+        sourcePkg: ['configuration/git'],
+    },
     'crypto.azure.keyvault': {
         conformance: true,
         requiredSecrets: [

.golangci.yml

@@ -173,6 +173,7 @@ linters-settings:
     # locale: Default
     ignore-words:
       - someword
+      - prompty
   lll:
     # max line length, lines longer will be reported. Default is 120.
     # '\t' is counted as 1 character by default, and can be changed with the tab-width option

configuration/git/README.md

@@ -0,0 +1,173 @@
+# Git Configuration Store
+
+A Dapr configuration store backed by a git repository. The store clones the
+configured repo on `Init`, polls the upstream for new commits at a configurable
+interval, and notifies subscribers when keys change.
+
+> **Status:** alpha. Requires a paired `dapr/dapr` PR registering
+> `configuration.git` (e.g. `cmd/daprd/components/configuration_git.go`)
+> before it is usable from a sidecar.
+
+## When to use it
+
+The component is intended for **operator-driven configuration repos**
+(prompts, instructions, agent definitions, feature flags) where:
+
+- The data is small (≤ 1 MiB per file by default).
+- Changes are infrequent (commits, not high-frequency writes).
+- A polling delay of 5–60 seconds is acceptable.
+
+It is **not** suitable for source-code monorepos or hot-path data planes.
+
+## Quick start
+
+```yaml
+apiVersion: dapr.io/v1alpha1
+kind: Component
+metadata:
+  name: configstore
+spec:
+  type: configuration.git
+  version: v1
+  metadata:
+    - name: url
+      value: "https://github.com/example/agent-config.git"
+    - name: branch
+      value: "main"
+    - name: pollInterval
+      value: "30s"
+```
+
+## Mapping modes
+
+The `mappingMode` metadata field selects how files in the repository become
+configuration items. Matching is case-insensitive.
+
+### `file` (default)
+
+Each file becomes one config item. The relative POSIX path is the key,
+the file contents the value.
+
+```
+repo/
+  agents/weather/agent_role.txt   → key "agents/weather/agent_role.txt"
+  agents/weather/agent_goal.txt   → key "agents/weather/agent_goal.txt"
+```
+
+This is the recommended mode when the consumer (e.g. dapr-agents) already
+expects scalar config keys.
+
+### `agentYaml`
+
+Each `*.yaml`, `*.yml`, or `*.json` file is parsed as a flat top-level map.
+Each top-level field becomes a key prefixed by the filename stem with
+directory separators replaced by `_`. Non-YAML/JSON files are silently skipped.
+
+```yaml
+# repo/agents/weather.yaml
+agent_role: Weather expert
+agent_goal: Help users plan trips
+agent_instructions:
+  - be concise
+  - cite sources
+```
+
+produces keys:
+
+```
+agents_weather/agent_role            = "Weather expert"
+agents_weather/agent_goal            = "Help users plan trips"
+agents_weather/agent_instructions    = (YAML-serialised list — round-trip via yaml.Unmarshal)
+```
+
+### `prompty`
+
+Each `*.prompty` file's YAML frontmatter and body are split.
+Frontmatter fields produce `<stem>/<field>` keys; the body is emitted as
+`<stem>/agent_system_prompt`. Non-`.prompty` files are skipped.
+
+```
+---
+name: Weather Agent
+agent_role: Weather expert
+agent_goal: Help users plan trips
+---
+You are a friendly weather assistant.
+```
+
+produces:
+
+```
+weather/name                  = "Weather Agent"
+weather/agent_role            = "Weather expert"
+weather/agent_goal            = "Help users plan trips"
+weather/agent_system_prompt   = "You are a friendly weather assistant."
+```
+
+## Authentication
+
+The `authMode` metadata field selects an auth profile. When empty, the
+component auto-detects: SSH-scheme URLs (`git@` or `ssh://`) → `ssh`,
+`githubAppId` set → `githubApp`, `token` set → `pat`, otherwise `none`.
+
+| Mode | Required fields |
+|------|-----------------|
+| `none` | (public HTTPS or `file://`) |
+| `pat` | `token` (sensitive); optional `username` (defaults to `x-access-token`) |
+| `ssh` | `sshPrivateKey` or `sshPrivateKeyPath` (sensitive); plus `sshKnownHosts`/`sshKnownHostsPath` unless `sshInsecureIgnoreHostKey: true` |
+| `githubApp` | `githubAppId`, `githubAppInstallationId`, `githubAppPrivateKey` or `githubAppPrivateKeyPath` (sensitive) |
+
+`http://` URLs are rejected for any authenticated mode to prevent cleartext
+credential transmission. Embedding credentials directly in the URL
+(e.g. `https://user:tok@host/`) is also rejected — use the appropriate
+profile with a Dapr secret reference.
+
+## Behavioural notes
+
+- **`Get` is cache-only.** It returns the most-recently polled snapshot
+  and may be up to `pollInterval` old. It does not contact the remote.
+- **`Subscribe` replays current state by default.** When `emitInitialState`
+  is true (the default), the handler receives the current snapshot
+  synchronously before `Subscribe` returns. Set `emitInitialState: false`
+  if the caller has just performed a `Get` and would receive a duplicate.
+- **Deletions are signalled** via `Item{Value: "", Metadata: {"deleted": "true"}}` —
+  the same shape as the kubernetes ConfigMap configuration store.
+- **Commits are never written.** The component is read-only; nothing it
+  does mutates the upstream repository.
+- **Rate-limit budget.** With `pollInterval: 30s` and 1 replica, the
+  component issues ~120 ref-fetches per hour — well under GitHub's 5 000/h
+  PAT limit. Multi-replica deployments multiply that rate
+  (`effective_rate = 3600/pollInterval × replicas`); if you push down to
+  `pollInterval: 1s` (the hard floor for remote URLs), 10 replicas burn
+  36 000 req/h, exhausting a PAT. Use a GitHub App (15 000/h) and tune
+  carefully.
+- **`.git/` is always excluded** from the worktree walk regardless of
+  `includeHidden`, so credentials in `.git/config` cannot leak into the
+  configuration items.
+- **Per-file size cap.** Files larger than `maxFileSize` (default 1 MiB)
+  are skipped with a warning. Protects the sidecar from OOM.
+- **LRU snapshot cache.** Diff bases for per-subscriber updates live in a
+  small LRU keyed by HEAD SHA (default size 4). On a miss the diff over-
+  emits a single batch (every key as added/changed) — idempotent on the
+  receiver. Tune via `snapshotCacheSize` for very high subscriber counts.
+
+## Limitations
+
+- **Shallow clone instability.** `go-git`'s shallow incremental fetch has
+  open issues; the default `depth: 0` (full clone) is the safe choice.
+  For repos with very deep history, set `depth: 1` and accept that
+  `git log` from inside the worktree won't show ancestors.
+- **No webhook support.** Polling only. A webhook listener would need an
+  inbound network endpoint, secret verification, and retry logic — out of
+  scope for v1.
+- **Single-installation GitHub App.** One installation per component
+  instance. Multi-tenant routing (different repos via different
+  installations) is not supported.
+
+## Daprd registration
+
+This component requires a paired `dapr/dapr` PR registering
+`configuration.git` so that daprd can load it via component spec. See
+`cmd/daprd/components/configuration_redis.go` for the registration shape.
+Until that PR lands, the component can be exercised via the certification
+test in `tests/certification/configuration/git/`.