Merge pull request #831 from basecamp/check-buildx-contexts

Check that we have valid contexts before building

lib/kamal/cli/build.rb

@@ -35,22 +35,25 @@ class Kamal::Cli::Build < Kamal::Cli::Base
 
     run_locally do
       begin
-        KAMAL.with_verbosity(:debug) do
+        context_hosts = capture_with_info(*KAMAL.builder.context_hosts).split("\n")
-          Dir.chdir(KAMAL.config.builder.build_directory) { execute *push }
+
+        if context_hosts != KAMAL.builder.config_context_hosts
+          warn "Context hosts have changed, so re-creating builder, was: #{context_hosts.join(", ")}], now: #{KAMAL.builder.config_context_hosts.join(", ")}"
+          cli.remove
+          cli.create
         end
       rescue SSHKit::Command::Failed => e
-        if e.message =~ /(no builder)|(no such file or directory)/
+        warn "Missing compatible builder, so creating a new one first"
-          warn "Missing compatible builder, so creating a new one first"
+        if e.message =~ /(context not found|no builder)/
-
+          cli.create
-          if cli.create
-            KAMAL.with_verbosity(:debug) do
-              Dir.chdir(KAMAL.config.builder.build_directory) { execute *push }
-            end
-          end
         else
           raise
         end
       end
+
+      KAMAL.with_verbosity(:debug) do
+        Dir.chdir(KAMAL.config.builder.build_directory) { execute *push }
+      end
     end
   end
 

lib/kamal/commands/builder.rb

@@ -1,7 +1,8 @@
 require "active_support/core_ext/string/filters"
 
 class Kamal::Commands::Builder < Kamal::Commands::Base
-  delegate :create, :remove, :push, :clean, :pull, :info, :validate_image, to: :target
+  delegate :create, :remove, :push, :clean, :pull, :info, :context_hosts, :config_context_hosts, :validate_image,
+    to: :target
 
   include Clone
 

lib/kamal/commands/builder/base.rb

@@ -2,6 +2,8 @@
 class Kamal::Commands::Builder::Base < Kamal::Commands::Base
   class BuilderError < StandardError; end
 
+  ENDPOINT_DOCKER_HOST_INSPECT = "'{{.Endpoints.docker.Host}}'"
+
   delegate :argumentize, to: Kamal::Utils
   delegate :args, :secrets, :dockerfile, :target, :local_arch, :local_host, :remote_arch, :remote_host, :cache_from, :cache_to, :ssh, to: :builder_config
 
@@ -30,6 +32,13 @@ class Kamal::Commands::Builder::Base < Kamal::Commands::Base
       )
   end
 
+  def context_hosts
+    :true
+  end
+
+  def config_context_hosts
+    []
+  end
 
   private
     def build_tags
@@ -74,4 +83,8 @@ class Kamal::Commands::Builder::Base < Kamal::Commands::Base
     def builder_config
       config.builder
     end
+
+    def context_host(builder_name)
+      docker :context, :inspect, builder_name, "--format", ENDPOINT_DOCKER_HOST_INSPECT
+    end
 end

lib/kamal/commands/builder/multiarch.rb

@@ -22,6 +22,10 @@ class Kamal::Commands::Builder::Multiarch < Kamal::Commands::Builder::Base
       build_context
   end
 
+  def context_hosts
+    docker :buildx, :inspect, builder_name, "> /dev/null"
+  end
+
   private
     def builder_name
       "kamal-#{config.service}-multiarch"

lib/kamal/commands/builder/multiarch/remote.rb

@@ -12,6 +12,16 @@ class Kamal::Commands::Builder::Multiarch::Remote < Kamal::Commands::Builder::Mu
       super
   end
 
+  def context_hosts
+    chain \
+      context_host(builder_name_with_arch(local_arch)),
+      context_host(builder_name_with_arch(remote_arch))
+  end
+
+  def config_context_hosts
+    [ local_host, remote_host ].compact
+  end
+
   private
     def builder_name
       super + "-remote"

lib/kamal/commands/builder/native/cached.rb

@@ -1,6 +1,6 @@
 class Kamal::Commands::Builder::Native::Cached < Kamal::Commands::Builder::Native
   def create
-    docker :buildx, :create, "--use", "--driver=docker-container"
+    docker :buildx, :create, "--name", builder_name, "--use", "--driver=docker-container"
   end
 
   def remove
@@ -13,4 +13,13 @@ class Kamal::Commands::Builder::Native::Cached < Kamal::Commands::Builder::Nativ
       *build_options,
       build_context
   end
+
+  def context_hosts
+    docker :buildx, :inspect, builder_name, "> /dev/null"
+  end
+
+  private
+    def builder_name
+      "kamal-#{config.service}-native-cached"
+    end
 end

lib/kamal/commands/builder/native/remote.rb

@@ -26,6 +26,14 @@ class Kamal::Commands::Builder::Native::Remote < Kamal::Commands::Builder::Nativ
     build_context
   end
 
+  def context_hosts
+    context_host(builder_name_with_arch)
+  end
+
+  def config_context_hosts
+    [ remote_host ]
+  end
+
 
   private
     def builder_name

test/cli/build_test.rb

@@ -21,6 +21,10 @@ class CliBuildTest < CliTestCase
         .with(:git, "-C", anything, :status, "--porcelain")
         .returns("")
 
+      SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
+        .with(:docker, :buildx, :inspect, "kamal-app-multiarch", "> /dev/null")
+        .returns("")
+
       run_command("push", "--verbose").tap do |output|
         assert_hook_ran "pre-build", output, **hook_variables
         assert_match /Cloning repo into build directory/, output
@@ -121,11 +125,9 @@ class CliBuildTest < CliTestCase
       SSHKit::Backend::Abstract.any_instance.expects(:execute)
         .with(:docker, :buildx, :create, "--use", "--name", "kamal-app-multiarch")
 
