dev: Make db-run check CockroachDB version (#427)

This should help catch when developers forget to upgrade their version
to match the one in use by the repo.

Example failure:
$ cargo run --bin omicron-dev db-run
   Compiling omicron-test-utils v0.1.0
    Finished dev [unoptimized + debuginfo] target(s) in 5.94s
     Running `target/debug/omicron-dev db-run`
omicron-dev: using temporary directory for database store (cleaned up on clean exit)
omicron-dev: will run this to start CockroachDB:
cockroach start-single-node --insecure --http-addr=:0 [...]
omicron-dev: temporary directory: /tmp/.tmpWJTKQn
omicron-dev: wrong version of CockroachDB installed. expected 'v21.1.11', found: 'Ok("v21.1.10")

test-utils/src/dev/db.rs

@@ -5,9 +5,10 @@ use anyhow::anyhow;
 use anyhow::bail;
 use anyhow::Context;
 use omicron_common::config::PostgresConfigWithUrl;
-use std::ffi::OsStr;
+use std::ffi::{OsStr, OsString};
 use std::fmt;
 use std::ops::Deref;
+use std::os::unix::ffi::OsStringExt;
 use std::path::Path;
 use std::path::PathBuf;
 use std::process::Stdio;
@@ -42,6 +43,13 @@ const COCKROACHDB_DATABASE: &'static str = "omicron";
  */
 const COCKROACHDB_USER: &'static str = "root";
 
+/// Path to the CockroachDB binary
+const COCKROACHDB_BIN: &str = "cockroach";
+
+/// The expected CockroachDB version
+const COCKROACHDB_VERSION: &str =
+    include_str!("../../../tools/cockroachdb_version");
+
 /**
  * Builder for [`CockroachStarter`] that supports setting some command-line
  * arguments for the `cockroach start-single-node` command
@@ -74,7 +82,7 @@ pub struct CockroachStarterBuilder {
 
 impl CockroachStarterBuilder {
     pub fn new() -> CockroachStarterBuilder {
-        CockroachStarterBuilder::new_with_cmd("cockroach")
+        CockroachStarterBuilder::new_with_cmd(COCKROACHDB_BIN)
     }
 
     fn new_with_cmd(cmd: &str) -> CockroachStarterBuilder {
@@ -281,6 +289,8 @@ impl CockroachStarter {
     pub async fn start(
         mut self,
     ) -> Result<CockroachInstance, CockroachStartError> {
+        check_db_version().await?;
+
         let mut child_process = self.cmd_builder.spawn().map_err(|source| {
             CockroachStartError::BadCmd { cmd: self.args[0].clone(), source }
         })?;
@@ -378,6 +388,9 @@ pub enum CockroachStartError {
         source: std::io::Error,
     },
 
+    #[error("wrong version of CockroachDB installed. expected '{expected:}', found: '{found:?}")]
+    BadVersion { expected: String, found: Result<String, anyhow::Error> },
+
     #[error("cockroach failed to start (see error output above)")]
     Exited,
 
@@ -548,6 +561,41 @@ impl Drop for CockroachInstance {
     }
 }
 
+/// Verify that CockroachDB has the correct version
+pub async fn check_db_version() -> Result<(), CockroachStartError> {
+    let mut cmd = tokio::process::Command::new(COCKROACHDB_BIN);
+    cmd.args(&["version", "--build-tag"]);
+    let output = cmd.output().await.map_err(|source| {
+        CockroachStartError::BadCmd { cmd: COCKROACHDB_BIN.to_string(), source }
+    })?;
+    if !output.status.success() {
+        return Err(CockroachStartError::BadVersion {
+            expected: COCKROACHDB_VERSION.trim().to_string(),
+            found: Err(anyhow!(
+                "error {:?} when checking CockroachDB version",
+                output.status.code()
+            )),
+        });
+    }
+    let version_str =
+        OsString::from_vec(output.stdout).into_string().map_err(|_| {
+            CockroachStartError::BadVersion {
+                expected: COCKROACHDB_VERSION.trim().to_string(),
+                found: Err(anyhow!("Error parsing CockroachDB version output")),
+            }
+        })?;
+    let version_str = version_str.trim();
+
+    if version_str != COCKROACHDB_VERSION.trim() {
+        return Err(CockroachStartError::BadVersion {
+            found: Ok(version_str.to_string()),
+            expected: COCKROACHDB_VERSION.trim().to_string(),
+        });
+    }
+
+    Ok(())
+}
+
 /**
  * Wrapper around tokio::process::Child::try_wait() so that we can unwrap() the
  * result in one place with this explanatory comment.

tools/ci_download_cockroachdb

@@ -14,7 +14,7 @@ SOURCE_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
 ARG0="$(basename ${BASH_SOURCE[0]})"
 
 # If you change this, you must also update the md5sums below
-CIDL_VERSION="v21.1.10"
+CIDL_VERSION="$(cat "$SOURCE_DIR/cockroachdb_version")"
 source "$SOURCE_DIR/cockroachdb_checksums"
 
 CIDL_ASSEMBLE_DIR="./cockroachdb"

tools/cockroachdb_version

@@ -0,0 +1 @@
+v21.1.10