Add 'stream sharing' feature, allowing avoidance of multiple syn… (#107)

.buildkite/local-pipeline.yml

@@ -10,4 +10,13 @@ steps:
           view: //depot/... ...
           root: p4_workspace
           parallel: 2
-          backup_changelists: yes
+          backup_changelists: yes
+
+  # - label: "Test Shared Streams"
+  #   command: echo "Hello World"
+  #   plugins:
+  #     - ./.buildkite/plugins/perforce:
+  #         p4port: localhost:1666
+  #         p4user: banana
+  #         stream: //stream-depot/main # will checkout to ../__stream_depot_main
+  #         share_workspace: yes

README.md

@@ -73,6 +73,17 @@ steps:
           parallel: 16
 ```
 
+Share a stream workspace between pipelines. Useful to avoid syncing duplicate data with large workspaces.
+Only allowed when there is a single buildkite agent running on the machine.
+
+```yaml
+steps:
+    plugins:
+      - ca-johnson/perforce:
+          stream: //dev/buildkite
+          share_workspace: true
+```
+
 ## Triggering Builds
 
 There are a few options for triggering builds that use this plugin, in this order from least valuable but most convenient to most valueable but least convenient.

hooks/environment

@@ -1,2 +1,23 @@
 # Allow steps to pick up perforce configuration used by the plugin
-export P4CONFIG=p4config
+export P4CONFIG=p4config
+
+# Allow sharing of perforce client workspaces for the same stream between pipelines
+if [[ "${BUILDKITE_PLUGIN_PERFORCE_SHARE_WORKSPACE}" == true ]] ; then
+    echo "Workspace sharing enabled"
+
+    STREAM="${BUILDKITE_PLUGIN_PERFORCE_STREAM}"
+    if [[ -z "${STREAM}" ]] ; then
+      echo "Error: You must use stream workspaces to enable shared workspaces" >&2
+      exit 1
+    fi
+    if [[ "${BUILDKITE_AGENT_META_DATA_AGENT_COUNT}" -gt 1 ]] ; then
+      echo "Error: You cannot share stream workspaces when running more than one agent" >&2
+      exit 1
+    fi
+    # Sanitize //depot/stream-name to __depot_stream-name
+    SANITIZED_STREAM=$(echo $STREAM | python -c "import sys; print(sys.stdin.read().replace('/', '_'));")
+
+    PERFORCE_CHECKOUT_PATH="${BUILDKITE_BUILD_CHECKOUT_PATH}/../${SANITIZED_STREAM}"
+    export BUILDKITE_BUILD_CHECKOUT_PATH="${PERFORCE_CHECKOUT_PATH}"
+    echo "Changed BUILDKITE_BUILD_CHECKOUT_PATH to ${PERFORCE_CHECKOUT_PATH}"
+fi

python/perforce.py

@@ -50,7 +50,8 @@ def __del__(self):
         self.perforce.disconnect()
 
     def _get_clientname(self):
-        clientname = 'bk-p4-%s-%s' % (os.environ.get('BUILDKITE_AGENT_NAME', socket.gethostname()), os.environ.get('BUILDKITE_PIPELINE_SLUG', ''))
+        """Get unique clientname for this host and location on disk"""
+        clientname = 'bk-p4-%s-%s' % (os.environ.get('BUILDKITE_AGENT_NAME', socket.gethostname()), os.path.basename(self.root))
         return re.sub(r'\W', '-', clientname)
 
     def _localize_view(self, view):