Feature/look in path

.baseline/findbugs/excludeFilter.xml

@@ -9,7 +9,7 @@
     <!-- Ignore the following bug patterns in test code -->
     <!-- (i.e., classes ending in 'Test' or 'Tests', and inner classes of same) -->
     <Match>
-        <Class name="~.*\.*Tests?(\$.*)?" />
+        <Class name="~.*\.*(Test|Tests|Should)?(\$.*)?" />
         <Or>
             <Bug pattern="NP_NONNULL_FIELD_NOT_INITIALIZED_IN_CONSTRUCTOR"/> <!-- common in tests to have non-final variables instantiated in @Before methods, which FindBugs can't detect -->
             <Bug pattern="NP_NULL_ON_SOME_PATH_FROM_RETURN_VALUE"/> <!-- if a null is dereferenced, test will fail anyway. Plus assertNotNull() is often a bad pattern. -->

docker-compose-rule-core/build.gradle

@@ -5,6 +5,7 @@ dependencies {
     compile "com.google.guava:guava:$guavaVersion"
     compile "joda-time:joda-time:$jodaVersion"
     compile "com.github.zafarkhaja:java-semver:$javaSemverVersion"
+    compile "com.google.code.findbugs:jsr305:3.0.0"
 
     compile 'com.jayway.awaitility:awaitility:1.6.5'
 
@@ -18,7 +19,6 @@ dependencies {
     testCompile "org.hamcrest:hamcrest-all:$hamcrestVersion"
     testCompile "org.mockito:mockito-core:$mockitoVersion"
     testCompile "com.github.tomakehurst:wiremock:2.0.6-beta"
-    testCompile "com.google.code.findbugs:jsr305:3.0.0"
     testCompile "com.github.stefanbirkner:system-rules:1.16.1"
 }
 

docker-compose-rule-core/src/main/java/com/palantir/docker/compose/execution/DockerCommandLocations.java

@@ -1,47 +1,75 @@
 /*
  * Copyright 2016 Palantir Technologies, Inc. All rights reserved.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
  */
-package com.palantir.docker.compose.execution;
 
-import static java.util.Arrays.asList;
+package com.palantir.docker.compose.execution;
 
 import java.io.File;
-import java.util.List;
-import java.util.Optional;
-import java.util.function.Predicate;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Map;
+import java.util.regex.Pattern;
+import java.util.stream.Stream;
+import javax.annotation.Nullable;
+import org.immutables.value.Value;
 
-public class DockerCommandLocations {
-    private static final Predicate<String> IS_NOT_NULL = path -> path != null;
-    private static final Predicate<String> FILE_EXISTS = path -> new File(path).exists();
+@Value.Immutable
+public abstract class DockerCommandLocations {
 
-    private final List<String> possiblePaths;
+    private static final Pattern PATH_SPLITTER = Pattern.compile(File.pathSeparator);
 
-    public DockerCommandLocations(String... possiblePaths) {
-        this.possiblePaths = asList(possiblePaths);
+    @Value.Default
+    protected Map<String, String> env() {
+        return System.getenv();
     }
 
-    public Optional<String> preferredLocation() {
+    @Value.Derived
+    protected String path() {
+        String path = env().get("PATH");
+        if (path == null) {
+            path = env().get("path");
+        }
+        if (path == null) {
+            throw new IllegalStateException("No path environment variable found");
+        }
+        return path;
+    }
 
-        return possiblePaths.stream()
-                .filter(IS_NOT_NULL)
-                .filter(FILE_EXISTS)
-                .findFirst();
+    @Value.Check
+    protected void pathIsNotEmpty() {
+        if (path().isEmpty()) {
+            throw new IllegalStateException("Path variable was empty");
+        }
     }
 
-    @Override
-    public String toString() {
-        return "DockerCommandLocations{possiblePaths=" + possiblePaths + "}";
+    @Nullable
+    protected abstract String locationOverride();
+
+    @Value.Default
+    protected Stream<String> macSearchLocations() {
+        return Stream.of("/usr/local/bin", "/usr/bin");
     }
+
+    private Stream<String> pathLocations() {
+        Stream<String> pathLocations = Stream.concat(PATH_SPLITTER.splitAsStream(path()), macSearchLocations());
+        if (locationOverride() == null) {
+            return pathLocations;
+        }
+        return Stream.concat(Stream.of(locationOverride()), pathLocations);
+    }
+
+    public Stream<Path> forCommand() {
+        return pathLocations().map(p -> Paths.get(p));
+    }
+
+    public static DockerCommandLocations withOverride(String override) {
+        return ImmutableDockerCommandLocations.builder()
+                .locationOverride(override)
+                .build();
+    }
+
+    public static ImmutableDockerCommandLocations.Builder builder() {
+        return ImmutableDockerCommandLocations.builder();
+    }
+
 }