-      SSHKit::Backend::Abstract.any_instance.expects(:execute)
+      SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-        .with { |*args| args[0..1] == [ :docker, :buildx ] }
+        .with(:docker, :buildx, :inspect, "kamal-app-multiarch", "> /dev/null")
         .raises(SSHKit::Command::Failed.new("no builder"))
-        .then
-        .returns(true)
 
       SSHKit::Backend::Abstract.any_instance.expects(:execute).with { |*args| args.first.start_with?("git") }
 
@@ -137,6 +139,9 @@ class CliBuildTest < CliTestCase
         .with(:git, "-C", anything, :status, "--porcelain")
         .returns("")
 
+      SSHKit::Backend::Abstract.any_instance.expects(:execute)
+        .with(:docker, :buildx, :build, "--push", "--platform", "linux/amd64,linux/arm64", "--builder", "kamal-app-multiarch", "-t", "dhh/app:999", "-t", "dhh/app:latest", "--label", "service=\"app\"", "--file", "Dockerfile", ".")
+
       run_command("push").tap do |output|
         assert_match /WARN Missing compatible builder, so creating a new one first/, output
       end

test/cli/cli_test_case.rb

@@ -36,6 +36,9 @@ class CliTestCase < ActiveSupport::TestCase
         .with { |arg1, arg2| arg1 == :mkdir && arg2 == ".kamal/locks/app" }
       SSHKit::Backend::Abstract.any_instance.stubs(:execute)
         .with { |arg1, arg2| arg1 == :rm && arg2 == ".kamal/locks/app/details" }
+      SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info)
+        .with { |*args| args[0..2] == [ :docker, :buildx, :inspect ] }
+        .returns("")
     end
 
     def assert_hook_ran(hook, output, version:, service_version:, hosts:, command:, subcommand: nil, runtime: false)

test/cli/main_test.rb

@@ -116,6 +116,10 @@ class CliMainTest < CliTestCase
       .with(:git, "-C", anything, :status, "--porcelain")
       .returns("")
 
+    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
+      .with(:docker, :buildx, :inspect, "kamal-app-multiarch", "> /dev/null")
+      .returns("")
+
     assert_raises(Kamal::Cli::LockError) do
       run_command("deploy")
     end
@@ -145,6 +149,10 @@ class CliMainTest < CliTestCase
       .with(:git, "-C", anything, :status, "--porcelain")
       .returns("")
 
+    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
+      .with(:docker, :buildx, :inspect, "kamal-app-multiarch", "> /dev/null")
+      .returns("")
+
     assert_raises(SSHKit::Runner::ExecuteError) do
       run_command("deploy")
     end

test/commands/builder_test.rb

@@ -158,6 +158,48 @@ class CommandsBuilderTest < ActiveSupport::TestCase
       builder.push.join(" ")
   end
 
+  test "multiarch context hosts" do
+    command = new_builder_command
+    assert_equal "docker buildx inspect kamal-app-multiarch > /dev/null", command.context_hosts.join(" ")
+    assert_equal "", command.config_context_hosts.join(" ")
+  end
+
+  test "native context hosts" do
+    command = new_builder_command(builder: { "multiarch" => false })
+    assert_equal :true, command.context_hosts
+    assert_equal "", command.config_context_hosts.join(" ")
+  end
+
+  test "native cached context hosts" do
+    command = new_builder_command(builder: { "multiarch" => false, "cache" => { "type" => "registry" } })
+    assert_equal "docker buildx inspect kamal-app-native-cached > /dev/null", command.context_hosts.join(" ")
+    assert_equal "", command.config_context_hosts.join(" ")
+  end
+
+  test "native remote context hosts" do
+    command = new_builder_command(builder: { "remote" => { "arch" => "amd64", "host" => "ssh://host" } })
+    assert_equal "docker context inspect kamal-app-native-remote-amd64 --format '{{.Endpoints.docker.Host}}'", command.context_hosts.join(" ")
+    assert_equal [ "ssh://host" ], command.config_context_hosts
+  end
+
+  test "multiarch remote context hosts" do
+    command = new_builder_command(builder: {
+      "remote" => { "arch" => "amd64", "host" => "ssh://host" },
+      "local" => { "arch" => "arm64" }
+    })
+    assert_equal "docker context inspect kamal-app-multiarch-remote-arm64 --format '{{.Endpoints.docker.Host}}' ; docker context inspect kamal-app-multiarch-remote-amd64 --format '{{.Endpoints.docker.Host}}'", command.context_hosts.join(" ")
+    assert_equal [ "ssh://host" ], command.config_context_hosts
+  end
+
+  test "multiarch remote context hosts with local host" do
+    command = new_builder_command(builder: {
+      "remote" => { "arch" => "amd64", "host" => "ssh://host" },
+      "local" => { "arch" => "arm64", "host" => "unix:///var/run/docker.sock" }
+    })
+    assert_equal "docker context inspect kamal-app-multiarch-remote-arm64 --format '{{.Endpoints.docker.Host}}' ; docker context inspect kamal-app-multiarch-remote-amd64 --format '{{.Endpoints.docker.Host}}'", command.context_hosts.join(" ")
+    assert_equal [ "unix:///var/run/docker.sock", "ssh://host" ], command.config_context_hosts
+  end
+
   private
     def new_builder_command(additional_config = {})
       Kamal::Commands::Builder.new(Kamal::Configuration.new(@config.merge(additional_config), version: "123"))