feat(ci): don't build storage on compute-releases and vice versa (#10841)

## Problem
Release CI is slow, because we're doing unnecessary work, for example
building compute images on storage releases and vice versa.

## Summary of changes
- Extract tag generation into reusable workflow and extend it with
fetching of previous component releases
- Don't build neon images on compute releases and don't build compute
images on proxy and storage releases
- Reuse images from previous releases for tests on branches where we
don't build those images

## Open questions
- We differentiate between `TAG` and `COMPUTE_TAG` in a few places, but
we don't differentiate between storage and proxy releases. Since they
use the same image, this will continue to work, but I'm not sure this is
what we want.

.github/scripts/generate_image_maps.py

@@ -0,0 +1,62 @@
+import itertools
+import json
+import os
+
+build_tag = os.environ["BUILD_TAG"]
+branch = os.environ["BRANCH"]
+dev_acr = os.environ["DEV_ACR"]
+prod_acr = os.environ["PROD_ACR"]
+dev_aws = os.environ["DEV_AWS"]
+prod_aws = os.environ["PROD_AWS"]
+aws_region = os.environ["AWS_REGION"]
+
+components = {
+    "neon": ["neon"],
+    "compute": [
+        "compute-node-v14",
+        "compute-node-v15",
+        "compute-node-v16",
+        "compute-node-v17",
+        "vm-compute-node-v14",
+        "vm-compute-node-v15",
+        "vm-compute-node-v16",
+        "vm-compute-node-v17",
+    ],
+}
+
+registries = {
+    "dev": [
+        "docker.io/neondatabase",
+        "ghcr.io/neondatabase",
+        f"{dev_aws}.dkr.ecr.{aws_region}.amazonaws.com",
+        f"{dev_acr}.azurecr.io/neondatabase",
+    ],
+    "prod": [
+        f"{prod_aws}.dkr.ecr.{aws_region}.amazonaws.com",
+        f"{prod_acr}.azurecr.io/neondatabase",
+    ],
+}
+
+outputs: dict[str, dict[str, list[str]]] = {}
+
+target_tags = [build_tag, "latest"] if branch == "main" else [build_tag]
+target_stages = ["dev", "prod"] if branch.startswith("release") else ["dev"]
+
+for component_name, component_images in components.items():
+    for stage in target_stages:
+        outputs[f"{component_name}-{stage}"] = dict(
+            [
+                (
+                    f"docker.io/neondatabase/{component_image}:{build_tag}",
+                    [
+                        f"{combo[0]}/{component_image}:{combo[1]}"
+                        for combo in itertools.product(registries[stage], target_tags)
+                    ],
+                )
+                for component_image in component_images
+            ]
+        )
+
+with open(os.environ["GITHUB_OUTPUT"], "a") as f:
+    for key, value in outputs.items():
+        f.write(f"{key}={json.dumps(value)}\n")

.github/scripts/previous-releases.jq

@@ -0,0 +1,25 @@
+# Expects response from https://docs.github.com/en/rest/releases/releases?apiVersion=2022-11-28#list-releases as input,
+# with tag names `release` for storage, `release-compute` for compute and `release-proxy` for proxy releases.
+# Extract only the `tag_name` field from each release object
+[ .[].tag_name ]
+
+# Transform each tag name into a structured object using regex capture
+| reduce map(
+    capture("^(?<full>release(-(?<component>proxy|compute))?-(?<version>\\d+))$")
+    | {
+        component: (.component // "storage"),  # Default to "storage" if no component is specified
+        version: (.version | tonumber),        # Convert the version number to an integer
+        full: .full                            # Store the full tag name for final output
+      }
+  )[] as $entry  # Loop over the transformed list
+
+# Accumulate the latest (highest-numbered) version for each component
+({};
+ .[$entry.component] |= (if . == null or $entry.version > .version then $entry else . end))
+
+# Convert the resulting object into an array of formatted strings
+| to_entries
+| map("\(.key)=\(.value.full)")
+
+# Output each string separately
+| .[]

.github/scripts/push_with_image_map.py

@@ -0,0 +1,22 @@
+import json
+import os
+import subprocess
+
+image_map = os.getenv("IMAGE_MAP")
+if not image_map:
+    raise ValueError("IMAGE_MAP environment variable is not set")
+
+try:
+    parsed_image_map: dict[str, list[str]] = json.loads(image_map)
+except json.JSONDecodeError as e:
+    raise ValueError("Failed to parse IMAGE_MAP as JSON") from e
+
+for source, targets in parsed_image_map.items():
+    for target in targets:
+        cmd = ["docker", "buildx", "imagetools", "create", "-t", target, source]
+        print(f"Running: {' '.join(cmd)}")
+        result = subprocess.run(cmd, text=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+
+        if result.returncode != 0:
+            print(f"Error: {result.stdout}")
+            raise RuntimeError(f"Command failed: {' '.join(cmd)}")