docker-compose-rule-core/src/main/java/com/palantir/docker/compose/execution/DockerCommandLocator.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2016 Palantir Technologies, Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.palantir.docker.compose.execution;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+import javax.annotation.Nullable;
+import org.apache.commons.lang3.SystemUtils;
+import org.immutables.value.Value;
+
+@Value.Immutable
+public abstract class DockerCommandLocator {
+
+    protected abstract String command();
+
+    @Value.Default
+    protected boolean isWindows() {
+        return SystemUtils.IS_OS_WINDOWS;
+    }
+
+    @Value.Derived
+    protected String executableName() {
+        if (isWindows()) {
+            return command() + ".exe";
+        }
+        return command();
+    }
+
+    @Nullable
+    protected abstract String locationOverride();
+
+    @Value.Derived
+    protected DockerCommandLocations searchLocations() {
+        return DockerCommandLocations.withOverride(locationOverride());
+    }
+
+    public String getLocation() {
+        return searchLocations()
+                .forCommand()
+                .map(p -> p.resolve(executableName()))
+                .filter(Files::exists)
+                .findFirst()
+                .map(Path::toString)
+                .orElseThrow(() -> new IllegalStateException("Could not find " + command() + " in path"));
+    }
+
+    public static ImmutableDockerCommandLocator.Builder forCommand(String command) {
+        return ImmutableDockerCommandLocator.builder()
+                .command(command);
+    }
+
+}

docker-compose-rule-core/src/main/java/com/palantir/docker/compose/execution/DockerComposeExecutable.java

@@ -29,19 +29,12 @@
 public abstract class DockerComposeExecutable implements Executable {
     private static final Logger log = LoggerFactory.getLogger(DockerComposeExecutable.class);
 
-    private static final DockerCommandLocations DOCKER_COMPOSE_LOCATIONS = new DockerCommandLocations(
-            System.getenv("DOCKER_COMPOSE_LOCATION"),
-            "/usr/local/bin/docker-compose",
-            "/usr/bin/docker-compose"
-    );
-
     private static String defaultDockerComposePath() {
-        String pathToUse = DOCKER_COMPOSE_LOCATIONS.preferredLocation()
-                .orElseThrow(() -> new IllegalStateException(
-                        "Could not find docker-compose, looked in: " + DOCKER_COMPOSE_LOCATIONS));
-
+        DockerCommandLocator commandLocator = DockerCommandLocator.forCommand("docker-compose")
+                .locationOverride(System.getenv("DOCKER_COMPOSE_LOCATION"))
+                .build();
+        String pathToUse = commandLocator.getLocation();
         log.debug("Using docker-compose found at " + pathToUse);
-
         return pathToUse;
     }
 

docker-compose-rule-core/src/main/java/com/palantir/docker/compose/execution/DockerExecutable.java

@@ -26,12 +26,6 @@
 public abstract class DockerExecutable implements Executable {
     private static final Logger log = LoggerFactory.getLogger(DockerExecutable.class);
 
-    private static final DockerCommandLocations DOCKER_LOCATIONS = new DockerCommandLocations(
-            System.getenv("DOCKER_LOCATION"),
-            "/usr/local/bin/docker",
-            "/usr/bin/docker"
-    );
-
     @Value.Parameter protected abstract DockerConfiguration dockerConfiguration();
 
     @Override
@@ -41,12 +35,11 @@ public final String commandName() {
 
     @Value.Derived
     protected String dockerPath() {
-        String pathToUse = DOCKER_LOCATIONS.preferredLocation()
-                .orElseThrow(() -> new IllegalStateException(
-                        "Could not find docker, looked in: " + DOCKER_LOCATIONS));
-
+        DockerCommandLocator commandLocator = DockerCommandLocator.forCommand("docker")
+                .locationOverride(System.getenv("DOCKER_LOCATION"))
+                .build();
+        String pathToUse = commandLocator.getLocation();
         log.debug("Using docker found at " + pathToUse);
-
         return pathToUse;
     }