Improve usability for garage in container by setting entrypoint (#1363)

- BREAKING: This update will probably break previous containers setups
that expect you to provide `/garage`

After the upgrade, instead of:
    docker run --rm dxflrs/garage:latest /garage --help
you need to run
    docker run --rm dxflrs/garage:latest --help

Signed-off-by: ieugen <eugen@ieugen.ro>

Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/garage/pulls/1363
Reviewed-by: Alex <lx@deuxfleurs.fr>
Co-authored-by: ieugen <eugen@ieugen.ro>
Co-committed-by: ieugen <eugen@ieugen.ro>

Dockerfile

@@ -4,4 +4,6 @@ ENV RUST_BACKTRACE=1
 ENV RUST_LOG=garage=info
 
 COPY result/bin/garage /
-CMD [ "/garage", "server"]
+
+ENTRYPOINT ["/garage"]
+CMD ["server"]

doc/book/cookbook/real-world.md

@@ -213,7 +213,12 @@ If your configuration file is at `/etc/garage.toml`, the `garage` binary should
 You can also use an alias as follows to use the Garage binary inside your docker container:
 
 ```bash
+# garage 3.x, we have an entrypoint and you can use
+alias garage="docker exec -ti <container name>"
+
+# For garage 2.x, you need to specify the absolute path to binary
 alias garage="docker exec -ti <container name> /garage"
+
 ```
 
 You can test your `garage` CLI utility by running a simple command such as:

doc/book/quick-start/_index.md

@@ -178,8 +178,11 @@ garage status
 
 If you are running Garage in a Docker container, you can use the following command instead:
 
+NOTE: Garage 3.x uses docker `ENTRYPOINT` and it's easier to use,
+while garage 2.x does not and you need to specify path `/garage`
+
 ```bash
-docker exec garage-container /garage status
+docker exec garage-container status
 ```
 
 This should show something like this:
@@ -320,7 +323,7 @@ If you are running Garage in a Docker container, you can set the following alias
 to provide a fake `garage`command that uses the Garage binary inside your container:
 
 ```bash
-alias garage="docker exec -ti <container name> /garage"
+alias garage="docker exec -ti <container name>"
 ```
 
 You can test that your `garage` CLI is configured correctly by running a basic command such as `garage status`.