public void install()

in software/database/src/main/java/org/apache/brooklyn/entity/database/postgresql/PostgreSqlSshDriver.java [108:188]
67 lines of code
3 McCabe index (conditional complexity)

    public void install() {
        String version = getEntity().getConfig(SoftwareProcess.SUGGESTED_VERSION); //10-10-2
        String majorMinorVersion = version.substring(0, version.lastIndexOf("-")); //10-10
        String shortVersion = majorMinorVersion.substring(0, majorMinorVersion.lastIndexOf("-")); //10

        String altTarget = "/opt/brooklyn/postgres/";
        String altInstallDir = Urls.mergePaths(altTarget, "install/"+majorMinorVersion);
        
        Iterable<String> pgctlLocations = ImmutableList.of(
            altInstallDir+"/bin",
            "/usr/pgsql-"+shortVersion+"/bin",
            "/usr/lib/postgresql/"+majorMinorVersion+"/bin/",
            "/opt/local/lib/postgresql"+shortVersion+"/bin/",
            "/usr/pgsql-"+majorMinorVersion+"/bin",
            "/usr/local/bin/",
            "/usr/bin/",
            "/bin/");

        DynamicTasks.queueIfPossible(SshTasks.dontRequireTtyForSudo(getMachine(),
            // sudo is absolutely required here, in customize we set user to postgres
            OnFailingTask.FAIL)).orSubmitAndBlock();
        DynamicTasks.waitForLast();

        // Check whether we can find a usable pg_ctl, and if not install one
        MutableList<String> findOrInstall = MutableList.<String>of()
            .append("which pg_ctl")
            .appendAll(Iterables.transform(pgctlLocations, StringFunctions.formatter("test -x %s/pg_ctl")))
            .append(installPackage(ImmutableMap.of(
                "yum", "postgresql"+shortVersion+" postgresql"+shortVersion+"-server postgresql"+shortVersion+"-contrib postgresql"+shortVersion+"-libs" ,
                "apt", "postgresql-"+majorMinorVersion,
                "port", "postgresql"+shortVersion+" postgresql"+shortVersion+"-server"
                ), null))
                // due to impl of installPackage, it will not come to the line below I don't think
                .append(warn(format("WARNING: failed to find or install postgresql %s binaries", majorMinorVersion)));

        // Link to correct binaries folder (different versions of pg_ctl and psql don't always play well together)
        MutableList<String> linkFromHere = MutableList.<String>of()
            .append(ifExecutableElse1("pg_ctl", chainGroup(
                "PG_EXECUTABLE=`which pg_ctl`",
                "PG_DIR=`dirname $PG_EXECUTABLE`",
                "echo 'found pg_ctl in '$PG_DIR' on path so linking PG bin/ to that dir'",
                "ln -s $PG_DIR bin")))
                .appendAll(Iterables.transform(pgctlLocations, givenDirIfFileExistsInItLinkToDir("pg_ctl", "bin")))
                .append(fail(format("WARNING: failed to find postgresql %s binaries for pg_ctl, may already have another version installed; aborting", majorMinorVersion), 9));

        newScript(INSTALLING)
        .body.append(
            dontRequireTtyForSudo(),
            ifExecutableElse0("yum", getYumRepository(version, majorMinorVersion, shortVersion)),
            ifExecutableElse0("apt-get", getAptRepository()),
            "rm -f bin", // if left over from previous incomplete/failed install (not sure why that keeps happening!)
            alternativesGroup(findOrInstall),
            alternativesGroup(linkFromHere))
            .failOnNonZeroResultCode()
            .queue();
        
        // check that the proposed install dir is one that user postgres can access
        // TODO if command above fails then the following `getUnchecked` blocks forever
        if (DynamicTasks.queue(SshEffectorTasks.ssh(sudoAsUser("postgres", "ls "+getInstallDir())).allowingNonZeroExitCode()
                .summary("check postgres user can access install dir")).asTask().getUnchecked()!=0) {
            log.info("Postgres install dir "+getInstallDir()+" for "+getEntity()+" is not accessible to user 'postgres'; " + "using "+altInstallDir+" instead");
            String newRunDir = Urls.mergePaths(altTarget, "apps", getEntity().getApplication().getId(), getEntity().getId());
            if (DynamicTasks.queue(SshEffectorTasks.ssh("ls "+altInstallDir+"/pg_ctl").allowingNonZeroExitCode()
                    .summary("check whether "+altInstallDir+" is set up")).asTask().getUnchecked()==0) {
                // alt target already exists with binary; nothing to do for install
            } else {
                DynamicTasks.queue(SshEffectorTasks.ssh(
                    "mkdir -p "+altInstallDir,
                    "rm -rf '"+altInstallDir+"'",
                    "mv "+getInstallDir()+" "+altInstallDir,
                    "rm -rf '"+getInstallDir()+"'",
                    "ln -s "+altInstallDir+" "+getInstallDir(),
                    "mkdir -p " + newRunDir,
                    "chown -R postgres:postgres "+altTarget).runAsRoot().requiringExitCodeZero()
                    .summary("move install dir from user to postgres owned space"));
            }
            DynamicTasks.waitForLast();
            setInstallDir(altInstallDir);
            setRunDir(newRunDir);
        }
    }