implemented index alias to make import atomic (#46)

scripts/import-channel

@@ -29,8 +29,7 @@ click_log.basic_config(logger)
 
 
 CURRENT_DIR = os.path.dirname(os.path.abspath(__file__))
-
-
+INDEX_SCHEMA_VERSION = 1
 ANALYSIS = {
     "analyzer": {
         "nixAttrName": {
@@ -70,6 +69,43 @@ ANALYSIS = {
         },
     },
 }
+PACKAGES_MAPPING = dict(
+    properties=dict(
+        attr_name=dict(
+            type="text", analyzer="nixAttrName", fields={"raw": {"type": "keyword"}},
+        ),
+        attr_set=dict(type="keyword"),
+        pname=dict(type="keyword"),
+        pversion=dict(type="keyword"),
+        description=dict(type="text"),
+        longDescription=dict(type="text"),
+        license=dict(
+            type="nested",
+            properties=dict(fullName=dict(type="text"), url=dict(type="text"),),
+        ),
+        maintainers=dict(
+            type="nested",
+            properties=dict(
+                name=dict(type="text"),
+                email=dict(type="text"),
+                github=dict(type="text"),
+            ),
+        ),
+        platforms=dict(type="keyword"),
+        position=dict(type="text"),
+        homepage=dict(type="keyword"),
+    ),
+)
+OPTIONS_MAPPING = dict(
+    properties=dict(
+        option_name=dict(type="keyword"),
+        description=dict(type="text"),
+        type=dict(type="keyword"),
+        default=dict(type="text"),
+        example=dict(type="text"),
+        source=dict(type="keyword"),
+    ),
+)
 
 
 def get_last_evaluation(channel):
@@ -235,75 +271,30 @@ def get_options(evaluation):
     return len(options), gen
 
 
-def recreate_index(es, channel):
-    packages_index = f"{channel}-packages"
-    if es.indices.exists(packages_index):
-        es.indices.delete(index=packages_index)
-        logger.debug(
-            f"recreate_index: index '{packages_index}' already exists and was deleted"
-        )
+def create_index(es, index, mapping):
+    if es.indices.exists(index):
+        logger.debug(f"create_index: index '{index}' already exists")
+        return
     es.indices.create(
-        index=packages_index,
-        body=dict(
-            settings=dict(number_of_shards=1, analysis=ANALYSIS),
-            mappings=dict(
-                properties=dict(
-                    attr_name=dict(
-                        type="text",
-                        analyzer="nixAttrName",
-                        fields={"raw": {"type": "keyword"}},
-                    ),
-                    attr_set=dict(type="keyword"),
-                    pname=dict(type="keyword"),
-                    pversion=dict(type="keyword"),
-                    description=dict(type="text"),
-                    longDescription=dict(type="text"),
-                    license=dict(
-                        type="nested",
-                        properties=dict(
-                            fullName=dict(type="text"), url=dict(type="text"),
-                        ),
-                    ),
-                    maintainers=dict(
-                        type="nested",
-                        properties=dict(
-                            name=dict(type="text"),
-                            email=dict(type="text"),
-                            github=dict(type="text"),
-                        ),
-                    ),
-                    platforms=dict(type="keyword"),
-                    position=dict(type="text"),
-                    homepage=dict(type="keyword"),
-                ),
-            ),
-        ),
+        index=index,
+        body={
+            "settings": {"number_of_shards": 1, "analysis": ANALYSIS},
+            "mappings": mapping,
+        },
     )
-    logger.debug(f"recreate_index: index '{packages_index}' was created")
+    logger.debug(f"create_index: index '{index}' was created")
 
-    options_index = f"{channel}-options"
-    if es.indices.exists(options_index):
-        es.indices.delete(index=options_index)
-        logger.debug(
-            f"recreate_index: index '{options_index}' already exists and was deleted"
-        )
-    es.indices.create(
-        index=options_index,
-        body=dict(
-            settings=dict(number_of_shards=1, analysis=ANALYSIS),
-            mappings=dict(
-                properties=dict(
-                    option_name=dict(type="keyword"),
-                    description=dict(type="text"),
-                    type=dict(type="keyword"),
-                    default=dict(type="text"),
-                    example=dict(type="text"),
-                    source=dict(type="keyword"),
-                ),
-            ),
-        ),
+
+def create_index_name(type_, channel, evaluation):
+    return (
+        f"latest-{channel}-{type_}",
+        f"evaluation-{INDEX_SCHEMA_VERSION}-{channel}-{evaluation['revisions_since_start']}-{evaluation['git_revision']}-{type_}",
     )
-    logger.debug(f"recreate_index: index '{options_index}' was created")
+
+
+def update_alias(es, name, index):
+    es.indices.put_alias(index=index, name=name)
+    logger.debug(f"'{name}' alias now points to '{index}' index")
 
 
 @click.command()
@@ -324,7 +315,12 @@ def main(es_url, channel, verbose):
 
     evaluation = get_last_evaluation(channel)
     es = elasticsearch.Elasticsearch([es_url])
-    recreate_index(es, channel)
+
+    # ensure indexes exist
+    packages_alias, packages_index = create_index_name("packages", channel, evaluation)
+    options_alias, options_index = create_index_name("options", channel, evaluation)
+    create_index(es, packages_index, PACKAGES_MAPPING)
+    create_index(es, options_index, OPTIONS_MAPPING)
 
     # write packages
     number_of_packages, gen_packages = get_packages(evaluation)
@@ -333,7 +329,7 @@ def main(es_url, channel, verbose):
         progress = tqdm.tqdm(unit="packages", total=number_of_packages)
         successes = 0
         for ok, action in elasticsearch.helpers.streaming_bulk(
-            client=es, index=f"{channel}-packages", actions=gen_packages()
+            client=es, index=packages_index, actions=gen_packages()
         ):
             progress.update(1)
             successes += ok
@@ -346,12 +342,16 @@ def main(es_url, channel, verbose):
         progress = tqdm.tqdm(unit="options", total=number_of_options)
         successes = 0
         for ok, action in elasticsearch.helpers.streaming_bulk(
-            client=es, index=f"{channel}-options", actions=gen_options()
+            client=es, index=options_index, actions=gen_options()
         ):
             progress.update(1)
             successes += ok
         print("Indexed %d/%d options" % (successes, number_of_options))
 
+    # update alias
+    update_alias(es, packages_alias, packages_index)
+    update_alias(es, options_alias, options_index)
+
 
 if __name__ == "__main__":
     main()

src/Page/Options.elm

@@ -219,7 +219,7 @@ makeRequest :
 makeRequest options channel query from size =
     ElasticSearch.makeRequest
         "option_name"
-        ("nixos-" ++ channel ++ "-options")
+        ("latest-nixos-" ++ channel ++ "-options")
         decodeResultItemSource
         options
         query

src/Page/Packages.elm

@@ -287,7 +287,7 @@ makeRequest :
 makeRequest options channel query from size =
     ElasticSearch.makeRequest
         "attr_name"
-        ("nixos-" ++ channel ++ "-packages")
+        ("latest-nixos-" ++ channel ++ "-packages")
         decodeResultItemSource
         options
         query