xref: /tonic/examples/src/gcp/client.rs (revision 1bef5f57)
1 pub mod api {
2     tonic::include_proto!("google.pubsub.v1");
3 }
4 
5 use api::{publisher_client::PublisherClient, ListTopicsRequest};
6 use tonic::{
7     metadata::MetadataValue,
8     transport::{Certificate, Channel, ClientTlsConfig},
9     Request,
10 };
11 
12 const ENDPOINT: &str = "https://pubsub.googleapis.com";
13 
14 #[tokio::main]
main() -> Result<(), Box<dyn std::error::Error>>15 async fn main() -> Result<(), Box<dyn std::error::Error>> {
16     let token = std::env::var("GCP_AUTH_TOKEN").map_err(|_| {
17         "Pass a valid 0Auth bearer token via `GCP_AUTH_TOKEN` environment variable.".to_string()
18     })?;
19 
20     let project = std::env::args()
21         .nth(1)
22         .ok_or_else(|| "Expected a project name as the first argument.".to_string())?;
23 
24     let bearer_token = format!("Bearer {}", token);
25     let header_value: MetadataValue<_> = bearer_token.parse()?;
26 
27     let data_dir = std::path::PathBuf::from_iter([std::env!("CARGO_MANIFEST_DIR"), "data"]);
28     let certs = std::fs::read_to_string(data_dir.join("gcp/roots.pem"))?;
29 
30     let tls_config = ClientTlsConfig::new()
31         .ca_certificate(Certificate::from_pem(certs))
32         .domain_name("pubsub.googleapis.com");
33 
34     let channel = Channel::from_static(ENDPOINT)
35         .tls_config(tls_config)?
36         .connect()
37         .await?;
38 
39     let mut service = PublisherClient::with_interceptor(channel, move |mut req: Request<()>| {
40         req.metadata_mut()
41             .insert("authorization", header_value.clone());
42         Ok(req)
43     });
44 
45     let response = service
46         .list_topics(Request::new(ListTopicsRequest {
47             project: format!("projects/{0}", project),
48             page_size: 10,
49             ..Default::default()
50         }))
51         .await?;
52 
53     println!("RESPONSE={:?}", response);
54 
55     Ok(())
56 }
57