Build arm64 docker image for arm-based Macs

Remove --patform args completely so that by default we build natively
on each platform.

Partial fix for #50

dangerzone/isolation_provider/container.py

@@ -188,11 +188,9 @@ class Container(IsolationProvider):
         container_runtime = self.get_runtime()
 
         if self.get_runtime_name() == "podman":
-            platform_args = []
             security_args = ["--security-opt", "no-new-privileges"]
             security_args += ["--userns", "keep-id"]
         else:
-            platform_args = ["--platform", "linux/amd64"]
             security_args = ["--security-opt=no-new-privileges:true"]
 
         # drop all linux kernel capabilities
@@ -203,7 +201,6 @@ class Container(IsolationProvider):
 
         args = (
             ["run", "--network", "none"]
-            + platform_args
             + user_args
             + security_args
             + prevent_leakage_args

install/linux/build-image.sh

@@ -3,7 +3,7 @@
 set -e
 
 echo "Building container image"
-podman build container --platform linux/amd64 --tag dangerzone.rocks/dangerzone
+podman build container --tag dangerzone.rocks/dangerzone
 
 echo "Saving and compressing container image"
 podman save dangerzone.rocks/dangerzone | gzip > share/container.tar.gz

install/macos/build-image.sh

@@ -3,7 +3,7 @@
 set -e
 
 echo "Building container image"
-docker build container --platform linux/amd64 --tag dangerzone.rocks/dangerzone
+docker build container --tag dangerzone.rocks/dangerzone
 
 echo "Saving and compressing container image"
 docker save dangerzone.rocks/dangerzone | gzip > share/container.tar.gz

install/windows/build-image.py

@@ -10,8 +10,6 @@ def main():
             "docker",
             "build",
             "container",
-            "--platform",
-            "linux/amd64",
             "--tag",
             "dangerzone.rocks/dangerzone",
         ]