1# Example: Run Chariot 2 locally using pubsub and storage emulators.
2
3### Contents
4
51. Prerequisites
62. Starting Emulators
73. Demo Program
84. Running Chariot
95. Pictures
106. Stopping the Demo
117. Inspecting Data Produced by the Demo
128. Clean Up
13
14# Prerequisites
15
160. [Chariot RFC For Reference](https://github.com/ncr-swt-retail/edge-roadmap/blob/master/src/rfc/0004-chariot-v2.md)
171. Google Pubsub Emulator
18 - The gcloud pubsub emulator command requires Java to work.
19 - [Google Pubsub Emulator tutorial and setup guide](https://cloud.google.com/pubsub/docs/emulator)
202. Fake GCS Server
21 - [Fake GCS Server Github Page](https://github.com/fsouza/fake-gcs-server)
22 - Either build from source or download compiled binary.
23 - Must be installed in a `$PATH` directory for scripts to work.
24
25# Starting Emulators
26
27The Pubsub & Storage emulators need to be running before the demo program or chariot is started.
28
29To start the pubsub emulator run the following:
30
31```sh
32# env-init.sh sets the GOOGLE_CLOUD_PROJECT_ID env var
33$(./env-init.sh)
34
35gcloud beta emulators pubsub start --project=${GOOGLE_CLOUD_PROJECT_ID}
36```
37
38[screenshot of emulator running](./assets/images/img-start-pubsub-emulator.png)
39
40To start the fake-gcs-server, run the `start-fake-gcs-server.sh` script.
41
42```sh
43./start-fake-gcs-server.sh
44```
45
46[screenshot of fake-gcs-server running](./assets/images/img-start-fake-gcs-server-script-before-sending-requests.png)
47
48
49# Demo Program
50
51The demo program in `main.go` is a simple demonstration of multiple producers to the request topic and multiple consumers on the responses topic. It loops forever producing random requests and awaiting their responses. Unfortunately subscription filtering is not implemented in the pubsub emulator, so the demo program must filter responses itself (see issue: [170471468](https://issuetracker.google.com/issues/170471468))
52
53To run the demo program, call the `run-demo.sh` script.
54If the demo is running before chariot, it will wait until a chariot subscription has been created before sending requests on the topic.
55
56```sh
57# To simulate multiple concurrent producers/consumers, run this demo script in multiple shell windows.
58./run-demo.sh
59```
60
61[screenshot of demo running](./assets/images/img-run-demo-script.png)
62
63# Running Chariot
64
65Chariot works out of the box on this demo when your environment is configured correctly. To build, run, and configure the correct environment for chariot, call the `run-chariot2.sh` script.
66
67```sh
68./run-chariot2.sh
69```
70
71[screenshot of chariot running](./assets/images/img-run-chariot2-script.png)
72
73# Pictures
74
75Before running the `run-chariot2.sh` script, your screen should look like the following.
76
77
78
79After running Chariot, you should see logs from the demo programs, chariot, and the emulators.
80
81
82
83# Stopping the Demo
84
85Call `ctrl-c` to stop the emulators, demo program, and chariot.
86
87# Inspecting Data Produced by the Demo
88
89The Fake GCS Server script creates a directory that represents a `gs://bucket/object` url on the filesystem.
90
91```sh
92ls ./fake-gcs-server-filesystem/demo
93```
94
95# Clean Up
96
97To clean up the data generated by this demo and its scripts, call the provided `cleanup.sh` script.
98
99```
100./cleanup.sh
101```
View as plain text