Use compute_ctl to manage Postgres in tests. (#3886)

This adds test coverage for 'compute_ctl', as it is now used by all
the python tests.
    
There are a few differences in how 'compute_ctl' is called in the
tests, compared to the real web console:
    
- In the tests, the postgresql.conf file is included as one large
  string in the spec file, and it is written out as it is to the data
  directory.  I added a new field for that to the spec file. The real
  web console, however, sets all the necessary settings in the
  'settings' field, and 'compute_ctl' creates the postgresql.conf from
  those settings.

- In the tests, the information needed to connect to the storage, i.e.
  tenant_id, timeline_id, connection strings to pageserver and
  safekeepers, are now passed as new fields in the spec file. The real
  web console includes them as the GUCs in the 'settings' field. (Both
  of these are different from what the test control plane used to do:
  It used to write the GUCs directly in the postgresql.conf file). The
  plan is to change the control plane to use the new method, and
  remove the old method, but for now, support both.

Some tests that were sensitive to the amount of WAL generated needed
small changes, to accommodate that compute_ctl runs the background
health monitor which makes a few small updates. Also some tests shut
down the pageserver, and now that the background health check can run
some queries while the pageserver is down, that can produce a few
extra errors in the logs, which needed to be allowlisted.

Other changes:
- remove obsolete comments about PostgresNode;
- create standby.signal file for Static compute node;
- log output of `compute_ctl` and `postgres` is merged into
`endpoints/compute.log`.

---------

Co-authored-by: Anastasia Lubennikova <anastasia@neon.tech>

libs/compute_api/src/responses.rs

@@ -5,13 +5,13 @@ use serde::{Deserialize, Serialize, Serializer};
 
 use crate::spec::ComputeSpec;
 
-#[derive(Serialize, Debug)]
+#[derive(Serialize, Debug, Deserialize)]
 pub struct GenericAPIError {
     pub error: String,
 }
 
 /// Response of the /status API
-#[derive(Serialize, Debug)]
+#[derive(Serialize, Debug, Deserialize)]
 #[serde(rename_all = "snake_case")]
 pub struct ComputeStatusResponse {
     pub start_time: DateTime<Utc>,
@@ -23,7 +23,7 @@ pub struct ComputeStatusResponse {
     pub error: Option<String>,
 }
 
-#[derive(Serialize)]
+#[derive(Deserialize, Serialize)]
 #[serde(rename_all = "snake_case")]
 pub struct ComputeState {
     pub status: ComputeStatus,
@@ -33,7 +33,7 @@ pub struct ComputeState {
     pub error: Option<String>,
 }
 
-#[derive(Serialize, Clone, Copy, Debug, PartialEq, Eq)]
+#[derive(Serialize, Clone, Copy, Debug, Deserialize, PartialEq, Eq)]
 #[serde(rename_all = "snake_case")]
 pub enum ComputeStatus {
     // Spec wasn't provided at start, waiting for it to be

libs/compute_api/src/spec.rs

@@ -5,6 +5,7 @@
 //! and connect it to the storage nodes.
 use serde::{Deserialize, Serialize};
 use serde_with::{serde_as, DisplayFromStr};
+use utils::id::{TenantId, TimelineId};
 use utils::lsn::Lsn;
 
 /// String type alias representing Postgres identifier and
@@ -14,7 +15,7 @@ pub type PgIdent = String;
 /// Cluster spec or configuration represented as an optional number of
 /// delta operations + final cluster state description.
 #[serde_as]
-#[derive(Clone, Debug, Default, Deserialize)]
+#[derive(Clone, Debug, Default, Deserialize, Serialize)]
 pub struct ComputeSpec {
     pub format_version: f32,
 
@@ -26,9 +27,32 @@ pub struct ComputeSpec {
     pub cluster: Cluster,
     pub delta_operations: Option<Vec<DeltaOp>>,
 
+    // Information needed to connect to the storage layer.
+    //
+    // `tenant_id`, `timeline_id` and `pageserver_connstring` are always needed.
+    //
+    // Depending on `mode`, this can be a primary read-write node, a read-only
+    // replica, or a read-only node pinned at an older LSN.
+    // `safekeeper_connstrings` must be set for a primary.
+    //
+    // For backwards compatibility, the control plane may leave out all of
+    // these, and instead set the "neon.tenant_id", "neon.timeline_id",
+    // etc. GUCs in cluster.settings. TODO: Once the control plane has been
+    // updated to fill these fields, we can make these non optional.
+    #[serde_as(as = "Option<DisplayFromStr>")]
+    pub tenant_id: Option<TenantId>,
+    #[serde_as(as = "Option<DisplayFromStr>")]
+    pub timeline_id: Option<TimelineId>,
+    #[serde_as(as = "Option<DisplayFromStr>")]
+    pub pageserver_connstring: Option<String>,
+    #[serde(default)]
+    pub safekeeper_connstrings: Vec<String>,
+
     #[serde(default)]
     pub mode: ComputeMode,
 
+    /// If set, 'storage_auth_token' is used as the password to authenticate to
+    /// the pageserver and safekeepers.
     pub storage_auth_token: Option<String>,
 }
 
@@ -47,13 +71,19 @@ pub enum ComputeMode {
     Replica,
 }
 
-#[derive(Clone, Debug, Default, Deserialize)]
+#[derive(Clone, Debug, Default, Deserialize, Serialize)]
 pub struct Cluster {
-    pub cluster_id: String,
-    pub name: String,
+    pub cluster_id: Option<String>,
+    pub name: Option<String>,
     pub state: Option<String>,
     pub roles: Vec<Role>,
     pub databases: Vec<Database>,
+
+    /// Desired contents of 'postgresql.conf' file. (The 'compute_ctl'
+    /// tool may add additional settings to the final file.)
+    pub postgresql_conf: Option<String>,
+
+    /// Additional settings that will be appended to the 'postgresql.conf' file.
     pub settings: GenericOptions,
 }
 
@@ -63,7 +93,7 @@ pub struct Cluster {
 /// - DROP ROLE
 /// - ALTER ROLE name RENAME TO new_name
 /// - ALTER DATABASE name RENAME TO new_name
-#[derive(Clone, Debug, Deserialize)]
+#[derive(Clone, Debug, Deserialize, Serialize)]
 pub struct DeltaOp {
     pub action: String,
     pub name: PgIdent,
@@ -72,7 +102,7 @@ pub struct DeltaOp {
 
 /// Rust representation of Postgres role info with only those fields
 /// that matter for us.
-#[derive(Clone, Debug, Deserialize)]
+#[derive(Clone, Debug, Deserialize, Serialize)]
 pub struct Role {
     pub name: PgIdent,
     pub encrypted_password: Option<String>,
@@ -81,7 +111,7 @@ pub struct Role {
 
 /// Rust representation of Postgres database info with only those fields
 /// that matter for us.
-#[derive(Clone, Debug, Deserialize)]
+#[derive(Clone, Debug, Deserialize, Serialize)]
 pub struct Database {
     pub name: PgIdent,
     pub owner: PgIdent,
@@ -91,7 +121,7 @@ pub struct Database {
 /// Common type representing both SQL statement params with or without value,
 /// like `LOGIN` or `OWNER username` in the `CREATE/ALTER ROLE`, and config
 /// options like `wal_level = logical`.
-#[derive(Clone, Debug, Deserialize)]
+#[derive(Clone, Debug, Deserialize, Serialize)]
 pub struct GenericOption {
     pub name: String,
     pub value: Option<String>,