Feature: Add Merge Snapshot API

Is part of Issue #176

api/router.go

@@ -159,6 +159,7 @@ func Router(c *ctx.AptlyContext) http.Handler {
 		root.GET("/snapshots/:name/packages", apiSnapshotsSearchPackages)
 		root.DELETE("/snapshots/:name", apiSnapshotsDrop)
 		root.GET("/snapshots/:name/diff/:withSnapshot", apiSnapshotsDiff)
+		root.POST("/snapshots/merge", apiSnapshotsMerge)
 	}
 
 	{

api/snapshot.go

@@ -3,6 +3,7 @@ package api
 import (
 	"fmt"
 	"net/http"
+	"strings"
 
 	"github.com/aptly-dev/aptly/aptly"
 	"github.com/aptly-dev/aptly/database"
@@ -397,3 +398,80 @@ func apiSnapshotsSearchPackages(c *gin.Context) {
 
 	showPackages(c, snapshot.RefList(), collectionFactory)
 }
+
+// POST /api/snapshots/merge
+func apiSnapshotsMerge(c *gin.Context) {
+	var (
+		err      error
+		snapshot *deb.Snapshot
+	)
+
+	var body struct {
+		Destination string   `binding:"required"`
+		Sources     []string `binding:"required"`
+	}
+
+	if c.Bind(&body) != nil {
+		return
+	}
+
+	if len(body.Sources) < 1 {
+		AbortWithJSONError(c, http.StatusBadRequest, fmt.Errorf("At least one source snapshot is required"))
+		return
+	}
+
+	latest := c.Request.URL.Query().Get("latest") == "1"
+	noRemove := c.Request.URL.Query().Get("no-remove") == "1"
+	overrideMatching := !latest && !noRemove
+
+	if noRemove && latest {
+		AbortWithJSONError(c, http.StatusBadRequest, fmt.Errorf("no-remove and latest are mutually exclusive"))
+		return
+	}
+
+	collectionFactory := context.NewCollectionFactory()
+	snapshotCollection := collectionFactory.SnapshotCollection()
+
+	sources := make([]*deb.Snapshot, len(body.Sources))
+	resources := make([]string, len(sources))
+	for i := range body.Sources {
+		sources[i], err = snapshotCollection.ByName(body.Sources[i])
+		if err != nil {
+			AbortWithJSONError(c, http.StatusNotFound, err)
+			return
+		}
+
+		err = snapshotCollection.LoadComplete(sources[i])
+		if err != nil {
+			AbortWithJSONError(c, http.StatusInternalServerError, err)
+			return
+		}
+		resources[i] = string(sources[i].ResourceKey())
+	}
+
+	maybeRunTaskInBackground(c, "Merge snapshot "+body.Destination, resources, func(out aptly.Progress, detail *task.Detail) (*task.ProcessReturnValue, error) {
+		result := sources[0].RefList()
+		for i := 1; i < len(sources); i++ {
+			result = result.Merge(sources[i].RefList(), overrideMatching, false)
+		}
+
+		if latest {
+			result.FilterLatestRefs()
+		}
+
+		sourceDescription := make([]string, len(sources))
+		for i, s := range sources {
+			sourceDescription[i] = fmt.Sprintf("'%s'", s.Name)
+		}
+
+		snapshot = deb.NewSnapshotFromRefList(body.Destination, sources, result,
+			fmt.Sprintf("Merged from sources: %s", strings.Join(sourceDescription, ", ")))
+
+		err = collectionFactory.SnapshotCollection().Add(snapshot)
+		if err != nil {
+			return &task.ProcessReturnValue{Code: http.StatusInternalServerError, Value: nil}, fmt.Errorf("unable to create snapshot: %s", err)
+		}
+
+		return &task.ProcessReturnValue{Code: http.StatusCreated, Value: snapshot}, nil
+	})
+}

system/t12_api/snapshots.py

@@ -262,9 +262,9 @@ class SnapshotsAPITestDiff(APITest):
         self.check_equal(self.upload("/api/files/" + d,
                          "libboost-program-options-dev_1.49.0.1_i386.deb").status_code, 200)
 
