Test Container test cases are failing due to "Could not find a valid Docker environment"

Question

I am very new to using test containers. My test is failing with below exception.

Running com.mastercard.example.testcontainers.testcontainersexampple.DemoControllerTest
2020-04-08 14:27:08.441  INFO   --- [           main] o.s.t.c.support.AbstractContextLoader    
: Could not detect default resource locations for test class 
resource found for suffixes {-context.xml, Context.groovy}.
2020-04-08 14:27:08.449  INFO   --- [           main] t.c.s.AnnotationConfigContextLoaderUtils : Could not detect default configuration classes for test class [com.mastercard.example.testcontainers.testcontainersexampple.DemoControllerTest]: DemoControllerTest does not declare any static, non-private, non-final, nested classes annotated with @Configuration.
2020-04-08 14:27:08.611  INFO   --- [           main] .b.t.c.SpringBootTestContextBootstrapper : Found @SpringBootConfiguration com.mastercard.example.testcontainers.testcontainersexampple.TestContainersExampleApplication for test class com.mastercard.example.testcontainers.testcontainersexampple.DemoControllerTest
2020-04-08 14:27:08.701  INFO   --- [           main] .b.t.c.SpringBootTestContextBootstrapper : Loaded default TestExecutionListener class names from location [META-INF/spring.factories]: [org.springframework.boot.test.mock.mockito.MockitoTestExecutionListener, org.springframework.boot.test.mock.mockito.ResetMocksTestExecutionListener, org.springframework.boot.test.autoconfigure.restdocs.RestDocsTestExecutionListener, org.springframework.boot.test.autoconfigure.web.client.MockRestServiceServerResetTestExecutionListener, org.springframework.boot.test.autoconfigure.web.servlet.MockMvcPrintOnlyOnFailureTestExecutionListener, org.springframework.boot.test.autoconfigure.web.servlet.WebDriverTestExecutionListener, org.springframework.test.context.web.ServletTestExecutionListener, org.springframework.test.context.support.DirtiesContextBeforeModesTestExecutionListener, org.springframework.test.context.support.DependencyInjectionTestExecutionListener, org.springframework.test.context.support.DirtiesContextTestExecutionListener, org.springframework.test.context.transaction.TransactionalTestExecutionListener, org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener, org.springframework.test.context.event.EventPublishingTestExecutionListener]
2020-04-08 14:27:08.725  INFO   --- [           main] .b.t.c.SpringBootTestContextBootstrapper : Using TestExecutionListeners: [org.springframework.test.context.web.ServletTestExecutionListener@117159c0, org.springframework.test.context.support.DirtiesContextBeforeModesTestExecutionListener@3e27ba32, org.springframework.boot.test.mock.mockito.MockitoTestExecutionListener@7ef82753, org.springframework.boot.test.autoconfigure.SpringBootDependencyInjectionTestExecutionListener@3b0fe47a, org.springframework.test.context.support.DirtiesContextTestExecutionListener@202b0582, org.springframework.test.context.transaction.TransactionalTestExecutionListener@235ecd9f, org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener@1ca3b418, org.springframework.test.context.event.EventPublishingTestExecutionListener@58cbafc2, org.springframework.boot.test.mock.mockito.ResetMocksTestExecutionListener@2034b64c, org.springframework.boot.test.autoconfigure.restdocs.RestDocsTestExecutionListener@75d3a5e0, org.springframework.boot.test.autoconfigure.web.client.MockRestServiceServerResetTestExecutionListener@74d1dc36, org.springframework.boot.test.autoconfigure.web.servlet.MockMvcPrintOnlyOnFailureTestExecutionListener@7161d8d1, org.springframework.boot.test.autoconfigure.web.servlet.WebDriverTestExecutionListener@74e28667]
2020-04-08 14:27:08.781 ERROR   --- [           main] o.t.d.DockerClientProviderStrategy       : Could not find a valid Docker environment. Please check configuration. Attempted configurations were:
2020-04-08 14:27:08.782 ERROR   --- [           main] o.t.d.DockerClientProviderStrategy       :     UnixSocketClientProviderStrategy: failed with exception InvalidConfigurationException (ping failed). Root cause NoSuchFileException (/var/run/docker.sock)
2020-04-08 14:27:08.782 ERROR   --- [           main] o.t.d.DockerClientProviderStrategy       : As no valid configuration was found, execution cannot continue

My question is do I need docker installed locally in order to use testcontainers? If yes, how does this works from pipeline like Jenkins?

Caused by: java.lang.IllegalStateException: Could not find a valid Docker environment. Please see logs and check configuration
at org.testcontainers.dockerclient.DockerClientProviderStrategy.lambda$getFirstValidStrategy$3(DockerClientProviderStrategy.java:158)
at java.util.Optional.orElseThrow(Optional.java:290)
at org.testcontainers.dockerclient.DockerClientProviderStrategy.getFirstValidStrategy(DockerClientProviderStrategy.java:150)
at org.testcontainers.DockerClientFactory.client(DockerClientFactory.java:111)
at org.testcontainers.containers.GenericContainer.<init>(GenericContainer.java:175)
at org.testcontainers.containers.JdbcDatabaseContainer.<init>(JdbcDatabaseContainer.java:36)
at org.testcontainers.containers.PostgreSQLContainer.<init>(PostgreSQLContainer.java:32)
at com.mastercard.example.testcontainers.testcontainersexampple.DemoControllerTest.<clinit>(DemoControllerTest.java:27)
... 25 more

UPDATE I have installed docker in local (to try it out) but still I am not able to run test cases due to not able to download image. My corporate network might be an issue here. Does anyone has good solution for above situations?

Caused by: com.github.dockerjava.api.exception.DockerClientException: Could not pull image: unexpected EOF
    at com.github.dockerjava.core.command.PullImageResultCallback.checkDockerClientPullSuccessful(PullImageResultCallback.java:96)
    at com.github.dockerjava.core.command.PullImageResultCallback.throwFirstError(PullImageResultCallback.java:111)
    at com.github.dockerjava.core.async.ResultCallbackTemplate.awaitCompletion(ResultCallbackTemplate.java:91)
    at com.github.dockerjava.core.command.PullImageResultCallback.awaitSuccess(PullImageResultCallback.java:124)

Answer 1

In my case this error caused by root permission. If you are using ubuntu, docker wants permission to create container and testcontainers can not ask you for this permission at runtime. So you need to make docker runnable without sudo.

Try this steps to create docker group and add connected user:

$ sudo groupadd docker
$ sudo gpasswd -a $USER docker
$ sudo service docker restart

Try this in step 3 if you are using Ubuntu 14.04-15.10:

$ sudo service docker.io restart

After all steps try some docker command in terminal without sudo like:

$ docker ps

If you are taking permission error, restart your computer then this must be fixed.

Answer 2

No other answers across the internet worked for me, likely because my case was somewhat unique. I am hoping this answer allows others in this weird, particular scenario to realize what is the problem.

So If:

1. You are on Linux
2. You are running your tests through an IDE
3. You installed IDE through flatpak, snap, or any other package manager that does sandboxing

The issue is that you are sandboxed by the package manager in the application. If you have a socket at /var/run/docker.sock (default), but the tests can't pick it up, this is why. That file does not exist in the sandbox, only on the host filesystem. Depending on the package manager, /var/run may be mounted inside the sandbox, so check your particular documentation. The most straightforward way to resolve this is to install the IDE outside of a sandbox via a tarball or some other thing.