build and spin the app

README.org

@@ -144,4 +144,94 @@ The manifest file is =spin.toml=
   command = "cargo build --target wasm32-wasi --release"
   watch = ["src/**/*.rs", "Cargo.toml"]
 #+end_src
+* Modifying the code
+We change the =qstar/lib.rs= file to display the =hello world= message.
+#+description: line change for message
+#+name: lib.rs diff
+#+begin_src shell
+  git diff
+#+end_src
 
+#+RESULTS: lib.rs diff
+: diff --git a/qstart/src/lib.rs b/qstart/src/lib.rs
+: index f3051ef..a51e027 100644
+: --- a/qstart/src/lib.rs
+: +++ b/qstart/src/lib.rs
+: @@ -8,5 +8,5 @@ fn handle_qstart(req: Request) -> anyhow::Result<impl IntoResponse> {
+:      Ok(http::Response::builder()
+:          .status(200)
+:          .header("content-type", "text/plain")
+: -        .body("Hello, Fermyon")?)
+: +        .body("Hello, World!")?)
+:  }
+* Building the app
+In the ~qstart/~ folder
+#+begin_src shell
+  cd qstart/
+  spin build
+#+end_src
+
+#+RESULTS:
+: Building component qstart with `cargo build --target wasm32-wasi --release`
+:     Finished release [optimized] target(s) in 0.17s
+: Finished building all Spin components
+* Running the app
+We could have done ~spin build --up~ to autostart the app once the build has
+been done.
+#+description: running the app once build is finished
+#+name: spin up the app
+#+begin_src shell
+  cd qstart/
+  spin up
+#+end_src
+
+#+RESULTS: spin up the app
+: Logging component stdio to ".spin/logs/"
+:
+: Serving http://127.0.0.1:3000
+: Available Routes:
+:   qstart: http://127.0.0.1:3000 (wildcard)
+: 2023-11-19T18:38:54.648503Z ERROR spin_trigger::cli: Trigger executor failed
+: Error: Unable to listen on 127.0.0.1:3000
+:
+: Caused by:
+:      Address already in use (os error 98)
+
+In this case we have another app running in the same port. Let's see which one.
+#+name: lsof
+#+begin_src shell
+  lsof -i tcp:3000
+#+end_src
+
+#+RESULTS: lsof
+: COMMAND     PID      USER   FD   TYPE  DEVICE SIZE/OFF NODE NAME
+: forgejo 1531870 haqadosch    7u  IPv6 8599019      0t0  TCP *:3000 (LISTEN)
+
+So we kill that one and restart the ~spin up~.
+#+name: spin up again
+#+begin_src shell
+  kill -9 1531870
+  cd qstart/
+  spin up
+#+end_src
+
+#+RESULTS: spin up again
+: Logging component stdio to ".spin/logs/"
+:
+: Serving http://127.0.0.1:3000
+: Available Routes:
+:   qstart: http://127.0.0.1:3000 (wildcard)
+* Try the app
+We can display the page in your favourite browser or confirm with ~curl~
+#+name: curl
+#+begin_src shell
+  curl -i localhost:3000
+#+end_src
+
+#+RESULTS: curl
+: HTTP/1.1 200 OK
+: content-type: text/plain
+: transfer-encoding: chunked
+: date: Sun, 19 Nov 2023 19:01:02 GMT
+:
+: Hello, World!

qstart/src/lib.rs

@@ -8,5 +8,5 @@ fn handle_qstart(req: Request) -> anyhow::Result<impl IntoResponse> {
     Ok(http::Response::builder()
         .status(200)
         .header("content-type", "text/plain")
-        .body("Hello, Fermyon")?)
+        .body("Hello, World!")?)
 }