-        self.check_equal(self.post_task("/api/repos/" + repo_name + "/file/" + d).json()['State'], TASK_SUCCEEDED)
+        self.check_equal(self.post_task("/api/repos/" + repos[-1] + "/file/" + d).json()['State'], TASK_SUCCEEDED)
 
-        resp = self.post_task("/api/repos/" + repo_name + '/snapshots', json={'Name': snapshots[0]})
+        resp = self.post_task("/api/repos/" + repos[-1] + '/snapshots', json={'Name': snapshots[0]})
         self.check_equal(resp.json()['State'], TASK_SUCCEEDED)
 
         resp = self.post_task("/api/snapshots", json={'Name': snapshots[1]})
@@ -287,3 +287,100 @@ class SnapshotsAPITestDiff(APITest):
         resp = self.get("/api/snapshots/" + snapshots[1] + "/diff/" + snapshots[1])
         self.check_equal(resp.status_code, 200)
         self.check_equal(resp.json(), [])
+
+
+class SnapshotsAPITestMerge(APITest):
+    """
+    POST /api/snapshots, GET /api/snapshots/merge, GET /api/snapshots/:name, DELETE /api/snapshots/:name
+    """
+
+    def check(self):
+        sources = [
+            {"Description": "fun snapshot", "Name": self.random_name()}
+            for _ in range(2)
+        ]
+
+        # create source snapshots
+        for source in sources:
+            resp = self.post_task("/api/snapshots", json=source)
+            self.check_equal(resp.json()["State"], TASK_SUCCEEDED)
+
+        # create merge snapshot
+        merged_name = self.random_name()
+        resp = self.post_task(
+            "/api/snapshots/merge",
+            json={
+                "Destination": merged_name,
+                "Sources": [source["Name"] for source in sources],
+            },
+        )
+        self.check_equal(resp.json()["State"], TASK_SUCCEEDED)
+
+        # check merge snapshot
+        resp = self.get(f"/api/snapshots/{merged_name}")
+        self.check_equal(resp.status_code, 200)
+        source_list = ", ".join(f"'{source['Name']}'" for source in sources)
+        self.check_subset(
+            {
+                "Name": merged_name,
+                "Description": f"Merged from sources: {source_list}",
+            },
+            resp.json(),
+        )
+
+        # remove merge snapshot
+        self.check_equal(
+            self.delete_task(f"/api/snapshots/{merged_name}").json()["State"], TASK_SUCCEEDED
+        )
+
+        # create merge snapshot without sources
+        merged_name = self.random_name()
+        resp = self.post(
+            "/api/snapshots/merge", json={"Destination": merged_name, "Sources": []}
+        )
+        self.check_equal(resp.status_code, 400)
+        self.check_equal(
+            resp.json()["error"], "At least one source snapshot is required"
+        )
+        self.check_equal(self.get(f"/api/snapshots/{merged_name}").status_code, 404)
+
+        # create merge snapshot with non-existing source
+        merged_name = self.random_name()
+        non_existing_source = self.random_name()
+        resp = self.post(
+            "/api/snapshots/merge",
+            json={"Destination": merged_name, "Sources": [non_existing_source]},
+        )
+        self.check_equal(
+            resp.json()["error"], f"snapshot with name {non_existing_source} not found"
+        )
+        self.check_equal(resp.status_code, 404)
+
+        self.check_equal(self.get(f"/api/snapshots/{merged_name}").status_code, 404)
+
+        # create merge snapshot with used name
+        merged_name = sources[0]["Name"]
+        resp = self.post(
+            "/api/snapshots/merge",
+            json={"Destination": merged_name, "Sources": [source["Name"] for source in sources]},
+        )
+        self.check_equal(
+            resp.json()["error"],
+            f"unable to create snapshot: snapshot with name {sources[0]['Name']} already exists",
+        )
+        self.check_equal(resp.status_code, 500)
+
+        # create merge snapshot with "latest" and "no-remove" flags (should fail)
+        merged_name = self.random_name()
+        resp = self.post(
+            "/api/snapshots/merge",
+            json={
+                "Destination": merged_name,
+                "Sources": [source["Name"] for source in sources],
+            },
+            params={"latest": "1", "no-remove": "1"},
+        )
+        self.check_equal(
+            resp.json()["error"], "no-remove and latest are mutually exclusive"
+        )
+        self.check_equal(resp.status_code, 400)